How to decide: TPC supercharger or Twin Turbo conversion? Detailed analysis.
#62
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My point was that there's no use for SAI if you don't have cats, since that's what it's there for. So that's obviously true for 1996 as well. But I think you get a CEL on a 1996+ if you remove the cats, or the SAI system, or both.
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No, still not running 100%. Had some normal problems - wrong fuel pressure and wrong spark plugs - but eventually figured those out. Very hard to diagnose, let me tell ya.
But I seem to be the first to run without cats, and the low backpressure and thus higher air flows have caused it to run lean, which is a problem since the injectors are maxed out at around 400 hp. So that meant new injectors, different fuel pressure regulator, and new programming. Still trying to get all that sorted. The upside is that I get a few more horsepowers.![Big Grin](https://rennlist.com/forums/images/smilies/biggrin.gif)
One thing I'll say is you definitely do NOT want to undertake a project like this unless you enjoy working on and learning about your car, which I do. I've learned a ton from the experience. And you also need a lot of time obviously.
But I seem to be the first to run without cats, and the low backpressure and thus higher air flows have caused it to run lean, which is a problem since the injectors are maxed out at around 400 hp. So that meant new injectors, different fuel pressure regulator, and new programming. Still trying to get all that sorted. The upside is that I get a few more horsepowers.
![Big Grin](https://rennlist.com/forums/images/smilies/biggrin.gif)
One thing I'll say is you definitely do NOT want to undertake a project like this unless you enjoy working on and learning about your car, which I do. I've learned a ton from the experience. And you also need a lot of time obviously.
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Turbos are installed and I gained around 105 hp (flywheel) with a chip conservatively designed for 91 octane. So we recently re-tuned it, and it feels a lot faster. I still need to get a few things done, like check for knock counts and do a dyno run.
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I am not a fan of either one primarily because the engine rods/pistonsetc. were not designed to be in a boosted engine. Rod bolts are a side issue ; they are only weak when overstretched on a missed shift or over-rev. Yes, the engines are overbuild and can take quite a load, but there are lots of additional factors like heat loading and possible misfires. Those can burn holes in pistons, especially on the track.
However, I seem to see reports of these sort of boosted systems being successfully installed and run for 10's of thousands of miles. I do not know if anyone hhas gathered the emperical data to prove longevity, but it seems the engines are so overdesigned as its not too much of a problem.
I will definitely watch this project with interested eyes though....
Cheers,
Mike
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Look at the price your car would bring, and then look at what you'd have to give for a 993TT.
Also the conversion WILL cost more than the up front estimate. I've done it, though not on a Porsche, but it was still more $$ than I originally estimated.
Putting turbos on an NA motor is a bundle of snakes, especially when you can buy a factory turbo for less $$.
It WILL NOT add value to your car, just the opposite. And it will severely limit the buyers when it's time to sell.
Not trying to shoot down your idea, I'm just offering a realistic point of view.
All that said if it's something you've just got to do, go for it.