Assuming the mechanical parts of the 4 Cylinder 914 motor have been modified, Cam, Ps & Cs.
What are the Pro & Cons between Carbs & the FI systems available – Megasquirt, Carson??, any others.
Would the Engine mods dictate which system to use??
Ease of set-up??
Need Dyno??
Cost??
Success stories??
Ken
EFI hands down and I've had my share of webers.
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Megasquirt, Carson??, any others |
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Would the Engine mods dictate which system to use?? |
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Ease of set-up?? |
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Need Dyno?? |
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Cost?? |
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Success stories?? |
EFI all the way (and I have carbs on my car now, but that's temporary).
The Kit Carlson system is not available yet, and may never be. It's pretty much down to Megasquirt and SDS, because those two systems have been adapted to the Type IV more than once, so you can get tuning help. MS is also easy to tune, but you do need a laptop, which isn't required with SDS.
A pre-assembled MS ECU is $350 from at least three suppliers, plus you'll need to buy or make a wiring harness. Some of the D-Jet sensors can be used straight with MS, but you'll need to fabricate a throttle position sensor replacement (have to do this with SDS, too). You can also use the stock D-Jet injectors, though they're very big. Even a decent 2270 can use the 1.7 injectors, they're so huge. The 2.0 injectors have to be run right on the limits to get good idle quality.
As Mark says, you can use the stock D-Jet plenum, throttle body, and runners up to roughly a 2.2 to 2.3 engine with a moderate cam. If you go wild on the cam or more displacement, you'll need a different setup for more flow, and the TWM IDF-style throttle bodies are the hot ticket.
Both systems can also run distributor or crank fire ignition, though crank fire with MS is a LOT more DIY than it is with SDS. With the most recent rev of MS (v3.0), you can run distributor fired ignition (you program the advance curve and lock the distributor advance mechanism) without having to hack anything up, just run the extra wires and flip a software switch.
So, if you're comfortable (or adventurous) with electronics and soldering, then MS will save you some money and give you a somewhat more flexible system than SDS. If you just want a plug and play system, SDS is a better bet.
In my experience, tuning FI to a drivable point is much more challenging than tuning carbs to a drivable point. I think most often dyno time is necessary for FI. But I'll still take FI over carbs every day of the week.
My EFI Retrofit kit is based on SDS electronics and works veryt well wityh stock injectors and plumbing. The tuning is much simpler because I load a fuel MAP from a near stock engine into the ECU before it's shipped and we also terminate the wires, etc, etc to make it easier to install.
I have sold at least a dozen of these in the past few months to teener owners
http://www.aircooledtechnology.com/store/home.php?cat=320
There is a very good reason that modern cars have fuel injection, it is better in essentially every respect.
Firstly I would say that whatever you do, you need to get on the dyno to tune it properly. You can get to a point where something is reasonably drivable with O2 sensor feedback, but it's not possible to get to all the places on the map.
Secondly - FI will always give you more control than carbs. This is principly because FI has more information than carbs do. Carbs get throttle position, manifold pressure and in some cases coolant temperature and have to mechanically figure out how much fuel is correct. You have little or no control over the fuelling at a specific intersection of those variables. FI has measured inputs for Manifold pressure, Intake temp, RPMs, in most cases closed loop mixture measurement from the tailpipe, coolant temp, etc. You can log enough data from an FI system to make adjustments to your curve. It's possible to get an LM1 to log with carbs, but when you determine that your carbs are lean at 3000RPM and 75kPA, you need to translate that information to quarter of a turn on some screw somewhere - or perhaps filing some material off of a needle.
When you tweak carbs you're typically moving a lot of stuff at once which can present the illusion that you are having an easier time of tuning - when you adjust a jet or a screw it's the equivalent of moving entire sections of the map around in one go. With FI theres a lot of rope to hang yourself, you could make your engine run at stoke at 1k, 3k, 5, and 7k rpms and run totally lean (or even cease fuelling alltogether) at 2k, 4, and 6k. It ought to be obvious when you look at the numbers in the map what is going on in this circumstance, but it's not impossible to do it.
When I say FI, btw, I mean something like Megasquirt, KitCarlsen or SDS that you can tune by hooking a laptop up to it. Whilst the D-jet is an FI system and is subject to the same inputs and outputs as a programmable system, it isn't tunable in the same way and most of the ways you can adjust it are by adjusting broader variables like injector size or fuel pressure, which are similar to adjusting the jet on a carb - they move entire sections of the map around in one go.
Between SDS and megasquirt - I think Lapuwali has pretty much covered that one. You should probably be aware that there are some ignition options for megasquirt that may not have been explored that might be better. Conventional wisdom is to run the EDIS module, but some of the newer code is capable of decoding more complex wheel setups and it may be possible to get this running with maybe an optical system and a fan that's missing a couple of blades, or something similar. Perhaps a few holes in the alternator pulley. It all depends how experimental you want to be .
Earlier in 2005, after a bunch of testing I integrated EFI into all my engine packages- If you want carbs its a downgrade...
The problem I'm having with carbureted engines/customers is the fact that no one understands them at local shops any more... New technicians are not taught5 anything about points, condensers and carburetors...
After swapping to EFI as a standard my customers have been much happier and the amount of questions I field about sputering and backfiring are greatly diminished.
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A pre-assembled MS ECU is $350 from at least three suppliers |
Hi
I currently looking at MSquirt, for my 383 Chev Stroker. Its a hard system to beet for the DIYers in the small block world. Lots of info everywhere...if you have the time/energy to spend and not so much bucks.
The "turn key" option is a great bang for the buck, but its out of my price range.
I have Dells on my 2.0l, and am very happy with them, when I get the SS down pat, you dam strait I will be scewing with a 914 and MS.
Keep us informed on what you chose.
Later
QUOTE (rdauenhauer @ Dec 13 2005, 08:53 PM) | ||
Who are these suppliers? |
RS and DIY Autotune have both had nice things said about them repeatedly on the MS forum, so they seem trustworthy businesses to deal with. There's tons of free information on the MSEFI forum, but the learning curve for this stuff is fairly steep if you've never really dealt with electronics or fuel systems before.
The thing I like about MS is these guys are trying to do EVERYTHING with it. Water and nitrous injection, traction control, every kind of ignition system under the sun, and engines from chainsaw engines to big-block Chevys with twin turbos making 800hp. The downside is there are a lot of options with so many projects going on at once, so it's fairly confusing for the novice.
Mike,
Any results on your MS setup yet??
Ken
QUOTE (McMark @ Dec 13 2005, 04:09 PM) |
In my experience, tuning FI to a drivable point is much more challenging than tuning carbs to a drivable point. I think most often dyno time is necessary for FI. But I'll still take FI over carbs every day of the week. |
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When I say FI, btw, I mean something like Megasquirt, KitCarlsen or SDS that you can tune by hooking a laptop up to it. |
The SDS programmer on my ashtray mount.
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Just a quick note....the reason us MS guys keep the laptop plugged in....its fun!
I always think that I can get this point just a little better..do I need to? no! I just want to...I do put all the geek stuff away when I just want to drive and have a ball.
having a car that can now accelerate like I have never felt before is kool too....
I have had my MS working for like 3 years now. One of the problems is the amount of options that you can use. I am now upgrading my CPU to the MSII version so that it will self tune the Ve table based on O2 feedback. Sounds like fun...I don't need to do this..I just want to....where will it end??
Last year the wife was getting pissy about all the wires, etc.
So I took it off and never put it back on.
This year I sold my engine and stuck my old 1.8 in, programmed it for 2-3 days (2-3 hours seat time), then removed it for the whole summer.
On a side note that has nothing to do with performance is the difference in sound. I had webbers when I first started out. I converted back to stock FI. With stock FI the air cleaner is heavy and in a central location. The webbers had 2 thin metal air filters on each side. When at full throttle, the sound comming from the engine is a lot louder!
Mark
Yes... but on a hi-po engine with dual TB's (TWM's etc) I think it would be just as loud as webers.
Thanks for all the inputs.
The only comments missing are regarding the the sensors and ease of hook-up - MS or SDS or is it about the same?
Are the proper sensors hard to get and mount??
I still haven't heard what Muller's MS results were???
To Summarize:
FI better than Carbs due to more tuning information available at various engine speeds and demands.
Existing Plenum and injectors usable to about 2300cc.
Megasquirt & SDS are the 2 choices for the 914.
MS is more Do-It-Yourself as far as building and is probably less expensive. Requires a Laptop to tune and see all the pretty pictures.
SDS more expensive but probably easier to tune and allows for easiy adjustments while driving.
I spoke with SDS today and their feeling is that for a race car where Idle and Full Throttle were the most important setting, tuning should be quite easy.
Ken
Sensors are pretty much stock, except for the throttle position switch. But that's not too big an issue. It's been done before.
He's a question or two..
Let's say Stock 1.7 with stock FI, porsche stock cam, compression, and exhaust motor is in good and usablecondition
vs the same motor with tunable MS or SDS.
is there any HP gain?
What about fuel economy?
We know it's a bad idea to bolt on carbs with the FI cam profile and we know fuel milage will also drop.
any real HP gain with carbs on that same stock motor or does it just sound like it...?
I am late to this thread...been too busy with work...
SDS and MS are good systems, but there is another PEFI option, from Emerald Performance, which looks really promising. The manufacturer is based in the UK and the system has been on the market for over 10 years, so its a proven commercial system, not 'experimental' like the MS. Their US dstributor is in Florida.
http://emeraldperformance.com
The M3DK ECU is a full-on engine mangement system including 3D mapping, ignition control, datalogging and more features and is competitive with SDS.
They also have a new ECU which I am told is almost done with beta testing and is due out anytime now, called the K2 which is fuel injection only (it should be a direct D-Jet swap), no ignition control. This ECU with a prewired (but not configured to the engine) generic wiring harness is the size of a cigarette box and will be about $800. It will fit into a stock D-Jet ECU case easily for those that want current technology with a stock look.
Mack, the owner of Emerald Performance in Florida, seems to be exceptionally knowledgeable about FI on aircooled engines (including turbo applications) and is a very nice guy as well, based on several phone conversations I have had with him. He tells me has the maps already for a 2L 914 setup.
Check out the exceptional free downloads of demo software from their website, as well as the links to the UK manufacturer and then try to tell us with a straight face, that you are not impressed...
Here is a photo of the M3DK ECU:
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Nice Jeff!
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Megasquirt & SDS are the 2 choices for the 914. |
Thanks for adding "Emerald Performance" and "Haltech" to the list.
What is the price range of a Haltech system. Higher lower than the others mentioned??
I did not include Motronic and Electromtive, etc due to high cost.
Ken
A Haltech E6X is about $1280 with sensors ( MAP, TPS, CLT,IAT) and a wiring harness and relays.
so its alot more than Megasquirt, and A bit more than SDS. It also has alot more features than the aforementioned systems.
Fuel only ECU + Aftermarket Distributor = Cost of Fuel & Ignition ECU
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He's a question or two.. Let's say Stock 1.7 with stock FI, porsche stock cam, compression, and exhaust motor is in good and usablecondition vs the same motor with tunable MS or SDS. is there any HP gain? What about fuel economy? We know it's a bad idea to bolt on carbs with the FI cam profile and we know fuel milage will also drop. any real HP gain with carbs on that same stock motor or does it just sound like it...? |
The primary reason I mentioned MS and SDS specifically is that there are multiple installations of both on the 914 by people on this board. There are plenty of other good systems, but being able to get good support from people here who've already been there is, I think, invaluable. Both systems also have very helpful and informative websites on their own, and I think that kind of behavior needs to be supported. I don't know of any other systems with nearly so extensive a library of data and advice online as these two.
There's also Perfect Power, which airsix has installed on his 1.7 (though I believe the exact ECU he used is no longer available), and Link, which Mueller is actually using now on his 914.
As far as I know, no one here has used the Emerald system on a 914, yet.
QUOTE (rick 918-S @ Dec 17 2005, 05:33 AM) |
He's a question or two.. Let's say Stock 1.7 with stock FI, porsche stock cam, compression, and exhaust motor is in good and usablecondition vs the same motor with tunable MS or SDS. is there any HP gain? What about fuel economy? We know it's a bad idea to bolt on carbs with the FI cam profile and we know fuel milage will also drop. any real HP gain with carbs on that same stock motor or does it just sound like it...? |
yipppeeeee.....
I went to hang out with a bunch of Volvo guys today in Elk Grove...glad I went, learned some good info for my 242 motor swap....but the best part was that I was talking fuel injection with one of the main guys there and he just walked over to his storage bench and handed me 2 complete early Megasquirts that to his knowledge work.
I started to hand them back to him and he said keep them, no charge, he had no use for them since he was going to use something else.....not bad, 2 free megasquirts....one I offered to Ken if he wants to go that route and other one will be going onto my spare 1.8 for R&D to work out a wiring harness kit for those that want to go that route as well as other MS related items to be used with the /4 motors...of course I still have to test these to make sure they work, but no signs of spilled coffee on them
When you say early do you mean v1 boards or v2.2 boards? Not that it really matters.
Mueller: I got the input stage of our circuit going today BTW, but couldn't find a couple of chips I need to finish it off. It's going pretty well tho!
I had a ball building my MS 2.2 board. It's still sitting downstairs on the stimulator since I don't have a motor to put it on yet...
But, in that timeframe, I've already flashed it to the new firmware with the larger VE table, self-learning curves with a WB-02, and all of the other fun features.
I like MS since it's really DIY, you learn SO much about the FI system, and it's cheaper and probably works just as well.
You can control the MS with an older palm pilot if you'd like (one of the serial ones) and that's what I plan to do after it's tuned with the laptop (thanks Mike!).
Later,
Tom
QUOTE (fiid @ Dec 18 2005, 12:28 AM) |
When you say early do you mean v1 boards or v2.2 boards? Not that it really matters. Mueller: I got the input stage of our circuit going today BTW, but couldn't find a couple of chips I need to finish it off. It's going pretty well tho! |
ha ha.... I just ordered my MS-II chip to upgrade my v2.2.
This will let the motor self tune Ve table on the fly....Kool!
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