2quik4u

HI people,

Just have broken in ***** thumper cams with 91 oct custom tune breenspeed tune and seem to have lost all low end power. When I power brake (TCM off) for hard leave, it almost stalls and seems like it is leaving in 2nd or 3rd gear?............ I can not get any tire spin power breaking....period. Any thoughts on what I am missing?

808muscle

Very common with a cam swap. Just add some 4.10 gears and or talk with brenspeed. They may be able to up some timing and improve it. I know my first cam tune with them was weak out of the hole.

Dino Dino Bambino

Low rev torque loss is inevitable when swapping in bigger cams, but the car shouldn't feel as soggy as you've described. A retune might improve things but I see a higher ratio rear axle gear swap in your future if you haven't done that already.

2quik4u

Do have 4:10's / ram air / BBK TB

jwog666

if you add cams, or heads you lose low end on a 2v. the only way around that is to go forced induction.

proeagles

I installed those in a 351 for my hot rod, worst decision ever. Sounded great at idle, no low end power, horrible for the street. Gears will help get some of the feeling of acceleration back but the engine will always feel dead in the low end.

09GT/CS

His profile says 3v which stage cams are you running? I've got the brenspeed Detroit rockers and their tune and it will spin at will in first and chirp second and I have no mods except for shorty headers and charge motion deletes. That's with stock airbox too. It shouldnt be that soft in first. The only time mine acts that way is at cold start. Once it has a little heat in it it's fine.

ghunt

My Cushman Stage 1's are like that too. A little fussy for the first 5-10 minutes you drive and fine after that. It does feel a little "soft" below 2000 RPM but I think that's more from the charge motion deletes than anything else because I noticed it right after I did them (which was well before the cams came along).

***** Thumpr's have tons of overlap, that's what gives them the super choppy idle and also kills the bottom end. I've seen some dyno charts for those on the 4.6 and the bottom end torque numbers aren't too great. Those cams are more for "show" than "go."

09GT/CS

that's what I was thinking I remember talking to brenspeed about it before purchase and they steered me towards the rockers. I have to say they have been great. And yeah mine can be show but I can also idle it up and drive like normal lol

cooperriver

I have just gotten my Brenspeed Rockers and I am heartbroken. Oh yeah they run great on the interstate but the red light is not what it was.