looking for 600rwhp or more

[mk99z28]

I have a hardtop, 99 Z28 M6 with 82,000 miles, and my plans for it someday is supercharged.. so i need your input for mods so over time I have the correct (internals and bolt-ons)heads, cam, gears, rear end, trans, ect... so i am not spending money twice... list your mods with prices without labor for i will do it with a buddy... the goal here is to have a quick weekend car that will stomp anything its up against.. thanks...

the mods i already have are ls6 intake mani, b&m short shifter, slp loudmouth cat back, slp lid with K&N, msd wires, skip shift eliminater, i might of missed some since the car is in storage ...and thank you all for helping out...

i know its going to be expensive.. but i want it done and done right the first time... i plan on doing the suspension mods after i get the horsepower...

i want to make a plan.. thats why i am asking...and get the right parts together before i rip apart the car... thanks

[qwkgto]

I have a hardtop, 99 Z28 M6 with 82,000 miles, and my plans for it someday is supercharged.. so i need your input for mods so over time I have the correct (internals and bolt-ons)heads, cam, gears, rear end, trans, ect... so i am not spending money twice... list your mods with prices without labor for i will do it with a buddy... the goal here is to have a quick weekend car that will stomp anything its up against.. thanks...

the mods i already have are ls6 intake mani, b&m short shifter, slp loudmouth cat back, slp lid with K&N, msd wires, skip shift eliminater, i might of missed some since the car is in storage ...and thank you all for helping out...

i know its going to be expensive.. but i want it done and done right the first time... i plan on doing the suspension mods after i get the horsepower...

i want to make a plan.. thats why i am asking...and get the right parts together before i rip apart the car... thanks

just bolt on a turbo kit ,upgrade the fuel system,tune and you can get what you want without going to all the parts,mods never end..for the $ turbos are the best way to go. you have left alot on the table what are your goals.

[mk99z28]

just bolt on a turbo kit ,upgrade the fuel system,tune and you can get what you want without going to all the parts,mods never end..for the $ turbos are the best way to go. you have left alot on the table what are your goals.

just want a street car that really gets up and goes... i am not interest in a turbo... i just want to learn how to build my engine with the right mods to someday put on a s/c..

[Richy_Rich67]

well on the headers end your going to want the 1 7/8 size and probabally a bigger inake and throttel bodie prob the fast and nick Williams 92/92

[Richy_Rich67]

really going to need a better rear end not sure on 12 bolt or 9 inch tho or what brand

[mk99z28]

really going to need a better rear end not sure on 12 bolt or 9 inch tho or what brand

what gears do you think i should go with? it will not be s/c for a while but when it is i hope to have the right gears in it already...

thanks

[qwkgto]

Any type of FI cost alot of money,when you have power you dont need alot of gear,you have m6 so you can run alil more gear if you like and still get good gas milage,SC are ok but belts are always an issue have had prochagers,nitrous,turbos are far the best bang for the buck,not trying to start a contriversary,just My opinion.im sure youll be happy with what ever you decide,best of luck with your stomping.

[Richy_Rich67]

ya thats alot of power your going to need some gear just to run the car under the red line I wouldn't go higher than 3:73. You would be able to pull just fine and still be streatable

[rc74racer]

If I were you I'd concentrate on suspension and driveline first or it will suck to drive on the street with that kind of HP. 9in rear 373s or less, clutch, slave, sfcs, etc...make sure the car can handle the HP before you start spending serious $$$ on a forged low compression motor and a supercharger. I wouldn't go FI on any motor with the miles you have without rebuliding first. Heads and cam will all depend on how much power you want and how much money you have.

[mk99z28]

If I were you I'd concentrate on suspension and driveline first or it will suck to drive on the street with that kind of HP. 9in rear 373s or less, clutch, slave, sfcs, etc...make sure the car can handle the HP before you start spending serious $$$ on a forged low compression motor and a supercharger. I wouldn't go FI on any motor with the miles you have without rebuliding first. Heads and cam will all depend on how much power you want and how much money you have.

so do all my suspension mods then go for hp... okay thanks for the info... so should i go with the 9" rear or the 12?

[01ws6er]

so do all my suspension mods then go for hp... okay thanks for the info... so should i go with the 9" rear or the 12?

9" is stronger and you have an M6 so most people tend to shy away from the 12 bolt because the housings can still flex and cause gear whine over time. Moser and Midwest make really nice 9" setups but they are kinda pricey.

And are you looking to SC a stock cube motor or step it up to 400+ci? A forged bottom end would be a good idea to ensure longevity either way.

[mk99z28]

9" is stronger and you have an M6 so most people tend to shy away from the 12 bolt because the housings can still flex and cause gear whine over time. Moser and Midwest make really nice 9" setups but they are kinda pricey.

And are you looking to SC a stock cube motor or step it up to 400+ci? A forged bottom end would be a good idea to ensure longevity either way.

okay so i would go with the 9" with 373s..


well i would like to forge the bottom end but dont know what internals to go with any ideas would help me out a great deal
thanks

[01ws6er]

okay so i would go with the 9" with 373s..


well i would like to forge the bottom end but dont know what internals to go with any ideas would help me out a great deal
thanks

as for gearing, there are some calcs either online or you can go to a rear shop or machine shop and have them spec out the gear ratio you want per the mods you have. 3.73's would probably be in the middle if you have an m6 and most people opt for 4.10's or bigger, but you could always go with 3.90's. Just giving you some options cause in the end it's gonna be your decision.

[rc74racer]

I'd go with a 9in since that seems to be the consensus for an M6. If my goals were 600rwhp and I was going to get there with supercharger I might go even lower than 373s. Something in the 300-33X range would be my preference with that kind of power and the TQ of an SC you really don't need a lot of gear unless you are racing all the time and the lowest timeslip possible is your goal.

[mk99z28]

I'd go with a 9in since that seems to be the consensus for an M6. If my goals were 600rwhp and I was going to get there with supercharger I might go even lower than 373s. Something in the 300-33X range would be my preference with that kind of power and the TQ of an SC you really don't need a lot of gear unless you are racing all the time and the lowest timeslip possible is your goal.

i am putting the supercharger on after i build the motor... so i would think i will be well over 600rwhp, so should i stay with the gears that are in the car already arent they 342s??

everyone says go with the 9 so i will..

thanks for the info..

as for gearing, there are some calcs either online or you can go to a rear shop or machine shop and have them spec out the gear ratio you want per the mods you have. 3.73's would probably be in the middle if you have an m6 and most people opt for 4.10's or bigger, but you could always go with 3.90's. Just giving you some options cause in the end it's gonna be your decision.

but with that much horse and when i get the supercharger 410s wouldnt be the best right... dont i want it lower?

[rc74racer]

If you are really going for 600 RWHP using a SC I would personally go lower than 342s just to make it more street friendly. With a properly tuned SC and the right bottom end and other mods you should have no problem making 600 streetable HP. I think 410s with an SC and that kind of power is too much for the street.

What kind of SC are you considering?

[01ws6er]

but with that much horse and when i get the supercharger 410s wouldnt be the best right... dont i want it lower?

Not really sure... It will rev faster but also be less street friendly and get worse mileage

[stevenm357]

from what a drag racer friend of mine told me with turbos, you want gears that are ( the lower higher confusion always gets me) say 3:23's or smaller those big 4:10 gears are better for naturally aspirated applications.

I'd go with things like lower control arms, torque arm better sway bars. pan hard bar ( I did strano springs etc.)but not everyone wants a lower car. i'd personally choose a turbo, depending how far you want to go, new tubular k-members, a-arms etc.

[Octavain]

Here my two cents on the rear end, I just replaced mine because I broke it drifting and messing around. I replaced the stock with a 9" Moser, so far it seems strong. But putting the beast in was a pain! I got the suppose direct bolt in, uhhh yea... don't ever believe that! Some things you want to take into consideration when doing the swap is the clearance between the axle housing and the rear sway bar, I had to get a spacer kit from Hawks. Fixed the clearance issue I was having. Next problem I incurred was a mystery noise, and I'm not sure exactly what it is, but I think it a adapter piece that Moser gives you to hook your torque arm up to the rear axle. I think that big piece of heavy metal is hitting on what would be under my back seats every time I hit a bump. So I would check more into which 9" you’re thinking about. Also I agree with everyone else you should work on your rear-end and your suspension before going for serious HP.

[Frost]

... I think that big piece of heavy metal is hitting on what would be under my back seats every time I hit a bump. .....

This is the cause, and it will make a floor pan hole before long. One of the guys I tuned fixed his and posted pics, lemme see if I can find em.