Turbo cams: VA Speed vs Speed Inc vs Brute Speed vs LS9?
09-16-2010, 08:55 AM
#21
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Sure, but people have been touting reverse-splits for LTx and SBC's for years, and they don't work that well on those. I don't see where the physics of the LSx is that much different (v-8, 2v, similar cid, similar pressure ratios).
I've never seen a back-to-back dyno test where a reverse-split gained power over a conventional split. I have seen the opposite.
I've never seen a back-to-back dyno test where a reverse-split gained power over a conventional split. I have seen the opposite.
09-16-2010, 10:07 AM
#22
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I think that the custom turbo cams are some what of a joke.
I have spoke to 3 cam companies and 4 of the big LS shops giving them the exact same setup specs/driving conditions/power (some of them I filled out there paperwork) and received 7 different cam specs (some not even close to one another). 2 of which were reverse splits, and one recommended the factory LS9 cam for the same combo. I even paid one of the “best” cam manufactures for there recommendation (which was a reverse split). All have excellent reputations, make fast cars and some killer power on there cams or engines that they build.
I also find it comical how some of them give specs to the tenth of a deg of duration (ex. 246.2). Yet the other expert cams don’t and are maybe 4-5 deg difference. But the first company nails it down to the tenth.
That must be so you can tell your friends that you have a very extra super spec top secret custom turbo cam.
I have spoke to 3 cam companies and 4 of the big LS shops giving them the exact same setup specs/driving conditions/power (some of them I filled out there paperwork) and received 7 different cam specs (some not even close to one another). 2 of which were reverse splits, and one recommended the factory LS9 cam for the same combo. I even paid one of the “best” cam manufactures for there recommendation (which was a reverse split). All have excellent reputations, make fast cars and some killer power on there cams or engines that they build.
I also find it comical how some of them give specs to the tenth of a deg of duration (ex. 246.2). Yet the other expert cams don’t and are maybe 4-5 deg difference. But the first company nails it down to the tenth.
That must be so you can tell your friends that you have a very extra super spec top secret custom turbo cam.
09-16-2010, 10:12 AM
#23
I think that the custom turbo cams are some what of a joke.
I have spoke to 3 cam companies and 4 of the big LS shops giving them the exact same setup specs/driving conditions/power (some of them I filled out there paperwork) and received 7 different cam specs (some not even close to one another). 2 of which were reverse splits, and one recommended the factory LS9 cam for the same combo. I even paid one of the “best” cam manufactures for there recommendation (which was a reverse split). All have excellent reputations, make fast cars and some killer power on there cams or engines that they build.
I also find it comical how some of them give specs to the tenth of a deg of duration (ex. 246.2). Yet the other expert cams don’t and are maybe 4-5 deg difference. But the first company nails it down to the tenth.
That must be so you can tell your friends that you have a very extra super spec top secret custom turbo cam.
I have spoke to 3 cam companies and 4 of the big LS shops giving them the exact same setup specs/driving conditions/power (some of them I filled out there paperwork) and received 7 different cam specs (some not even close to one another). 2 of which were reverse splits, and one recommended the factory LS9 cam for the same combo. I even paid one of the “best” cam manufactures for there recommendation (which was a reverse split). All have excellent reputations, make fast cars and some killer power on there cams or engines that they build.
I also find it comical how some of them give specs to the tenth of a deg of duration (ex. 246.2). Yet the other expert cams don’t and are maybe 4-5 deg difference. But the first company nails it down to the tenth.
That must be so you can tell your friends that you have a very extra super spec top secret custom turbo cam.
The thing is that the "pros" usually dont pick the correct cam on the first try even for themselves. The guys that are squeezing the most power out and are racing competitively with big budgets for R&D will order up three or 4 cams before they find the best one. There are just too many variables and no magic formula.
Another thing to note is that if you took the first three cams that the OP posted and did a head to head comparison between them with the exact same combo on the exact same boost, they would all be within 20 rwhp of each other. So if you did end up with the slowest one, you could just turn up the boost .25 psi and make up the difference.
09-16-2010, 10:37 AM
#24
The thing is that the "pros" usually dont pick the correct cam on the first try even for themselves. The guys that are squeezing the most power out and are racing competitively with big budgets for R&D will order up three or 4 cams before they find the best one. There are just too many variables and no magic formula.
Another thing to note is that if you took the first three cams that the OP posted and did a head to head comparison between them with the exact same combo on the exact same boost, they would all be within 20 rwhp of each other. So if you did end up with the slowest one, you could just turn up the boost .25 psi and make up the difference.
09-16-2010, 10:39 AM
#25
FormerVendor
Saying a certain combination needs a reverse split is like saying it needs a certain LSA. They both mean almost nothing.
If you want to debate cams talk about valve events.
You will max out a single 76GTS before a TU1 cam is leaving anything on the table.
If you want to debate cams talk about valve events.
You will max out a single 76GTS before a TU1 cam is leaving anything on the table.
09-16-2010, 11:02 AM
#26
09-16-2010, 11:03 AM
#27
I don't know what you consider a small exhaust housing for the cubes, but I was running a 76GTS on 388 cid and lost power when going from a conventional split to a single pattern.
09-16-2010, 02:12 PM
#31
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more than 115-it will make power from 3000rpm to over 7000 if you have the turbo and valvetrain to get it there.We have found the turbo dictates the power range more than the cam does
09-16-2010, 03:32 PM
#36
Call me crazy, but it seems like a couple of guys running 9's at 140 - 150 mph, who gained performance when switching away from a reverse-split, experience would be more applicable to a 346/T76 than a 240 mph 105mm combo.
09-16-2010, 03:43 PM
#37
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interested in this also wondering on street manners and recommended stall
sent pm few weeks ago with no answer your probably super busy and i am deployed so there is no rush,
thanks for all the great info guys!
09-16-2010, 04:25 PM
#39
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The reverse split stuff has always worked well for me also in the LS series of engine. I have used them in high power stuff, but also run one in my 900hp Silverado. Not sure they will produce the highest dyno numbers, but in car/truck testing has shown better et in quarter mile racing.Longer ex duration would help the hp numbers with a faster ramp of the rpm like on a chassis dyno, but should show tq loss at lower rpm and struggle a bit when the gear change happens and the engine needs to accelerate after getting the wind knocked out of it.
OP: Virginia Speed/Speed inc will not steer you wrong on your project although they may have different opinions. Generalization is a tough road, but in your case I would run the reverse split as I believe it will help you overall with drivability coupled with smaller turbo/combo.
Kurt
OP: Virginia Speed/Speed inc will not steer you wrong on your project although they may have different opinions. Generalization is a tough road, but in your case I would run the reverse split as I believe it will help you overall with drivability coupled with smaller turbo/combo.
Kurt
09-16-2010, 05:05 PM
#40
FormerVendor
Hi Kurt 
What is it you like about a reverse split cam on a turbo application? What are you trying to achieve with the valve events that the cam ends up being that way?
Another thing is, I wish we were talking more actual numbers.
I mean, if my cam is 225/225 @.050 and someone goes with a 225/223 @.050 because it's a reverse split I find that amusing as the valve events would be very similar.
What is it you like about a reverse split cam on a turbo application? What are you trying to achieve with the valve events that the cam ends up being that way?
Another thing is, I wish we were talking more actual numbers.
I mean, if my cam is 225/225 @.050 and someone goes with a 225/223 @.050 because it's a reverse split I find that amusing as the valve events would be very similar.