GT3 Throttle Body Upgrade - Who has done it?

Greetings folks, More threads from me - I apologize. For those of your that have done the GT3 Throttle Body upgrade to your vehicles: 1) How much do you like it? 2) What is the most noticeable difference compared to prior to the modification? I'm just thinking about doing the upgrade, and I'm just curious for people's thoughts!

I did it, but it was one piece of a larger mod job. After I finished everything, my butt dyno told me that low end torque was not significantly affected like others have reported. There is a huge improvement from 3500rpm all the way to redline. If it is the only mod, you�ll probably be disappointed.

I have one too, but like Tex, it was with other modifications, so I can't speak to it as a stand-alone mod.

From your other post, its to go along with a 3.4 to 3.8 rebuild, right? I'm curious as well. Going from 3.4 to 3.8 along with a big intake valve job from Hoffman.

Here is one 2003 3.6L dyno @ 65,000 miles. Tune is required to max the intended performance gains. You Tube

Correct, it's part of a 3.4 to 3.8L build as well. I haven't contacted the shop to see what they think yet, but they also didn't list it as a definite "must" when we were thinking what kind of build we wanted to do, which is a mostly street, a couple track weekends a year sort of car. -Matt

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How did your dyno run plot out with the plenum, TB, exhaust and tune? Met your expectations?

I had it with 200cell cats, went back to standard size IPD plenum and stock throttle body. The resonator delete made too much noise for me as the car is DD and my kids also join me. Basically it�s a mechanical version of amplifying the signal of your throttle respons. The resonator delete gives you the sound of a more powerful engine. At wide open throttle it gives some more punch and in the higher rpms. Its benefits are higher in synergy with other mods which let breath the engine better: higher displacement, high flow exhaust etc and a custom tune.

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Yes this was on a cold dynojet. There are alot of mods that went with this along with a Evom Stage IV tune The LWFW, from what was explained to me, will take away a little from torque readings The power band (see torque) is about as wide as I have seen from a flat 6 without getting into rods, piston, cams etc.

I did the IPD plenum and GT3 (82mm) TB on my FSI 3.8 stage II. I can't comment on power #'s as I haven't dyno'd it. I can say that fuel efficiency has gone from around 19mpg to 23mpg with a mix of around town and highway driving. FWIW (butt dyno) it certainly hasn't lost anything and feels smooth and powerful through the entire torque range. ** Last week I was at a red light and a jacked up pickup truck pulled up and started revving his engine... I'm not sure what he had in there but it was big and loud (it wasn't an off road "car crusher" type build - it was only slightly lifted and had street tires on it). He gunned it off the line, and my car was warm so I figured what the hell... I wound first gear up to about 5500 and shifted there (probably around 4800-5k) through the next 3 gears. He never got out more than 20 feet in front of me, and that didn't last more than 5 or 6 seconds. By the time I hit around 95 mph (he wasn't lifting) I was 2 or 3 lengths in front of him and I lifted off the gas. I think I surprised him as well as myself - these are not "drag cars" by any means, but they're no slouches either - the FSI stage II 3.8 is a monster!

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Is a sub-4.3 0-60 weak these days?

There is a reason its the "Secret Supercar" Its interesting that he 996 is still in the top few percent of performance cars, only really beaten by cars costing upwards of 3x as much.. The gap in speed and top speeds are < 2 seconds and < about 30 mph..

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Serious? no offence! A more then 20% increase in fuel efficiency? from a TB upgrade? That is what you are stating there?! Any critical reader will scratch it�s head seeing such numbers. I think your mix around driving is significantly incomparable and if you would do a deeper statistical analysis the fault margin in this comparative exercise related to your foot on the throttle only is already 15-20% maybe even more. 😉

I'd guess that the improvement was "new part" effect.. Did the TB include a new throttle drive/tps? I've swapped a tps and gained 10% I've also lost 20 because the new part was crappy.. New IAT? When changing out the plenum lots of opportunity to refresh parts.. The 3.8 bump also could have been really choking on the smaller TB ,, running at a lower throttle position to get the same RPM should be slightly leaner..