1999 FRC LS7 Swap
#1
Melting Slicks
Thread Starter
1999 FRC LS7 Swap
Starting this as a placeholder for recording work I've built so many cars that the details are starting to get fuzzy between them. I am also not as well versed on the C5 chassis as other cars and this may potentially help avoid some simple mistakes from other posters more versed than I am.
I bought a "one owner corvette" that needed some work. Some being the transmission not staying in reverse and needing to hold the shifter handle to stay engaged. Turns out every gear has issues and the "corvette expert" he had do the clutch didn't do a great job and there's some serious driveline vibration and chatter.
The interior was also disgusting, blood, spit, cig smoke but that's a thread for another day.
I decided with how much work it is to drop the torque tube, do the clutch, and rebuild the transmission I'd build another motor "while i'm in there". Since the car is also a turd, it's pretty gutless below 4k and even adding H/C/I won't do what a 4" stroke crank will.
So I built a hybrid LS3/LS7 engine with mostly new parts, bought a low mileage pull apart LS7 and used a new LS3 production block. Listed for sale here, until I have everything to swap, including motivation.
https://www.corvetteforum.com/forums...ong-block.html
For this that don't want to click, here it is
New LS3 block
Alper Head and Main studs
Stock LS7 Crank and Ti Rods with 24x reluctor balanced to within 1.5g
Custom Racetec-Autotec Forged pistons 4.065 Bore for use with LS7 crank/rods
Hastings rings
Clevite 77 Moly Coated Race bearings
Stock LS7 Cam with ARP hardware
LS2 Cam gear
Morel Link Bar street lifters
Comp pro magnum rockers 1.8
Lingenfelter CNC LS3 Heads with Ferrea SS Valves
BTR .660 Spring kit with Ti Hardware
BTR Single piece chromoly pushrods .080 wall
GM MLS Head gaskets
Stock LS7 Oil Pump, windage tray, oil pan, valley cover and front/rear covers
ATI Balancer and ARP Crank bolt
Stock LS7 Manifolds and Cats
It was really important that I pass smog, retain stock driveability and still have great fuel mileage with dry sump and air conditioning. I still plan on adding the Improved Racing sump baffle and crank scraper.
I just dropped off the LS7 manifolds for black ceramic and I'm still looking over options for an intake. With what used factory LS3 manifolds are going for, I may just run a fast LSXR.
Since I am really tired of spending my weekends wrenching I nabbed this for cheap to build up and assemble first, before the car comes apart. I'll keep it simple replace worn parts, billet keys, steel shift forks, bronze pads, carbon blocker rings, and hardened input shafts in the diff, or what other trans builders call a stage 7 . I will also track down an 01+ torque tube to go through
So far the plan is to build it all separate, so I can continue to drive the car, then assemble it all as one piece and do the swap in a single day and sell what comes out. I also plan on putting the dry sump tank in the drivers side fender as opposed to the common passenger side mount which has to move the battery. I figure with this way, the hardest thing will be extending the fill neck and adding a dipstick to the ARE dry sump tank. I am also torn on using SS braided lines with spring inserts for the dry sump plumbing, or to use all SS hard line to reduce cost.
For anyone curious this is the turd in question
I bought a "one owner corvette" that needed some work. Some being the transmission not staying in reverse and needing to hold the shifter handle to stay engaged. Turns out every gear has issues and the "corvette expert" he had do the clutch didn't do a great job and there's some serious driveline vibration and chatter.
The interior was also disgusting, blood, spit, cig smoke but that's a thread for another day.
I decided with how much work it is to drop the torque tube, do the clutch, and rebuild the transmission I'd build another motor "while i'm in there". Since the car is also a turd, it's pretty gutless below 4k and even adding H/C/I won't do what a 4" stroke crank will.
So I built a hybrid LS3/LS7 engine with mostly new parts, bought a low mileage pull apart LS7 and used a new LS3 production block. Listed for sale here, until I have everything to swap, including motivation.
https://www.corvetteforum.com/forums...ong-block.html
For this that don't want to click, here it is
New LS3 block
Alper Head and Main studs
Stock LS7 Crank and Ti Rods with 24x reluctor balanced to within 1.5g
Custom Racetec-Autotec Forged pistons 4.065 Bore for use with LS7 crank/rods
Hastings rings
Clevite 77 Moly Coated Race bearings
Stock LS7 Cam with ARP hardware
LS2 Cam gear
Morel Link Bar street lifters
Comp pro magnum rockers 1.8
Lingenfelter CNC LS3 Heads with Ferrea SS Valves
BTR .660 Spring kit with Ti Hardware
BTR Single piece chromoly pushrods .080 wall
GM MLS Head gaskets
Stock LS7 Oil Pump, windage tray, oil pan, valley cover and front/rear covers
ATI Balancer and ARP Crank bolt
Stock LS7 Manifolds and Cats
It was really important that I pass smog, retain stock driveability and still have great fuel mileage with dry sump and air conditioning. I still plan on adding the Improved Racing sump baffle and crank scraper.
I just dropped off the LS7 manifolds for black ceramic and I'm still looking over options for an intake. With what used factory LS3 manifolds are going for, I may just run a fast LSXR.
Since I am really tired of spending my weekends wrenching I nabbed this for cheap to build up and assemble first, before the car comes apart. I'll keep it simple replace worn parts, billet keys, steel shift forks, bronze pads, carbon blocker rings, and hardened input shafts in the diff, or what other trans builders call a stage 7 . I will also track down an 01+ torque tube to go through
So far the plan is to build it all separate, so I can continue to drive the car, then assemble it all as one piece and do the swap in a single day and sell what comes out. I also plan on putting the dry sump tank in the drivers side fender as opposed to the common passenger side mount which has to move the battery. I figure with this way, the hardest thing will be extending the fill neck and adding a dipstick to the ARE dry sump tank. I am also torn on using SS braided lines with spring inserts for the dry sump plumbing, or to use all SS hard line to reduce cost.
For anyone curious this is the turd in question
Last edited by Shaolin Crane; 10-28-2017 at 11:17 PM.
The following 3 users liked this post by Shaolin Crane:
#2
Safety Car
Here are some threads I have read on the rear rebuild.
https://www.corvetteforum.com/forums...-z06-guts.html.
https://www.corvetteforum.com/forums...ld-how-to.html
I will probably end up getting a diff from RPM after reading all that. http://www.rpmtransmissions.com/page8.html
https://www.corvetteforum.com/forums...-z06-guts.html.
https://www.corvetteforum.com/forums...ld-how-to.html
I will probably end up getting a diff from RPM after reading all that. http://www.rpmtransmissions.com/page8.html
#3
Melting Slicks
Thread Starter
Here are some threads I have read on the rear rebuild.
https://www.corvetteforum.com/forums...-z06-guts.html.
https://www.corvetteforum.com/forums...ld-how-to.html
I will probably end up getting a diff from RPM after reading all that. http://www.rpmtransmissions.com/page8.html
https://www.corvetteforum.com/forums...-z06-guts.html.
https://www.corvetteforum.com/forums...ld-how-to.html
I will probably end up getting a diff from RPM after reading all that. http://www.rpmtransmissions.com/page8.html
I'm trying to avoid letting this snowball into the $$$$$ range. The trans on the other hand I'll do everything short of a viper shaft as I won't be putting down anywhere near the power to justify the cost and work. It'll never see a clutch dump and I only run NT01s at the track, but after the dry sump I plan to move to Hoosiers.
#4
Safety Car
It is probably a good idea to rebuild an '01-'04 torque tube for the build.
I was wondering about the carbon clutch disk too.
Zr1 shafts aren't that much more than the Z06 ones.
I have never been able to keep a project car in budget. If your gonna do this you might as well do that and while you have it apart you might as well change the thingy...
The engine looks pretty b/a.
I was wondering about the carbon clutch disk too.
Zr1 shafts aren't that much more than the Z06 ones.
I have never been able to keep a project car in budget. If your gonna do this you might as well do that and while you have it apart you might as well change the thingy...
The engine looks pretty b/a.
Last edited by Rob 02; 10-29-2017 at 02:59 AM.
#5
Melting Slicks
Thread Starter
It is probably a good idea to rebuild an '01-'04 torque tube for the build.
I was wondering about the carbon clutch disk too.
Zr1 shafts aren't that much more than the Z06 ones.
I have never been able to keep a project car in budget. If your gonna do this you might as well do that and while you have it apart you might as well change the thingy...
The engine looks pretty b/a.
I was wondering about the carbon clutch disk too.
Zr1 shafts aren't that much more than the Z06 ones.
I have never been able to keep a project car in budget. If your gonna do this you might as well do that and while you have it apart you might as well change the thingy...
The engine looks pretty b/a.
I'm actually pretty good about keeping stuff under budget and breaking even with what comes out. 300m shafts aren't that much more than the Z setups and I don't have to change the spider gears, so it's pretty close to even.
Last edited by Shaolin Crane; 10-29-2017 at 03:29 AM.
#7
Melting Slicks
Thread Starter
Yes I know, but I'm certain the guibos in mine are trashed and there's no need for them IMO. Billet ones won't break again and beefing up the trans and diff allow me to run two instead of one.
#8
Safety Car
I have only read about them and it seems like having billet on bout ends is not the way to go. I have heard good things about the DSS poly ones. Maybe billet in the rear and poly in the front.
The poly Prothane Six Shooter and non GM rubber ones have gotten bad reviews for not lasting long.
The poly Prothane Six Shooter and non GM rubber ones have gotten bad reviews for not lasting long.
#9
Melting Slicks
Thread Starter
I have only read about them and it seems like having billet on bout ends is not the way to go. I have heard good things about the DSS poly ones. Maybe billet in the rear and poly in the front.
The poly Prothane Six Shooter and non GM rubber ones have gotten bad reviews for not lasting long.
The poly Prothane Six Shooter and non GM rubber ones have gotten bad reviews for not lasting long.
I can see how using billet pieces would increase strain on weak parts of the drivetrain, which will be addressed anyhow.
#12
Melting Slicks
Thread Starter
I don't need to reinvent the wheel on this, the T56 setup works perfectly after some tweaks. Nor am I interested in trying something out that hasn't been out long enough to know if there's potent issues with.
#13
Drifting
Good luck with the build, I'll be following.
#15
Sounds like quite the project. GL.
#16
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Looking forward to following your build as you move along with the project.
#17
Melting Slicks
Thread Starter
So I spent most of the day pricing out what I will need for the diff rebuild since I'm waiting for a price quote on parts for the transmission, my transmission guy will build the trans for me and do his magic while I do the diff.
Parts for the stock unit are stupid expensive and I really don't see why, and with how I drive the clutches might last a year at most. Carbon clutch packs are almost $500, plus bellville washers, Z06 spider for the upgraded output shafts and it's nearly a grand just to reuse the stock parts.
There's three diff options
The Eaton LSD, clutch style but a much better design and includes 4340/300M Output shafts for ~$550 which is the cheapest option.
Quaife and Wavetrac, both worm gear style and both around ~$950, which I would prefer since they are pretty much a lifetime kinda deal. No clutches to wear out and the Wavetrac has a lifetime warranty. Both would require 300m shafts but I wouldn't have to buy new spiders.
The thing that I am unsure about is the technical specs for the Quaife and Wavetrac. I am a little unclear about how the input shafts are retained in the housing, I would assume they are to be split open, shafts slid in and the c clips holding them in place, but I don't like to assume. I didn't get a chance to ask my trans guy as another customer walked in and I had to leave anyhow.
Parts for the stock unit are stupid expensive and I really don't see why, and with how I drive the clutches might last a year at most. Carbon clutch packs are almost $500, plus bellville washers, Z06 spider for the upgraded output shafts and it's nearly a grand just to reuse the stock parts.
There's three diff options
The Eaton LSD, clutch style but a much better design and includes 4340/300M Output shafts for ~$550 which is the cheapest option.
Quaife and Wavetrac, both worm gear style and both around ~$950, which I would prefer since they are pretty much a lifetime kinda deal. No clutches to wear out and the Wavetrac has a lifetime warranty. Both would require 300m shafts but I wouldn't have to buy new spiders.
The thing that I am unsure about is the technical specs for the Quaife and Wavetrac. I am a little unclear about how the input shafts are retained in the housing, I would assume they are to be split open, shafts slid in and the c clips holding them in place, but I don't like to assume. I didn't get a chance to ask my trans guy as another customer walked in and I had to leave anyhow.
Last edited by Shaolin Crane; 10-30-2017 at 10:08 PM.
#18
Melting Slicks
Thread Starter
So with more reading i'm fairly certain I'm going to try the Eaton Tracaide, seems to do well in the Corvettes and with the more than $1000 in savings in running it I can satisfy the cheap **** inside of me, and since it's a 3 gear spider setup it should be a few years before it actually needs to be rebuilt and to be honest, with how I drive i'll probably break something else in the drivetrain before then anyhow.
Last edited by Shaolin Crane; 10-31-2017 at 03:02 AM.
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ArmchairArchitect (10-31-2017)
#20
Melting Slicks
Thread Starter