Turbo cam?
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On The Tree
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Hello Gentlemen. How can we help? OP, the basic story on the Pro LS turbo cams is the run the same intake lobe and valve events as our N.A. cams and the exhaust opening point is often the same as well. Where they differ is we close the exhaust valve a bit earlier and soften the lobe just a bit. This reduction in overlap is needed to offset the increase in reversion seen with most single turbos with T4 hotsides and full length exhaust system. They are American made and extremely high quality in manufacture. Here's an article on that. Here is a little bit on how the stage 1-4 cams are designed in increments and around lifts required by factory rockers and common .600 beehive and .660 dual spring packs. Here's an article that goes into a little more detail on the truck and turbo cams. We also have another on specific valve events and how they affect performance. Turbo Cams don't have a lot of overlap of course so you're not going to get the idle of our N.A. cams, but then again you don't get melted down pistons etc. either 
. At your weight, manual trans etc. the Stage 3 is the one we'd lean toward. Either the 2 or 3 have been well past 1000whp though so if you are looking for a bit better spool, the 2 would be a little easier to bring on boost.
. At your weight, manual trans etc. the Stage 3 is the one we'd lean toward. Either the 2 or 3 have been well past 1000whp though so if you are looking for a bit better spool, the 2 would be a little easier to bring on boost. You are going to want to run something like a 3:55 gear out back.... as those 4:11's are going to be too short and you will be shifting too fast.
I run a 3.31 gear and 26" tall tire.... while it is long in each gear... once you make boost it feels great. It just pulls and pulls and pulls. Turbos like load.... superchargers need gearing.
I run a 3.31 gear and 26" tall tire.... while it is long in each gear... once you make boost it feels great. It just pulls and pulls and pulls. Turbos like load.... superchargers need gearing.
You are going to want to run something like a 3:55 gear out back.... as those 4:11's are going to be too short and you will be shifting too fast.
I run a 3.31 gear and 26" tall tire.... while it is long in each gear... once you make boost it feels great. It just pulls and pulls and pulls. Turbos like load.... superchargers need gearing.
I run a 3.31 gear and 26" tall tire.... while it is long in each gear... once you make boost it feels great. It just pulls and pulls and pulls. Turbos like load.... superchargers need gearing.
Last edited by Forcefed86; Feb 12, 2021 at 11:35 AM.
Thread Starter
On The Tree
Joined: Nov 2015
Posts: 171
Likes: 5
You are going to want to run something like a 3:55 gear out back.... as those 4:11's are going to be too short and you will be shifting too fast.
I run a 3.31 gear and 26" tall tire.... while it is long in each gear... once you make boost it feels great. It just pulls and pulls and pulls. Turbos like load.... superchargers need gearing.
I run a 3.31 gear and 26" tall tire.... while it is long in each gear... once you make boost it feels great. It just pulls and pulls and pulls. Turbos like load.... superchargers need gearing.
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I have twin gt35s with same size as you. 5.3 motor with 4.08s made 702 on 18psi. The 4.08s were useless. Went to 3.37 and loved it. Then I went th400 and swapped to 3.54, cars now a t56 magnum and getting couple more psi on the tune soon.
3450 weight for my car. So we pretty identical. Do waste a minute of your time with the 4.08s. Also my car has the btr stage 2 turbo cam. Works fine. My dyno graphs looks exactly like there comparison charts. Tq drops off around 6000ish and hp Meets there and climbs.
3450 weight for my car. So we pretty identical. Do waste a minute of your time with the 4.08s. Also my car has the btr stage 2 turbo cam. Works fine. My dyno graphs looks exactly like there comparison charts. Tq drops off around 6000ish and hp Meets there and climbs.
Thread Starter
On The Tree
Joined: Nov 2015
Posts: 171
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I have twin gt35s with same size as you. 5.3 motor with 4.08s made 702 on 18psi. The 4.08s were useless. Went to 3.37 and loved it. Then I went th400 and swapped to 3.54, cars now a t56 magnum and getting couple more psi on the tune soon.
3450 weight for my car. So we pretty identical. Do waste a minute of your time with the 4.08s. Also my car has the btr stage 2 turbo cam. Works fine. My dyno graphs looks exactly like there comparison charts. Tq drops off around 6000ish and hp Meets there and climbs.
3450 weight for my car. So we pretty identical. Do waste a minute of your time with the 4.08s. Also my car has the btr stage 2 turbo cam. Works fine. My dyno graphs looks exactly like there comparison charts. Tq drops off around 6000ish and hp Meets there and climbs.
The gear ratios in the manual are what make the shorter gears harder to plant. A 2.66 first gear is pretty nutty, you need really good suspension and tires to plant that, but guys do it all the time. With a heavier car I'd still think a shorter gear is the way to go. I'd try the 4.11's personally first.
The starting line ratio seems better in 2nd gear. Starting in 2nd with a 4.56 is the same as starting in 1st with a 3.08. Should be much more manageable, but you can't "drop" the clutch and go.
*IF* you have the rpm on tap for your power level, a shorter gear will defiantly be better in a heaver car. To say a short gear is unusable isn't exactly true. Tune the setup around the gear and trans and sort he the suspension out to handle the shorter gear. You'd be much better off IMO.
At 3450 and 700hp you should be trapping 135-140. I'd gear the car for 140 at your redline/tire size... what ever that gear may be.
A 26" tire and 7k would put you at 153 with the 3.55. 132mph with a 4.11
Rev it to 7400 and you'd be at 139 with the 4.11. About perfect IMO.
The clutch slipper valves make for pretty exact repeatable launches VS just trying to do it manually. There are a few different types, but if I were doing any racing with a manual trans from a stop, I'd want something like this.
https://www.grannasracing.com/produc...solenoid-valve
The starting line ratio seems better in 2nd gear. Starting in 2nd with a 4.56 is the same as starting in 1st with a 3.08. Should be much more manageable, but you can't "drop" the clutch and go.
*IF* you have the rpm on tap for your power level, a shorter gear will defiantly be better in a heaver car. To say a short gear is unusable isn't exactly true. Tune the setup around the gear and trans and sort he the suspension out to handle the shorter gear. You'd be much better off IMO.
At 3450 and 700hp you should be trapping 135-140. I'd gear the car for 140 at your redline/tire size... what ever that gear may be.
A 26" tire and 7k would put you at 153 with the 3.55. 132mph with a 4.11
Rev it to 7400 and you'd be at 139 with the 4.11. About perfect IMO.
The clutch slipper valves make for pretty exact repeatable launches VS just trying to do it manually. There are a few different types, but if I were doing any racing with a manual trans from a stop, I'd want something like this.
https://www.grannasracing.com/produc...solenoid-valve
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Alright. Better to error on the side of caution and go with 2. You can always apply more boost but if you get stuck with a lazy combinations...that's hard to fix. Go with 8706 and don't look back.
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