Printable Version of Topic
Click here to view this topic in its original format
914World.com _ 914World Garage _ Weird (?) Dyno Results, 4-banger
Posted by: MikeInMunich Jan 1 2015, 07:48 AM
Can a few of you veterans out there please offer feedback regarding this dynograph?
This is new to me, but I am skeptical here. 
Thanks!
Mike in Munich
Attached thumbnail(s)
Posted by: Jon H. Jan 1 2015, 08:01 AM
Can a few of you veterans out there please offer feedback regarding this dynograph?
This is new to me, but I am skeptical here.
Thanks!
Mike in Munich
I agree for some reason the HP numbers are higher then I thought they would be
. Joking aside, that would be disappointing given the money you've invested in the engine. Was this dyno done at the wheels?
Jon h.
Posted by: JStroud Jan 1 2015, 08:28 AM
Doesn't look bad, 95hp for a 2.0, wasn't stock only around 80, thats 15 over stock.
Doesn't a 2056 only put out 110-120hp.
Posted by: RobW Jan 1 2015, 08:44 AM
Low HP motor with high torque? Interesting configuration.
I'm guessing from your personal description the chart is from your 1.8 converted to 2.0.
Do a search under dyno and Jake Raby for comparable posted numbers, but its all in how you built your motor.
How does it drive?
Happy New Year!
Posted by: MikeInMunich Jan 1 2015, 09:20 AM
The P&Cs add up to about 2.0. Stock cam, mega squirt, MSD electronic ignition, OBX headers. I have not driven it yet but my man on the job says it is indeed "torquey".
I receive another image of the graph with RPM instead of MPH. I've read that the torque and HP lines are supposed to insect at 5220 RPM. This is not the case here. One statement posted by a member read that if they don't the test is bogus or something to that affect.
M.i.M.
Posted by: MikeInMunich Jan 1 2015, 09:21 AM
Doesn't look bad, 95hp for a 2.0, wasn't stock only around 80, thats 15 over stock.
Doesn't a 2056 only put out 110-120hp.
Pretty sure a stock 2.0 puts out about 100.
Posted by: MikeInMunich Jan 1 2015, 09:23 AM
I agree for some reason the HP numbers are higher then I thought they would be
. Joking aside, that would be disappointing given the money you've invested in the engine. Was this dyno done at the wheels?
Jon h.
I don't know where you got any idea about how much I've invested in this engine Jon. The car had it as is when I bought it. I've only invested in the ignition and headers.
Posted by: rnellums Jan 1 2015, 10:07 AM
My understanding is you lose a minimum of 15% off your power going through the transmission. If this is wheel power, Maybe it isn't far off?
Posted by: BeatNavy Jan 1 2015, 10:29 AM
I've read that the torque and HP lines are supposed to insect at 5220 RPM. This is not the case here. One statement posted by a member read that if they don't the test is bogus or something to that affect.
That's my understanding (albeit limited). Based on the definitions of HP (work, or power over time) and torque (power), at ~5200 RPM they have to equate, by definition and math. But I don't really understand how dynos work. I've seen several graphs and the HP and torque lines always do seem to intersect at 5200.
Posted by: MikeInMunich Jan 1 2015, 01:03 PM
My understanding is you lose a minimum of 15% off your power going through the transmission. If this is wheel power, Maybe it isn't far off?
Yes, this is at the wheels, putting output over 90 HP, but we're not seeing the intersection that must be there, mathematically. Also, this motor should be putting out at least 100 HP, or at least we believe it should be. If it's correct we're losing about 10 HP somewhere for some reason.
Posted by: r_towle Jan 1 2015, 01:08 PM
Sorry, I don't see RPM,s on this graph.
Stock camshaft, 1.8 heads, it will lose air at the top end and wither away in power fast from what I have seen.
Rich
Posted by: MikeInMunich Jan 1 2015, 05:04 PM
Sorry, I don't see RPM,s on this graph.
Stock camshaft, 1.8 heads, it will lose air at the top end and wither away in power fast from what I have seen.
Rich
Here is the graph with RPMs. So the heads (and the cam, I knew that) are the weakest link(s). There's a lesson for ya, P&C upgrade to 2.0 ain't doin'
without the top end being upgraded as well. Veterans, please resist to comment "duh" and the like. We all gotta learn the hard way sometimes. 
Attached thumbnail(s)
Posted by: r_towle Jan 1 2015, 05:09 PM
It's an air pump.
The best money is spent on heads and camshaft.
You may be able to squeeze out a bit more if he changes you over to chomoly push rods, rocker arm shims and sets the valve train geometry properly.
That can all be done without taking the whole motor apart.
It will starve out for air, just as you see it.
That is physics, valves, ports, exhaust.....
Rich
Posted by: messix Jan 1 2015, 05:29 PM
loosing every thing starting at 4,200 rpm is really weird.
did you monitor the ignition curve and af/r through out the dyno run?
is this d-jet or l-jet?
some thing is dumping the power way too soon.
I would double check ignition timing and then. and the af/r
this looks more like what a bus motor might look like.
Posted by: krazykonrad Jan 1 2015, 06:38 PM
Are you sure you don't have bus heads on this engine?
Konrad
Posted by: edwin Jan 1 2015, 07:10 PM
Are you sure you're reading the graph correctly?
I'm reading that you have 76hp at the wheels and 96ft-lbs torque.
Has anyone ever tuned the mega squirt or is it just auto tuned?
Posted by: messix Jan 1 2015, 07:42 PM
mega squirt.....
are you dropping in fuel pressure in the higher rpm?
what injectors are you using?
you need to data log on the dyno to figure this out.
I don't see a 1.8 or 1.7 head dumping this much on a 2.0, maybe on a 2.5L+
it's a nice toque curve at first, just getting starved for timing or fuel 4k+rpm
Posted by: Jon H. Jan 1 2015, 08:02 PM
I agree for some reason the HP numbers are higher then I thought they would be
. Joking aside, that would be disappointing given the money you've invested in the engine. Was this dyno done at the wheels?
Jon h.
I don't know where you got any idea about how much I've invested in this engine Jon. The car had it as is when I bought it. I've only invested in the ignition and headers.
Sorry, I assumed you did the the re-build.
Jon H.
Posted by: CG-914 Jan 1 2015, 08:11 PM
Doesn't look bad, 95hp for a 2.0, wasn't stock only around 80, thats 15 over stock.
Doesn't a 2056 only put out 110-120hp.
Pretty sure a stock 2.0 puts out about 100.
All cars had more hp in other countries especially in Europe...
This is because of less good gas and different emission laws in the USA and especially in CA.
This was mostly done by lower compression in the engines for the US market:
914 2.0 had 7.6:1 compression in the US and 8:1 everywhere else, the Result:
88hp in the USA and 100hp in Germany.
Cornelius
Hamburg and USA
Posted by: MrLeeS Jan 1 2015, 10:19 PM
Data logging the run should be standard nowadays. I had a chassis dyno in my shop for 3 years and always ran a wideband just to give the customer something useful from their runs. First thing I'd look at in your case is the throttle and make sure it's opening all of the way. Your graph is a classic example of not enough air flow. And at 2 liters this smaller valves heads shouldn't be pulling you down that much at the top end.
Also, it is obvious the Tourqe and hp are headed for the 5250 intersection, if you can get there.
Good luck.
Posted by: MikeInMunich Jan 2 2015, 04:23 PM
Are you sure you're reading the graph correctly?
I'm reading that you have 76hp at the wheels and 96ft-lbs torque.
Has anyone ever tuned the mega squirt or is it just auto tuned?
They tuned the Megasquirt while it was on the dyno. They said they love MS and have experience with it.
Posted by: MikeInMunich Jan 2 2015, 04:28 PM
Data logging the run should be standard nowadays. I had a chassis dyno in my shop for 3 years and always ran a wideband just to give the customer something useful from their runs. First thing I'd look at in your case is the throttle and make sure it's opening all of the way. Your graph is a classic example of not enough air flow. And at 2 liters this smaller valves heads shouldn't be pulling you down that much at the top end.
Also, it is obvious the Tourqe and hp are headed for the 5250 intersection, if you can get there.
Good luck.
Thanks for all the feedback and advice, all of you. I will look into the potential issues and post again. I forgot what injectors we have, but they were not Bosch or original.
Posted by: MikeInMunich Jan 2 2015, 04:34 PM
Are you sure you don't have bus heads on this engine?
Konrad
At the moment, not 100%. Inquiring...
Posted by: MikeInMunich Jan 2 2015, 04:37 PM
I agree for some reason the HP numbers are higher then I thought they would be
. Joking aside, that would be disappointing given the money you've invested in the engine. Was this dyno done at the wheels?
Jon h.
I don't know where you got any idea about how much I've invested in this engine Jon. The car had it as is when I bought it. I've only invested in the ignition and headers.
Sorry, I assumed you did the the re-build.
Jon H.
No problem.
Posted by: MikeInMunich Jan 2 2015, 04:47 PM
This car is FINALLY going on a ship in less than 2 weeks, and will be my little pride and joy (I HOPE!!) 
beginning this spring over here in Munich. I haven't driven one of these things for over a quarter century (OMG, seems like yesterday 
)
Is losing power at 4500 rpm going to be seriously irritating or do ya reckon I'll just want to shift around there anyway? I guess that is a bit of a dumb question, as it depends on whether yer racing or not, what you're used to and what you expect.
I'm not going to be racing it, just possible occasional auto cross.
I'm not used to anything but my 125 HP turbo diesel family wagon which handles great, for what it is, and is peppy. I like driving it, so if I enjoy taking an Opel Zafira hard into curves, I'm pretty confident this 914 is going to be a blast one way or another. 
And as far as expectations go... Can't say if I'll get used to "expecting" to lose power at 4500 RPM, but I guess that's going to be inevitable. until I get another one that's done right in the first place. I should have had this thing put on the dyno early in the project instead of last minute. If I had I would have upgraded the heads and cam first. Now it's too late for my taste as I've already invested way more into this car than I originally planned to and I think doing the heads over here would just be too expensive and going too far overboard budget-wise.
M.i.M.
Posted by: Sea Dragon 914 Jan 2 2015, 06:17 PM
Stock for a 73 or 74 2.0 was 95 DIN or 91 SAE.
Doesn't look bad, 95hp for a 2.0, wasn't stock only around 80, thats 15 over stock.
Doesn't a 2056 only put out 110-120hp.
Pretty sure a stock 2.0 puts out about 100.
Posted by: r_towle Jan 2 2015, 07:00 PM
This car is FINALLY going on a ship in less than 2 weeks, and will be my little pride and joy (I HOPE!!)
beginning this spring over here in Munich. I haven't driven one of these things for over a quarter century (OMG, seems like yesterday
) Is losing power at 4500 rpm going to be seriously irritating or do ya reckon I'll just want to shift around there anyway? I guess that is a bit of a dumb question, as it depends on whether yer racing or not, what you're used to and what you expect.
I'm not going to be racing it, just possible occasional auto cross.
I'm not used to anything but my 125 HP turbo diesel family wagon which handles great, for what it is, and is peppy. I like driving it, so if I enjoy taking an Opel Zafira hard into curves, I'm pretty confident this 914 is going to be a blast one way or another.
And as far as expectations go... Can't say if I'll get used to "expecting" to lose power at 4500 RPM, but I guess that's going to be inevitable.
until I get another one that's done right in the first place. I should have had this thing put on the dyno early in the project instead of last minute. If I had I would have upgraded the heads and cam first. Now it's too late for my taste as I've already invested way more into this car than I originally planned to and I think doing the heads over here would just be too expensive and going too far overboard budget-wise. M.i.M.
You will love it.
Posted by: MikeInMunich Jan 3 2015, 03:09 AM
Thanks Rich, I reckon you're very right. Nonetheless, I've decided these results and this "situation" isn't quite acceptable for my expectations of what this car was supposed to be and that I will now attempt to organize a ready-to-go / plug-and-play top end package, for which I will now make a separate post, today, under WTB.
Please feel free to make suggestions for what it is exactly that I should include and possible sources, as well as what ya reckon the parts should cost!
When finished I will have it back on the Dyno and post the new results.
Thanks! 
M.i.M.
Posted by: JStroud Jan 3 2015, 08:30 AM
M.i.M.
Not sure it's that simple, to replace the heads you would need to recheck your deck height, redo the valve train geometry, plus I don't think just replacing the heads will give you the results you want, if you have a stock cam, that will limit you, to change the cam is splitting the case....
If it's a 1.8 built to a 2.0, did they change the crank? If not then it's not even a true 2.0.
Not sure who is helping you with your engine building, but I'm surprised there wasn't better communication about what you expected from this motor. If you had a hp rating in mind, they should have been able to come up with a combo to produce that.
I'm just wondering if you need to talk with a more experienced engine builder to get what you want, hate to see you throw more money at it only to be disappointed again.
Would it be an option to just take the car as is, then eventually have the motor built you want, then swap them and sell the first. Keeps the car driving.
Good luck hope it all works out.
Jeff
Posted by: MikeInMunich Jan 3 2015, 09:50 AM
Hi Jeff,
Thanks for your input.
I would have been specific but the engine was already done before I bought the car. I do realize that it would be recommendable to change the cam as well as the valves, etc. along with the heads. I may well just accept it as is and if I am not satisfied with its performance I may, as you suggest, eventually have an entire engine sent over here next time I re-import one. 
Extra space in the container goes for about $175 a cu. meter.
I'm interested in opinions about HAVING to shift at 4500 or lower. Is this normal? Would it be extremely annoying? Not optimal but acceptable? Opinions? ![popcorn[1].gif](style_emoticons/default/popcorn[1].gif)
M.i.M.
Posted by: Racer Chris Jan 3 2015, 10:04 AM
Hi Jeff,
Thanks for your input.
I would have been specific but the engine was already done before I bought the car. I do realize that it would be recommendable to change the cam as well as the valves, etc. along with the heads. I may well just accept it as is and if I am not satisfied with its performance I may, as you suggest, eventually have an entire engine sent over here next time I re-import one.
Extra space in the container goes for about $175 a cu. meter. I'm interested in opinions about HAVING to shift at 4500 or lower. Is this normal? Would it be extremely annoying? Not optimal but acceptable? Opinions?
M.i.M.
There will be times when you want at least another 500 rpm.
Without a build sheet for that engine its impossible to prescribe any remedy short of a complete rebuild.
Posted by: r_towle Jan 3 2015, 10:26 AM
Call European Motor Werks in California.
He may have all the parts you need.
have him pull the motor out , pull the heads, and post up some pictures and measurements.
Measure the crankshaft throw so you know what you are dealing with when you go buy Pistons.
Posted by: Bleyseng Jan 3 2015, 10:41 AM
What cam was used besides it being called a "stock cam"? The Web142? What is the CR? 4500 is where a stock engine starts to fall off powerwise unless you go to better cam and bigger valves with better springs. What intake setup are you running? 1.7 or 2.0L?
The dyno graph isn't too far off a 1911 build at 76 rwhp. That's about 85flywheelhp which is what you expect.
Posted by: MikeInMunich Jan 3 2015, 10:57 AM
Hi Jeff,
Thanks for your input.
I would have been specific but the engine was already done before I bought the car. I do realize that it would be recommendable to change the cam as well as the valves, etc. along with the heads. I may well just accept it as is and if I am not satisfied with its performance I may, as you suggest, eventually have an entire engine sent over here next time I re-import one.
Extra space in the container goes for about $175 a cu. meter. I'm interested in opinions about HAVING to shift at 4500 or lower. Is this normal? Would it be extremely annoying? Not optimal but acceptable? Opinions?
M.i.M.
There will be times when you want at least another 500 rpm.
Without a build sheet for that engine its impossible to prescribe any remedy short of a complete rebuild.
Thanks for the feedback Chris. No build sheet available at the moment. Will inquire. Have a great weekend!
Posted by: hydroliftin Jan 3 2015, 01:13 PM
Am I the only one noticing he is running the OBX header? I have no personal experience with them, but from what I have read they could be the problem.
Posted by: SirAndy Jan 3 2015, 01:16 PM
I'm sure *if* one manages to make them fit, they probably work fine. However, last i heard, they need cutting and rewelding to fit and seal correctly.
Posted by: MikeInMunich Jan 3 2015, 01:28 PM
I'm sure *if* one manages to make them fit, they probably work fine. However, last i heard, they need cutting and rewelding to fit and seal correctly.
Hello Sir Andy,
we die have to modify them and did MAKE them fit. I was not personally involved in this "we", but it is my project, so...
This thread has photos:
http://www.914world.com/bbs2/index.php?showtopic=231038&st=20
Posted by: MikeInMunich Jan 3 2015, 01:31 PM
Am I the only one noticing he is running the OBX header? I have no personal experience with them, but from what I have read they could be the problem.
See reply above...
Other than making them fit, what could be a problem with them?
Posted by: r_towle Jan 3 2015, 01:54 PM
What cam was used besides it being called a "stock cam"? The Web142? What is the CR? 4500 is where a stock engine starts to fall off powerwise unless you go to better cam and bigger valves with better springs. What intake setup are you running? 1.7 or 2.0L?
The dyno graph isn't too far off a 1911 build at 76 rwhp. That's about 85flywheelhp which is what you expect.
Posted by: r_towle Jan 3 2015, 01:59 PM
Because it's probably a short stroke with the 1.7 or 1.8 heads, you may want to consider buying a built motor from one of our vendors here and just bolt it in place.
A 2056 motor may give you what you need.
The difference between that and your motor is as follows.
Larger stroke crankshaft
Larger Pistons and cylinder ( Pistons will have a different pin height for the larger stroke)
Most likely a different camshaft and lifters
2.0 liter heads.
When you add up all those parts, and the cost to take apart the motor you have now, it may be a better use of your money to pull that motor and sell it, it's probably a decent motor, just not what you want.
One of our vendors here can set you up with a long block in pretty short order and send it to your mechanic to install it.
Rich
Posted by: MikeInMunich Jan 4 2015, 03:52 AM
Update:
Thanks for your feedback gentlemen. Sorry for not answering specific questions, as I did not have the info. By the way, though I don't know any of you personally, I think y'all are awesome and I want to say here and now that I LOVE 914 WORLD! 
If any of you are ever in Munich, DO get in touch and I'll be happy to let you enjoy my car with me a bit out in the gorgeous Bavarian countryside! 
As I'm sure many were thinking while being reluctant to come out and say it, the idea of a quick changeover of the top end and the cam is too hectic and just asking for trouble. Last night I stumbled upon a J.R. comment on the Samba about doing research for SIX MONTHS before making any decisions on a rebuild. Sounds a bit extreme, but does make one think 6 days just ain't gonna cut it.
So, I've decided to leave it alone...BUT...we will be trying to determine if there is an easy fix to this rapid drop in power after 4500 rpm...
We will check the timing and valve adjustment again, and the throttle, and...what else could be the culprit?
M.i.M.
Posted by: wndsrfr Jan 4 2015, 08:37 AM
Update:
So, I've decided to leave it alone...BUT...we will be trying to determine if there is an easy fix to this rapid drop in power after 4500 rpm...
We will check the timing and valve adjustment again, and the throttle, and...what else could be the culprit?
M.i.M.
Post up the fuel values table for the MS....you might be running out of fuel at the top end??
Posted by: JStroud Jan 4 2015, 08:55 AM
Mike,
I think you made the right decision, trying to basically rebuild the motor in your time frame just has disaster written all over it. Too many things that could go wrong, getting the right parts could take that long....then if you needed machine work....
I think trying to optimize what you have is the right move for now, you would hate for your car to miss the container or be loaded not running.
You may be surprised with what you have, unless you plan on racing it I'm not sure it will affect anything, forget HP ratings, just turn the key and drive it.
They're still the funnest car to drive.....regardless of power.
Expect to have fun and you will.
Jeff
Posted by: MikeInMunich Jan 4 2015, 02:38 PM
Great post here by The Master himself...
He says the 1.7 case is the best and the 1.8 heads have advantages over the 2.0 heads as well. Performance should be better with the 2.0 heads, but it comes at a price.
"The 2.0 914 heads are the only real "Porsche" heads found on the Type 4 engine. They feature 3 stud intake manifolds, the largest chambers and their own spark plug location. These are the most rare heads and also the heads that have the weakest combustion chambers, 95% of the time they are cracked and require machine work and a full rebuild. They are the most expensive heads to work with- period. They will make the most power of any stock head, due to the plug location, valve sizes and combustion chambers but the performance comes with a cost."
http://www.914world.com/bbs2/lofiversion/index.php?t141448.html
Posted by: MikeInMunich Jan 16 2015, 01:58 AM
Update: I never did get values for the AFR, but we did discover that the throttle wasn't opening all the way. Apparently the accelerator pedal stop screw in the floorboard was out too far.
New results were somewhat better but not much. Max torque was 106 at around 3500 rpm, HP at the flywheel maxed out at just under 95, allowing for 15% loss in the drive train.
Power drops off by 5 HP between 4500 and 5000 RPM and more steeply after that.
Compared to the original results, max torque went up from 94 to 106 and max HP went from 76 to 81. Supposedly the engine was not fully warm at the time of the test. The results, as you can see, got better with each run. Not sure if the engine was fully warm at the time of the last temp. At optimum temp we might be able to eek out 100 HP.
I was told that in the graph below...Green is in 3rd gear, Red is in 2nd, Blue is in 4th. I was told that the blue line is jagged because it is in 4th gear. Jake Raby chimes in below and suggests that the reason for this is that the plugs are fouled. But they are brand new. Looking into it...
Strange is that the torque and RPM intersect at 4300 and not at 5200 where they should. ?? Dave Darling however comments on the likely reason for this below.
M.i.M.
Attached image(s)
Posted by: Dave_Darling Jan 16 2015, 11:01 AM
95 DIN HP is stock for a 2.0 motor. I forget if that's what you have or not.
The lines do not intersect at 5250 RPM because the torque and power are using different scales. The line showing 30 HP, for instance, is at about 43 lb-ft of torque.
--DD
Posted by: MikeInMunich Jan 16 2015, 11:12 AM
95 DIN HP is stock for a 2.0 motor. I forget if that's what you have or not.
The lines do not intersect at 5250 RPM because the torque and power are using different scales. The line showing 30 HP, for instance, is at about 43 lb-ft of torque.
--DD
Thanks Dave.
The engine is a 1.8 with stock cam and heads. P&Cs are 96 mm. Not sure if the displacement is 1971 or 2056 as I am not sure of what the stroke of this crank is. Only the P&Cs were changed. The car has headers.
M.i.M.
Posted by: McMark Jan 16 2015, 11:36 AM
1.8 crank is66mm stroke
Posted by: MikeInMunich Jan 16 2015, 11:44 AM
1.8 crank is66mm stroke
Correction. I forgot, it has a stock 2 liter crank. Is that 71 mm?
Can you tell me what the volume is in total? I seem to be adding it up wrong on the calculator.
Posted by: MikeInMunich Jan 16 2015, 11:48 AM
95 DIN HP is stock for a 2.0 motor. I forget if that's what you have or not.
The lines do not intersect at 5250 RPM because the torque and power are using different scales. The line showing 30 HP, for instance, is at about 43 lb-ft of torque.
--DD
Dave, the dyno was done in CA. Max HP was 81.5. Is this DIN HP or are you assuming this measurement was done over here in DE. Not finding a quick answer to this question online. Is DIN HP PS...Pferdestaerke...literally, "horse strength". DIN, by the way, stands for Deutsche Industry Norm...or in English...GIN. German Industry Norm.
Posted by: r_towle Jan 16 2015, 03:00 PM
I agree that you need to look at your A/F tables.
Do you have an A/F meter or can they stick a probe up the tailpipe while they do another dyno run?
Might show you what is happening above 4500 rpms.
I did not know you have megasquirt for EFI.
what are you using for ignition?
Seems bouncy to me.
Rich
Posted by: MikeInMunich Jan 16 2015, 04:56 PM
1.8 crank is66mm stroke
Correction. I forgot, it has a stock 2 liter crank. Is that 71 mm?
Can you tell me what the volume is in total? I seem to be adding it up wrong on the calculator.
Ok, answering my own question, for those interested...a topic that's been likely gone over dozens of times times here over the years and earning a big sigh from some veterans...
9.6 / 2 = 4.8 (formula for area of a circle...Pi x r squared: take half of diameter)
4.8 x 4.8 = 23.04 (...square that number)
23.04 x Pi = 72.35 (multiply by 3.142)
72.35 x 7.1 = 513.65 (multiply above result by stroke length...71 mm in my case)
513.65 x 4 = ~2055 ml (...multiply that volume by number of cylinders)
Had I learned what I know now sooner I would have had the 1.8 heads ported and changed the valve train and cam. Perhaps another day. Oh well. Will just have to accept life with just 95 HP on this one for a while.
Posted by: MikeInMunich Jan 16 2015, 04:59 PM
I agree that you need to look at your A/F tables.
Do you have an A/F meter or can they stick a probe up the tailpipe while they do another dyno run?
Might show you what is happening above 4500 rpms.
I did not know you have megasquirt for EFI.
what are you using for ignition?
Seems bouncy to me.
Rich
Hi Rich, that blue line was, I believe in 4th gear and that made it inconsistent, or so I was told. It has Subaru injectors, MSD + electronic ignition with new plugs, wires and a powerful coil.
I'm inquiring about the AFR report. Learning as I go here...
For those curious about potential temperature issues with this combination, the car does have an extra oil cooler and a deep sump, so we are quite cool on that front. Pun intended.
M.i.M.
Posted by: r_towle Jan 16 2015, 05:39 PM
You need more data from these pulls than just HP.
Get the AF readings and timing statistics for each pull.
It just seems a bit early for you to be running out of power...
My theory is you are either running out of fuel, or your timing is wrong.
The heads will go further in stock form, so I do not think you are running out of air at 4500 rpms.
Posted by: messix Jan 16 2015, 07:56 PM
the jagged trace of 4th gear looks to indicate a problem too, ignition and fuel needs to be looked at further.
Posted by: Jake Raby Jan 17 2015, 01:13 AM
the jagged trace of 4th gear looks to indicate a problem too, ignition and fuel needs to be looked at further.
When you see this on a denote the engine needs spark plugs. It only occurs when in a higher gear at WOT.
Posted by: MikeInMunich Jan 17 2015, 03:59 AM
the jagged trace of 4th gear looks to indicate a problem too, ignition and fuel needs to be looked at further.
When you see this on a denote the engine needs spark plugs. It only occurs when in a higher gear at WOT.
Thanks for chiming in here Mr. Raby. The plugs are new, but we will do a check on them.
Here is the AFR chart from the first test, before we realized the throttle was not getting wide open. Hope to have the other one later today.
Mike
Attached image(s)
Posted by: edwin Jan 17 2015, 05:03 AM
So the operator ran this car on the dyno multiple times and wonders why it was down on power when it's that lean?
Give up with these guys and have it tuned when it gets to you
Posted by: MikeInMunich Jan 17 2015, 06:27 AM
So the operator ran this car on the dyno multiple times and wonders why it was down on power when it's that lean?
Give up with these guys and have it tuned when it gets to you
Thanks for the input. Hope you're right!
Posted by: brant Jan 17 2015, 07:32 AM
More fuel.
I think you need a new tuner!
Posted by: MikeInMunich Jan 17 2015, 10:41 AM
The red line was clearly too lean. Then it was adjusted to about 13.5. Is this with some degree of certainty too lean?
Does the octane that's in the car make a difference here? It was running 87 at the time of the test. Apparently the higher the octane the higher the optimum AFR., at least according to this article / thread.
http://www.914world.com/bbs2/lofiversion/index.php?t193629.html
The timing is set at 5 degrees advanced. We are going to advance more, but could use some feedback here about what's best with this 1.8 cam.
M.i.M.
Posted by: Dave_Darling Jan 17 2015, 12:05 PM
There is no "optimum" AFR. The 14.7:1 is best for complete burn while keeping catalytic converters happy, but it is not the single and only best ratio.
Our engines seem to like to be a bit richer, especially while accelerating. On the order of 12-13:1. Cruise can be 13-14.7 or so, and idle can be whatever it needs to be to get the 3% CO reading and an idle that doesn't hunt.
Different octane numbers don't really change the preferred mixture for any given set of circumstances.
I agree with the above comments about finding a different tuner. Someone doesn't appear to know WTF they're doing...
Your power levels appear to be at least in a reasonable ballpark over all, if a touch low for a 2056 with a stock cam and such. Though the power dropping off so quickly does not seem quite right.
That said, you can drive around at or under 4500 RPM all day. Most of us don't get over 5K on a daily basis, I don't think.
--DD
Posted by: MikeInMunich Jan 17 2015, 12:17 PM
There is no "optimum" AFR. The 14.7:1 is best for complete burn while keeping catalytic converters happy, but it is not the single and only best ratio.
Our engines seem to like to be a bit richer, especially while accelerating. On the order of 12-13:1. Cruise can be 13-14.7 or so, and idle can be whatever it needs to be to get the 3% CO reading and an idle that doesn't hunt.
Different octane numbers don't really change the preferred mixture for any given set of circumstances.
I agree with the above comments about finding a different tuner. Someone doesn't appear to know WTF they're doing...
Your power levels appear to be at least in a reasonable ballpark over all, if a touch low for a 2056 with a stock cam and such. Though the power dropping off so quickly does not seem quite right.
That said, you can drive around at or under 4500 RPM all day. Most of us don't get over 5K on a daily basis, I don't think.
--DD
Thanks for your input here Dave. Apparently I was wrong in my post about the blue line being too lean. According to what you say here the lower numbers are more rich and higher is more lean. I was assuming it was the other way around.
What do you think about the timing advance? Should it, IYO, be more than 5° advanced?
M.i.M.
Posted by: Bleyseng Jan 17 2015, 12:24 PM
Too lean for WOT as it should be 11.5-12.5 to start at low rpms.
Timing should be set at 28 degrees @3500rpms so the Max advance in all in. Is the vacuum advance hooked up?
Posted by: MikeInMunich Jan 17 2015, 02:55 PM
Too lean for WOT as it should be 11.5-12.5 to start at low rpms.
Timing should be set at 28 degrees @3500rpms so the Max advance in all in. Is the vacuum advance hooked up?
The vacuum advance is hooked up. The AFR is at 13.5. Timing is advanced 5 degrees. We will advance it to about 25, but believe the AFR can stay where it is.
Posted by: Bleyseng Jan 17 2015, 07:36 PM
Set the timing with a timing light to 28 degrees @ 3500rpms. Yep, it's a pain to do. Pelican Parts has a timing mark guide you can see to make sure its right.
Posted by: Mueller Jan 17 2015, 07:39 PM
Set the timing with a timing light to 28 degrees @ 3500rpms. Yep, it's a pain to do. Pelican Parts has a timing mark guide you can see to make sure its right.
http://www.pelicanparts.com/techarticles/914_timing/914_timing.htm
Yep, I've used this before!
Posted by: a914622 Jan 18 2015, 01:51 AM
Are the injectors firing sequential or batch? If sequential I'm thinking 2 might be called out in the wrong order? With the sudden drop in power and still running rich could the engine be sucking puddled fuel? I helped a guy tune the maga squirt on a subaru that dropped power right at 5k , but the a/f was 16.5.
Jcl
Posted by: MikeInMunich Jan 18 2015, 02:41 AM
Are the injectors firing sequential or batch? If sequential I'm thinking 2 might be called out in the wrong order? With the sudden drop in power and still running rich could the engine be sucking puddled fuel? I helped a guy tune the maga squirt on a subaru that dropped power right at 5k , but the a/f was 16.5.
Jcl
As may be pretty clear to most, I'm no a car-tech guy nor the one working on this vehicle. I'm learning a lot as I go, but this suggestion sounds pretty odd to me. Without learning more about the possibility suggested here, I'll be bold to just say that I would certainly presume the injectors fire sequentially.
16.5 is very lean. I guess that was your point? It's a shame that while the car was going to the dyno shop I wasn't aware that the timing was only advanced 5 degrees when it should be around 27.
This, based on what I've been reading, is the most likely cause for loss of power in the higher RPM range, (along with the limitations of the relatively small valves and cam). This, IMO, should have definitely been the first thought and suggestion of the guys at the dyno shop. I've learned a lot since I began this thread and I hope it's not just been educational for myself but many others as well, and will remain so for many in the future.
Next thing to look into and learn more about for me is this notion of the FI firing non-sequentially.
M.i.M.
Posted by: MikeInMunich Jan 18 2015, 03:14 AM
Are the injectors firing sequential or batch? If sequential I'm thinking 2 might be called out in the wrong order? With the sudden drop in power and still running rich could the engine be sucking puddled fuel? I helped a guy tune the maga squirt on a subaru that dropped power right at 5k , but the a/f was 16.5.
Jcl
I stand educated. My source: http://www.sdsefi.com/techseq.htm
I am not sure yet, but I reckon it's likely batch. ? Apparently it doesn't make any noticeable difference, surprisingly.
Posted by: brant Jan 18 2015, 08:06 AM
You need to richened the mixture. A dyno run is wide open throttle
Wot needs to be 12.5 ish on a 914 at redline
Richer as it is building up to redline is ok.
But running a car lean at redline is very bad and will lead to a failed engine
Posted by: MikeInMunich Jan 18 2015, 10:50 AM
You need to richened the mixture. A dyno run is wide open throttle
Wot needs to be 12.5 ish on a 914 at redline
Richer as it is building up to redline is ok.
But running a car lean at redline is very bad and will lead to a failed engine
Redline is at 5600. Apparently I won't ever be taking this thing over 5000 and if I use a higher octane the burn will be slower and cooler as well as partially compensate for the current AFR (with 87 octane) being a bit leaner than your recommendation. For use as a daily driver I think I should be OK with the AFR at 13.5. No? I will test the car with different octane ratings and perhaps buy a sensor to measure the AFR. If I do I will post the results. It seems to be debated as to whether octane ratings affect AFR significantly or not.
As far as heat, this car seems to run very cool, generally under 175 F iirc. Is this TOO cool? It has an extra oil cooler and a deep sump.
M.i.M.
Posted by: brant Jan 18 2015, 11:00 AM
No it needs to be richer. 12.5 through the range while under load/wot
Cruising at third throttle on the hwy is not full load.
12.5ish. (12.1 - 13.0) is where you need to be under load
You really need a new shop
They should know this and more
Your timing can't be that far off and they are using the wrong timing mark on the flywheel is my guess. You need someone that knows this motor if you are going to do it remotely.
Fire them. Get the car delivered. And do it yourself
Posted by: Dave_Darling Jan 18 2015, 12:28 PM
Are the injectors firing sequential or batch?
D-jet fires the injectors in pairs, diagonally across the engine. One cylinder gets its fuel pretty much as the valve is opening, while the other gets sprayed against the back of the intake valve.
L-jet is batch-fire, with all four injectors being triggered twice per cycle (with half the required fuel quantity being injected each time). I believe that means that every cylinder gets fuel against the back of the closed intake valve, and also gets fuel when the intake valve is open, but I could be wrong on that.
--DD
Posted by: MikeInMunich Jan 18 2015, 01:02 PM
Your a wealth of info Mr. Darling,
The car has an OEM 1.8 cam. Care, Dave, to chime in again regarding timing advance and the stoichiometric AFR?
Posted by: Dave_Darling Jan 18 2015, 06:31 PM
Nope.
The whole question of "optimum" timing and mixture are complex enough, and I don't know enough, to be able to tell you what they are remotely like this.
Setting things up with the stock settings is usually a good start, and is generally quite good enough for driving around on a stock motor. But if you are trying to get the "best", then you need to experiment. Small things in the exact setup of the engine, or the environment, or whatever, can add up and mean that the "best" is different for different examples of the same motor.
--DD
Posted by: Bleyseng Jan 18 2015, 08:26 PM
You should set it up so at partload (which could be driving on the freeway at 70mph) up a slight incline so its not coasting, the AFR range is 13.0-13.9 to one. Forget 14.7 to one AFR as that is too lean for a aircooled engine.
Wide Open Throttle should start out at 11.5-12.0 to one and at 5000rpms be 13.5max.
The engine has to be timed correctly at 28degrees @3500rpms BDTC hoses off and plugged on the dizzy. This is because the mechanical advance has to be at max advance to set it correctly and mostly dizzys are all in by 3200rpms. We do not set it at idle nor do we care what it is at idle.
Powered by Invision Power Board (http://www.invisionboard.com)
© Invision Power Services (http://www.invisionpower.com)