I have a ITR that I road race and I'm needing some more power to keep up with some of the other cars on the straight away. The motor is built all ready and I have around 12:1 to 12:5 comp. So my question is can I boost it with this high comp and still be reliable? I would put a thicker head gasket on it if I do so. I am not looking for crazy hp numbers maybe around 300-350.

 

Compression really doesn't matter. The good thing about your compression is that it will take less boost to make the 300-350 that you want to make compared to if you had a stock compression of 11.1.

Just choose the right turbo & manifold for you application.

 

Actually, compression does matter, particularly with the type of fuel you plan to run with the purpose you're using it for. Especially when it comes to ignition timing that can, if not retuned properly, can become a very real issue for any kind of enduro racing.

The one area you want to look at is the turbocharger you plan to use for the power level you're attempting create. Having a reasonably higher compression than stock can help with acceleration and off-boost/off throttle steering, but with OEM rods and such high compression pistons, the amount of increased cylinder pressures from going turbocharged can be catastrophic if you don't address them

Simply changing head gaskets isn't going to help you here. You need to bring everything down in compression by just a bit, so that you can run a little less ignition timing, and run a bit more fuel to reach your goal safely and repeatedly.

My suggestion is to stay small on the turbocharger, but not so small that you're going to lose midrange torque. (I'd say around the GTX2860S-GTX2971R or EFR6358-EFR7064 Range). I also suggest proper aftermarket rods and a different set of pistons. Make static compression about 10.0:1-10.5:1. Keep the head gasket to OEM with ARP studs.

It's one thing to take your car from high-compression NA to Turbocharging. It's entirely another concept to go from High compression to turbocharging and still race on the circuit. With the increased cylinder temperatures that are sustained in road racing, you have to consider other supplemental equipment, so that you can consistently keep up with others "in the straights".

Now all you have to do is plan out your turbocharger - Circuit build. Here's the basics needed outside of the engine block / head itself. And you cannot half-*** eBay this if you're going on the circuit with it.

*Quality "Hot parts --- Exhaust manifold/downpipe/dumptube/wastegate/water-cooled turbocharger
*Quality Intercooler
*Quality Radiator / Fan combination
*Quality oil cooler (No, the OEM water/oil cooler will not suffice)
*Much larger brake system/fluids. Minimum OEM should be ITR.
*Proper Helical or clutch-type LSD. No OEM Torsen
*Good quality vacuum hoses, heat shielding and engine bay venting...

etc. etc..

 

I knew this was gonna be good after this sentence, LOL.

 

The almighty Shodan has arrived. Oh how I have fore shaken you with my statement.

So wouldn't the use of E-85 solve his increased cylinder temperature problem? So he wouldn't have to get new Pistons? I take it that he has rods because he said his type r was "built".

 

That's why I'm hear buddy

 

Not necessarily. E85 is a band-aid like any other higher-knock resistant fuel; it can only help with so much. You would still need more robust hardware in order to work in the realm of road racing repeatably and reliably. All the fuel will do is allow for increased ignition timing to continue to make power; but considering the fact that both the piston and the wrist pins that he has in the current engine are for NA purposes, the increased cylinder pressures would wreak havoc on the internals, and he wouldn't realize it until it is too late. If he wants to do what Muckman did... READ WHAT MUCKMAN DID, to make it possible. Just adding magic corn water to the formula isn't going to solve this person's problems.

Plus,

Remember that being "built" has several meanings, and it's rather subjective in its definition.. I can be considered "built" on my NA car. I'm running 12.5:1 as well. Doesn't mean that I have aftermarket rods, and even then, not for turbocharging.. Even so, knowing what I've experienced, I don't recommend just relying on fuel to solve a larger set of issues.

Not for road racing, not for that kind of abuse.

 

I here ya..

 

Thanks for the clarification Mr. Shodan.

 

My English professor would be disappointed.... Lol

 

Acutally I am running aftermarket pistons and rods. Wiseco pistons with eagle h beam rods. also running skunk2 pro1 cams

 

That's great, then that will mean that switching over to another set of Pistons to be a proper compression to get a better effect of compression for your use will be even better this time around. One less item you have to buy.

Unless you have a turbo charger that you are about to use is about the size of a GT35R, (which will be to large for the circuit) your pro 1s will not be very effective. Step it down a small notch to a GSR