this maybe a stupid ??? , but if temp. has everything to do with HP in an air cooled engine wouldn't this improve preformance?




George

Yes, I think it's something like 1% power gain for every 10 degree temperature drop.

The problem is how to cool it to get an adequate boost?

Exotic chemical based systems? Use an intercooler in conjunction with CO2? Or Frion? Keep in mind that flow rate is also a problem.

i was thinking about the simple AEM systems they have that just relocate the air intake out of the engine bay.



George

It does seem to help. Demick (member on this BBS though I haven't seen him post in a while) did some testing, and he figured it was worth a few HP to route cold outside air directly to the intake on his 2056cc motor. The engine bay--particularly the middle where most 914s draw their air from--is quite warm.

The real question is, where do you get the cold air from? It needs to be somewhere that is fairly well sheltered from rain, debris, dust, etc.

Demick finally tried simply flipping a stock air cleaner around so the snorkel pointed off to the side of the engine bay. He said it worked almost as well as his downspout ducting, and was much easier.

--DD

QUOTE

Dave_Darling Posted on Mar 24 2006, 11:22 PM The real question is, where do you get the cold air from? It needs to be somewhere that is fairly well sheltered from rain, debris, dust, etc.

i was thinking with all of the heating equipment removed, thru the longs and place filters behind front bumper.
i know it would be alot of work, but it wouldn't be that bad working on a bare tub.

George

all of my heater stuff is removed. I should be able to build a plenum and route everything from the grill on the hood straight into the engine bay. Maybe I will give it a try when I go to replace my hood...

I remember a thread a while back... a guy ran air tubes through the longs, and put the intake under the fresh air grill. He did a nice job and had some pretty solid stats to back his efforts.

If you didn't mind cutting the body sheet metal, it seems like putting a duct in the front of the rear fender just behind the door would be logical. All the modern mid-engined cars have a grill there.

I took the easy route... my filter is just under the engine lid grill with the rain tray out. Works nice. Fab a half round shield to mount just off the filter so it can be rotated... a rain shield above for winter, or below for a heat sheild.

The benefits are HUGE! According to the rest of the climate the benefits can be even bigger.

Yesterday I was able to observe a 6 HP gain across the board from a 10 degree cooler intake charge. This is why 95% of all new cars have a fresh air intake right from the factory as the colder air charge also burns cleaner for a more efficient engine.

I have been working on something I "invented" that may help control air ntake temperatures year round to keep the charge warmer in the winter at start up and colder the rest of the time, thats what I was playing with yesterday so it's funny that this came up!

Cryo2

Cryo2 website

Not even close to my idea... It gives a similar effect though

I did something like this, and was drawing air from the left side grill on the drivers side.

throttle gives more zip when pressed down sooner, but at WOT it lags like a dog...sounds LOUD tho.

probably my exhaust slowing things up or something....

b

QUOTE (Jake Raby @ Mar 25 2006, 08:38 AM)

Not even close to my idea... It gives a similar effect though

Yes Jake, but can your idea do this?

Yeah, Grantsfo

That's EXACTLY what everyone needs. MORE smoke coming out of their 914s.

Sheesh!

What DDD said....

914 Cold Air Intake

We have recently been testing the effects of phonelic materials that have near zero heat transfer to be used for intake manifold to head gaskets as well as carb/manifold gaskets.

The benefits of this has been huge as it keeps throttle bodies cooler, plenums cooler and runners cooler. The data logger aith 8 thrmocouples in place on my test car has already seen a carb temp near 40 degrees cooler, that means cooler air and cooler fuel being introduced into the engine, both of which are huge power makers.

These will be released in May- they REALLY work, especially with the New Genaration heads because they allow port work that are otherwise not a possibility..

Definitely easier to bring cold air to the filter source. If you had to relocate the filter into a cold air source , you need to snake it out of the eng bay with min 2.5" preferably 3.0" OD alum tubing. This would be a task--but do'able. 2" tubing is much easier to route in our cars, but can't flow the cfm needed.
Here is a crude cold air ducting that I ran in the 80's on the 3.0 biturbo, boost cooled by methanol inj. so no intercooler. It simply took in cold air off the side of the sail panel and dumped it into the air filter area. I've seen some MR2's with spec-made intakes that don't look too bad.
Hey, that's DE instructor Jeff Erickson in there
Marty

I was impressed by the study that Demick did. I'm glad DD pointed it out. Related to this is the work done by this guy:
http://members.rennlist.com/chuxter/TempTests.htm
The scoop he came up with is attractive but looks like a fair weather solution.

The experiments that amateurs like Demick or Charlie (chuxter) do are straighforward but take time, equipment and are tedious. We all benefit from their work.

Interesting... I have no idea how advancing the timing would have decreased oil temps, that big of a change should increase oil temps by quite a bit.

I'd also like to know what instrumentation he was using to measure a 1 degree variance accurately, even my data acquisition equipment has a +/- 2.5 degree range.

The duct work that was done is impressive

Here are the specs for the instrument that chuxter used:

The OMEGA® HH501DK is a rugged, easy to use thermometer with 4 standard miniature connector inputs. It accepts K type thermocouple probes and covers ranges from -50 to 1300°C (-58 to 1999°F). It also provides differential temperature measurement readings of T1-T2, T1-T3, T1-T4, as well as individual readings of the 4 inputs.

Specifications
Temperature Range: -50°C to 1300°C (-58 to 1999°F)
Input: Type K thermocouple
Accuracy:
±(0.3% rdg + 1°C) -50 to 1000°C
±(0.5% rdg + 1°C) 1000 to 1300°C
±(0.3% rdg + 2°F) -58 to 1999°F
Display: 3 1/2 digit liquid crystal display (LCD) with maximum reading of 1999
Polarity: Automatic, positive implied, negative polarity indication.
Overrange: (OL) or (-OL) is displayed
Zero: Automatic Low Battery Indication: visual indicator is displayed when battery voltage drops below operating level.
Measurement Rate: 2.5 times Operating Environment: 0 to 50°C @ <70% RH
Storage Temperature: -20 to 60°C, 0 to 80% RH with battery removed from meter
Accuracy: Stated accuracy @ 23°C ±5°C <75% relative humidity. (accuracy specification does not include type K thermocouple probe accuracy)
Dimensions: 195 x 92 x 53 mm (7.7 x 3.6 x 2.1")
Weight: Approx. 250 g (9 oz) including battery

If l interpret this correctly then the accuracy is similar to the instrumentation that Jake is using. Resolving a 1 degree change with any confidence would be difficult. You can't argue with a 30 degree change but that last improvement due to a timing change does seems questionable.

Accurately measuring the exact temperature isn't important. Measuring a difference is. The accuracy on the unit was +- 5deg. The accuracy of calipers are +- 0.002". But in the case of either, you will notice a difference between one measurement to the next. This isn't random. It indicates differences in sizes between one measurement to the next. Is one inch exactly one inch when checked with calipers? Maybe. Maybe not. Is the next part, that measured 1 thou bigger than the last part, 1 thou bigger? Yes. Unless you went out of your way to disprove that by purposly botching the measurements of either. Same for the temp probe. Is the inital temp exactly 95 deg? Maybe. Is the next reading, at 98deg, three deg hotter? Yes.

My arrangement also uses a "K" type thermocouple... I agree thatb temperature differences are the biggest thing that one should use when analyzing data, but to me 1 degree IS within the variance of the instruments being used to gather data and I'd write off the change.

If I can't make a change that nets at least a 5 degree difference, the effort was wasted.

Jacking up the timing 6-7 degrees should make at least a notable change in the oil temps.

Don't forget that tests require controls to be effective, unless you can monitor (and sustain) load and RPM there is no control with the test he completed.

If his ignition timing test would have included EGT and AFR monitoring as well as oil temp the results could be more closely compared.... Thats why I have a 32 channel data logger.

By no means am I doubting his work with this testing, because I know how much it sucks to do test work, share the data and then be questioned by the very individuals that you intended to assist. Thats the reason why I quit posting my test results and started charging for the data...

Roger that, Jake. Actively applying the scientific process is tough when other people are involved. Nobody trusts anybody these days.

So... What do you think about a chambered FI plenum cooloed by liquid CO2?

QUOTE (Jake Raby @ Mar 26 2006, 06:51 AM)

...By no means am I doubting his work with this testing, because I know how much it sucks to do test work, share the data and then be questioned by the very individuals that you intended to assist. Thats the reason why I quit posting my test results and started charging for the data...

My opinion:
Well, I've seen/heard plenty of people make claims to improvements via their "testing" just to find out their "testing" was less than scientific. Not knowing how testing was done raises suspicion with me. Maybe I'm scarred from my Business Statistics professor In the scientific community, having your results scrutinized and you able to back up the data is par. I basically have to do the same stuff when creating executive-level reports for my customers. Just because one may be an expert -- or have good intentions -- doesn't necessarily mean they're right.

GM and Mopar used cold air as options in the '60/ '70s. My '69 SS350 drove the 1/4 mile 3 tenths faster than my pals RS 350 w/o cold air. Both cars were identically mod'ed otherwise, and weighed within 20 lbs. of each other. On my 986 Boxster filter kits, the unit is located right in the airflow of the fender duct.
Marty

I've been looking at fab'ing a scoop/engine cover. I'm still early in the planning stage, but it will stick out through the roll bar like this pic shows. I have been running it w/out anything over the engine and I know sooner of later somebody will fill a protest because I don't have a "hood".

Maybe I can get it to seal over the carbs and than I'll only run one air filter. But that seems like a lot of work. Keep it simple.

If you look at my avatar and look at the pic below you can see how I want it to look.

I like the idea of a single intake for your race car, however (there's always those ), all your induction noise will be funneled through it and at you! My good friend has a mid-engined Notchback roadster (no roof) and it used to have a scoop over the engine somewhat similar to what you're talking about but it was loud! Step on the gas and it was louder still! Yeah, initially it was great but on any road trip it became fatiguing and forget about holding a conversation.

Granted, your's is for a race car (which will make even MORE noise) but still...do you really need all that extra noise in your right ear? Maybe if you placed it off-center, more to the right of the car? Just something to consider.

Here is a pic I found for the fun of it.

QUOTE (Air_Cooled_Nut @ Mar 27 2006, 10:45 AM)

I like the idea of a single intake for your race car, however (there's always those ), all your induction noise will be funneled through it and at you! My good friend has a mid-engined Notchback roadster (no roof) and it used to have a scoop over the engine somewhat similar to what you're talking about but it was loud! Step on the gas and it was louder still! Yeah, initially it was great but on any road trip it became fatiguing and forget about holding a conversation. Granted, your's is for a race car (which will make even MORE noise) but still...do you really need all that extra noise in your right ear? Maybe if you placed it off-center, more to the right of the car? Just something to consider.

Good idea. I thought about locating it off-center away from my head a little bit.

I would think with a full face helmet and if I need to, I'll put ear plugs in that I would be OK.

I only need to put up with it for a few minutes at a time.

This is the MR 2 that I saw on the street, nicely done in fiberglass L and R sides. I've also seen them on another car still in primer (ricer style) , so these are more than likely mfg'd and sold in speed shops in San Gabriel Valley. Dedicated fit to the MR2 though...anyone handy in F'glass (Morphen Spectra) could make these up
Marty

nuther from the rear angle. I'm sure that it gets some cold stuff in there.
Marty

Looks kinda a stupid to me 'cause the intakes don't or bearly go above the roof line and the openings are so small. But I realize with the ricer crowd it's looks first, function last.

Now if you're going to aiir to the engine you need a SCOOP like this....

You guys are IDIOTS!

Many of you removed your A/Cs... FOOLS!

DPD air injection, YO!


M

Elise air intake snorkel is right there on the side!

Here's my take on it. It seems to help a bit when I watch the intake temp but, I can't feel any difference

originally those snorkels were for the turbo'd 2nd generation mr2's w/ their intercooler mounted against the wall of the engine bay.

I think I'm going to find an intercooler of some sort that has the same diameter ports as my intake boot (between the AFS and Plenum), run it right under the decklid grille (a-la 930 style). Or better yet, in front of the cooling fan with a shroud made up around it... Forcing air through the intercooler. The fan is nothing but a huge vacuum...