Independent1

Have a 99 FRC. Motor is stock right now. Plan to do a heads/cam this winter.

Want to know how well these non-forged motors hold up to the demands of HPDEs?

Any suggestions for improving reliability?

Thanks

jlucas

They hold up very well which is one of the reason I bought mine.

BTW, if lots of HPDEs are in your future, your head & cam work will be money wasted IMHO. Spend the money on more track time/instruction and you'll get more out of it than if you bought cams.

Cobra4B

79,xxx on my LS6, put the cam in at 70k, they're awesome motors.

davidfarmer

The 97-00's have weaker rod bolts than the 01-up engines. Your 99' is safe up to 6500rpm, the newer engines up to 6900rpm sustained.

I would suggest you put the new style rod bolts and a JWIS timing chain in when you do your mods. One of the points of doing heads/cam is more breathing and more rpm, so you need all of the overhead that you can get. Camming a car and keeping it below 6500rpm is really a waste in my opinion.

btw, the rod bolts are really cheap, and totally bolt right in. JWIS is also bolt on, and you don't need to change the sprockets. Thunder racing has them.

Cobra4B

Wrongo Check my latest dyno graph w/ my cam:



I have more torque and power accross the board w/ a cam that supposedly only makes high end power. It starts to fall off after 6600 rpms. On track I shift by ear between 6000-6500 as I'm not "racing".

John Shiels

H&C help a bunch. I redline at 6700 and make 450 RWHP. I usually shift at 6500. Huge gain over a stock motor. I would add a big radiator and oil cooler.

95jersey

I ran an aggressive G5X3 cam only on my LS6 with nothing more than the cam, appropriate valve train, dual roller timing chain, high flow oil pump, thermostat and ran 423RWHP. This was with stock heads, but headers and open exhaust.

If I were in your shoes, I would personally try to find a used set of LS6 heads, LS6 intake, and put a G5X3 cam in the car. You will save big money over a complete H&C package, get very simliar performance (within 10hp) and have a couple thousand left over for brakes or suspension mods!

I think my G5X3 installed with the parts above and tune was just a little over $2000. Also, they need to take the radiator out to install the cam, so it is a good time to replace with a dual oil/radiator combo unit and not pay for any additional labor. Bottom line, be smart, do your research and use every last dollar to your advantage. Most H&C packages are $5000. For that kind of money, I could put in the above cam, new radiator, new shocks, sway bar and corner weight, and be within 10-15hp of a H&C car with much better handling. Or you could buy a set of Wilwoods with the money left over!

96CollectorSport

With the long runners on the LS6 intake they will always make there best power between 6000 and 6500 rpm. It's just the nature of the intake, you can still make power but your peak is still somewhere in that range. The only point of spinning a LS motor (even the LS7) past 6500 is so you don't have to shift coming up to a corner.

Independent1

^^Thanks. I have the $$ to do both. I agree you get more bang for the buck by learning how to drive than from engine mods.

Independent1

^^I follow your exploits regularly. Great car you have put together!!

Independent1

^^I had read about the weak rod bolts and was thinking of going with some ARPs. What do you think of them?

Excuse my ignorance, but what is a JWIS timing chain? I had figured on putting in a new timing chain, as well a ported LS6 oil pump. I have seen posts that recommend LS2 timing chain.

In terms of power, I am looking for gains across the entire RPM range.

I ran across this dyno at LG motorsports. Car has a LG G5X3 cam and LG LT headers, which is an option I was leaning toward. Pretty impressive numbers.

Independent1

^^Any suggestions. I have been looking at these also. Seems like Dewitts and Ron Davis on the big names for radiators.

I have read that it is better to have a separate EOC because it provides better cooling. At least that seems to be the theory. Could not find a lot of evidence to back this up. The guys over in FI were talking a lot about this, especially those with turbos.

davidfarmer

Wrongo is "wrongo". You are still making lots of power at 6500, and you are putting more torque to the ground in the lower gear revving higher, than by short shifting.

I understand you are running conservatively, but even the T1 racers (running stock LS6's) shift at over 7000rpm because they go faster that way.

Put those numbers in a spread sheet, speed vs wheel torque, and you'll see how much you are missing.

But to clearify, I did mis-speak. You can make more power without shifting higher, HOWEVER the greatest gains are made if you let the engine rev higher.

96CollectorSport

There is a lot of information on LS1tech, it's easy to get overwhelmed, best option is to talk to people that put packages together for roadracing, LG, DRM etc. They know what will last under the strain of HPDE's.

If you do wander over to LS1tech remember most of those guys are drag racing so a lot of the big numbers they put out with "just a cam" or "just brand X head" is being pushed too far fot DE's.

Personally I wouldn't go nut's with the cam something under .600" lift and around 224 to 226 duration with a good set of heads will make good power and be reliable. Make sure you install good springs, PSI makes some awesome springs, and upgrade the timing set. The LS2 chain has a great reputatuion, also a chian dampener will help the life of the chain.

With extra power will come extra heat so an add on oil cooler is a must, and like 95jersey said you have to take the radiator out anyway so a DeWitt's of a Ron Davis from DRM would bw a great idea.

If you can try to see as many dyno graphs of a combo before you decide, the smoother the tq line is the better it will be for the track, you don't want big dips or sudden rushes of power. The graphs will show you what your butt feels.

davidfarmer

JWIS is a brand. It is a heavy duty chain that works with the stock timing gears, so it is a much easier bolt on.

http://www.thunderracing.com/catalog...d=349&pcid=222

Independent1

^^Good advice. I have read that a set of ported LS1 heads will easily outflow the stock LS6 heads. While it's probably a little more expensive than buying a used set of LS6 heads it could turn out to be a good investment.

Did you use the stock rocker arms or did you upgrade?

I am definitely trying to do this on a modest budget. I am lucky that my brother is very good with cars and will help me. So my labor costs are pretty low. Really only foresee having to pay for tune and to get suspension set-up.

Will be puttiing on Pfaadt coilovers, VBP bushings, and some other suspension goodies. I have the DRM stainless steel Z06 brakes that I am going to install also.

Going to be really busy this winter.

Independent1

^^I was planning upgrading to an LS6 intake. Good point about shifting points. I don't want to overstress motor since it's not forged. Like to have a little margin of safety.

96CollectorSport

David,

I have seen the T1 cars running at Road America and they do run some fast a$$ times but they also replace motors at the end of each year.

Spinning a motor that high for DE's just doesn't make sense, better to make the power lower and keep the rev's down and run the motor for a few years.

Independent1

^^Thanks. I will look into this.

I appreciate the advice.

96CollectorSport

Here is a pic of the LS2 chain vs the stock LS6 chain, you can use the stock gears with the LS2 chain as well. It's just bigger. Plus they are around $35.



oops that was a little big.