onebadvert

88 gt
Tfs tw 170 heads
Fti custom cam
.614 int lift
.607 exh lift
1.72 rr
Tfs double springs
Wieand stealth intake

Im running a 670 street avenger carb. I have a wideband af gauge. I just recently upgraded to the fti cam. Before that I was running a b303. With the b303 I was working on getting my af tamed then the lifters went out. So I never really had it better than a 15:1 af ratio.

This 15:1 with the b303 was already increasing the carb jets 4 sizes. Now with the new cam I cant even run it yet. I had it running for a couple minutes and its so lean my headers started turning red quickly. Right now my af is around 18:1.

My question is am I gonna need more than just huge jets? Do I need to modify the air bleeds? Maybe change accelerator pump?

I havent ran it past idle yet. But I know to the accelerator pump will cause a stumble if its not good enough for my setup.

Any carb tuning tips would be greatly appreciated. I do have a vacuum gauge and know that trick to setting the air bleeds. But I have had them all over the pkace with no avail. I also am running a steady 5-6 psi. And the pressure doesnt drop at all so I would think my pump is ok.

Here is an idle video if anyone is curious.

onebadvert

No carb guys or anyone used to tuning super high lift cams eh?

Fox85

I'd play around with your timing to start off. Then maybe make adjustments to the carb. What's your fuel pressure?

91notchback

I think it's gonna be hard to find someone with experience in a cam with over .600 lift Dream!!!lmao

onebadvert

15* initial 36* total
6-7 psi.
I have played with timing and fuek pressure to no avail.
I wondering if I need a vacuum canister to help pull fuel?
Right? Lol

skunk21

make sure you don't have a vacuum leak.

onebadvert

Funny. Cause I actually just called holley to verify my setup is up to the task. They said I shouldnt have any issues and to check for a vacuum leak.

Thanks

skunk21

yeah a nasty vacuum leak can cause a problem, both lean and rich conditions can get the headers to glow. you figured out it was lean. check for things like timing that is too retarted ( verify timing marks/pointer are marked correct ), vacuum leak(s) etc.

onebadvert

I also have a high idle. Which is another reason the vacuum leak makes sense. Now I just need to track it down.

I know my timing, fuel pressure, etc are all good. So hopefully I can find the leak. Ill get some propane and start spraying suspect areas.

Fox85

Check all vacuum lines. And try replacing your map sensor out

onebadvert

No map sensor. Im running a carb with no ecu. I did find a vacuum leak but haven't had time to try and re tune it.