Honda-Tech - Honda Forum Discussion - Going to the dyno on Monday-quick question

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Re: Going to the dyno on Monday-quick question

Oops add 100hp to those final numbers.
256whp and 243tq. Still used to having a stock ls. Haha
car is bone stock ls except modified vc for catch can.
Sc34 with blox mani and full 3" downpipe and exhaust. No cat
gm 3 bar with precision 1000cc injectors walbro 255
2.5" charge pipes and eBay front mount 27x10x3 turbo xs mbc
a/f are @ 11.9 12.0 under full boost and about 14.5 cruising in 5th

Re: Going to the dyno on Monday-quick question

Quote:

Originally Posted by SovXietday (Post 41879773)

Wow, this is news to me. Bad news actually.

Done that a million times, but always get off right away as soon as I feel it happen (usually ends with me almost smacking my face on the steering wheel anyway). I blow charge pipes at upwards of 25psi sometimes too. :crook:

How common is this? Just curious, always thought that overspinning a turbo was caused by little resistance for the compressor basically causing the shaft to spin too fast to be cooled and lubricated correctly by the oil. IE, heat buildup, which usually needs some length of time.

It isn't the MOST common, but typically it happens when a car is on a dyno during a high rpm pull where the high pressure is constant enough (for those 20 seconds) for any bad pipes to blow off. the sudden shift of that turbine shaft at that speed causes it to "overspin".