whats the difference in a turbo cam and a blower cam
08-14-2008, 08:54 PM
#1
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whats the difference in a turbo cam and a blower cam Ok I know nothing about blower or turbo cams is there a difference and what is it thanks guys
08-14-2008, 09:08 PM
#2
Ok. Here is my NON-TECHNICAL OPINION.
Any cam will obviously work in either. In general, the bigger the cam (duration and lift) the more power it will make, and the higher in the RPMS it will make. Cams with less over lap will "bleed" off more boost than smaller ones. You will hear endless differing opinions about this subject and proponents of standard split duration, reverse splits, and straight patters.
You really need to just make a DETAILED post about your set-up and goals......and then let some of the sponsors of knowledgeable members help you select what's right for YOU.
Any cam will obviously work in either. In general, the bigger the cam (duration and lift) the more power it will make, and the higher in the RPMS it will make. Cams with less over lap will "bleed" off more boost than smaller ones. You will hear endless differing opinions about this subject and proponents of standard split duration, reverse splits, and straight patters.
You really need to just make a DETAILED post about your set-up and goals......and then let some of the sponsors of knowledgeable members help you select what's right for YOU.
08-14-2008, 09:24 PM
#3
I agree with ninetres, opinions will vary. The turbo cam I installed has exactly the same lift and duration for the intake and the exhaust; the blower cam I removed did not. Some will agree with this approach, some may not.
You may want to start here: https://ls1tech.com/forums/generation-iii-internal-engine/327734-cam-guide.html
for a general understanding of cam parameters. But, as the thread suggests, it all boils down to you having to make a decision. Personally, I called Comp Cams and spoke to folk that do it for a living. JMHO.
BOL.
You may want to start here: https://ls1tech.com/forums/generation-iii-internal-engine/327734-cam-guide.html
for a general understanding of cam parameters. But, as the thread suggests, it all boils down to you having to make a decision. Personally, I called Comp Cams and spoke to folk that do it for a living. JMHO.
BOL.
08-15-2008, 07:51 AM
#4
Not enough testing has been done on turbo setups to really prove what a turbo cam should be anyway.
A few years back, I converted from a supercharger to a turbo. After proving the setup, I removed the supercharger cam (224/236-114) and installed a supposed turbo cam (226/226-114). The car lost power and response, so I put the supercharger cam back in it.
It later occurred to me, what was I thinking??? That reducing duration anywhere on the cam would increase power??? Not unless the cam is WAY out of whack to begin with.
I've said this before and still believe it. The exhaust pressure vs. intake pressure (boost) difference should be key to turbo cam selection. Some setups have the same boost as exhaust pressure, and these should have cams pretty close to NA. Other setups have exhaust pressure 3 times the boost level. Clearly, these cams should be different, but nobody knows in what way exactly.
Mike
A few years back, I converted from a supercharger to a turbo. After proving the setup, I removed the supercharger cam (224/236-114) and installed a supposed turbo cam (226/226-114). The car lost power and response, so I put the supercharger cam back in it.
It later occurred to me, what was I thinking??? That reducing duration anywhere on the cam would increase power??? Not unless the cam is WAY out of whack to begin with.
I've said this before and still believe it. The exhaust pressure vs. intake pressure (boost) difference should be key to turbo cam selection. Some setups have the same boost as exhaust pressure, and these should have cams pretty close to NA. Other setups have exhaust pressure 3 times the boost level. Clearly, these cams should be different, but nobody knows in what way exactly.
Mike
08-18-2008, 08:30 PM
#6
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The plan for this build is a forged 355 lt1 with ported and polished stock heads ported matched intake and the turbo system I'm not quite sure about yet I'm just working my way up. The car is mainly just gun a be a show car and weekend driver so it doesn't have to be anything thing extreme maybe like 10 or 12 pounds of boost and try to make 550 plus
08-18-2008, 09:07 PM
#7
I had a Lingenfelter GT-7 208/230 121lsa in my Magnuson engine. I changed to the MS4 239/242 111lsa and added an O.D. pulley to spin the blower and lost 10rwhp. Bigger is not always better. The GT-7 is what Lingenfelter uses in the 427TT package. The idea is that the intake charge is forced in, but the exhaust needs help, hence the huge split. Taking away the overlap and putting the cam on a 121 builds cylinder pressure early bringing in the boost early also creating great driveability.
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08-18-2008, 09:31 PM
#10
I had a Lingenfelter GT-7 208/230 121lsa in my Magnuson engine. I changed to the MS4 239/242 111lsa and added an O.D. pulley to spin the blower and lost 10rwhp. Bigger is not always better. The GT-7 is what Lingenfelter uses in the 427TT package. The idea is that the intake charge is forced in, but the exhaust needs help, hence the huge split. Taking away the overlap and putting the cam on a 121 builds cylinder pressure early bringing in the boost early also creating great driveability.
08-19-2008, 10:42 AM
#13
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Not enough testing has been done on turbo setups to really prove what a turbo cam should be anyway.
A few years back, I converted from a supercharger to a turbo. After proving the setup, I removed the supercharger cam (224/236-114) and installed a supposed turbo cam (226/226-114). The car lost power and response, so I put the supercharger cam back in it.
It later occurred to me, what was I thinking??? That reducing duration anywhere on the cam would increase power??? Not unless the cam is WAY out of whack to begin with.
I've said this before and still believe it. The exhaust pressure vs. intake pressure (boost) difference should be key to turbo cam selection. Some setups have the same boost as exhaust pressure, and these should have cams pretty close to NA. Other setups have exhaust pressure 3 times the boost level. Clearly, these cams should be different, but nobody knows in what way exactly.
Mike
A few years back, I converted from a supercharger to a turbo. After proving the setup, I removed the supercharger cam (224/236-114) and installed a supposed turbo cam (226/226-114). The car lost power and response, so I put the supercharger cam back in it.
It later occurred to me, what was I thinking??? That reducing duration anywhere on the cam would increase power??? Not unless the cam is WAY out of whack to begin with.
I've said this before and still believe it. The exhaust pressure vs. intake pressure (boost) difference should be key to turbo cam selection. Some setups have the same boost as exhaust pressure, and these should have cams pretty close to NA. Other setups have exhaust pressure 3 times the boost level. Clearly, these cams should be different, but nobody knows in what way exactly.
Mike
08-20-2008, 03:04 PM
#17
Even if that had been done, it still would only be applicable to that particular backpressure/boost ratio. If it's 3/1, then obviously the results wouldn't apply to an application that was 1/1.
08-20-2008, 07:28 PM
#20
Exactly. What do you want to do with your car and how are you going to build it? (Weight, Suspension etc.)
I am about to have a 383 stroker 2.8L Kenne Bell and I already know anything below 80MPH will blow the tires off in any gear except for 6th. I am going to put a nasty so called N/A cam in it to move my power a little further up in the r.p.m. and run a stupid tall gear so I can act like I am a Supra 80 m.p.h. roll racer. Seriously you need to determine what your goal and setup will be in the interim for now or the end build.
I am about to have a 383 stroker 2.8L Kenne Bell and I already know anything below 80MPH will blow the tires off in any gear except for 6th. I am going to put a nasty so called N/A cam in it to move my power a little further up in the r.p.m. and run a stupid tall gear so I can act like I am a Supra 80 m.p.h. roll racer. Seriously you need to determine what your goal and setup will be in the interim for now or the end build.