here's another stupido question from me. I'm sure there are some high HP TypeRs here. I'm sure it's fast in straights but how is it overall? I have FWD turbo car and I battle with torque steer.(Doesn't have LSD ) But even with factory LSD, I'd imagine it being very much tougher to handle than stocker. Track event or similar experience/impression would be nice.

 

In general, turbo cars (especially aftermarket, which tend to be set up for drag) are difficult to handle in the corners, because the power comes on in a nonlinear fashion, which can break the tires loose at inopportune moments. That said, if you tuned the turbo for the track instead of the strip, and learned how to drive it, i'm sure you'd have a very fast car. But there's also reliability issues when track driving, at the track you won't spend much time below 6000 RPM

 

We had a guy in a turbo Miata at the track last weekend. He was horrible out of the corners. You could hear him comming out with the throttle on, then off, then on, then off. It was very hard for him to regulate the power.

I think in the straights a turbo R would be good. Slow and hard ot control in the twisties.

 

Not to mention that your car will be running HOT... unless some serious cooling mods are performed.

 

Generally turbo cars require modifications to cooling systems in order to run problem free at road courses. Just the turbo housing and exhaust manifold generate huge amounts of heat that soak into the engine block and compartment taxing all the rest of the systems. This can be remedied with heat wrap - but it still remains a problem.

The other issue that has not been addressed is brakes. Typically whenever you increase the power a great amount the brakes become out of balance with the power characteristics of the car - i.e. you need bigger and bigger brakes the faster you go to keep the same margin of safety. In addition to that you need better cooling of the front brakes, which is hard when you have a hot engine to deal with as well. If you don't upgrade brakes - you will likely have to brake earlier in the turns and they will fade earlier as well - which negates all the advantages of going faster in the straights.

The last issue is turbo lag and throttle modulation. Depending on the turbo design and size - turbo lag can be anything from a mild problem to a big one. Having the turbo spool up mid corner when you are exiting a turn makes maintaining traction very difficult - especially if you are already at the limit of adhesion with your tires. Anticipating this you might have to decrease your speed in the turn so that tire grip is still available (not being used for cornering) when the turbo comes on. This again makes you slower.

The key to making a turbo car work well at the track is balance. Everything - power, braking and handling - should all be balanced. This is hard (read expensive) with an N/A car that gets turboed with aftermarket stuff.


[Modified by Big Phat R, 9:53 AM 10/2/2001]

 

2 words.... power understeer

 

heh, read my signature quotes

 

I think an ITR has the brakes and handling to be able to take about double the hp without sacrificing anything in terms of brakes or handling. In fact I think it's way underpowered for for its stock setup.

Still for road racing or autocross, I don't think a turbo is a good setup, unless it's a real small turbo. Lag and the surge of power make for an unstable car around corners.

Inevitable plug - I think a blower is a much better way to go if you're into road racing or autox. People will tell you that blowers don't do anything for ITRs, but I'm over a second faster and have improved drivability over stock. All while keeping the shape of the ITRs powerband EXACTLY the same as stock.

 

i havnt been to a road course with the turbo, and my job seems to know every time the autoX is in town and never lets me go, but i do make weekly blasts up the mountain, and its very tight with lots of elevation changes. you have to get use to really watching your RPM, but the lag seems to work pretty well for me on exits. over all, i think im faster through the mountain with the turbo, and it feels soooooo good to be plastered into the seat back on the little straights.

 

well said Patrick. Yeah if going FI is a must, then go supercharged (ie JRSC not vortech). The linear power is great. As for heat, well I stress tested my engine with the blower at the ITR expo and held it at redline (9000rpms) and used the engine to slow the car down by downshifting for 20mins straight. At no time did we see any signs of pinging, detionation, etc... All I could feel was a slight power loss after then first 15min. I later found out it was because my header gasket broke/blew off while I was testing in on the track.
I'm in the process of taking this test even more by raising the boost and stress testing it.

 

Thanks Mike.

I'm looking forward to an intercooler right now. Apperently JR is working on one, release time around Xmas (honey I know what you can get me ). A buddy of mine is also working on a design that fits between the blower and the manifold, that should be ready to go in a few weeks.

After the intercooler, 10psi pully here I come (which will actually get me about 8psi up here in nosebleed land).