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Looking for some advise on where to go next on this build. 1999 FRC M6.
Trying to get the car into the 10's off the bottle as I know once I really start putting the boots to it at the track on the juice, I won't stop unless the bottle is empty.
History:
I just recently swapped out my Dorman LS2 for a Mamofied Fast 102. Gains were roughly 19whp. I know this is in STD and per the internet bragging rights I need to be in SAE, whatever; call it "445hp".
Last time at the track (Fast 102) wasn't good as I was working with a hydraulic clutch slipper and too little tire pressure; bog city. Driver errors, still learning.
Went 11.49@121.75, poor 1.689 and 11.496@121.95 - 1.691 60'. In hindsight I should have aired up the hoosiers and let it roll out. Car would dead hook at 4800-5900rpm and just bog.
Both good passes have a 3000rpm bog after the initial hit. With that data I don't think it'll hit that 10.xx I'm after (I'm anticipating 11.0-1 ish @ 123-5ish on a good clean run. Dyno graph below).
FAST 102. Timing is a bit soft 4600-5200 as I planned on bringing the nitrous in there and wanted a little extra insurance on top of the LNC2000.
Setup is pretty basic:
TSP 228/232 112+2 Cam (.600/.600). Installed dot to dot.
PRC 225 as cast heads. .660 dual spring kit with TI retainers, hollow intake valves, 60cc chambers.
5/16" pushrods (TSP), "LS7" lifters, new trays
Mamofied Fast 102, mamofied 90mm TB, 4" intake, speed density, blackwing intake.
Hinson Longtubes 1-7/8", no cats, 3" exhaust to corsa catback
Drivetrain is pretty decent.
McLeod RST
12mm Torque Tube, DSS couplers, ARP hardware
TR6060 - 13z06
C6Z diff, 3.42 gears - 08z
16x8 Fbody wheels, Hoosier QTP 26x9.5x16,
Heavy Vision 471 sport star skinnies with M&H bias front runners
~3400lbs with driver in track mode.
Car also has nitrous. Hit it one time on the dyno with a lean spike (BAP wasn't activating, that's been fixed). It did 560/513 ramping it in at 4600rpm. That's been fixed and I think it'll be a solid 560 on the 100 pill, can probably grow that up a bit more as I continue to lean on it.
Lately I've been wondering if the cam is the next bottleneck on this setup. That's the point of this thread and ramble. I really want to hit that 10.xx N/A.
With that in mind I should not be lazy, pull the valve cover and toss in checker springs in #1 and see how much room I have and upsize the cam this winter; but to what avail? I have no idea how much is on the table. 5hp? 20hp? The right way would be to pull the head and put in a solid lifter as well, correct?
(On the install I just went off TSP's recommendations and research and stabbed this one in; didn't check PTV as they said it was enough; wish I would have as I would have the numbers here already).
Do I spend the time pulling apart the perfectly fine running combo and go larger on the cam? Worth it to send the heads out for port work and swap lifters out?
Do I spend big bucks on lighter wheels to save some rotating weight? (Probably start with front runners as I'm torn if I want to do spindles and 15's or just be happy with 16's).
Swap out suspension for coil overs? (Some guys can seem to get 1.3-1.4 60's on stockish suspension; I'm hoping for 1.5 60's next time out)
Gut the car to reduce some weight? (Car has full interior, a/c, dual din radio, full street car)
Better exhaust? (Swap long tubes, add cut outs?)
Start to save for forged internals so I can rev it more/hit hit harder with nitrous?
Abort the goal and just start playing with nitrous?
FYI, At the track I'm shifting around 6500rpm, rev limiter 6700. I know the combo wants more RPM; but I don't really want to ask the stock rod bolts for their opinion on that.
I'm "Niterydr" on corvette forum, don't post here much but this seems to be the place where people really pushed the Gen III stuff "back in the day". Trying to get that knowledge here and consolidated after reading a few hours of threads.
Roast away or add input as to how to get a bit more out of here. Bang for the buck ideally as it's at the point I am contemplating building a forged 346-383 with a larger cam or dumping in a larger motor. I don't know why I am so hung up on that 10 second NA Slip but I am. I'm not putting an auto in it.
If it's a track only car, then go with a bigger cam but you really need to rev to 7200-7500 to get the max from a larger cam. If it's street driven the current cam will probably be more responsive at lower rpm.
If it's a track only car, then go with a bigger cam. If it's street driven the current cam will probably be more responsive at lower rpm.
I used to think I liked to drive it on the street, but living in the middle of BFE East Texas I hop in my truck 9 out of 10 times. I'm just not interested in hitting a racoon, turkey vulture, skunk, wild hog, deer, random cow when out driving that car.
So it's slowly becoming just a track toy I pretend to drive on the street.
I would put the money towards 410s. 3.42 and a 2.66 first gear youll need all the rpms and clutch slip to get it to leave ok. The 2.66 first is tough and coupled with a 3.42 there isnt alot of torque multiplication. Im wondering where your shifting at rpm wise, that combo will probably like 7000rpm shifts
From: Coast of San Mateo County Between Pacifica & HMB
I would raise limiter to 7000 and shift @ 6800 minimum.
You have enough power to hit 10.9xx in good conditions with more practice.
Valvetrain is more critical than reciprocating assembly up to about ~7200 RPM.
I wouldn't change the cam unless for a Cam Motion Low Lash Solid Roller.
Check out Darth's threads on his SBE LS1 W LLSR
*Rpm will be slightly less i didnt account for tire growth.
Thanks! I was thinking of potentially going with 3.90's (to account for the project MPH on the spray). I'm sure that versus the 3.42's would help a lot.
I would raise limiter to 7000 and shift @ 6800 minimum.
You have enough power to hit 10.9xx in good conditions with more practice.
Valvetrain is more critical than reciprocating assembly up to about ~7200 RPM.
I wouldn't change the cam unless for a Cam Motion Low Lash Solid Roller.
Check out Darth's threads on his SBE LS1 W LLSR
I'll have to read that one. Think the SBE will hold 7k? Why do I keep reading these tails of them coming apart at 6500rpm, wives tales?
My sbe LS1 (02 TA) went 10.92 at 126 basically full weight with a fast 102 prc 215 and ms4 with 430 gears. I spun it 7100. 02 had Ls6 rod bolts though.
Thanks! I was thinking of potentially going with 3.90's (to account for the project MPH on the spray). I'm sure that versus the 3.42's would help a lot.
With the 4.10s and accounting for growth youre looking at 123mph @ 6400 and 135mph @ 7000. Should be good for 130hp worth of spray at the wheels over na.
Since you're in Texas, You may wish to add meth injection, yes on an N/A car because if you're IAT's are over 112 with the hood closed, the car is pulling 10 degrees timing due to heat soak.
Nitrous entering the intake is not freezing the gas that is injected with it because it is mixing with 100 degree air. Gas freezes at -100 degrees and methanol freezes at -140 degrees. That's why it's used in windsheild washer fluid. Injecting water instead of meth will not freeze either. I did it for years. Your IAT's will drop to around 60-70 degrees.
A huge benefit is that it cleans the heads/pistons at the time you use it. It also adds protection against detonation so there's no issue with running full timing.
Optimizing these 2 things may add as much as 25rwhp. Meth induced IAT temperature drops don't show up on a dyno because the hood is open with cool air being blown in from a fan. Meth injection used in this way is not for HP gains due to octane. You are going to be using WW fluid instead of meth here so the WW tank is not breaking road course rules with washer fluid.
Get a shift light. I know it sounds petty but I know of a member on here that went faster doing so.
113 mph without shift light .
117 mph after shift light.
I shift at 6450-6550rpm. I've actually programmed the 1-4 upshift light as a shift light; but think I can have it come on a bit later. Interest idea though and I have noticed that the car goes faster the higher I shift it.
Since you're in Texas, You may wish to add meth injection, yes on an N/A car because if you're IAT's are over 112 with the hood closed, the car is pulling 10 degrees timing due to heat soak.
Nitrous entering the intake is not freezing the gas that is injected with it because it is mixing with 100 degree air. Gas freezes at -100 degrees and methanol freezes at -140 degrees. That's why it's used in windsheild washer fluid. Injecting water instead of meth will not freeze either. I did it for years. Your IAT's will drop to around 60-70 degrees.
A huge benefit is that it cleans the heads/pistons at the time you use it. It also adds protection against detonation so there's no issue with running full timing.
Optimizing these 2 things may add as much as 25rwhp. Meth induced IAT temperature drops don't show up on a dyno because the hood is open with cool air being blown in from a fan. Meth injection used in this way is not for HP gains due to octane. You are going to be using WW fluid instead of meth here so the WW tank is not breaking road course rules with washer fluid.
"Math" says the static is 11.286:1. DRC is 8.617:1. Cranking pressure is 210+ per cylinder. "Baby" cam problems.
I've thought about potentially looking at meth injection, will read that thread; thanks!
FYI, I have started to experiment with Boostane and noted it'll take 2 degrees additional timing without fuss/knock retard (and picked up 9rwhp on the rollers). Setting it for 99 octane, fairly cost effective race gas. (Ironically it actually took the full 100 shot without timing retard or issue/detonation/knock as I didn't have the correct pulldown set in the promax so the LNC wasn't getting activated; rookie error).
IAT: I'm scooping air from the radiator shroud area and putting it directly on my blackwing. Doesn't show on the dyno but was a big seat of the pants change (and hp tuners confirmed an dynamic airflow increase, when it was MAF and then in straight speed density). IAT sensor is in the filter.
No need to change the cam with a few bolt ons you’ll get there. The 60’ is what needs focus first. You should be able to do 1.50 with what you have but a 15” wheel will make that easier. Then, 3.90 gear and Fidanza aluminum flywheel minimum or just change to a lighter unit altogether. 6800-7200 should be common shift points for a h/c sbe ls1. Remember a little tire spin is better than letting the motor bog down to 2-3k rpms. Last, I’m not sure how much fuel you run with in the tank but try to run with a full tank next outing that weight may not be a bad thing back there when you’re trying to leave hard.
No need to change the cam with a few bolt ons you’ll get there. The 60’ is what needs focus first. You should be able to do 1.50 with what you have but a 15” wheel will make that easier. Then, 3.90 gear and Fidanza aluminum flywheel minimum or just change to a lighter unit altogether. 6800-7200 should be common shift points for a h/c sbe ls1. Remember a little tire spin is better than letting the motor bog down to 2-3k rpms. Last, I’m not sure how much fuel you run with in the tank but try to run with a full tank next outing that weight may not be a bad thing back there when you’re trying to leave hard.
usually 1/4 to 1/2 tank. I do need to work on the 60' and maybe then I'll hit that goal. Just need to figure out the "next step" if it doesn't get there.
Looking for some advise on where to go next on this build. 1999 FRC M6.
Setup is pretty basic:
TSP 228/232 112+2 Cam (.600/.600). Installed dot to dot.
PRC 225 as cast heads. .660 dual spring kit with TI retainers, hollow intake valves, 60cc chambers.
5/16" pushrods (TSP), "LS7" lifters, new trays
Mamofied Fast 102, mamofied 90mm TB, 4" intake, speed density, blackwing intake.
Hinson Longtubes 1-7/8", no cats, 3" exhaust to corsa catback
Drivetrain is pretty decent.
McLeod RST
12mm Torque Tube, DSS couplers, ARP hardware
TR6060 - 13z06
C6Z diff, 3.42 gears - 08z
16x8 Fbody wheels, Hoosier QTP 26x9.5x16,
Heavy Vision 471 sport star skinnies with M&H bias front runners
~3400lbs with driver in track mode.
Car also has nitrous. Hit it one time on the dyno with a lean spike (BAP wasn't activating, that's been fixed). It did 560/513 ramping it in at 4600rpm. That's been fixed and I think it'll be a solid 560 on the 100 pill, can probably grow that up a bit more as I continue to lean on it.
Lately I've been wondering if the cam is the next bottleneck on this setup. That's the point of this thread and ramble. I really want to hit that 10.xx N/A.
I had a lot of fun chasing 10s n/a in my SBE 6 liter. I was able to run a series of 11.0s in good weather with my 226/234 hydraulic roller. At that point, I went to a 235/247 low lash solid roller and went 10.80s. The car basically picked up 2 tenths and 2 mph making the switch. Here is a video of the 3700# tank bullying its way down the track: SBE 6 liter, PRC CNC 799 heads, Vic Jr, 4000 Stall and 3.90 gear. If you want me to create you a faster camshaft, it would be my privilege to help you get to the 10s.
Going from 6500 shift point to 7000+ should yield a tenth and a mph. Your average hp will go up.
Your average hp from start to finish will increase with 4.10s. In the power sooner and finishing at 6400 where you make 460 vs 5500 w/3.42 where you make 440. It should knock atleast 2 tenths off
eliminating the bog will gain pretty good
in my experience i could cut say 1.70 60' dead hooking and bogging then increase tire pressure or launch rpm and spin to a 1.80 but pull a better ET & MPH the whole way down the track. Its all about forward momentum and keeping the nose up.
i would focus on how to get it not to bog even if the 60' suffers it will go quicker. Id say theres atleast another tenth
Time for more Cam? 228/232 SBE LS1 
