turbocharging a late model C4. whats involved?
02-09-2009, 12:19 PM
#1
Race Director
Thread Starter
turbocharging a late model C4. whats involved?
7 years ago, I remember trading stories about my hotcam/heads/LT headers swap. In '03 it was a 100 shot of NX nitrous.
I like front mount turbos... I imagine something more like lcvette's setup, or a twin turbo setup making 800 rwHP.
My questions are:
1. Whats better auto or manual trans?
2. You still using stock LT block?
3. Stock ignition? (opti?)
4. What heads?
5. Where do you get the special exhaust manifolds that a turbo needs to bolt up to?
6. Whats controlling A/F? A wide-band O2 sensor FAST type setup?
7. How do you make that work in conjunction with stock PCM?
8. What fuel system improvements? New pump and injectors? Do you also need bigger lines from fuel tank?
9. You guys run w/ cats and are emissions legal?
10. Who's doing your tubing bends? You, or is there someone out there that has these pre-fab'd for LTx style C4's?
Im thinking more and more about this.
I got my a$z handed to me this summer by a 4 cylinder Evo that ran 11.2 against me w/ me running 11.5 on nitrous. Nitrous doesnt cut it anymore.
I like front mount turbos... I imagine something more like lcvette's setup, or a twin turbo setup making 800 rwHP.
My questions are:
1. Whats better auto or manual trans?
2. You still using stock LT block?
3. Stock ignition? (opti?)
4. What heads?
5. Where do you get the special exhaust manifolds that a turbo needs to bolt up to?
6. Whats controlling A/F? A wide-band O2 sensor FAST type setup?
7. How do you make that work in conjunction with stock PCM?
8. What fuel system improvements? New pump and injectors? Do you also need bigger lines from fuel tank?
9. You guys run w/ cats and are emissions legal?
10. Who's doing your tubing bends? You, or is there someone out there that has these pre-fab'd for LTx style C4's?
Im thinking more and more about this.
I got my a$z handed to me this summer by a 4 cylinder Evo that ran 11.2 against me w/ me running 11.5 on nitrous. Nitrous doesnt cut it anymore.
Last edited by dizwiz24; 02-09-2009 at 12:27 PM.
02-09-2009, 01:21 PM
#2
Melting Slicks
Its kind of hard to keep up with an awd car from a stop. You would do just fine against him from a roll though.
You are asking a bunch of questions. Very few people on this board have made 800rwhp, and most of them are in the C5 forced induction section. Chris's setup is wonderful, but it runs on E85(110+ octane). If it was running pump gas I'm guessing the numbers would be much lower.
If you decide to do this, its not going to be a small undertaking and it will cost $10k at a minimum. You are best off doing it in steps. Start with the turbo setup, that will be the hardest. There are no kits out as of yet. Raptor is working on it and that would be the easiest way of doing it. If you want a front mount setup then you're going to have to do some welding, or pay someone to do it. You can use existing headers and build pipes off of those into the turbo but that will limit your turbo placement. The best way is to build new headers yourself to get the best possible flow into the turbo.
1. Whats better auto or manual trans?
Either one - stock 6-speed holds more than the stock auto
2. You still using stock LT block?
You can, a partial block fill might be usefull
3. Stock ignition? (opti?)
Its better to do an aftermarket system, but you can get away with a BTM if need be
4. What heads?
Good flowing...it helps to get larger combustion chambers to lower the CR
5. Where do you get the special exhaust manifolds that a turbo needs to bolt up to?
You have to build them
6. Whats controlling A/F? A wide-band O2 sensor FAST type setup?
The A/F is controlled throught the ECM, aftermarket or stock reprogrammed. You will also need an Wideband O2 to monitor everything.
7. How do you make that work in conjunction with stock PCM?
They don't work together, the wideband is just a check to make sure you got it right. You can get an aftermarket ECM to adjust the tune with wideband O2 feedback though.
8. What fuel system improvements? New pump and injectors? Do you also need bigger lines from fuel tank?
You'll definately need bigger injectors and fuel pump. The stock lines are good up to 6-700chp or so accroding to racetronix.
9. You guys run w/ cats and are emissions legal?
Sorry the dog chased the cats up a tree. If you need to keep things like EGR and cats then it might be easier to look into a supercharger.
10. Who's doing your tubing bends? You, or is there someone out there that has these pre-fab'd for LTx style C4's?
You can purchase mandrel bends from several places out there. Then you have to cut and weld them into the perfect pipe for your car.
Something else to think about, are you planning on keeping the A/C for this car? If so doing a turbo setup will be alot more work given the extra components that you have to work around.
If you can get all of these things worked out and have been running your 6-8psi for a while then you can start thinking about changing the engine to make some big HP.
This is definately not a bolt on deal, you could get a supercharger which would be easier, but they also have their issues. Good luck.
You are asking a bunch of questions. Very few people on this board have made 800rwhp, and most of them are in the C5 forced induction section. Chris's setup is wonderful, but it runs on E85(110+ octane). If it was running pump gas I'm guessing the numbers would be much lower.
If you decide to do this, its not going to be a small undertaking and it will cost $10k at a minimum. You are best off doing it in steps. Start with the turbo setup, that will be the hardest. There are no kits out as of yet. Raptor is working on it and that would be the easiest way of doing it. If you want a front mount setup then you're going to have to do some welding, or pay someone to do it. You can use existing headers and build pipes off of those into the turbo but that will limit your turbo placement. The best way is to build new headers yourself to get the best possible flow into the turbo.
1. Whats better auto or manual trans?
Either one - stock 6-speed holds more than the stock auto
2. You still using stock LT block?
You can, a partial block fill might be usefull
3. Stock ignition? (opti?)
Its better to do an aftermarket system, but you can get away with a BTM if need be
4. What heads?
Good flowing...it helps to get larger combustion chambers to lower the CR
5. Where do you get the special exhaust manifolds that a turbo needs to bolt up to?
You have to build them
6. Whats controlling A/F? A wide-band O2 sensor FAST type setup?
The A/F is controlled throught the ECM, aftermarket or stock reprogrammed. You will also need an Wideband O2 to monitor everything.
7. How do you make that work in conjunction with stock PCM?
They don't work together, the wideband is just a check to make sure you got it right. You can get an aftermarket ECM to adjust the tune with wideband O2 feedback though.
8. What fuel system improvements? New pump and injectors? Do you also need bigger lines from fuel tank?
You'll definately need bigger injectors and fuel pump. The stock lines are good up to 6-700chp or so accroding to racetronix.
9. You guys run w/ cats and are emissions legal?
Sorry the dog chased the cats up a tree. If you need to keep things like EGR and cats then it might be easier to look into a supercharger.
10. Who's doing your tubing bends? You, or is there someone out there that has these pre-fab'd for LTx style C4's?
You can purchase mandrel bends from several places out there. Then you have to cut and weld them into the perfect pipe for your car.
Something else to think about, are you planning on keeping the A/C for this car? If so doing a turbo setup will be alot more work given the extra components that you have to work around.
If you can get all of these things worked out and have been running your 6-8psi for a while then you can start thinking about changing the engine to make some big HP.
This is definately not a bolt on deal, you could get a supercharger which would be easier, but they also have their issues. Good luck.
02-09-2009, 02:15 PM
#4
Race Director
Thread Starter
thanks for the advice.
I was throwing 800 rwhp out there just as a number. I dont know whats realistic and whats not.
A/C is not a requirement in ohio. I would leave that OFF.
I did not realize you all are fabricating your own exhaust manifolds. I dont know how to weld and usually rely on my uncle for any simple welding needs.
Im also assuming 6-8 PSI out of a turbocharger makes you faster than 6-8 PSI out of an S/C..
For the simple fact that the boost comes on and stays consistent vs. an S/C where the boost is linear (vs. RPM) and achieved at some max RPM.
I was throwing 800 rwhp out there just as a number. I dont know whats realistic and whats not.
A/C is not a requirement in ohio. I would leave that OFF.
I did not realize you all are fabricating your own exhaust manifolds. I dont know how to weld and usually rely on my uncle for any simple welding needs.
Im also assuming 6-8 PSI out of a turbocharger makes you faster than 6-8 PSI out of an S/C..
For the simple fact that the boost comes on and stays consistent vs. an S/C where the boost is linear (vs. RPM) and achieved at some max RPM.
02-14-2009, 01:42 PM
#5
3rd Gear
Member Since: Feb 2009
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
This is my first time on this website I was looking for some info on what some of you guy's think of turbo set ups so I opened this thread, and I read that mn_vette said "There are no kits out as of yet". So I thought I'd show you guy's this website and see what you think. It's a shop out of New Mexico that does full kit's for Mustang's and and some other car's inclunding C4, C5, C6's here is a link to the kit for the C4 if you want to take a look. http://www.turbochargedpower.com/85-96%20Corvette.htm I myself was looking in to this kit.
02-14-2009, 04:14 PM
#6
Melting Slicks
hey guys,
the HP kit has been reviewed several times, we believe that the very few out there (i can only think of one actual runing kit) had several issues prior to getting the setup to run correctly. the location is poorly thought out, and the quality from HP has been questionable (from most of the mustang guys i know, they tend to stay away from HP). I have not had any direct relations with the company, so i cannot make an option. this is just stuff that i have heard.
I would shy away from the HP kit, do a search on that company here on the C4 FI forum, and you should come up with a lot of threads....
the stock computer on the pre-94' vette's wont recognize boost and are slightly tougher to program... in other words, for any serious power, you're going to have to look into stand alone computers to manage everything.
I no that most serious LT-x guys run AFR or Trickflow (trickflow would be slightly more boost friendly with the larger combustion chambers). "Advance Induction" is an awesome company that will port these Trickflow heads.... Lloyd Elliot is also a reputable vendor....
I am curious to know the goals of the OP?
are you looking to run fast track times, or get 800rwhp? i think you will soon find that the correct combination is more important that just HP numbers.... you're going to start breaking driveline components left and right if you get that 800rwhp to hook (without serious expense to modify these parts). With that said, a big-inch Lt-x with the right heads, cam, etc and a reasonable shop of NOS will definately get you into the 10's or better.... Advance induction has 9 second Lt-x based F-bodies without any weight reduction tricks!
Automatics are much better for turbo applications... the converter and speed of the automatic's shifting ability is better suited to the turbo (keep in mind we are not talking about a stock or even near stock automatic).
go with a 383-396 all motor with a built automatic and correct stall converter (take driving error out of the equation), swap to a live-axle 9".... spray with 200 shot, and see some eye-popping 1/4 mile times.
the HP kit has been reviewed several times, we believe that the very few out there (i can only think of one actual runing kit) had several issues prior to getting the setup to run correctly. the location is poorly thought out, and the quality from HP has been questionable (from most of the mustang guys i know, they tend to stay away from HP). I have not had any direct relations with the company, so i cannot make an option. this is just stuff that i have heard.
I would shy away from the HP kit, do a search on that company here on the C4 FI forum, and you should come up with a lot of threads....
the stock computer on the pre-94' vette's wont recognize boost and are slightly tougher to program... in other words, for any serious power, you're going to have to look into stand alone computers to manage everything.
I no that most serious LT-x guys run AFR or Trickflow (trickflow would be slightly more boost friendly with the larger combustion chambers). "Advance Induction" is an awesome company that will port these Trickflow heads.... Lloyd Elliot is also a reputable vendor....
I am curious to know the goals of the OP?
are you looking to run fast track times, or get 800rwhp? i think you will soon find that the correct combination is more important that just HP numbers.... you're going to start breaking driveline components left and right if you get that 800rwhp to hook (without serious expense to modify these parts). With that said, a big-inch Lt-x with the right heads, cam, etc and a reasonable shop of NOS will definately get you into the 10's or better.... Advance induction has 9 second Lt-x based F-bodies without any weight reduction tricks!
Automatics are much better for turbo applications... the converter and speed of the automatic's shifting ability is better suited to the turbo (keep in mind we are not talking about a stock or even near stock automatic).
go with a 383-396 all motor with a built automatic and correct stall converter (take driving error out of the equation), swap to a live-axle 9".... spray with 200 shot, and see some eye-popping 1/4 mile times.
02-15-2009, 12:38 AM
#7
Safety Car
There is guy or was a guy here with almost my exact setup, which is about 600 fwhp, running high tens. Difference in his setup, it was auto, had slicks and suspension set up for the 1/4 mile. The only reason I would choose to turbo instead of blower is belt slip or lack of. Once you try to get up to higher hp and boost levels you are fighting belt slip issues.
02-15-2009, 03:31 PM
#9
Race Director
Thread Starter
are you looking to run fast track times, or get 800rwhp? i think you will soon find that the correct combination is more important that just HP numbers.... you're going to start breaking driveline components left and right if you get that 800rwhp to hook (without serious expense to modify these parts).
Im just like the rest of you guys. I love to tinker w/ stuff. A 93 C4 vert 6spd (stock bottom end, hotcam/heads, LT headers) is what Ive got to play with. Im tired of seeing cool setups for the C5's while the C4 just gets pushed aside.
02-16-2009, 12:45 AM
#10
Melting Slicks
the c4 did spend a good deal of time in the spot light. i think with this new "wave" of c4 owners we just get the impression that there is no love for the c4. There have been a lot of developers over the years that have tinkered with these c4's and several are still around offering a relatively wide range of aftermarket goods.
the c5 is a superior platform (aside from opinion on appearance or "feel").
it seems as though a decent bottom end build is always well appreciated, so again a 350-383-396 combo is the way to go. I think the highest HP numbers i've seen (on this forum) from an Lt-x based engine is about 480-ish rwhp on pump gas (even this guy was starting to press the limit of the stock drivetrain). that combo was probably good for seriously low 11's and high 10's. the average (high HP NA builds) yield about 450-ish RWHP (hyd. roller cam based builds... haven't seen a solid roller build). The LS-x's (especially big-inch examples) can pump out well over 500 rwhp NA (check out the C5/c6 forums).
I don't believe anything beats the dependability of a solid NA combo. Boosted applications just put more strain on all the components, not to mention they are going to be tougher to keep cool on "any" track. I also don't think the added weight to the front-end would help in your efforts to make a decent "trackable" combo (i mean by adding a turbo or blower).
if you want to keep the IRS for other track events i can understand (it's also why i love the corvette and didn't go F-body etc), but your original post focused heavily on getting your @$$ beat by a 4-banger evo in the straight line. So i figured that was the main intention of the vette' you own.
335's are huge, there are a "few" guys on the forum that have played around with that size tire, and i believe you are going to run into clearance issues. It's also too much tire for an 11 inch rim. 315's (in a number of tire vendors) will do the job (depending on final combo).
the c5 is a superior platform (aside from opinion on appearance or "feel").
it seems as though a decent bottom end build is always well appreciated, so again a 350-383-396 combo is the way to go. I think the highest HP numbers i've seen (on this forum) from an Lt-x based engine is about 480-ish rwhp on pump gas (even this guy was starting to press the limit of the stock drivetrain). that combo was probably good for seriously low 11's and high 10's. the average (high HP NA builds) yield about 450-ish RWHP (hyd. roller cam based builds... haven't seen a solid roller build). The LS-x's (especially big-inch examples) can pump out well over 500 rwhp NA (check out the C5/c6 forums).
I don't believe anything beats the dependability of a solid NA combo. Boosted applications just put more strain on all the components, not to mention they are going to be tougher to keep cool on "any" track. I also don't think the added weight to the front-end would help in your efforts to make a decent "trackable" combo (i mean by adding a turbo or blower).
if you want to keep the IRS for other track events i can understand (it's also why i love the corvette and didn't go F-body etc), but your original post focused heavily on getting your @$$ beat by a 4-banger evo in the straight line. So i figured that was the main intention of the vette' you own.
335's are huge, there are a "few" guys on the forum that have played around with that size tire, and i believe you are going to run into clearance issues. It's also too much tire for an 11 inch rim. 315's (in a number of tire vendors) will do the job (depending on final combo).
02-16-2009, 12:58 AM
#11
Safety Car
the c4 did spend a good deal of time in the spot light. i think with this new "wave" of c4 owners we just get the impression that there is no love for the c4. There have been a lot of developers over the years that have tinkered with these c4's and several are still around offering a relatively wide range of aftermarket goods.
the c5 is a superior platform (aside from opinion on appearance or "feel").
it seems as though a decent bottom end build is always well appreciated, so again a 350-383-396 combo is the way to go. I think the highest HP numbers i've seen (on this forum) from an Lt-x based engine is about 480-ish rwhp on pump gas (even this guy was starting to press the limit of the stock drivetrain). that combo was probably good for seriously low 11's and high 10's. the average (high HP NA builds) yield about 450-ish RWHP (hyd. roller cam based builds... haven't seen a solid roller build). The LS-x's (especially big-inch examples) can pump out well over 500 rwhp NA (check out the C5/c6 forums).
I don't believe anything beats the dependability of a solid NA combo. Boosted applications just put more strain on all the components, not to mention they are going to be tougher to keep cool on "any" track. I also don't think the added weight to the front-end would help in your efforts to make a decent "trackable" combo (i mean by adding a turbo or blower).
if you want to keep the IRS for other track events i can understand (it's also why i love the corvette and didn't go F-body etc), but your original post focused heavily on getting your @$$ beat by a 4-banger evo in the straight line. So i figured that was the main intention of the vette' you own.
335's are huge, there are a "few" guys on the forum that have played around with that size tire, and i believe you are going to run into clearance issues. It's also too much tire for an 11 inch rim. 315's (in a number of tire vendors) will do the job (depending on final combo).
the c5 is a superior platform (aside from opinion on appearance or "feel").
it seems as though a decent bottom end build is always well appreciated, so again a 350-383-396 combo is the way to go. I think the highest HP numbers i've seen (on this forum) from an Lt-x based engine is about 480-ish rwhp on pump gas (even this guy was starting to press the limit of the stock drivetrain). that combo was probably good for seriously low 11's and high 10's. the average (high HP NA builds) yield about 450-ish RWHP (hyd. roller cam based builds... haven't seen a solid roller build). The LS-x's (especially big-inch examples) can pump out well over 500 rwhp NA (check out the C5/c6 forums).
I don't believe anything beats the dependability of a solid NA combo. Boosted applications just put more strain on all the components, not to mention they are going to be tougher to keep cool on "any" track. I also don't think the added weight to the front-end would help in your efforts to make a decent "trackable" combo (i mean by adding a turbo or blower).
if you want to keep the IRS for other track events i can understand (it's also why i love the corvette and didn't go F-body etc), but your original post focused heavily on getting your @$$ beat by a 4-banger evo in the straight line. So i figured that was the main intention of the vette' you own.
335's are huge, there are a "few" guys on the forum that have played around with that size tire, and i believe you are going to run into clearance issues. It's also too much tire for an 11 inch rim. 315's (in a number of tire vendors) will do the job (depending on final combo).
02-16-2009, 01:12 AM
#12
Melting Slicks
bam92- i stand corrected! lol...
Mojave was having fitment issues with the 335's he was running (track tires, must have been a wider contact patch than the Michellins)? are you using the 17x11 zr1's with 50mm offset? I know that Birancunningham is also running 335's but on CCW's.
Mojave was having fitment issues with the 335's he was running (track tires, must have been a wider contact patch than the Michellins)? are you using the 17x11 zr1's with 50mm offset? I know that Birancunningham is also running 335's but on CCW's.
02-16-2009, 01:24 AM
#13
Safety Car
bam92- i stand corrected! lol...
Mojave was having fitment issues with the 335's he was running (track tires, must have been a wider contact patch than the Michellins)? are you using the 17x11 zr1's with 50mm offset? I know that Birancunningham is also running 335's but on CCW's.
Mojave was having fitment issues with the 335's he was running (track tires, must have been a wider contact patch than the Michellins)? are you using the 17x11 zr1's with 50mm offset? I know that Birancunningham is also running 335's but on CCW's.
02-18-2009, 12:44 AM
#14
Race Director
Thread Starter
[QUOTE=mnstrlt1;1568964305]
it seems as though a decent bottom end build is always well appreciated, so again a 350-383-396 combo is the way to go. I think the highest HP numbers i've seen (on this forum) from an Lt-x based engine is about 480-ish rwhp on pump gas (even this guy was starting to press the limit of the stock drivetrain). that combo was probably good for seriously low 11's and high 10's. the average (high HP NA builds) yield about 450-ish RWHP (hyd. roller cam based builds... haven't seen a solid roller build). The LS-x's (especially big-inch examples) can pump out well over 500 rwhp NA (check out the C5/c6 forums).
I don't believe anything beats the dependability of a solid NA combo. Boosted applications just put more strain on all the components, not to mention they are going to be tougher to keep cool on "any" track. I also don't think the added weight to the front-end would help in your efforts to make a decent "trackable" combo (i mean by adding a turbo or blower).
[QUOTE]
mnstr,
I cant get out of my head cars like:
Porsche 959
Ferrari F40
Corvette Sledgehammer (streetable C4 w/ A/C that could outrun an indy car in the straights @ 254.xxx MPH in 1988!)
Streetable Lingenfelter 427TT C5 0-60 in not 3 or 2, but 1.97 seconds (motor trend 06/02 edition)
All of these things are turbocharged and streetable. If you want street-bike beating performance, thats what you need now.
Back in the 90's, a full frame car, high stall converter, big motor, E/T streets, and a 4.11 rear was what you ran if you wanted to be in the 10's. That car was something you trailered in and was good for one thing only. 1/4 mile.
These evo's are driven to the track and smash us C4 owners. There was another evo there that was trapping out at 130+ MPH. Had that thing got a good hook it would have been in the 10's. Sure, its AWD. Put a turbo setup w/ sticky tire and we can overcome that.
it seems as though a decent bottom end build is always well appreciated, so again a 350-383-396 combo is the way to go. I think the highest HP numbers i've seen (on this forum) from an Lt-x based engine is about 480-ish rwhp on pump gas (even this guy was starting to press the limit of the stock drivetrain). that combo was probably good for seriously low 11's and high 10's. the average (high HP NA builds) yield about 450-ish RWHP (hyd. roller cam based builds... haven't seen a solid roller build). The LS-x's (especially big-inch examples) can pump out well over 500 rwhp NA (check out the C5/c6 forums).
I don't believe anything beats the dependability of a solid NA combo. Boosted applications just put more strain on all the components, not to mention they are going to be tougher to keep cool on "any" track. I also don't think the added weight to the front-end would help in your efforts to make a decent "trackable" combo (i mean by adding a turbo or blower).
[QUOTE]
mnstr,
I cant get out of my head cars like:
Porsche 959
Ferrari F40
Corvette Sledgehammer (streetable C4 w/ A/C that could outrun an indy car in the straights @ 254.xxx MPH in 1988!)
Streetable Lingenfelter 427TT C5 0-60 in not 3 or 2, but 1.97 seconds (motor trend 06/02 edition)
All of these things are turbocharged and streetable. If you want street-bike beating performance, thats what you need now.
Back in the 90's, a full frame car, high stall converter, big motor, E/T streets, and a 4.11 rear was what you ran if you wanted to be in the 10's. That car was something you trailered in and was good for one thing only. 1/4 mile.
These evo's are driven to the track and smash us C4 owners. There was another evo there that was trapping out at 130+ MPH. Had that thing got a good hook it would have been in the 10's. Sure, its AWD. Put a turbo setup w/ sticky tire and we can overcome that.
02-18-2009, 01:27 PM
#16
Race Director
Thread Starter
I hope he posts a detailed write up w/ how to and a parts list on this build.
C4 owners, like myself, are getting are a$$zes handed to us by 4 cylinder cars.
02-19-2009, 11:58 AM
#18
Melting Slicks
Just to throw something in there.. about the weakest link on these cars is the rear. I have seen 360-400rwhp C4s snap the hubs multiple times. RUKWKR on this board happens to be one of them, he broke 2 sets I believe. We put a Mcleod Twin Disk in his car and on a drag radial it would instantly snap. Making the power on the dyno is one thing, but going to the track chasing evos is another. Just my .02
02-20-2009, 12:39 PM
#19
Drifting
You bring a good point to the table.
Buy a good electronic boost controller that varies boost (torque) by speed.
No/low boost in first, 7psi in second, 14 in 3rd, and 27 in 4th= no broken parts.
Buy a good electronic boost controller that varies boost (torque) by speed.
No/low boost in first, 7psi in second, 14 in 3rd, and 27 in 4th= no broken parts.
02-20-2009, 10:28 PM
#20
Melting Slicks
It depends on the clutch and how you drive the car. I broke 10 times the parts RUKWKR did with half the horse power. It all depends on how you launch the car.
McLeod twin + clutch drops = broken parts regardless of HP. I could break outer stub axles from a roll if I wanted to with the McLeod twin. It's an awesome clutch, but without a ton of finesse (something I don't have) it will find the next weakest link in the drive train.
The problem with removing the dual mass and installing a clutch like the McLeod, a clutch that has absolutely no give or slip; is that when you drop the clutch, full engine power is applied to the rear end instantly. With all stock parts and at stock ride height, the center line of the rear end is above the center line of the wheels. To put it another way, the axles point down. That angularity is what breaks the parts with relatively modest horse power.
If you can give the car a split second to squat before applying full engine power, the rear end sit down, the half shafts straighten out, and the angularity goes away. The dual mass does a GREAT job allowing the car to move a few inches and squat down before completely locking up and transferring 100% of engine power to the rear end.
If you have the self control and the finesse with your left foot, the McLeod can do the same thing; you just have to slip the clutch via slower release. I tried it with some success, but ultimately I don't have the self control in the heat of battle to rely on a gradual clutch release to keep from breaking my car.
I'm now running a dual friction centerforce and a steel flywheel. At low RPM, the clutch doesn't have much grip, as the RPM increases the clutch grabs harder. This puts some give into the unit and thus far has kept me from breaking parts. However, north of 500 RWHP and you start to push the limit of this clutch. My new combination should test the waters at about 625 RWHP, so I'll let you guys know how this clutch handles ~100 more RWHP than it's supposed to.
McLeod twin + clutch drops = broken parts regardless of HP. I could break outer stub axles from a roll if I wanted to with the McLeod twin. It's an awesome clutch, but without a ton of finesse (something I don't have) it will find the next weakest link in the drive train.
The problem with removing the dual mass and installing a clutch like the McLeod, a clutch that has absolutely no give or slip; is that when you drop the clutch, full engine power is applied to the rear end instantly. With all stock parts and at stock ride height, the center line of the rear end is above the center line of the wheels. To put it another way, the axles point down. That angularity is what breaks the parts with relatively modest horse power.
If you can give the car a split second to squat before applying full engine power, the rear end sit down, the half shafts straighten out, and the angularity goes away. The dual mass does a GREAT job allowing the car to move a few inches and squat down before completely locking up and transferring 100% of engine power to the rear end.
If you have the self control and the finesse with your left foot, the McLeod can do the same thing; you just have to slip the clutch via slower release. I tried it with some success, but ultimately I don't have the self control in the heat of battle to rely on a gradual clutch release to keep from breaking my car.
I'm now running a dual friction centerforce and a steel flywheel. At low RPM, the clutch doesn't have much grip, as the RPM increases the clutch grabs harder. This puts some give into the unit and thus far has kept me from breaking parts. However, north of 500 RWHP and you start to push the limit of this clutch. My new combination should test the waters at about 625 RWHP, so I'll let you guys know how this clutch handles ~100 more RWHP than it's supposed to.
Last edited by neat; 02-21-2009 at 11:28 AM.