Dimi 944

I've decided to experiment/upgrade the intake on my 944 NA. I am testing out my friend's set up shown below. Today, I had a few dyno runs on Dyno Jet and the 26-year-old track toy did 135 HP and 135 FT/LBS TQ !! I was pleasantly surprised because I was expecting lower number in all honesty.

Tomorrow, I will run it with stock and then with the set up in the pic below.

Stock set up


Experimental set up



The car has stock exhaust and MaxHP chip.
The Dyno results of stock vs experimental set up are shown below (the blue line is the stock intake and the red line is experimental set up).

Darwantae951

Aren't the runners shorter than ideal for an N/A application?

Paulyy

Pictures of the dyno chart?

I thought the 951 intake wad designed for more bottom end torque to help with the turbo lag.

MAGK944

It is, generally longer runners favor lower rpms. Also the 951 plenum will be larger to account for boost. Interesting experiment but I think everything else being equal you will lose power with the 951 intake on the na.

carlege

It sure is a prettier intake compared to the NA

nasty9er

cant wait to see what comes out of this

M758

132/132 is pretty common for these cars. So at least your baseline numbers are reasonable That is aways a good start

ZR8ED

The runner length for the n/a and turbo intake are very close in length. I used a crude method of measuring runner lengths, and determined that both manifolds have equal length runners, and that the difference between manifolds was negligable using the method I used. (I inserted a rubber hose into each runner, and compared them. I did not calculate a precise measurement due to other variables that make the actual length difficult to determine.)

I'm very excited to see the results as well. Whether it works or not is not the point. Determining which is better for basic n/a engine is more important. If the n/a manifold is better, so be it, and we can move on to other ideas.

As for the final results, it looks like adapter to the AFM could make or break the results of this test. Do you have any pics or description of what that adapter is and how it transitions from a round to a square port?

pettybird

I have a friend running GTS1 with a turbo intake making good numbers. will be interested to see the back to back, too.

SpeedBump

Where you getting the dyno done?

MAGK944

I just measured both of mine on the car. Used string to go around the bends from flange to plenum. Surprisingly the turbo intakes are all approx 13.5in and the na all approx 15in. So the na intakes are quite a bit longer. The plenums on both seem to be about the same, about 12in long.

ritzblitz

Nice base line numbers!!

Darwantae951

Having no serious knowledge base to fall back on, my assumption was that the NA would use longer runners to increase velocity of the air. A turbo, having help, wouldn't need runners quite as long. Maybe one of the more knowledgable individuals could chime in and shed a little more light.

Dimi 944

Done testing the new intake set up!
Overall, there is no change in the average horsepower. However, between 5500 and 6400 rpm the car made 139 HP - gain of 4 HP. Between 2000 and 5000 rpm the car made 131-132 HP - loss of 4 HP.
Having in mind, I predominantly track the car the gain does help me. Also, my friend and I are working on an air scoop/collector to generate/simulate ram intake. This should lead to some power increase at speed. However, more than likely the mapping has to be changed because the ECM wouldn't know of the increased air flow/pressure at WOT at speed.

Btw, the car has stock exhaust and MaxHP chip.

Pending dyno graph and sheet....

I had it dyno'd at PF Supercars in Frederick, MD on a Dyno Jet.

GTSilver944

Err... isn't the area under the curve that matters, not the peak? 4 hp lost over a 3000 rpm range is more than 4 hp over a 1400 rpm range. Ram air does not work at NA speeds.