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Mantic Twin makes a nice set up they also have a light weight steel and aluminum flywheels. Do not go to light on flywheel - beware of drivability is for nerds as you will wish you were a nerd if you get stuck on a hill at a light in stop and go traffic - stick with a clutch / flywheel set up that weighs at least 40 pounds. OEM is 56 pounds and is a little heavy I think Mantic has a 24 pound steel flywheel and the clutch itself weighs 18-20 pounds so that gets you in the low 40s. One thing nice about a steel flywheel is you do not have to heat it up to get it on (expansion issues).
Can't believe I did it! I don't think I broke anything either but we'll see how long that lasts. YouTube and some wrenches is a hell of a drug
With Black Friday nearing I think I'm going to purchase a clutch as it makes way more sense to not labor over this again just because I was impatient and wanted to get this thing going asap. Buy once, hopefully only cry once. Friend helped me pick out the McLeod RXT Twin disk clutch. Probably going to go with the aluminum flywheel because drivability is for nerds! Open to ideas also.
If you have a suggestion for pilot bearing styles and anything else to replace while I'm in the area do let me know, thanks!
Did I misunderstand something? The motor in the pics has cathedrals, but you're running an LS7 intake?? Or, is the motor in the pics the old motor??
Mantic Twin makes a nice set up they also have a light weight steel and aluminum flywheels. Do not go to light on flywheel - beware of drivability is for nerds as you will wish you were a nerd if you get stuck on a hill at a light in stop and go traffic - stick with a clutch / flywheel set up that weighs at least 40 pounds.
Out of curiosity, I checked if the RXT had sprung clutch discs. The information I found said that they were solid discs. That's a mistake on a street car, IMHO. I was running an RPS Billet Carbon twin disc in my LS3 Miata for a while, with an aluminum flywheel, total weight 25#. The driveability **sucked**. Not only was the combination light enough that getting even my ~2400# Miata moving was a bit sketchy, but the unsprung discs caused a **lot** of NVH around 1800 rpm ... so bad that I avoided cruising in 4th gear between 1600 and 2000 rpm. Replaced with a Mantic twin disc setup (still only 32# total weight) and those problems are **gone**. For a 'Vette or other normal sized car, the recommendation to stick with a 40# minimum weight setup is probably a very good one.
RXT is a good clutch. Aluminum flywheel will be good.
Originally Posted by Double06
Mantic Twin makes a nice set up they also have a light weight steel and aluminum flywheels. Do not go to light on flywheel - beware of drivability is for nerds as you will wish you were a nerd if you get stuck on a hill at a light in stop and go traffic - stick with a clutch / flywheel set up that weighs at least 40 pounds. OEM is 56 pounds and is a little heavy I think Mantic has a 24 pound steel flywheel and the clutch itself weighs 18-20 pounds so that gets you in the low 40s. One thing nice about a steel flywheel is you do not have to heat it up to get it on (expansion issues).
Originally Posted by grubinski
Out of curiosity, I checked if the RXT had sprung clutch discs. The information I found said that they were solid discs. That's a mistake on a street car, IMHO. I was running an RPS Billet Carbon twin disc in my LS3 Miata for a while, with an aluminum flywheel, total weight 25#. The driveability **sucked**. Not only was the combination light enough that getting even my ~2400# Miata moving was a bit sketchy, but the unsprung discs caused a **lot** of NVH around 1800 rpm ... so bad that I avoided cruising in 4th gear between 1600 and 2000 rpm. Replaced with a Mantic twin disc setup (still only 32# total weight) and those problems are **gone**. For a 'Vette or other normal sized car, the recommendation to stick with a 40# minimum weight setup is probably a very good one.
So I got jay saying go for the RXT w/ aluminum flywheel but 006 and Grubinski saying no RXT and definitely no aluminum flywheel.
Choices, choices....
I don't plan to get stuck on hills, I took the wrong route to Sonoma Raceway once.... it sucked especially when packed to the brim with radials and a jack lol.
If the aluminum flywheel makes it genuinely undrivable even in a significantly lighter car I will have to do some hard thinking. I don't care too much for the NVH, this car is getting straight pipes and CHP can blow me
I might just have to bite the aluminum bullet to find out. How else does one learn? Drivetrain needs to come out shortly after getting the car running anyways so I can run through it all as well....
Russdawd1,
Has HPR ever had any problems running stock style LS7 rocker with Brodix heads? I take it you shouldn’t have any guide issues?
I’m just trying to learn. I’m really not trying to pester you with dumb questions.
thanks,
jimbo
No probs, I'm just trying to learn too
These BR7 heads are the ones that accept the factory style rocker (I bet you could use ls3 rockers if you wanted to for less lift).
I know some of the other BR7 models accept a custom or shaft mount rocker that is different and more expensive. I believe its these: CROWER 74164F
As far as I was told, almost all aftermarket LS7 heads are without the guide issue. GM just really dropped the bag on the manufacturing of the stock LS7 heads.
If you are doing a lot of road racing a dry sump (and you have blown two motors) - even the C6 Z06 one may be your answer. If you are worried about oiling issues with C5 pan there is a reason GM went to the dry sump on the C6 LS7. It may not be the best dry sump in the world but it is better than what you got. If you do go that route you might want to go with the 2009 and later set up (oil pan and tank) which has the 10 quart dry sump tank. You will need to move your battery to trunk which is a bonus for road racing guy.
If you are doing a lot of road racing a dry sump (and you have blown two motors) - even the C6 Z06 one may be your answer. If you are worried about oiling issues with C5 pan there is a reason GM went to the dry sump on the C6 LS7. It may not be the best dry sump in the world but it is better than what you got. If you do go that route you might want to go with the 2009 and later set up (oil pan and tank) which has the 10 quart dry sump tank. You will need to move your battery to trunk which is a bonus for road racing guy.
I'm not worried about the oiling issues with the C5 pan, I bought it specifically the remedy the C6 pan that failed me. In the future I'm definitely open to swapping to a dry sump, but it just wasn't in the cards for this stage of the build where a wet sump that will be avoiding tracks for the time being will suffice. But noted!
Like I was telling Jay, car is still just being moved along by me and eventually I'll decide what I want to do. Hence why a lot of my build is just figuring stuff out as I go. No real solid plan besides GET CAR RUNNING
I've bought a bunch of LS2 shortblocks all with rod knocks.... GTO and Corvette. I don't know why they have this issue. Luckily most have just needed a couple rods and rings/bearings. A couple have needed a new crankshaft.
I run the RXT plus aluminum flywheel in my 416/LS7 small bore headed (600rwhp or so) 2900lbs with a/c RX-7 road race/street car and my '69 Chevelle with 1000rwhp (not tuned yet) turbo LS ProTouring setup (1200HD RXT version) without issues. Yes at 1800-2000rpm if you lug the engine in a gear or two higher than needed and tip into the throttle barely....
you can get engine harmonics/vibrations which rattles the clutch discs.... if you actually try to do it.... just don't do it. Upshift a gear... On the freeway I cruise around 2200rpm+ anyway (75mph+). Bang for the buck they are great clutches. Low effort pedal pressure and really non grabby (need to break them in properly) even the 1200HD version.
I've bought a bunch of LS2 shortblocks all with rod knocks.... GTO and Corvette. I don't know why they have this issue. Luckily most have just needed a couple rods and rings/bearings. A couple have needed a new crankshaft.
I run the RXT plus aluminum flywheel in my 416/LS7 small bore headed (600rwhp or so) 2900lbs with a/c RX-7 road race/street car and my '69 Chevelle with 1000rwhp (not tuned yet) turbo LS ProTouring setup (1200HD RXT version) without issues. Yes at 1800-2000rpm if you lug the engine in a gear or two higher than needed and tip into the throttle barely....
you can get engine harmonics/vibrations which rattles the clutch discs.... if you actually try to do it.... just don't do it. Upshift a gear... On the freeway I cruise around 2200rpm+ anyway (75mph+). Bang for the buck they are great clutches. Low effort pedal pressure and really non grabby (need to break them in properly) even the 1200HD version.
Thanks for the info! Feels nice to be reaffirmed about the LS2 issues
Will add this to the box of considerations. It sounds like both of your cars are more track use than street use, any comment on how they are with trying to daily it every once in a while?
Things on the list are:
Starter (or maybe just the solenoid)
Billet Throwout Support
Clutch/FW (Obviously)
Fuel Rail
Injectors (Undecided at the moment, I like the idea of ID1050x as they hold their resale pretty good)
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