GT350 vs Stock Intake Manifold

V8EATR said:

Hello all, just wanted to report on my experiences. 15' GT PP, full catless exhaust, e85, JLT cai, Mcleod RST, aluminum DS, lightly ported stock intake mani, 17" dark stars with 275/50/17 M&H out back, stock front wheels. Best track time [email protected], 1.65 sixty foot, 3880 race weight. (200-300 DA)

Then comes GT350 mani/tb (still kept the original JLT cold air). Add 18x5 skinnies up front and rear seat delete (total weight savings of 75 lbs). Same track, ran [email protected], 1.70 sixty foot, 3800 race weight. (1600-1700 DA)

So car gained .15 while loosing .05 on sixty and gained 3mph while increasing DA by 1500 ft.

Overall very happy with it. Very much worth the cost. Hope this helps anyone on the fence.

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armykyle1 said:

Definitely a solid gain. I'd be curious what the difference is without the front runners.

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Rhamlinii said:

Good data, thank you for posting. What was you shifting at for both setups and what's your rear gear and RPM thru the traps for both setups?

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Mark5825 said:

I would say adding skinnies and being 80 lbs lighter provided the majority of the gains, always good to see progress.

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V8EATR said:

About 7k for the stock mani, 7800 for the GT350. Not sure on the traps but I'm sure the GT350 was marginally higher.



You really think 80lbs and a DA of 1000+ higher accounts for 3mph? The car is noticeably faster on the streets too. I have a couple local cars I have ran before that haven't changed anything and there is a 3 car or so difference in the same race.

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Mark5825 said:

With converted D/A factor you gained .35 so that takes air out of it. Your 60' is going to suffer with the loss of torque.

So .35 with GT350, skinnies, and other static weight. I saw .2-.3 with skinnies and some weight reduction on my setup but debatable. I've run at 3750 to 4150 lbs and have seen how much just the amount of gas in the tank affects things. So after all the funny math roughly .1 for the manifold.

With the GT350 I've seen countless people get 2-4 higher MPH with no improvement in ET so it's nice to see that. I'd agree the MPH part to the manifold. Raced in 1/4 mile or "elsewhere" because from what I've seen it kicks in right at 120 ish so anything over that I'd expect gains.

Some bias because my goal was also to see what the stock manifold could do because I didn't see enough data in 1/4 mile times to try any of the aftermarket ones but I also run a S550 list with 79 N/A cars with various setups (you would be 26th). Dyno and HP and 120+ agree with gains.

It's also a manual vs auto so more variability in general.

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