Grant B

224/229 0.570/0.578 114 LSA cam, degreed to 112 degrees at the intake centerline
205cc AFR heads, 60cc chambers.
0.036" Cometic gaskets for a 0.030" quench.
11.8:1 CR.
Stock bottom end with Katech rod bolts.
1-3/4 LG Longtubes, no cats.
UD pulley.
VaraRam 2b intake.
LS6 intake manifold.
HPTuners, tuned by me.
Stock throttle body.
Stock MAF with stock screen.
C5 Z06 Ti mufflers.
28.8 lb injectors @ 92% DC
LuK Pro Gold clutch with 12lb Fidanza flywheel.
Stock everything else.
All pulls done in 4th gear on stock 3.42s, with 315/30/18 rear tires on a DynoJet 248.

The car's been running on this setup for a while, I just never bothered to dyno it or really fine-tune it. With the rate it goes through brakes (PBR calipers are just awful) I just didn't feel the need for more power.

Let me take a moment to say how impressed I am with these AFR heads. On 93 octane (and once even 92), they don't knock, ever. The only time I've had issues with detonation is when my condenser was blocked by grass and coolant temps hit 225F after multiple laps (I would say the problems started at 220F). You could set the timing anywhere from 23 to 27 degrees with almost no effect on power at all (it maybe lost a few ponies at 23, so I left it at 25). Even when the AF hit 14.2:1 and timing at 6000 was 27 degrees, the car did not knock. It was actually much more knock prone when it was totally stock with just a K&N filter and HPTuners! It is really, really nice not having to worry about detonation on the road course.

The blue pull was the first one of the day, while the red one was the last:

Most all of the gains showed were from AF tuning.

I pulled the intake and filter one run, just running open MAF. The car made the same power at 0.7 points richer AF. MAP pressure didn't change, hovering around 95-96 kPa. I could post the graph if anyone wants, but since I didn't bother to tune for running open MAF it really isn't a apples-apples comparison.

Overall I'm very impressed with how well the car moves with so little power. It is pretty light, being 3225 with 10 gallons of gas and me in the car, but its trapped as high as 124.5 on a cold night (using PerformanceBox DAQ, manually averaging the speed over the last 66') with a 11.8 ET on Kumho MX tires. Still, I expected it to put down 435, and certainly more torque. Some people are telling me the dyno (Rollins Automotive in Gainesville, Florida) reads low, but everyone seems to say that about places they've dynoed. I'm skeptical inertia dynos really vary that much.

I've got to replace the timing cover gasket soon, to fix an oil drip. Can anyone suggest a cam shaft that might make more power? When I originally bought this cam, I was paranoid of valvetrain failure since so many cams are speced for drag racing. However, everyone seems to have good luck with AFRs, so now I'm thinking I could have gone more aggressive. When I installed it, valve clearance was 0.92" intake 0.112" exhaust (though I may have those backwards, its been a while). I don't care about low-end or any of that; power below 4000 RPM isn't of any concern to me, but I don't want to flycut the pistons or install something that will beat up the valvetrain.

I know it would probably pick up power with a MAF, FAST and TB. I don't think dropping the money on a FAST is worth it to me (more $$ spent on power equals more $$ spend on tires and brakes as well), but I'm thinking about porting the TB and trying a 85mm MAF. 95-96 kPa seems like a lot of pressure drop.

allngn_c5

iTrader: (3)

At your power level the stock maf is fine. Try the 85 if you want. Anyways very nice results for such a small cam. Going to be a very well mannered car until you punch it. Congrats on tuning it yourself too. Very good job, you should be proud.

allngn_c5

iTrader: (3)

One more Q, whats the duty cycle on those stock inj's ??

Grant B

Touching 92% for one frame at 6500 RPM. The correction factor was 0.98, so it would take some really cold weather to hit 100%. I'm skeptical that high DCs can really harm peak-hold injectors and drivers.

I may do a temporary speed density tune and eliminate the MAF to see if MAP increases. Something is causing that 5-6 kPa pressure drop, after all.

jmilz28

iTrader: (13)

Port the TB and an 85mm MAF, you'll likely pick up st least 5-10hp and some throttle response, by most folks' experience. A ported FAST, TB, and MAF would likely put you into needing bigger injectors, given your concern for knock. It's significant coin, but no other downside to reliability, and you'd likely pick up at least 20 ponies and pounds. You wouldn't do much, if any, better than that with a cam swap - given your concern for reliability. A custom cam may get you there, though, talk to Pat G. I say, do it all ...
I think you'd see 40-45 hp and 30 ft lbs if you did it right, as you have so far. Keep us posted.

Grant B

For the hell of it, here are some more graphs:

25 (green) vs. 27 (red) vs. 23 (blue) degrees of timing. No other changes were made:


Red graph: Open MAF (stock, with the stock C5 air bridge and a smooth coupler to the stock throttle body)
vs.
Blue graph: All of that connected to a VaraRam2B with a Green filter:

Note how differently the MAF reads on this run, causing the A/Fs to go richer (this is visible in the logs as well). It seemed to like to be richer in the mid-range, so it made more power there. The higher AF on the top end was probably offset by slightly better flow.

Grant B

I'm ok with buying injectors, or anything that will carry over to a larger motor if this one ever pops. I favor the cam over the FAST because its cheaper, will probably offer the same or better gains, and I can get some of the benefit of a FAST 90/90 setup just by porting the throttle body.

But who am I kidding... I need brakes, badly, and wheels to fit over a Wilwood 14.25" setup. Why did GM have to make the cheapish C6Z brakes suck so badly? Sigh.

mathia

iTrader: (2)

Thanks for sharing! Looks like it must be fun on the track. I have a 224/228 114 cam with XE-R lobes (.581/.585) I'm going to run when I install my H/C/I setup. I do about 4-8 HPDEs a year.

For brakes, I run LG Motorsports package that uses Wilwood 6 piston calipers over the OEM rotors. It works well and is a lot cheaper than the other options, especially since you can run OEM C5 Z06 front wheels over them. You may want to consider them:

http://www.lgmotorsports.com/catalog...oducts_id=1882

I run Wilwood H compound pads in those, which are also a good bang for the buck. They will tend to crack the OEM rotors after 5-6 track days, but the rotors are fairly cheap.

You can use the savings on the brakes to get the Fast intake

corvet786c

iTrader: (6)

I thought with your compression ratio and 60cc heads and thinner gaskets would would be about 440rwhp and 415 trq. seems a little low to me.

Grant B

I'd considered that kit, but I think its too pricey for what you get. For not a whole lot more you can buy a 14.25" W6A Wilwood package with 2-piece rotors. $20 NAPA rotors are great, but they crack all the time. I'm just going to hold out for 18s in the front; I really want to put a 19x13 on the rear anyways. I thought about trying to put the GStop package on the rear when I did get larger fronts, but the piston area seems to be all wrong for that. The problem with stock rotors (or rotors of any smaller diameter) seems to be that its hard to get enough cooling into the center hat section, due to the design of the upright.

To me as well. I'm told that dyno (DynoJet 248) "reads low", for whatever thats worth. I don't know how much the cam is holding me back, however.

corvet786c

iTrader: (6)

No Actually that is a nice streetable cam, a lil more than mine. I am thinking for another 20 rwhp get a fast intake.

Demonicbird00

iTrader: (17)

nice results! the curve looks nice and smooth.

i think the cam is def holding you back along w/ a 92/92 setup

change them and you should be 460+

if you want i have a stock ported maf thats sitting in my room if you wanna buy it.

-brandon

Grant B

I got the cam card from FlowTech. Its: 224/229, 0.570/0.578, 114 LSA, with the intake centerline at 112 degrees. I'm wondering how much more power the cam would make if its lift and ramp rates were just kicked up a notch.

No thanks; if I find myself motivated to mess with tuning again, I'm probably going speed density.

Chrome355z

iTrader: (1)

I'd go with a slightly larger cam... g5x2 232/240 112 or a streetsweeper 236/240 111.

Just depends how much low vs high end do you want (x2 may be too much split for AFR 205 heads; talk to your cam guy).

Looks like a fun car! And don't get too caught up on Dyno numbers. some are loose, some are tight...

Spectre86

iTrader: (42)

im with doug. just saw you had a ls6 on there too.
pretty high compression

vettenuts

iTrader: (4)

I think you may be between a rock and hard place to some degree. With the milling on the heads, you may not be able to go much bigger on the cam. If you get faster lobes, you DCR may get too high. Run the numbers. I have the AFR 6016 cam (224/228) and my AFR's are milled to 60 cc prior to Tony re-working the chambers such they are now 62 cc. However, the AFR cam barely made PTV so be careful on your selection unless you are willing to flycut. Wondering what a FAST ported by Tony would do for you.

Grant B

I'm not worried about going up on DCR. Even when tracking the car on 93 octane, it has great knock resistance. As mentioned previously, it only had knock issues when the coolant temperatures rose above 220F (there was grass blocking the condenser), which is really too high. I really don't want to flycut, which might limit me, but considering the abuse I put my engine through, I'd rather err on the side of not enough lift.

The car does drive like stock at lower RPMs. Its perfectly happy lugging around at 1200, without issue. However, the car is no longer my daily driver, so performance below 4000 RPMs is no longer of any concern. To be honest I was hoping for more mid-range power (i.e., a higher torque peak).

vettett15

Nice power man, I have a very similar setup but I have TSP stage 1 LS6 heads milled to 59cc and a MTI G1 cam 228/232 114+1

Dyno'd at Mike Norris' place 440/411 STD and 430/??? SAE, some say his reads low too but use what you will.

I had my static around 11.4:1 and DCR at 8.7 or so, car runs great and feels strong, I'm a strong believer in high compression & smaller cam over just huge cam method.

Silver98vette

They have a 228/232 grind you might want to look at.

LS1-450

iTrader: (33)

Grant B, Thanks for the post.

I have a very similar set-up & have self tuned it, no dyno. I use MAF, MAP & injector duty, in conjunction w/ A/F ratio, to indicate the most effective tune.

What's your MAF (air speed) @ 5200 RPM, 5800 RPM, & 6200 RPM. @ what RPM does the MAP drop to 95-96 kPa?

Seems to me that if stock injectors are not above 100% w/ that set-up, then there is restricted pressure & airflow. A stock LS6 intake can be opened to 88-90mm if you've got ***** & if pressure is a problem, the runners can also be slightly ported (home ported).
IMO, a cheap Summit 85mm TB & a home tweaking of the LS6 intake will improve your numbers, along w/ Accel 30# ers or GM 42# injectors.