The Zombie rear mount turbo saga
12-21-2007, 10:32 AM
#41
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Ack!! Jeremy you beat me to it... I have like a three page post I have been writing on my build to talk to many of the same things... Great post though!! Great info too!!
I dont exactly follow Jermey's build path... but we have always been close to eachother and talk often. He is easily one of the best (his builder 1320 too) and most experienced rear-mount guys out there.
I am curious if the statements about our efficiently due to our mounting method will subside when we can post up track times comparable to the same setup front mounted.
That beings said... there is additional science that we (rear-mount guys) must take into account when engineering a build that many other builders dont. What size exhaust pipe... for what size motor:
ie: I believe that 2.5" is fine for a 346, ok for a 370, but too small for a 400+ ci motor.
Surface area... I dont think anyone has had to consider surface area of exhaust or charge piping until the rear-mount came along. When you do a measurement of the square inch coverage of surface space for LT's vs Manifolds.. if I recall (I think Engine Joe did the math) is 2.7 times more surface area to loose heat on (this = 2.7 x more exhaust pipe then just Manifolds and exhaust).
There have (a long time ago) also been some very in-depth conversations about air density and the effect of heat on the efficiency of turbo's... this also led people like Jeremy and I to explore heat retention methods to maximize the heat that reaches the turbo (its actually not heat... its the volume of air that is directly effected by the temperature of the air).
Anyways... great post man!!! I am not gonna try to out do ya... but mine will at least have pic's!! Hahahaha
I dont exactly follow Jermey's build path... but we have always been close to eachother and talk often. He is easily one of the best (his builder 1320 too) and most experienced rear-mount guys out there.
I am curious if the statements about our efficiently due to our mounting method will subside when we can post up track times comparable to the same setup front mounted.
That beings said... there is additional science that we (rear-mount guys) must take into account when engineering a build that many other builders dont. What size exhaust pipe... for what size motor:
ie: I believe that 2.5" is fine for a 346, ok for a 370, but too small for a 400+ ci motor.
Surface area... I dont think anyone has had to consider surface area of exhaust or charge piping until the rear-mount came along. When you do a measurement of the square inch coverage of surface space for LT's vs Manifolds.. if I recall (I think Engine Joe did the math) is 2.7 times more surface area to loose heat on (this = 2.7 x more exhaust pipe then just Manifolds and exhaust).
There have (a long time ago) also been some very in-depth conversations about air density and the effect of heat on the efficiency of turbo's... this also led people like Jeremy and I to explore heat retention methods to maximize the heat that reaches the turbo (its actually not heat... its the volume of air that is directly effected by the temperature of the air).
Anyways... great post man!!! I am not gonna try to out do ya... but mine will at least have pic's!! Hahahaha
12-21-2007, 11:43 AM
#42
I will be changing up my exhaust to 2.5 all the way back, eliminating the factory driver side 2" crossover we have on the GTO's going into the single that runs to the turbo. I was also considering LT's, but I am glad to see Factual proof that it will do no good over ported stockers or shorties.
A rear mounted setup will not achieve the same effeciency as standard turbo setup, it's just physics. The trick with a rear mount is maximizing the effeciency of it since it's so much more important to the performance of the system.
Last edited by Zombie; 12-21-2007 at 11:50 AM.
12-21-2007, 12:14 PM
#43
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Just because the location has implications... and requires mitigation.. dosnt mean that equal efficiency (or near equal) cant be achieved!
12-21-2007, 03:06 PM
#44
Ack!! Jeremy you beat me to it... I have like a three page post I have been writing on my build to talk to many of the same things... Great post though!! Great info too!!
I dont exactly follow Jermey's build path... but we have always been close to eachother and talk often. He is easily one of the best (his builder 1320 too) and most experienced rear-mount guys out there.
I am curious if the statements about our efficiently due to our mounting method will subside when we can post up track times comparable to the same setup front mounted.
That beings said... there is additional science that we (rear-mount guys) must take into account when engineering a build that many other builders dont. What size exhaust pipe... for what size motor:
ie: I believe that 2.5" is fine for a 346, ok for a 370, but too small for a 400+ ci motor.
Surface area... I dont think anyone has had to consider surface area of exhaust or charge piping until the rear-mount came along. When you do a measurement of the square inch coverage of surface space for LT's vs Manifolds.. if I recall (I think Engine Joe did the math) is 2.7 times more surface area to loose heat on (this = 2.7 x more exhaust pipe then just Manifolds and exhaust).
There have (a long time ago) also been some very in-depth conversations about air density and the effect of heat on the efficiency of turbo's... this also led people like Jeremy and I to explore heat retention methods to maximize the heat that reaches the turbo (its actually not heat... its the volume of air that is directly effected by the temperature of the air).
Anyways... great post man!!! I am not gonna try to out do ya... but mine will at least have pic's!! Hahahaha
I dont exactly follow Jermey's build path... but we have always been close to eachother and talk often. He is easily one of the best (his builder 1320 too) and most experienced rear-mount guys out there.
I am curious if the statements about our efficiently due to our mounting method will subside when we can post up track times comparable to the same setup front mounted.
That beings said... there is additional science that we (rear-mount guys) must take into account when engineering a build that many other builders dont. What size exhaust pipe... for what size motor:
ie: I believe that 2.5" is fine for a 346, ok for a 370, but too small for a 400+ ci motor.
Surface area... I dont think anyone has had to consider surface area of exhaust or charge piping until the rear-mount came along. When you do a measurement of the square inch coverage of surface space for LT's vs Manifolds.. if I recall (I think Engine Joe did the math) is 2.7 times more surface area to loose heat on (this = 2.7 x more exhaust pipe then just Manifolds and exhaust).
There have (a long time ago) also been some very in-depth conversations about air density and the effect of heat on the efficiency of turbo's... this also led people like Jeremy and I to explore heat retention methods to maximize the heat that reaches the turbo (its actually not heat... its the volume of air that is directly effected by the temperature of the air).
Anyways... great post man!!! I am not gonna try to out do ya... but mine will at least have pic's!! Hahahaha
12-21-2007, 04:04 PM
#45
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Some mid length 1.75" cast headers would be right up you rear mount guy's alley. Something that has a better merge than stock manifolds and alittle more room to carry the exhaust. You could venturi it down at the y-pipe if you want to speed the velocity up.
12-21-2007, 07:18 PM
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good read wait till you guys see the new setup Rear Mounts are going to a new level.
BTW there is a 8.5 rear mount Vette out there to (Bowery Boy)
BTW there is a 8.5 rear mount Vette out there to (Bowery Boy)
12-23-2007, 12:42 PM
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Very nice read for someone who has a rear mount and was thinking about canning it for a front mount. You saved me 6,000+. All I want is a 10.XX pass. I having a Iron block 370 with stock 317 heads upgraded springs built right now. I have long tubes but after your read I'm going back to stock manifolds and wrap them. Porbably get a custom cam done and going from a 60 to a 67 till I got the $$$ for a bigger one. Thanks Zombie great read.
05-16-2008, 11:46 AM
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I understand the logic of using stock manifolds vs LT's due to decreased surface area (concerning heat retention). I've wondered if anyone has wrapped their LT's and see how that makes a difference. I have the exhaust wrapped from the Y-pipe back. Never wrapped the headers cause they're Jet-Hot coated. Wondering how things would change if I wrapped the headers too. 
Not too worried about increased heat....they're stainless steel and should hold up better than mild steel headers.
Anyhow....anyone done that yet? If so, notice a difference?
Good info overall Zombie
Not too worried about increased heat....they're stainless steel and should hold up better than mild steel headers.Anyhow....anyone done that yet? If so, notice a difference?
Good info overall Zombie
05-16-2008, 10:11 PM
#53
I understand the logic of using stock manifolds vs LT's due to decreased surface area (concerning heat retention). I've wondered if anyone has wrapped their LT's and see how that makes a difference. I have the exhaust wrapped from the Y-pipe back. Never wrapped the headers cause they're Jet-Hot coated. Wondering how things would change if I wrapped the headers too. Not too worried about increased heat....they're stainless steel and should hold up better than mild steel headers.
Anyhow....anyone done that yet? If so, notice a difference?
Good info overall Zombie
Not too worried about increased heat....they're stainless steel and should hold up better than mild steel headers.Anyhow....anyone done that yet? If so, notice a difference?
Good info overall Zombie
05-16-2008, 11:18 PM
#54
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Yes, I ve done the fabrication on zombies car and several others......Yes I have wrapped lt's ...........yes it helps a lot. Is it best no. I will not build a turbo car with lt's...I just wont. Ive done a lot of testing.....If I do someones car, I do it right, or I wont do it. The best is a coated and wrapped short header, but look at the OB racing car, 6.0 manifolds gong high7's on a front mount.
Part of the problem with builds, is a competent builder being forced into going one direction or most likely not even knowing the entire combination, and not getting the outcome wanted because of other circumstances. You can have the coolest turbo system in the world, but if you have the wrong injectors, no diagnostics, the wrong plug gap, the wrong compression for the fuel, the wrong gears, the wrong trans, the wrong convertor, the wrong tires, the other stuff suffers.
Zombies car has more in it, because he doesnt give much attention to other aspects of the car, he hasnt needed too, but its getting to that point.
Part of the problem with builds, is a competent builder being forced into going one direction or most likely not even knowing the entire combination, and not getting the outcome wanted because of other circumstances. You can have the coolest turbo system in the world, but if you have the wrong injectors, no diagnostics, the wrong plug gap, the wrong compression for the fuel, the wrong gears, the wrong trans, the wrong convertor, the wrong tires, the other stuff suffers.
Zombies car has more in it, because he doesnt give much attention to other aspects of the car, he hasnt needed too, but its getting to that point.
05-17-2008, 09:03 AM
#57
I'll use my car as an example (I don't have any other examples, HAH!) of how important keeping this heat in the exhaust is and how backpressure can affect the performance of your setup.
I started out with a T67 using a P-Trim exhaust wheel and a .81 a/r exhaust housing. My car had a 10:1 compression 346 LS1 engine with SLP long tube headers. This turbo spooled decent (how little I really knew). Would make 10 psi of boost and was fun to drive. I then tried to turn it up. I managed to get 14psi regularly but it struggled to go any higher. I could occasionally reach 16psi in high gear, but it was difficult and took a long time.
Best 1/4 mile pass: 11.7 @ 126 MPH, 15psi
14.5psi waste gate spring = 10psi
I then decided to try a Innovative T76 R-trim wheel with a .81 a/r exhaust housing. The car would make 5psi of boost quickly but then take until 6000 rpms until it would reach 11psi in high gear. Even if I blocked off the waste gate completely. Frustrated by this, I broke out my trusty credit card and purchased a .70 a/r housing and installed it. The result was excellent, I could now make 12psi and then slowly creep up to 14psi and occasionally it would reach 16psi in high gear. It spooled the same at the T67 but made a little more power.
Best 1/4 mile pass: 11.7 @ 127 MPH, 15psi
14.5psi waste gate spring = 11psi
In my quest to go ever faster, I changed my setup. I replaced the stock engine with a 8.7:1 comp 370 cu inch iron block Ls1 and a Th400 transmission. The previous transmission was a T56 6speed. While still running the same 3" exhaust after the turbo .70 a/r housing and 15psi I managed to go faster.
Best 1/4 mile pass: 11.3 @ 128 MPH, 15psi
14.5psi waste gate spring = 11psi
I still had problems though. I could only build a little boost on the line or none at all, boost was limited to 15psi max even with the waste gate blocked off and it took forever to get there. I decided to get rid of the headers and go back to stock manifolds. Wow what a difference! Now the car spooled faster and make 15psi reliably. The power range was very limited though. I was making my shifts at 5700 rpms because power was falling off fast after that and it would get detonation even on 100 octane gas if I revved past 6000. It spooled so well that I decided to try the .81 a/r housing again. I barely noticed any difference in spool time, but now the car felt like it was making a little more power. It spooled slowly on the transbrake (about 5 seconds to get 10psi) and I had to leave on 10psi of boost to get a good 60' (1.6x
range) because it would reach max boost faster that way, but it was working.
Best 1/4 mile pass: 10.54 @ 129.9 MPH, 16psi
14.5psi waste gate spring = 11psi
I started doing some research; I measured my back pressure and was seeing 45psi of back pressure at 15psi of boost. After talking to some more people it appeared that back pressure was still killing my performance. In my research I had found out that having your exhaust after the turbo to be 1.5 (or more) times the diameter of the exhaust wheel was better for back pressure after the turbo I had a new exhaust setup made up. The old exhaust was a 3.5' section of 3" pipe off the turbo exiting behind the rear wheel, it was a straight shot with no bends. I didn't think that this could be the problem but figured I'd give it a shot any ways. My exhaust housing used a 3.5" v-band to make the connection and I basically had a 3" exhaust butted right up against it. The new piece used a 3.5" v-band to a 3.5" to 4" transition and then a 4"
90 degree dump. Total exhaust length after the turbo, about 1 foot. The result was excellent, faster spool! Top end power seemed to be better but I was still limited to 16psi of boost even with the waste gate blocked off. It would build to 13 and then slowly go up to 16psi from there.
Best 1/4 mile pass: 10.56 @ 131 MPH, 16psi
14.5psi waste gate spring = 12psi
The waste gate was not opening at high boost. I didn't have enough exhaust energy to be bypassing any exhaust, it was taking every molecule of exhaust to reach 16psi (slowly). I talked to my friend Jon Whittington (he built my car and turbo setup) about this. After some discussion and further research we decided that it was the lack of heat in the exhaust causing us issues. He tried the experiment first on his car. He had a completely stock exhaust setup that spooled well to 12psi on a stock engine and a T70 .81 p-trim turbo. He swapped out to Jet hot long tubes. The result was amazingly disappointing. With no other changes besides the long tubes, the car
would barely build 5psi of boost and took seconds to even achieve that. He then pulled the exhaust system and headers off the car and wrapped it in header wrap. The result was fantastic, it spooled as well as it did on the stock uninsulated exhaust. Seeing how well this worked I decided to have him fabricate an entire new exhaust system for me. The exhaust is made out of 2.5" OD from the manifolds to the turbo and then insulated with fiberglass header wrap to just over the rear axle (we ran out). The end result of this was much much faster spooling and I could now achieve 20psi of boost with the waste gate still opening. I now had to leave on 5-6psi of boost because
it spooled so much faster it would blow the tires off if I left higher. It would also build 10psi of boost in 2.5 seconds now when using the transbrake, a huge improvement.
Best 1/4 mile pass: 10.13 @ 132 MPH, 19psi (best MPH of 134.55)
14.5psi waste gate spring = 13psi
Chapter 4... Return of the Jedi
I've now swapped to a .96 a/r housing. The turbo spools identically as it did on the .81 housing but it makes much more top end power. Instead of shifting at 6000 like previously I'm now able to shift it at 6500 and the power doesn't fall off. I'm hoping to get track results on this setup soon.
Best 1/4 mile pass: x.xx @ xxx MPH, 20psi
14.5psi waste gate spring = 14.5psi
The car feels like a completely different animal on this housing, the top end is
amazing, it actually feels like a turbo car should now. It took 3 years to get the car to this point by making a lot of small changes and observing how they affected it.
(keep in mind that I run at a track at high elevation that often sees 5000+ density altitude when trying to compare times to sea level tracks)
Chapter 5. Epilogue
Trying to go fast with a rear mounted turbo is possible and there are a few doing it, one car has even made it to the 7's and at least 3 others that have run 9's. It's not easy and not everyone will share their tricks and research which makes it harder for others to duplicate. If you quest is for get ET slips then changing to a built automatic is the easiest and cheapest route. Some people are die hard 6 speed fans like I use to be, but once you experience how much fun a built RMVB trans braked Th400 is you might change your mind. A huge advantage of an auto is that it never drops boost between shifts and shifts faster than any human can. It can take some experimentation with torque converters to get it to behave exactly the way you require though.
You don't have to spend a lot of money on parts to go fast on a turbo setup either. Most of the parts on my engine are stock with the exception of the pistons and rods. You don't have to spend a lot of money on high flowing heads and a magical cam either, the stock parts will do just fine. If you do spend the money for a nice set of heads and a good turbo cam you will make more power at a lower boost. I suggest against them when first starting out since it's a lot of extra cost that could be used towards getting the car running.
My setup is simple:
6.0 iron block bored .030 over
Diamond 4.030 dished pistons
Eagle I-Beam SBC 6.125 rods
60lb/hr injectors
Stock 317 heads with good springs (130 seat pressure)
Stock valves
Stock 02+ Z06 cam
stock intake
stock exhaust manifolds
2.5" custom exhaust wrapped in DEI header wrap (no cats)
ITS T76 R trim turbo with .96 a/r housing
Ebay intercooler
SMC Methanol kit
Rossler Th400 with transbrake
Vigilante 9.5" converter made as tight as they could make it
Moser 30 spline 9" with 2.75 gears and a spool
Hoosier 275/50/15 drag radial tires on 15x8 wheels
Only suspension mods are a RR airbag and BMR LCA's
I hope some of this will help some of the rear mount turbo guys out who are trying to go faster.
Jeremy Wolf, aka ZombieSS/Zombie
Credits:
1320 AKA Jon Whittington (my fabricator)
JZ 97 SS 1500 AKA Jose from forced inductions
EnineerMike (knows his physics and compressor theory)
(If I got any theory wrong let me know so I can correct it)
I started out with a T67 using a P-Trim exhaust wheel and a .81 a/r exhaust housing. My car had a 10:1 compression 346 LS1 engine with SLP long tube headers. This turbo spooled decent (how little I really knew). Would make 10 psi of boost and was fun to drive. I then tried to turn it up. I managed to get 14psi regularly but it struggled to go any higher. I could occasionally reach 16psi in high gear, but it was difficult and took a long time.
Best 1/4 mile pass: 11.7 @ 126 MPH, 15psi
14.5psi waste gate spring = 10psi
I then decided to try a Innovative T76 R-trim wheel with a .81 a/r exhaust housing. The car would make 5psi of boost quickly but then take until 6000 rpms until it would reach 11psi in high gear. Even if I blocked off the waste gate completely. Frustrated by this, I broke out my trusty credit card and purchased a .70 a/r housing and installed it. The result was excellent, I could now make 12psi and then slowly creep up to 14psi and occasionally it would reach 16psi in high gear. It spooled the same at the T67 but made a little more power.
Best 1/4 mile pass: 11.7 @ 127 MPH, 15psi
14.5psi waste gate spring = 11psi
In my quest to go ever faster, I changed my setup. I replaced the stock engine with a 8.7:1 comp 370 cu inch iron block Ls1 and a Th400 transmission. The previous transmission was a T56 6speed. While still running the same 3" exhaust after the turbo .70 a/r housing and 15psi I managed to go faster.
Best 1/4 mile pass: 11.3 @ 128 MPH, 15psi
14.5psi waste gate spring = 11psi
I still had problems though. I could only build a little boost on the line or none at all, boost was limited to 15psi max even with the waste gate blocked off and it took forever to get there. I decided to get rid of the headers and go back to stock manifolds. Wow what a difference! Now the car spooled faster and make 15psi reliably. The power range was very limited though. I was making my shifts at 5700 rpms because power was falling off fast after that and it would get detonation even on 100 octane gas if I revved past 6000. It spooled so well that I decided to try the .81 a/r housing again. I barely noticed any difference in spool time, but now the car felt like it was making a little more power. It spooled slowly on the transbrake (about 5 seconds to get 10psi) and I had to leave on 10psi of boost to get a good 60' (1.6x
range) because it would reach max boost faster that way, but it was working.
Best 1/4 mile pass: 10.54 @ 129.9 MPH, 16psi
14.5psi waste gate spring = 11psi
I started doing some research; I measured my back pressure and was seeing 45psi of back pressure at 15psi of boost. After talking to some more people it appeared that back pressure was still killing my performance. In my research I had found out that having your exhaust after the turbo to be 1.5 (or more) times the diameter of the exhaust wheel was better for back pressure after the turbo I had a new exhaust setup made up. The old exhaust was a 3.5' section of 3" pipe off the turbo exiting behind the rear wheel, it was a straight shot with no bends. I didn't think that this could be the problem but figured I'd give it a shot any ways. My exhaust housing used a 3.5" v-band to make the connection and I basically had a 3" exhaust butted right up against it. The new piece used a 3.5" v-band to a 3.5" to 4" transition and then a 4"
90 degree dump. Total exhaust length after the turbo, about 1 foot. The result was excellent, faster spool! Top end power seemed to be better but I was still limited to 16psi of boost even with the waste gate blocked off. It would build to 13 and then slowly go up to 16psi from there.
Best 1/4 mile pass: 10.56 @ 131 MPH, 16psi
14.5psi waste gate spring = 12psi
The waste gate was not opening at high boost. I didn't have enough exhaust energy to be bypassing any exhaust, it was taking every molecule of exhaust to reach 16psi (slowly). I talked to my friend Jon Whittington (he built my car and turbo setup) about this. After some discussion and further research we decided that it was the lack of heat in the exhaust causing us issues. He tried the experiment first on his car. He had a completely stock exhaust setup that spooled well to 12psi on a stock engine and a T70 .81 p-trim turbo. He swapped out to Jet hot long tubes. The result was amazingly disappointing. With no other changes besides the long tubes, the car
would barely build 5psi of boost and took seconds to even achieve that. He then pulled the exhaust system and headers off the car and wrapped it in header wrap. The result was fantastic, it spooled as well as it did on the stock uninsulated exhaust. Seeing how well this worked I decided to have him fabricate an entire new exhaust system for me. The exhaust is made out of 2.5" OD from the manifolds to the turbo and then insulated with fiberglass header wrap to just over the rear axle (we ran out). The end result of this was much much faster spooling and I could now achieve 20psi of boost with the waste gate still opening. I now had to leave on 5-6psi of boost because
it spooled so much faster it would blow the tires off if I left higher. It would also build 10psi of boost in 2.5 seconds now when using the transbrake, a huge improvement.
Best 1/4 mile pass: 10.13 @ 132 MPH, 19psi (best MPH of 134.55)
14.5psi waste gate spring = 13psi
Chapter 4... Return of the Jedi
I've now swapped to a .96 a/r housing. The turbo spools identically as it did on the .81 housing but it makes much more top end power. Instead of shifting at 6000 like previously I'm now able to shift it at 6500 and the power doesn't fall off. I'm hoping to get track results on this setup soon.
Best 1/4 mile pass: x.xx @ xxx MPH, 20psi
14.5psi waste gate spring = 14.5psi
The car feels like a completely different animal on this housing, the top end is
amazing, it actually feels like a turbo car should now. It took 3 years to get the car to this point by making a lot of small changes and observing how they affected it.
(keep in mind that I run at a track at high elevation that often sees 5000+ density altitude when trying to compare times to sea level tracks)
Chapter 5. Epilogue
Trying to go fast with a rear mounted turbo is possible and there are a few doing it, one car has even made it to the 7's and at least 3 others that have run 9's. It's not easy and not everyone will share their tricks and research which makes it harder for others to duplicate. If you quest is for get ET slips then changing to a built automatic is the easiest and cheapest route. Some people are die hard 6 speed fans like I use to be, but once you experience how much fun a built RMVB trans braked Th400 is you might change your mind. A huge advantage of an auto is that it never drops boost between shifts and shifts faster than any human can. It can take some experimentation with torque converters to get it to behave exactly the way you require though.
You don't have to spend a lot of money on parts to go fast on a turbo setup either. Most of the parts on my engine are stock with the exception of the pistons and rods. You don't have to spend a lot of money on high flowing heads and a magical cam either, the stock parts will do just fine. If you do spend the money for a nice set of heads and a good turbo cam you will make more power at a lower boost. I suggest against them when first starting out since it's a lot of extra cost that could be used towards getting the car running.
My setup is simple:
6.0 iron block bored .030 over
Diamond 4.030 dished pistons
Eagle I-Beam SBC 6.125 rods
60lb/hr injectors
Stock 317 heads with good springs (130 seat pressure)
Stock valves
Stock 02+ Z06 cam
stock intake
stock exhaust manifolds
2.5" custom exhaust wrapped in DEI header wrap (no cats)
ITS T76 R trim turbo with .96 a/r housing
Ebay intercooler
SMC Methanol kit
Rossler Th400 with transbrake
Vigilante 9.5" converter made as tight as they could make it
Moser 30 spline 9" with 2.75 gears and a spool
Hoosier 275/50/15 drag radial tires on 15x8 wheels
Only suspension mods are a RR airbag and BMR LCA's
I hope some of this will help some of the rear mount turbo guys out who are trying to go faster.
Jeremy Wolf, aka ZombieSS/Zombie
Credits:
1320 AKA Jon Whittington (my fabricator)
JZ 97 SS 1500 AKA Jose from forced inductions
EnineerMike (knows his physics and compressor theory)
(If I got any theory wrong let me know so I can correct it)
05-17-2008, 10:49 AM
#58
Great Post This is a great, informative post from someone who has been there and done that, and not listened to everyone else telling them that it won't work, knowing with enough trial and error that it will! I love trying and listening to someone else who "thinks outside the box" and tries new things, successful or failure, it's all good results.
I too have been watching the rear mount stuff since the start, and from what I've seen is you have to get a larger turbo on the rear mounts to make the same power level as the front mounts.
The same goes for budget builds, you CAN do it, I just did it (<$2500), and it works. It may not look like the 30K builds, but when you run with them, that's when it gets fun!
Lets keep this post rolling with facts, no bs theory's or hear says, real time trial's, and we just may get a sticky!
A FI remote mount sections would be the shiznit!
I too have been watching the rear mount stuff since the start, and from what I've seen is you have to get a larger turbo on the rear mounts to make the same power level as the front mounts.
The same goes for budget builds, you CAN do it, I just did it (<$2500), and it works. It may not look like the 30K builds, but when you run with them, that's when it gets fun!
Lets keep this post rolling with facts, no bs theory's or hear says, real time trial's, and we just may get a sticky!
A FI remote mount sections would be the shiznit!
05-18-2008, 12:20 AM
#60
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1. what kind of 383? sbc, lt1, ls1, ls2
2. head flow?
3. cam?
4. weight?
5. transmission
6. gear ratio
7. exhuast type?
I would have to asume, air to air with water /meth, and I m guessing its rear mount?
The st80 is working great, but its very sensitive, like if it gets a small leak, its dead in the water. So to anyone, going as large as a st80, be aware that the system needs to very very good. Doing pressure checks on the entire system are routine.
FYI, I recently did a twin rear mount vette, and many of the clamps were the same part number, but for some reason some were about 1/4 inch larger. So when completely tight they would bottom out, be snug on the boot, but during the pressure check, it leaked like a sive. Swap some clamps and fixed.
I did temp readings on the exhuast testing, lt vrs manifold, lt unwrapped to wrapped, lt coated to uncoated, to wrapped etc..etc....but I dont have handy.