is my car too slow?

Comp HR's have extremely steep ramps, and NEED significantly stronger springs than what the catalog recommends. Once this issue is addressed, it will rpm on up close to 6500. A good set of beehives from PAC will also give you more rpm range.

PAC is who used to supply Comp with beehives... before Comp cheaped out and started using springs from overseas.

PAC Racing

There is more in the combo as is with a little tuning. Try shifting it about 5900-6000 instead of going higher. The tires appear to have too much air judging from this pic. http://bowtie0069.fotki.com/2008-irw...x/img7031.html Try lower pressure and leaving at a higher RPM.
If you don't want to fight the Thursday night crowds,Irwindale has a T&T day on Sunday,June 29,or you can run T&T at this Sunday's(June 8) Summit races.Maybe I'll see ya there?

Wow Jim, impressive research to find that photo! Yeah, that was a red light and that run just sucked overall. Next I dropped the air pres to 20lbs, did a 2nd gear burn, and ended up with my best 60foot and et of the night.

Next week I am hoping that the private track day at Fontana will happen on Friday. There I can do 10 or more runs and really get this going. If not back to Irwindale on Thurs.

After the dyno run yesterday, I see that I am shifting a bit high, so, good advise to bring it down a little.

The best launch, was at 3500, I will try 4500 and 5000 and see if I can get it to stick. Wheels up right!!??

On the valve springs: they came with the heads. I had them on my 302 for about 500 miles. When I did this motor I had them checked by Jim Grubbs shop. If they pass inspection can they still be wrong?

I am going to check the timing again as it might have moved, which my friend pointed out that the gear may have worn out already.

Thanks or all the good points.

If you are using the standard AFR 185 dual springs, they are recommended for flat tappet cams. Comp Xtreme hydraulic roller cams need MUCH more valve spring to control the ramp rates and weight of the roller valvetrain.

n2omike is right on about PAC having the correct springs for your application.

Your 60foot is not to good. That is what is making you slow.

Put the tire pressure down to about 18psi. Do a good burnout in second gear.

Stage the car at 3000 rpm. Go on the thrid yellow bulb to cut a light.

If you feel it spin then feather it out of the hole.

You need to try and get better than 1.90 60' I'd say in the low 1.80's or even 1.70's with a light car like you have.

JustJim is a good guy to meet up at the track with. I'm sure I'll see you up there once I get my car back together. Shouldn't be too much longer.

At LACR (R.I.P.) I ran a 8.38 second 82.26 mph 1/8 mile with a 1.84 sixty foot. Corrected for altitude it should be pretty close to what you ran at Irwindale. That was with an about 3,000 lbs with driver '65 mustang, a very mild 300'ish flywheel hp 289, T5, and slicks. You certainly have more left in what you've got. But, that always seems to be the case with a new combo.

Jim Grubbs Motorsports (JMG) has a VERY good reputation around here. Did they say the springs were fine for your cam or that they were still within spec for what AFR advertises them at? Big difference.

There is a lot of debate on just how much spring pressure you can throw at a SADI (selectively austempered ductile iron) core cam. My opinion is that Comp suggests less spring due to the core material and not due to what the lobe requires in cases like these. They are no dummies and certainly have a reason for what they recommend. Giving the lobe the spring that it needs can be too much for the SADI core. Billet core is a different story.

I think the tires will be happier between 12 and 14 psi. My 26x8 slicks like 15psi. Larger tires like less air. You should be able to tell by the surface of the tire. It should be roughed up evenly across the tire. Smooth on the edges means too much air. Smooth in the middle means not enough.

Karguy,

If you would like to compare, I'm posting my combo and you can draw your own conclusions? The results below was my best run at Irwindale back on April 10

67 Fairlane, all steel @3440lbs w/ me in it, 347, Edelbock RPM heads and manifold (out of the box), MSD dizzy and 6AL all in by 3,000RPM, Hooker Comps, Holley 650 VS, Sharp roller rockers, C-4 w/ Hughes 3,000 stall (actual stall is 2,700RPM), 3.89 locker, M/T 255-60 drag radials w/14lbs., running slapper bars.

Best run:
60ft - 1.81
1/8th - 7.97
MPH - 86.7

I'm hoping to be there on Sunday the 29th to try a few small changes?