S5 NA. Stock port. Typical SCCA ITS class build using a long primary exhaust system with primaries measuring around 84". Haltech PS1k. LS2 truck coils. AFM still in place per rules. True Dyno Dynamics numbers. Lowest run was the baseline "tuned" run. The next highest was made pinning the BAC valve wide open under full load. Shows about a 2-3 hp increase across the rev range which we've seen consistently with other cars as well. The highest run was a cheater run where fans we turned on the intake to get it nice and cool. Illustrates the importance of heat management very well.

 

So the normal peak HP is around 170? So the car has a gutted AFM?

Those nomber are great, and I wonder if creating a custom cold intake from the front section of the AFM to the front of the radiator (or where the wiper fluid tank is) would help at all.

As always, good job!

BTW - Any pics of the exhaust?

 

Thanks.

The AFM is fully intact as the rules require. It's the S4 AFM actually as the car had been running a stock S4 system. The only thing I did to the AFM was release all spring tension from the flapper door. Other than that the intake tract from AFM to throttle body is completely stock. I made pulls with and without the AFM and was surprised that it really made no difference in power. I would of sworn going in that the AFM was a restriction.

Rules require that air be sourced from the "engine compartment". So on this car we couldn't run a snorkel to the front of the radiator. For something in a different class or a street car that would be a great idea. On this car, if it were mine, I would try to install a NACA duct at the bottom of the engine bay to draw air from under the car. That would be the only place that is fully exposed to air outside the engine bay but is considered in the engine compartment for the purposes of the rules. I'd also go wild on heat treatments and heatshielding of the manifold as the rules allowed.

I was frankly shocked at the large gain from just cooling off the manifold. Ambient temps were 72*. The dyno was rolled outside and there was direct sunlight on the engine bay, so surface temps of the engine and body would of been much higher. I didn't measure them but I would guess 90+* on there own without the added heat of the running engine. Intake temps were right around 90* most of the time, showing that even though the ambient temp wasn't that hot the area that the engine was drawing air from around the car is still pretty warm. I'd be interested to see what the car actually moving would do to intake temps. On the pull I cooled the intake the actual intake temps didn't change by much at all. The increase in power had to come from the aluminum manifold being cooled off substantially and not heating the air as it made it's way into the engine.

The exhaust is a custom long runner system. Probably about 84" (I guess) primaries. I haven't done any of the mechanical work on the car, just installed the EMS and tuned it. So it's hard to say exactly what the dimensions of the exhaust are without spending some time measuring it.

 

Nice run. I thought you had gotten out of ITS, Chad?

 

I sold my car a few years ago. I still build engines and setup cars though.

 

first of all, great results. i like to see real-world results like this, too. i mean, the really big numbers are always nice, but unlike many people, i understand that they are not commonplace. i'd like to see the exhaust, too, if you can.

as for the AFM-thing, it's a natural thought (for guys that actually think about these things), but yes, i remember reading somewhere that someone tested and found the same results you did. it would seem that on stock ports (perhaps, maybe even mild streetports) the AFM shows virtually no restrictions.

keep doing your thing ...

 

Awesome! I hope I can run around the same numbers, this has given me hope. I'm running a stock s4 with s5 mani and all ports open with a haltech e8.

 

If you think the AFM shows no restriction, try testing one where you still have spring tension. You'll see different results.

 

I was about to post the same thing. Great numbers BTW. I really want to build a ported 6 port and see if I can get it to put 230 to the wheels.

 

Bringing it back from the dead

I plan on running A haltech on my S5 and it'll be a street car I don't want to pull the motor I was thinking would an air filter directly on the intake elbow make a difference? Were these numbers using one of those pineapple 5/6 port sleeves?

Any other little tricks that could be used? I like the one with the idle control valve opening at Wot never would've thought of that one lol

Can the pics of the dyno be reposted?