LT-5 performance upgrades? - Page 2 - ZR-1 Net Registry Forums

efnfast · 06-29-2017

Just dyno'd at 530 CSHP. Pete did the work. My wife is learning to hate it.
The single mass flywheel makes the tranny noisy when sitting still. Sounds like the engine is coming apart.
I reduced rotating mass, 15# flywheel, light weight pulleys, plus reground cams. The car is lurchy when moving at an idle, like in stop and go traffic or parking lots. This was a side affect I had not anticipated.

secondchance · 06-29-2017

Quote:

Originally Posted by efnfast

Just dyno'd at 530 CSHP. Pete did the work. My wife is learning to hate it.
The single mass flywheel makes the tranny noisy when sitting still. Sounds like the engine is coming apart.
I reduced rotating mass, 15# flywheel, light weight pulleys, plus reground cams. The car is lurchy when moving at an idle, like in stop and go traffic or parking lots. This was a side affect I had not anticipated.

Going back to dual mass and OEM clutch/pressure plate might help. Increasing the idle will help reduce the thump also.

XfireZ51 · 06-29-2017

I think if u want the car to idle like stock, but w a bit more power, then go for the ported top end w headers and exhaust. 400rwhp is nothing to laugh at.

jss06c6 · 06-29-2017

Quote:

Originally Posted by XfireZ51

I think if u want the car to idle like stock, but w a bit more power, then go for the ported top end w headers and exhaust. 400rwhp is nothing to laugh at.

Completely agree, especially at 7,000 rpm!

Sent from my QTAIR7 using ZR-1 Net Registry mobile app

ZR1North · 06-30-2017

I too went with Marc H's 510 three years ago and couldn't be happier with the service or the performance; it's a different car for all the right reasons. I retained the dual mass FW to avoid the noise that Steve referred to, but it still made 416hp at the rear wheels (with the DM FW delete, it is about 490 rather than 510 at the crank). I went with 410s which I think complements the top end work and headers well. It's not a cheap upgrade, but well worth it if you intend to keep the car.

msorenso · 06-30-2017

Pete blessed mine and I am extremely happy with it!

BigJohn · 06-30-2017

Quote:

Originally Posted by efnfast

Just dyno'd at 530 CSHP. Pete did the work. My wife is learning to hate it.
The single mass flywheel makes the tranny noisy when sitting still. Sounds like the engine is coming apart.
I reduced rotating mass, 15# flywheel, light weight pulleys, plus reground cams. The car is lurchy when moving at an idle, like in stop and go traffic or parking lots. This was a side affect I had not anticipated.

Steve keep your rpm up and stay in lower gears longer; you will get used to it.
I have had a single mass flywheel for twenty one years; it only rattles in neutral with the clutch out.

efnfast · 06-30-2017

Quote:

Originally Posted by BigJohn

Steve keep your rpm up and stay in lower gears longer; you will get used to it.
I have had a single mass flywheel for twenty one years; it only rattles in neutral with the clutch out.

I a definatly getting used to it, and not sure I would give up a single hp.
Yes, it only rattles at a standstill with the clutch out.
The hp curves are interesting also, when I dyno'd, my curve continues up until redline. When my brother did his mustang, it peaked and then dropped off as the rpm continued.

XfireZ51 · 06-30-2017

Quote:

Originally Posted by efnfast

I a definatly getting used to it, and not sure I would give up a single hp.
Yes, it only rattles at a standstill with the clutch out.
The hp curves are interesting also, when I dyno'd, my curve continues up until redline. When my brother did his mustang, it peaked and then dropped off as the rpm continued.

One of the beauties of 4V DOHC motors.

WARP TEN · 06-30-2017

Can't add much more but to reiterate what others have said. Marc's work is first class and reasonably priced for what you get. Best initial mods for me have been (on both cars) 4.10 gears, Hurst short shifter, headers and Corsa and on the 95, Marc's 510 package. He is now getting very close to 520 at the crank with his stock cams 350 package, if you opt for everything including the lightweight flywheel. For reasons noted above, I went with the stock dual mass to avoid the trans noise and it was fine. Costs about 15 hp on the dyno but frankly I didn't notice it, as it was so much faster than stock. --Bob

06-29-2017	#11
efnfast Join Date: Nov 2011 Location: Dunbarton NH Posts: 7,451	Re: LT-5 performance upgrades? Just dyno'd at 530 CSHP. Pete did the work. My wife is learning to hate it. The single mass flywheel makes the tranny noisy when sitting still. Sounds like the engine is coming apart. I reduced rotating mass, 15# flywheel, light weight pulleys, plus reground cams. The car is lurchy when moving at an idle, like in stop and go traffic or parking lots. This was a side affect I had not anticipated.

06-29-2017	#13
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,702	Re: LT-5 performance upgrades? I think if u want the car to idle like stock, but w a bit more power, then go for the ported top end w headers and exhaust. 400rwhp is nothing to laugh at. __________________ [SIGPIC][/SIGPIC]Former Membership Chairman Former ZR-1 Registry - BOD 1972 Corvette 4speed base Coupe SOLD long time ago 1984 Corvette Z-51/4+3 SOLD 1992 Corvette ZR-1 Aqua/Gray #474 SOLD 1992 Corvette ZR-1 Black Rose/Cognac #458 2014 Honda VFR Interceptor DX

06-30-2017	#15
ZR1North Join Date: Feb 2007 Location: Komoka, Ontario, Canada Posts: 582	Re: LT-5 performance upgrades? I too went with Marc H's 510 three years ago and couldn't be happier with the service or the performance; it's a different car for all the right reasons. I retained the dual mass FW to avoid the noise that Steve referred to, but it still made 416hp at the rear wheels (with the DM FW delete, it is about 490 rather than 510 at the crank). I went with 410s which I think complements the top end work and headers well. It's not a cheap upgrade, but well worth it if you intend to keep the car. __________________ 1991 ZR-1 (SN666) - Haibeck 510; 410s, Corsa, SW Headers; Hurst SS; DeWitts Rad; RC Injectors; LEDs throughout; `93 MF Sawblades 2016 Z06 - Stock 1971 Stingray 454 LS5 - Sold

06-30-2017	#16
msorenso Join Date: Apr 2013 Location: South Dakota Posts: 85	Re: LT-5 performance upgrades? Pete blessed mine and I am extremely happy with it! __________________ Dr. Pete "Frankenstein's" Ported and Polish combo Cam retiming & Chip Tune Corsa Exhaust No Cat SW Stainless Long Tube Headers MSD Coils DRM Coil Overs Hurst Shifter ZF Doc Beam Plates Center Force Dual Friction

06-30-2017	#20
WARP TEN Join Date: Apr 2007 Location: Lake Bluff, IL Posts: 2,087	Re: LT-5 performance upgrades? Can't add much more but to reiterate what others have said. Marc's work is first class and reasonably priced for what you get. Best initial mods for me have been (on both cars) 4.10 gears, Hurst short shifter, headers and Corsa and on the 95, Marc's 510 package. He is now getting very close to 520 at the crank with his stock cams 350 package, if you opt for everything including the lightweight flywheel. For reasons noted above, I went with the stock dual mass to avoid the trans noise and it was fine. Costs about 15 hp on the dyno but frankly I didn't notice it, as it was so much faster than stock. --Bob __________________ 2016 Long Beach Red Z06 #10281 "POPS Z" 1995 Polo Green #409 "WARP TEN"--Haibeck 350/510 package, 4.10s, Hurst, Stock Exhaust with QTP Cutouts --Sold but still running strong 1993 Quasar Blue #161 "HIL KING" --Sold but still running strong, now with more than 120,000 miles 1967 Marlboro Maroon/Saddle Corvette Coupe 300 hp/4-spd --Sold a long time ago ZR-1 Net Registry Founding Member #95 NCM Lifetime Member Favorite Quote--Attributed to Mickey Thompson: "Too Much Horsepower is Almost Enough"