downshifting a turbo

I was just wondering what sort of risks are involved in downshifting a turbo civic. For instance, a '99 or '00 Si, crusing along in 5th at about 50/55 mph, having the right fuel set up, engine management, and running 6 to 8psi (stock internals). What would happen if I geared down to 3rd and dropped the hammer? Will I blow the thing sky high, melt it from the inside out, or will i be safe? I never had any trouble doing this sort of thing in my Eclipse GSX with small factory turbo. But if I turbo charge my Si, can i still do this? Also, on the occasional back road romp or playing in trafic, when frequent downshifts are involved. (Supercharger territory I know, but its just not the same) Will I detinate my engine, or will I be ok with the right turbo kit? Any help would be great.

you'll be fine, depending on what type of fuel management system you're running. if you have a rising rate regulator controlling fuel pressure to provide more fuel, then you may wanna be a bit more careful, since it takes a split second for the boost to reach the RRR, thus causing "tip in detonation", basically the fuel system has to catch up to the amount of air being thrust in.

computer controlled fuel management systems or additional injector systems will be a bit more stable since it responds to electrical impulses, therefore responding faster.

I had the trill of being in the HKS WRX as a passenger once and we were on the freeway and some camaro was taunting my friend. He dropped it into 3rd and OMG talk about whiplash!! We were freakin gone!!!!!! Of course, the whole thing was built up, but none the less, it was very very fun :)

So I have to make sure that the fuel gets there fast enough, not just in the right amouts. What about going into a corner hard. Downshifting and using the clutch to help brake. Will the wastegate by pass enough exhaust and not allow the turbo to produce boost? Or will the high rpm from the downshift with no fuel being delivered (ie. one foot on clutch, other on brake) cause this "tip in detanation"?

like i said, just be a bit more careful... you know your car better than anyone else.

if things are working properly, then downshifting wont be a problem. if there's ANY hesitation or sense of tip in detonation, check it out before going berzerk.

Originally posted by super 96 accord
I had the trill of being in the HKS WRX as a passenger once and we were on the freeway and some camaro was taunting my friend. He dropped it into 3rd and OMG talk about whiplash!! We were freakin gone!!!!!! Of course, the whole thing was built up, but none the less, it was very very fun :)


ohh man ur one lucky bish!! :D The WRX one of my dream cars! :rolleyes:

Thanks for the advice drift.