GT4 power modifications
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Drifting
Joined: Feb 2015
Posts: 3,344
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GT4 power modifications
Hey guys, I was wondering what kind of gains have you guys experienced with the Fabspeed power package and the IPD plenum on 991/991S motor? Any additional bolt on mods that are worthwhile? As you can see I'm already planning ahead 
Rennlist Member
Joined: Oct 2002
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From: S.F Bay Area
I'm pretty sure that the engine actually makes closer to 400 than 385, so there wont be that much left on the table to "recover"... of course the car will attract the usual tuners who will flash the ECu (if they can) build exhausts and headers etc etc...
better to spend the money to get coaching to extract the most from the platform...
Burning Brakes
Joined: Nov 2006
Posts: 1,020
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From: Jupiter Island
Exhaust, intake, cams, head porting, cracking the ecu, bigger injectors, light weight Pistons and con rods, smaller pulleys, lw fly wheel, general weight reduction, all will yield results but it's a matter of value. 50-75 na hp increases were possible on gen 1s I'm sure between 991S and GT4 owners the 3.8 will get some attention from aftermarket tuners.
Rennlist Member
Joined: May 2001
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From: Norcal
Most Porsche aftermarket HP claims in their normally aspirated models may tout gains of " x " hp with tune and exhaust / cat mods ...but when you look carefully,at a dyno graph , that extra " x " may be just a brief blip lasting only a couple hundred rpms in the upper rev band on the way to redline , so that stop watch and more importantly seat of the pants improvements are next to zilch.
OTOH, American car owners will install different cams, cranks, long tube headers ,etc., in their brand new Corvettes , Mustangs, Camaros and Vipers , etc, for significant gains .
New 991/981 owners rarely do that .
OTOH, American car owners will install different cams, cranks, long tube headers ,etc., in their brand new Corvettes , Mustangs, Camaros and Vipers , etc, for significant gains .
New 991/981 owners rarely do that .
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Race Director
Joined: Nov 2014
Posts: 13,799
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From: FL
Most Porsche aftermarket HP claims in their normally aspirated models may tout gains of " x " hp with tune and exhaust / cat mods ...but when you look carefully,at a dyno graph , that extra " x " may be just a brief blip lasting only a couple hundred rpms in the upper rev band on the way to redline , so that stop watch and more importantly seat of the pants improvements are next to zilch. OTOH, American car owners will install different cams, cranks, long tube headers ,etc., in their brand new Corvettes , Mustangs, Camaros and Vipers , etc, for significant gains . New 991/981 owners rarely do that .
These various exhaust guys were claiming ridiculous claims in the past. They have been toning it down a bit lately before being called out on it. At the end of the day, it's just a louder exhaust. Look on 6Speed. More exhaust posts than you care to see.
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Race Director
Joined: May 2013
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From: Hypercar Invitational
I may have posted this before, but I noticed we don't get penalized for repetition on this forum so I'll risk repeating myself: what I learned from owning many Ducati motorcycles over the years, is that they are best left alone. All the money I spent on titanium valves, race cams, light flywheels, different exhaust,… The list goes on and the list of dollars and goes on even further…
With all that money spent, I learned one major lesson, and that is that you buy stock from the factory and generally are happier when you leave it alone. Engine modifications just make the engines less tractable, more temperamental, and the gains are often more perceived more than real, and difficult to access on the road if ever.
If you want a more powerful car, buy a more powerful car from the get-go… Modifying a GT4 seems ludicrous to me... Just buy a gt3, it will be cheaper.
With all that money spent, I learned one major lesson, and that is that you buy stock from the factory and generally are happier when you leave it alone. Engine modifications just make the engines less tractable, more temperamental, and the gains are often more perceived more than real, and difficult to access on the road if ever.
If you want a more powerful car, buy a more powerful car from the get-go… Modifying a GT4 seems ludicrous to me... Just buy a gt3, it will be cheaper.
Race Director
Joined: Nov 2014
Posts: 13,799
Likes: 209
From: FL
I may have posted this before, but I noticed we don't get penalized for repetition on this forum so I'll risk repeating myself: what I learned from owning many Ducati motorcycles over the years, is that they are best left alone. All the money I spent on titanium valves, race cams, light flywheels, different exhaust,… The list goes on and the list of dollars and goes on even further… With all that money spent, I learned one major lesson, and that is that you buy stock from the factory and generally are happier when you leave it alone. Engine modifications just make the engines less tractable, more temperamental, and the gains are often more perceived more than real, and difficult to access on the road if ever. If you want a more powerful car, buy a more powerful car from the get-go… Modifying a GT4 seems ludicrous to me... Just buy a gt3, it will be cheaper.
Resale is terrible on cars with a lot of mods too.
Rennlist Member
Joined: May 2001
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From: Norcal
You forgot to mention there is practically ZERO $$ return on any of those mods, and warranty issues. Porsche is never jumping through hoops to get things addressed as it is. Throw in a bunch of engine mods, and you're on your own.
Resale is terrible on cars with a lot of mods too.
Resale is terrible on cars with a lot of mods too.
Certainly that has always been the approach I would have taken , but I never by any cars used , even if " stock " , because I am VERY fussy with them.
Rennlist Member
Joined: May 2011
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From: SF Bay Area
I was a bit surprised the GT4 didn't come stock with the power kit (x51). Seems like it would have been a natural part of the build out. Maybe they're saving something for a GT4RS if the GT4 sells well.
Rennlist Member
Joined: Oct 2013
Posts: 553
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From: SoCal
AP said; its not the Carrera S engine it's "derived" from the Carrera S engine.
With only 100lb less weight, than a Carrera GTS, it posts the same 0-60 time.
Maybe even better in real life?
AP teased the engine was laughably under-rated.
For a car like the GT4, why not use the PowerKit Heads & Cams, so it gets the extended torque curve, above 6.5K?
That's where this car will live, right?
If they did it, they would not be able to admit it
AP's bragging about Torque Limiting also suggests there is more, than he can admit, going on.
Who knows, until one gets to drive one and see how it pulls on the top-end.
Rennlist Member
Joined: Apr 2014
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From: Somewhere in middle america
A poster in the gt3 section on the gt4 said he was told by Porsche higher ups at Daytona a week or two ago the the engine was the 3.8 power kit engine. It doesn't quite produce 430 hp because the intake is a little different because the 991 intake wouldn't fit in the cayman body. So it is probably breathing a little less and producing at least 400 hp and maybe a little more. They would want the better internal parts in the gt4 for sustained track duty reliability. We will know soon enough as soon as cars start to arrive and are put on the dyno.