power band

i wanted to know where the 4.3 CPI peaked in torque. i was driving my truck which is a 95 jimmy with cpi caold air intake and flowmaster on it that if i take off with the truck it has some force pushing me into the seat and then it hits 2,500 RPM it all of a sudden acts like a turbo kicks in and the truck all of a sudden thows me into the seat more. it will stay like this until it shifts gears. i haven't changed the way i'm pushing the pedel and the trucks in 1st gear the whole time. any ideas?

Yes, what you are seeing is the IMTV valve opening up.

It opens up around 3000rpms or at high throttle angle.

You get the best of both worlds with the CPI. High torque at low rpms and when the IMTV valve opens up, you also get torque in the higher rpms.

i just think its kinda cool that if u have somebody with u and it kicks in that they ask if it has turbo. i've had somebody ask me before. also when does the 4.3 peak in HP?

could it also be the cat taking a dump? it rattles sometimes.

you sure it is what is rattling?

the mufflers a flowmaster. can't be from it. cats never been changed and u can smell it sometimes.

Why can't it be from the muffler?

Flowmasters have spot welding on their baffles and do rot out, causung them to shift and rattle. It's why I didn't get one. ;)

the mufflers only a month or so old. when it rattles you can hear it under it from the cat. plus it stinks. the cats going bad and the CPI dumped in it for a few months.

If the noise is coming from the cat, take it back to where you had it installed.

It will have a warranty.

the cats never been changed. 77,000 miles on it. alot of city driving shook it loose. muffler and exhaust was custom by me.

Easy then, replace the cat.