SoFast

Hi all,

I am new to this forum. I am a car guy and love timkering on them. I just purchased this Porsche back in March. This is my first Porsche and fell in love with this body back in the 80's. It had been heavily modified, but Isee that it is mild compared to the majority of the proshces on here. OMG...Amazing I am all over the board when it comes to cars. Each one serves a purpose. I own a 1970 Hemi Road Runner, two BMW's(M5 and M3) and a Hummer. I can tinker on them all, and I want to get my hands dirty on this master piece. I was coinsidering having the car sent to image auto for some mods, but I was considering doing a winter project rebuild in my garage. The best way to learn is by sinking in head first. Anyway, what I want to know is that I want to modify this car to a twin turbo setup, with EFI and Valve control, boost control, the works. Driveability is the key here, but I want some crazy HP that isnt over the top.
Since I do not know the exact mods that have been done, a full rebuild is in order. I would like as much info as possible going forward intot this venture. Your suggestions and tech input are greatly appreciated.

Thanks,
Paul

SoFast

BTW, I changed my avatar to reflect this decision. LOL

Geoffrey

With what you want, it really isn't difficult to get 700hp out of the engine as well as the drivability you want. The most challenging part will be finding the right person to work with you on the EFI side.

SoFast

I am not sure what the EFI entails, but I want to know exactly the steps that are needed to fully complete a thorough job. Beyond that of the EFI. Are there any engine modification manuals that are thorough and concise? Are there any tech manuals on twin turbo setups?

Kevin

If you want a quick spooling no lag experience then a twin turbo setup would be the ticket. The best way and easiest way is to purchase 993TT heat exchangers and turbo's along with manifold, scavenge pump and lightweight flywheel. The other option is to purchase a 95-98 993TT engine and drop it in. There are a few books out there, but nothing really in the twin turbo conversion area. You can start by ordering the Factory repair manuals, or a Bently manual.

SoFast

Well, what I want is something in the range of 600-700 hp. Dropping in a 993tt sounds the easiest way, but what mods need to be done to that engine to reach those numbers?

Kevin

The 993TT engine is very capable of getting in the 550-650 range. At 650 and over you will need to replace the rod bolts.. The stock K16 will have to be modified to provide more air/boost.

SoFast

So why do so many guys on here modify the old engine instead of upgrading to the 993tt?

Is therea significant cost variation? Performance variation?

Geoffrey

If you are lucky you can find a 993tt engine for 15k, then as Kevin mentioned you really want to address the rods or rod bolts for over the 550hp mark since it is a weak link. Converting to twin turbo is not as easy as just bolting things in, even if you wanted to use a stock 993tt. There are packaging challenges you will have, especially in the right rear qtr where the oil tank has clearance for the right turbo bank. For what you are asking for EFI is the only route to go, and you can go single or twin turbo and get some significant performance in either configuration. The 3.3 engine properly built is a great reliable engine.

SoFast

Well, that is what I need to hear. I knew logistically that it wouldnt be as easy as a bolt up and go process....Some configurations would need to be met. I was just considering a tt setup for the reason that the car gets mighty squirley when the boost kicks in. My friends tt is really smooth and doesnt have the harsh kick....But his is stock, and my car isnt...Anyway, I will take any advice given and sort through it through the next month or so. Thanks for the help. Keep it comming.

Paul

Geoffrey

A single turbo setup does not have to be harsh. I don't get any wheelspin with my setup unless the road is cold and I'm real agressive in the bottom gears. Here is a link to a video of my car on the track...no lag, no problems.

1 lap of Watkins Glen

Red Rocket

OFF TRACK---BUT THE GLEN VIDEO REMINDED ME THAT THERE IS A RENNLIST GLEN EVENT IN OCTOBER ARE YOU GOING GEOFFREY?
DON

SoFast

That is an awesome video, you needed to shield the Mic though. Wanted to hear more of that sweet engine....So, why did you want to go tt then? What is the advantage?

Is this specifically a Porsche event at the Glen?

Are you going to Hershey this year for the PCA event?

graham_mitchell

Geoffrey - thanks for posting. Very nice! How much power is your car making in that clip?

Geoffrey

The event was the PCA Zone 1 event this past summer, so all Porsche. I think I spent about 14 out of my 20 track days this year at Watkins Glen. Unfortunately, I'll not be able to go to the Rennlist PDA event in a few weeks due to some committments to my Grand Am customers. However, I'll be there Holloween weekend at Tracquest which will be my last event of the year.

I had originally considered a twin turbo setup because I was frustrated with finding a single turbocharger that would live in a 911 Turbo in a track environment and would provide the performance envelope my engine needs. I think we went through 3 or 4 iterations with several different Garretts before my turbocharger partner Kevin came up with a design that both delivers the airflow the engine needs with acceptable lower end performance and the reliability to last. We've since taken the turbo apart each year for the past 2 years and there has been no real wear issues and this last time we experimented with his Zero Clearance technology which boosts turbocharger efficiency to 90-95% compared with 70-78% stock. I use Kevin's turbos in all of the cars I work on and have yet to be disapointed, this includes his line of k16 based turbos.

My engine is currently running only .7bar of boost (stock) for about 550hp because the car is still very much a street car with torsion bar suspension and when I cranked it up to the 1.2bar@700hp it was designed for, the chassis doesn't really handle it well, and my lap times were the same. In either setting, it is nice to get 400miles to a tank traveling to the track, run it all day, and drive it home all on 93 octane street fuel.

I have considered following through with a twin turbo setup this winter and using individual throttle bodies with a completely new induction package, but since the car is really too nice to cut up into a track only car, I've decided to sell it and move on to something specifically track oriented. Hopefully it will be gone this winter.