Hey turbo folks!

I am new to 993 turbos but very familiar with normally aspirated 993s (and lately supercharged ones too).

Just as a background, I have an extensively modified 90% track 10% street 993.
I am currently working on improving my charge air cooling (I have the TPC supercharger kit) but already I am looking into 1-2 years ahead and seeing my self longing for big power, turbo power!

If you had a 100% stock 993 turbo engine to start with (cost about 10-15k euros here) and you'd like to squueze reliable and usable (at track) 600-700hp out of it, what would be the recipe and what to budget? I would do all engine work my self (except for machining etc.).
I suppose 2-3K is in just gaskets, bearings, bolts etc. for a total rebuild but what parts to use crank, conrods, P/C, heads, cams etc.? And what to budget?
10k will probably not get me far but will 20keur be enough?
I have Motec engine management so that is no problem, just looking for the cost of pumping out an additional 200-300hp of the stock engine.

I am currently racing in the Finnish Endurance Saloon series with a BMW (6hr enduros), but I would like to up the ante a bit and go race in the open GT class and the gentlemens series of Porsche Racing Club here. With the current 400hp I will not be competitive in either.

The 993 is ready for big power (motons with GT2 uprights, RS brakes etc.) I have a rollbar but a proper cage is going in this winter or the next.
Oh, and I will also do a GT2 body conversion in order to fit proper racing slicks.

 

I don't think 20k will do it.

You'd likely run arrow rods, custom je/mahle/cp etc piston, twin plugged, case machining, possibly a 3.8, ported heads, probably a GT3R crank and oil pump, etc.

Then you have the K24 or garret turbos, custom intercooler (a secan is like 30k by itself), bigger injectors, serious duty clutch, etc.

i'd say for a reliable 700bhp engine, you are looking at $30k...at least.

 

996 turbo motor. done.

 

As a data point for you, the most recent Andial 3.8 twinplug conversions were rated at 575 hp and cost $60,000 US.
As they say:
Fast
Cheap
Reliable

Pick two.

 

lots of hp experts on this forum i am sure one will chime in shortly

 

my motor cost 20k pounds in parts alone plus the 993 turbo engine but this already had gt3r crank. i got a great deal on the 6 throttle inlet with carbon plenums 3k used. the turbos off a sponsor and used secan swapped for a 996 road car.and unused but 2nd hand aquamist system so my point being for big 6-700hp i would guess 30k with you doin the build yourself plus intercooler unless you search out bargains like i did! then you need a gearbox to handle it. i would say 550-575bhp is more usable and reliable on the engine and transmission.i wind the boost down to this power at most tracks, apart from spa and silverstone gp circuit. you can drive it flat out then, instead of easing the power in

regards mark

 

Hey Juha, you also need to consider the transmission in this equation. Our NA transmissions are good for approx 450hp (a little more with cooling) , if you go where you want to go you would also be looking for a 993TT transmission and convert it back to 2wd.

My guess with doing all the work yourself you will be at about $50k including the purchase of the engine. I know you have the skills to do the work, and alot of the stuff you already have can be used (GT2 Intercoolers etc).

 

A 996TT engine isn't such a bad idea, there were some pictures of an installation into a 993 in germany a few years ago. Toby may know.

 

the 996tt isn't a straight swap in would it........ they are cheaper to buy now and these days.....

 

You can easily spend 10G fabbing an exhaust to accomodate Garrett Turbos, and another 10 fabbing and plumbing an intercooler to keep IAT's down. you are at 20 there without actually touching the motor or turbos. I love these philosophical, money no object, dream motors.

 

Excuse me? If you have nothing to contribute to this thread, please don't post in it...geez...

Thanks for all the feedback but the recipe is still missing. C'mon guys, I know there are a lot of track junkies here with 600-800hp turbos. Please share your knowledge.

I know I would be better off just selling the car and getting a factory turbo or even better a 996/997tt. BUT, I love the 993 and don't want to part with it. Plus I have already close to 70k in modifications so no point in buying a turbo just for the engine, gearbox and the wider fenders (and dropping another 50k on it, before even getting to the engine).

996/997tt engines are out of the question because I want to stay period correct, waterpumps don't belong to this car.

Ps. Here's what happened last winter in my garage:

http://m3supercar.1g.fi/kuvat/993/Winter+2012/

Right now I'm fabbing charge air piping for the GT2RS intercoolers I bought and shoved in the engine bay, and it won't cost me 10k...

 

Great spirit Juha! I think you're too much an engineer to not know the answer to your question.

Step one: fit turbo's capable of flowing enough air for 650HP

Step two: make sure everything stays together without breaking the bank;-)

Tial A28 roller bearing turbo's are a straight fit and have great spool up characteristics. Since there's no need to rev past 6250-6500 rpm to achieve your power goal there's no real need for aftermarket crank, pistons and rods...in standard form it could do 300km/h all day long. Uprated head studs are a good measure to handle increased cilinder pressure.

Aircooled turbo engines are really sensitive to IAT's and CHT's, I think factory protocol is to pull back timing above 37celcius IAT whereas 996tt's run freely up to 55(?). Good intercooling such as your GT2rs setup is of crucial importance, water injection makes a great addition as a means to reduce temps and suppress detonation.

Motul 300 running through GT2 oil cooler takes care of engine cooling and lubrication. Your Motec setup coupled to big enough injectors take care of proper fueling.

We're only talking 165 HP / litre here.....easy!;-)

 

You'll need to go with a GT3 crank if you want the motor to survive over 50 track hours with anything close to 600HP+.

A hard to acquire and very expensive bit is an intercooler. As far as I know, only the Secan (sp?) will come close and they are tens of thousands $'s, if you can find one.

Personally, I would not go over 550HP on a heavily tracked 993TT.

 

Check Kevins "8500 RPM engine built thread", that will give you an idea on what it will take.

 

Im going through this as we speak. So for starters... After you acquire the 993 TT engine core you are looking at approximately 50K more to go. With a reliable and experienced builder with good machining and fabrication experience that is. Pretty cut and dry. The parts are pricey. the hours are long too.