I just got off the dyno with my SS 2.4 Auto. Bear in mind this is at a mile high and with a dyno that the owner says "reads a little low" (a definite understatement). However it isn't the total figures that are interesting, but the percent change with the GMPP intake. Here's the numbers:

Configuration___Max HP___Max Torque___% increase HP___% increase Torque

Stock intake____124.6____124.4

GMPP_________126.3____124.5___________1.346%______ _____0.08%

GMPP + Scoop__133.8____131.5___________6.876%__________5. 400%

Conditions: For the first run I re-installed the stock intake. For the second run, I installed the GMPP intake and sealed it from the hood scoop (forcing it to breathe through the stock air box bottom) This is the configuration most people have been installing it in, since they seal it to the bottom of the hood. The last run was as I drive the car, with the GMPP intake and the scoop open.

The most glaring conclusion is that the stock inlet through the fender is VERY restrictive. The GMPP didn't help much at all breathing through the stock inlet. Second, I was astounded at how much performance the hood scoop added. It may be "rice" to some people, but I'm sure glad to see that drilling holes in a new car wasn't a totally crazy idea!

So, with a scoop (or a hood ducted to the intake) 6.876% increase in HP is really great. Calculated against the flywheel HP numbers GM provides, that makes my car about 183 HP. That's a 12 HP gain from an intake!

One final note. As anyone who has messed with the 2.4 tuning knows, we saw that at idle and low throttle openings it runs somewhat lean (16.3:1), but at WOT and higher RPMs it really runs rich (like a peak of 10.8:1 at redline). We added a MAF corrector box set at 4% WOT lean and the peak richness went down to 10.6. Not a huge improvement, but the HP went from 133.8 to 135.4 and the Torque went from 131.5 to 131.8. So there's certainly room for improvement using HPTune on the 2.4.

Next stop: magnaflow exhaust and new dyno numbers!

Jay

 

LewiSS, I originally thought the look was 'ricey' but with the numbers you've thrown up here I honestly I think the payoff is worth it.

I'll be doing a bunch of mods all at once. Intake, extrusion honed exhaust manifold & sport exhaust - all GMPP & all courtesy of a GM Employee discount.

Is there a GMPP Extruded Intake manifold as well?

 

this goes to show, when people speak of vented hoods there really is a performance gain from them

 

nice to see someone finally getting a gmpp intake on a dyno !!!! and even nicer to see that ram air does work !!!

 

is your car broke? 124hp stock?

 

Haha, now I'm offially sold on my scooped hood idea . Thanks for the numbers!!

Similiar question - does GMPP have a downpipe/hi flo cat option?

 

some mustang dynos can give low numbers,the one I had my car done on would have a 2.2 at 110whp

 

^^ Yeah, besides he said at the beginning of his post he was at high alt and the guy told him dyno read a bit low, and that it was the change that was impressive - not the actual numbers.
Relativity man - go to class sometimes .

 

Nice numbers man! Good to see that the hood scoop is doing its thing!

 

wow, hood scoop made a great difference, i cant wait to ge my rk sport hood in and feel some kick from that

 

Thanks to all for the kind words. We had this dyno day scheduled 2 months ago and then the winter storms set in. Drove me crazy waiting!

I'm more than glad to be able to supply some numbers. No one was more surprised than I that the scoop was so effective.

As for the low numbers, as they say "your mileage may vary." No 2 dynos can be compared - do all your mod testing on the same dyno, however, and you can tell percent improvement for each. That's my plan.

I'll try to get the graphs scanned and posted. More mods and runs to come!

Well, the intake is thin-wall plastic. I think if you extrude honed it you wouldn't have anything left!

 

I got dibs!

 

so i guess the SS hood will improve HP numbers a little....i was gonna get it cause its a functional hood.

 

Hmm that scoop really helped huh. I wonder if that Rk Sport Cobalt hood would do anything special

 

Lol, not at all, with a 6.8% increase I'm about to do it... if only i had the ***** to...

 

damn. hood scoop ftw it looks like!

any hoods available to buy that do the same thing as the scoop? im not really inclined to tear apart my hood and put a scoop on it...especially since i would totally mess it up lol...and im not even a year on the financing so my parents would kill me...but another hood to pop on..why not?!

 

rk sport hood is fully functional

 

nice!!

 

No, GMPP does not offer any type of Downpipe option. The GMPP honed/extruded manifold is just that also, manifold and not a header.

 

From the pics I've seen of the RKSport hood, it should do exactly the same thing as my scoop. It has a molded-in duct that brings the air from the scoop over to the top of the GMPP intake.

The SS hood isn't ducted over to the intake - it's just a hole in the middle of the hood. I guess it cools the coil pacs. You would have to mold or fabricate a duct from the scoop hole over to the intake. That's why I didn't go with that hood (when I did mine, either the RKSport wasn't out or I hadn't seen it yet, don't remember which).

You will get part (if not most) of the effect of the scoop with a short ram intake. The only down side is that it will be breathing warm air from under the hood, so in summer it won't be as effective. CAI (long ram) intakes should get close to these numbers as well, but the drawback is succeptability to hydraulic lock if you live somewhere that you might get into water up to the bumper.

I cut my hood when the wife was out of town on a business trip. When she came back it was done.

 

pretty decent numbers!! is that a 2.2 or 2.4

 

SS 2.4 VVT Auto

 

bump - added graph with HP and torque curves for stock, intake, and intake + scoop.

 

sweet numbers and love the design of the intake i was very impressed with how clean it looks and the concept!

 

I know what I'm getting for myself for my birthday now... a Functional hood with a cold air intake!