67Firebird455

iTrader: (27)

Running 6-8# currently, kept the hot cam i had in it when it was NA, seems to run excellent, and recently purchased a set of #317 6.0l heads and looking at another block to build a low-comp shortblock, but anyway... I know turbocharging "requires" a reverse/split cam for maximum efficiency... how much would you say I'm loosing by allowing boost out the exhaust? Experienced users, please give me your opinions and suggestions!

engineermike

Reverse split turbo cams are way over-rated. There are very few back-to-back dyno tests available, but in the testing I've seen a single pattern or regular split makes as much or more power. The Hot Cam will be fine at "low" boost levels, and okay for higher ones.

67Firebird455

iTrader: (27)

I also thought it was over-rated, but... My friend just got back from getting his Z dyno-tuned and he's running about 9:1 with 11-12# through an auto with 3.73's and they got an extra 60rwhp out of it, but still only just over 400 rwhp/tq. They removed the MAF and 2 bar MAP apparently, I really don't understand that, but his numbers are dang low, and he's running a Z06 cam (less overlap than mine). What do you guys think?

PS - The guys at the speed shop said his turbo was done "blowing" at around 5200 rpm where the hp would fall off. He's got a 1-bar spring in the WG, and ocassionally gets 12# out of it, nothing more, his reference is up front, turbo in the back.

I don't want to show up and be disappointed as hell with my setup running 7-8# and only making 400rwhp.

DeltaT

iTrader: (5)

Did they replace the 2-bar with a 3-bar? Nothing else makes sense. You need a MAF or a MAP or some other metering device.

What speed shop ar you dealing with? I'm in Santa Clara.

There's a lot of people out there that knew cars when they were carbs and know jack about EFI or boost or tuning.

Jim

67Firebird455

iTrader: (27)

I'll have to find out what shop it is, I know it's in Roseville, and the guy has no signs out front and spent 12 hours on the car. They supposedly eliminated the MAF altogether, but only 410rwhp at that much boost? Personally, I'll be heading to Synergy next month to have mine done. I need to know what I'm going to need when I go to Fremont. My buddy spent $1400 with all the work done, including have a catch can installed, seems a little high, but as long as he's happy. I'm just so confused about this...

engineermike

It's not the cam's fault.

67Firebird455

iTrader: (27)

Kinda figured that... one guy said it was the cam, the owner (force fed performance) in Sacramento said his turbo was done blowing early. Doesn't surprise me, that thing spools instantly.

Pro Stock John

iTrader: (34)

Dyno it and tell us how it does. Maybe we can use your hotcam dyno sheet and look at what happens to the power.

Personally, I was told to go single pattern or reverse split by someone who I highly respect in the LSx FI field, so that is what my decision is based on.

67Firebird455

iTrader: (27)

John, I also agree with you. My new motor will have a reverse split for torque reasons (not going stroker) and I can't have it loping like it does, I'm in California, and you know how those **** smog officials/cops are. I just drive my TA on Saturday's or Sunday, drove it 50 miles today, big whoop. I messed with the BC today and it hit 10#, I was logging in EFI live, and didn't get any KR, kinda strange isn't it? My #317's should be here Wednesday, might put them on this 96k mile shortblock, let it live a LITTLE longer! =)