I think the time has come to consider a major upgrade on Frankencar. For those of you who don't know, Franky is my track car, a 924S with a 968 engine pushing 227 rwhp (dynojet). There is no doubt that Franky is fast, having taken many podiums in NASA GTS3, PBOC R4, and PCA GT4S over the past two years. The question is, how much power and by what means.

1. My first thought was to upgrade my 968 engines (currently have two and many parts). I've already got the RSBarn chip, header, open pipe, and head work. I might be able to get about 20-30 more ponies with cams and an overbore but is won't be cheap. I'm guessing I could get in the 245 rwhp range.

2. I good friend has a 2.7 head that I could put on one of my 968 bottom ends and then turbo it.

3. Drop in an LS1 engine. I friend of mine has done quite a few and he is willing to show me the ropes.

For now the goal would be to get a reliable 310 rwhp to run in NASA ST2. Why ST2, well, good class size, and I would have fun playing with all the corvettes.

Why only 310 rwhp, well, that's about what my current car setup will easily handle with respect to wheel/tires and brakes.

 

Why not a custom manifold/crossover, and turbo the current setup with appropriate pistons and rods??

 

Rules let you supercharge?

 

$$$$$ - I'm thinking that this is going to cost an arm and leg.

Yes, I'm no longer in stock or production mode for any class.

 

You still need to modify the intake for the 2.7 head, either way a little $$. Use a turbo manifold and use the flange and a portion of your current manifolds runners

The crossover would be easy. Just get a crossover and cut the pipes before they merge. Cut the pipes at the same place on the current exhaust and weld them together (may need a small amount of massaging).

Anyone who can tig weld should be able to do it for you.

 

Selling the 968 engine will help offset the cost of a ls1 too...

But a built NA 968 engine making 310whp would be way cooler than a 310whp LS1. Too bad it would cost a lot.

 

Chevy all the way. no timing belt issues, no blah blah blah. and, if you blow it up during a weekend you can pull the motor from your tow vehicle, finish the weekend ...

 

LS1 is always so boring though..

 

Really at this point... Sell the 968 motors and get a turbo motor. 310 whp in 2.5 turbo motor is pretty easy to achieve and can be done very reliably. No need for super high boost or anything strange like that. You would need an intercooler too, but that will fit under your front nose anyway.

Not only that you maybe able to get more torque for that 310 whp you are looking at in ST2. The fatter the power curve the better if you can stay under 310 whp. Now you could also make a 3.0 turbo from your 968 motors, but from a cost basis it may may more sense to sell them and get 2.5L motor. If you were looking for 350-400 whp then the 968 blocks may make more sense to start with, but at 310 whp? All you need is a solid turbo motor and a nice turbo.

For reference my stock 88 Turbo S put down 230 whp on dyno jet with 243 ft-lbs of torque. So getting to 310 whp in 2.5L turbo is very simple.

 

Racing is much more expensive that I estimated. Clearly one issue is that I choose to run in non-spec classes and don't like to lose, hence increased cost I do not see this changing if I jump up to beat the Corvette boys, in fact, it may get worse. Having said that, I am looking for something drop dead reliable and cheap to maintain. I've never owned an FI car, but I will tell you that my wallet is afraid of them My fear may be unfounded, but it is a fear nonetheless.

 

Tim,
At 310 whp a 944 Turbo motor is very reliable. It does not take alot of work to get to that power level and that makes it more reliable. If you were looking at 350 whp then things are different. At 400 whp you really need to watch things. The key with 310 whp is doing a good job selecting the turbo and then making sure you have good tune. You could try to squeeze 300 whp from a k26/8 but that is not idea. I would guess that a Nice Vitesse turbo could easly be down rated to 310 whp. Then by keeping the heat down you increase the relability.

Turbo suffer when you try to max out a turbo. The turbo can still make the hp, but tends to add in alot of heat and that heat takes its toll. Put on a slightly larger turbo and back off it flow rates so you run it more relaxed and the tune it well you are should be fine. Consider also that a 310 whp vs 229 whp the chassis is put through more stress. Makes no difference about FI or NA motor.

 

install the 3.0 in my 924s and i will help buy you a turbo motor. what fun is it to beat up on corvettes using a vette motor?

 

would it be more fun if the motor came from a gto or camaro?

 

This is an issue and is why I went with a 968 engine and not an LS1 a few years ago. In the meantime, the suspension has been updated, I'm running solid suspension all around, late offset spindles and hubs in front allowing for 968 brakes all around (got some big blacks sitting in a box for the next upgrade), bigger wheels/tires (9x17/275's all around), and an S2 gearbox. Still, my vet friends are trying to convince me to sell Franky and all my spares and buy a well sorted C5

 

I may have two engines for sale in the new future, pm me for details.