Russian Rocket

hmm.. weird, i read an old 80's article that raved about the GTI and mentioned that it was faster/just as fast as a 944. Maybe it was a Euro test car compared to the US 944s or maybe they compared overall performance. My GTI with some breathing mods felt somewhat faster than my 84 944. Tranny also make a difference, i have a 4K which is more acceleration friendly it was found in post 83 GTIs.

Serge944

Maybe you're thinking of the Civic SI?

Geo

Webber DCOE carbs (or more modern copies) have short intake runners and generally produce higher top-end power. But carbs suck. They don't meter worth a damn compared with fuel injection. Anyone could do better my making a short runner intake manifold with ITBs.

michaelathome

"By making a short runner intake manifold with ITBs." What are ITBs? I could go to google but I would rather you explain cause I really don't know.

Michael

If ya want I'll start a new thread.

Manning

I doubt the flow is laminar for very long in the stock intake. You have sharp turns and sharp edges through the intake on these cars.

944CS

Individual throttle bodies..ITB

Danno

"This is my first post, but i have been following these forums here for sometime. I am Mech. engineering student and also agree with serge, It is a fact that bends decrease the flow rate. This occurs because the flow is no longer laminar and has turbulance."

"I doubt the flow is laminar for very long in the stock intake. You have sharp turns and sharp edges through the intake on these cars."

Eh... piece of cake! Add a Tornado!!!

FSAEracer03

Sorry Geo, but that's incorrect. The AFM interferes with that a lot. More importantly the resonance is controlled by the manifold as the runers all join by the TB.

Actually it's 2 fires per revolution. We have 4-stroke motors

With respect to what? Mass is conserved yes, but how it enters the engine is different. The mass remains the same obviously, but it enters at a higher rate proportional to the boost increase... I think I'm missing something because I didn't get that statement.

AlexE

........and thats why this won't work. You may move your torque curve here and there with this but overall gains will be few.

The 40-50+ rwhp is attainable (someone mentioned this earlier as a possible goal). Its the $$$$ that will always hold everyone back.

Fuel management, timing and intake changes will not gain you the 40-50rwhp. Not in this lifetime. You need major engine work to get those kind of gains.

Interesting exercise but thats all it is. Just my 2 cents.

L8 APEKS

Holy ****...9 pages just because of an INTAKE?! For cryin' out loud, you guys need to get out more! lol!

It should ABSOLUTELY wait until your car is running PERFECTLY. Wasn't the whole point of doing this to get some closure on the subject? To know, once and for all, whether or not a decent intake setup would make any power on the N/A motor?

Well...unless your car is running perfectly...and unless you dyno both BEFORE and AFTER this mod...then you'll NEVER know if it did anything at all, and the whole project is utterly pointless.

You need to wait.

It sounds like you have a vac leak, BTW. Just because you looked at the vac lines twice doesn't necessarily mean you should rule them out...and there are other places air could get into the motor behind the AFM (J-boot, intake manifold gasket, etc) to cause a vac leak!

Geo

Sorry, but it IS correct. It is the ONLY way that CAI make the sort of power they do. If you get your nose out of a book and into the real world you will find that people are making significant power increases with NA engines every day by using long tube CAIs. The power comes from resonance tuning.

The 7-8 hp a SE-R gains from a CAI is certainly not from cold air because the underhood temps at speed are near ambient - this comes from testing using thermocouples (which has been done with other cars as well - I know of at least 4 such tests all with the same result).

OK, the above discussion was relative to intercoolers and the effect on metering. The point is that air entering an intercooler is indeed more dense, but the mass is the same and the mass has already been measured at that point. However, changing the VE of an engine that does not use a MAF will screw with the calculation of air mass. Improve the air flow of the 944 and the mixture will be off because the AFM does not measure air mass.

Mongo

Hey Geo you mentioned the Milledge cam. Webcam makes a grind much like John Milledge's camshaft. I'm interested in doing a camshaft upgrade and an FR Wilk chip to increase the compatibility of the air/fuel ratios with the lift of the cam. Unfortunately sicne Mr. Wilk is still MIA, who else burns chips that is compatible with a .480" lift cam???

EDIT: Oh another thing!!! What does the Stahl Header look like and where can I get one???

Geo

I love people who say "it won't work" when others have already done it. Simply amazing.

I don't think anybody has said fuel management, timing, and intake changes will get anyone 40-50 hp. Now you're either just not reading well or making things up.

That said, Jon Millege gets 185 bhp from an IT legal 944 engine. That's 27 hp from the 158 bhp late 944 engine. If you're not familiar with IT rules, they are quite strict indeed. Compression (which doesn't add that much hp) can be raised a half point. Exhaust is free from the head back. Internals must be stock including the cam. The head and intake manifold may be port matched up to 1" from the mating surface (not enough to P&P). Intake before the TB is free. Engine mapping is free. Jon now installs MoTeC units inside the stock box (only way to use one legally), but the 185 bhp is from before this was legal. That's it. And he gets 27 hp. So don't bloody tell me it cannot be done w/o extensive modifications. Then again, you've aleady said something other people are doing is impossible.

I would suggest you open your mind to what may actually be possible.

To get 40-50 more hp, I'm sure a simple P&P and and a cam would get you there from the 27 Jon already gets.

Geo

I don't know. Have you talked with Danno? I know he's been working on NA maps, but don't know what all he's done.

Also, you can't just go by the lift or even the lift and duration. That still doesn't tell you the whole story of a cam's profile. Area under the curve is the key (and usually highly guarded). You can have two cams with the exact same lift and duration that are very very different. One may ramp up quite aggressively (a lot of lift fast) and another may ramp up much more slowly. Also, it's wise to know what valve springs the cam maker specifies.

JWT, the premier tuner for Nissans in the US undertook a huge cam development program. Without going into long details they now offer valve springs that are required for one series of cam. They are made of unobtainium and the wire is produced by only one manufacturer in the world. Just one. Now here's the cool information..... The valve springs alone, with a stock cam make 2 additional hp, such is the improvement in valve control. Most people just throw heavier valve springs on a car to control unwanted valve motion and float. But, the heavier springs also induce parasitic drag and suck up power that would otherwise be available. So, the point? There can be other factors that may affect the power you get from a more aggressive cam.

I wish I knew what they looked like and how much power they make. The only place that sells them is listed on the Stahl web site. I've only heard of one or two people who have them. I'd love to see dyno charts for them before and after.

I also have the specs Jon Millege calls out for a 944 header and may have my own made. The information is proprietary and I got it as part of a $100 information booklet I bought from Jon. It's not my information to give otherwise I would.

L8 APEKS

The Stahl header is supposed to be pretty decent, and the specs of the Web cam look promising.

But damn...$1100 bucks for the pair. Then the money required to remove/port/mill/re-install the head. You're up into the $1700+ range with gaskets. Replace the valves, springs and lifters and you're above $2000.

If I had the bucks, I'd try it. But damn...that's a lot of dough!