Active Supercharger Control

[Gollum]

If the guy has too much boost at low rpms, he doesn't have proper boost control OR wastegate control.

 

I should clarify, it's not that he has TOO much persay, it's that until he converted to a dual controller setup (adding a manual controller) he had too little control at the low end. In stock form (but much higher than stock boost, stock turbo) the turbo would create boost at even the lightest of throttle levels. So driving around town the car was a handful, and you had to be really careful with the throttle. It basically drove like a BIG displacement engine.

 

With the manual added in, bleeding off a little bit of pressure until it hits it's max PSI, the car became much more manageable.

 

We both gladly admit though, the biggest problem is that the stock turbo is just too small for the application.

 

Going to a larger turbo helped immensely.

[Tony D]

Having an 'undersized' turbo is not necessarily a bad thing. Having a car that drives like a much larger engined vehicle is not necessarily a bad thing. Methink's he exaggerates the effects or has a brick foot. I could get 17psi at 1700 rpms on my old 73, and with the right tires it wasn't an issue at all, modulation was touchy with ITB's and any appreciable throttle input would put the manifold positive... but that's a driver technique issue. I guess you could blow off turbine gas to keep it out of boost at the lower rpms... but what's the point of that?

[Gollum]

Oh it was so funny Tony. I was explaining this banter back and forth to this friend, and mentioned your last post, and we both got a good laugh from it.

 

Yes, of course he's a lead foot. A very, VERY good driver still, but he's anything but delicate with the throttle. It's the main reason I'm usually faster than him when we go carting. But he's certainly got amazing car control.

 

His new setup though (just converted to E85) now breaks the tires loose if he punches it at 3500 in 3rd gear.... That's pretty scary for a mostly stock all wheel drive car. We were going over today what all he has invested in this engine, since he went back to the stock turbo for now, and one of the most expensive things he's bought is his wideband, then downpipe, and behind that his $60 USB tuning cable. It's just plain stupid. Now, he did get his 1000cc injectors for free, but still. Stock intake, stock intercooler, stock turbo, stock ECU.

 

Oh, and to show he's not a total idiot, he's thinking of going with a high end GT30 instead of a GT35 for his next turbo, simply because he's seen guys with 30's hit pretty impressive numbers and it still spools in the 3k range well.

 

In the ride I took today though (my first ride since the E85 swap) I couldn't believe how much power is there, and how instantly. Turbo lag??? Wha???? Almost 400 torque to the wheels, at around 3700 iirc. And those are conservative numbers.