ejbta

I just added a typhoon intake so now I have a full bolt on car I am shifting at 6250 am I over reving, with my stock cam?

LASTOFTHEBREED02T/A

iTrader: (15)

Dont think so, I believe im set at 68k rpm shift points on wot.

mrvedit

This is more of an engine question; the first limiting factor is often the valve springs. I shift at 7000, but I have dual valve springs, a hot cam, etc.

There are several "improvements" recommended for 4L60E that rev over 5500, but I don't know how necessary they are. The first is a stiffer spring in the pump to keep line pressure at high rpm. The other involve changing the input drum's 3/4 check valve and a stiffer 3/4 clutch spring cage.

Hopefully a more experienced person can answer your concerns.

ejbta

I have the comp cams valve springs beehive with the most seat pressure and .650 lift capability

TransAmWS.6

With stronger valvesprings I'd say that you're probably fine. But, I don't see the point in revving that high with the stock cam since it's done making power at that point, also the extra RPM's aren't exactly good for your transmission either.

RPM WS6

iTrader: (3)

The stock 4L60Es (at least those spec'ed for service in LS1 cars) were designed to rev to 6000rpm max, which is the stock shift point for these cars. They are programmed from the factory to shift well above 5500, so if 5500 was their safe limit in stock form at stock power levels, then factory programming would not allow for 6k rpm upshifts.

Now, that's not to say that lower shift rpms wouldn't extend life of the trans (they would), but I don't think you have to worry about significantly increased wear until you get beyond 6k at stock power levels. At higher than stock power levels, there would be more concern.

As for the ideal shift point with the stock cam, there is usually something to be gained by bumping the shift points just a bit closer to the rev limiter....especially if you have full bolt-ons (and thus a better breathing engine). I would not rev stock valve springs past 6200rpm though.

ejbta

Thanks for the info I will back off rpms to 6000 and see if my times change. My best times sHifting at 6250 were 12.23 Last weekend. My worst times were 12.38.