Question why would pat take the 72 cc heads and mill them to 65cc instead of just buying the 62 cc vesion? That would put him around 11:2:1 wouldn't it? Also not only are people just to caught up in flow numbers but they get to cought up in dyno numbers as well. Afr heads power the fastest heads cam gto here in ohio, an 04 stalled auto with 205's on it. Car makes 445 rwhp and ran 11.4 @ 122.5. Heres another example, had a friend with a c5 zo6 with the new afr 215's his car made 455rwhp and beat a 660rwhp turbo fox body that had never lost till then. Afr makes a bad *** product thats all I have to say.

 

Good question. Here's the answer. I needed the highest flowing version that gave me 11.0:1 static compression while still having enough valve drop to run a decent sized cam. These heads at 65cc have .135" of valve drop. With that much real estate, I can run a 231 intake duration lobe at 112 intake centerline and still maintain .080" P to V clearance. Any smaller than 65cc and I'd either have to run a smaller intake lobe or flycut the pistons (which I did not want to do). In comparison, an LS3/L92 head has .133" of valve drop at 69.8cc. So basically, I got a 5cc smaller chamber with similar valve drop and more airflow & port velocity.

For what it's worth, the 72cc versions of the AFR 230 v2s flow slightly more than the 62cc versions because of the more generous chamber area opened up around the valves. Less shrouding, better flow.

 

Got some track times from San Antonio Raceway last night. The density altitude was 2706' so the ET and mph was not like we'd expect in cool, dry weather with a high barometer. I ran with heavy factory wheels and a half tank of fuel and no weight removed.

60' 1.8275 (spinning)
330 5.0621
1/8 7.7373
mph 92.14
1000 10.0237
1/4 11.9535
mph 116.82

Correcting to sea level would be 11.688 @ 119.55mph.

My previous best ET when I was making 394rwhp (with bolt-ons) was run in 278' density altitude. It was a 12.65 at 110.17mph. Correcting to sea level makes it 12.642 at 110.17 mph.

So correcting to sea level, my gains from 394rwhp to 497rwhp (unlocked converter power) was a .954 second reduction in ET and a 9.38 gain in mph trap speed. With a race weight of 4230 (both times), use your slide rules and see if the mph gains back up the dyno gains.

Just watch out for me if I decide to add some light drag wheels, drop some weight, change to a 3.45 gear, and run when the DA is closer to 0.

 

11.90's in a 4200+ lb. beast, with heads and cam? Sick, great work Patrick.

 

I gained over 9 mph (when correcting for DA), not 4.

 

Even the actual gains are 6.65 mph. The reason you want to correct for weather at the track is the same reason you correct for weather on the dyno. You have to know how much you gained with all weather conditions being equal. Going from 110.17mph in 278' DA to 116.82mph in 2706' DA is a nice gain for sure.

 

Good run Pat G and what I am about to say is nothing to you but Tony has pounded his chest and made jokes about the cognitive dissonance.... what I am about to say is like two guys sitting back drinking a beer shooting the ****....


@ Tony........ Remember this Tony........

My point has been confirmed......

No more excuses Tony.......

11.22 trap 120 MPH poor budget head vs 11.9 116 MPH AFR 230v2 head.....

The 11.22(Poor budget head) was made at 628ft(more like around +1500-+2000 DA.....
Runs a consistant 11.6 and 119-120 MPH with less than optimal or poor DA

The 11.9 was made at 600ft around 2500-2700 DA.....

So you can argue a rough difference in 500 DA would net 4 more mph...lol

So using the math presented here the 11.22 run should be equated to 10.9 and 124 MPH? corrected for sea level right? 4000LB+ car

Tony you should walk light not to **** the ground off...... lol......

The ET is truly not the story but the 116 MPH ...... closet to an online calculator as I have ever seen..... 510-512 rwhp 116mph per online calculator


Pat.......

the altitude at San Antonio Raceway is 600' right?

Running it in Houston would have squashed the need for a conversion or justification.... Houston Raceway is 39ft...... I would have been there brotha, I was off this weekend too.....

 

Nice run Pat. I would be curious to see what it could do on a good day with some weight reduction.

To clear up bozz's post.

The 11.22 @ 120mph was made at a track that is 600ft above sea level and that day the DA was around 0 when I made the run. I have a stack of timeslips between 11.39-11.54 all between 118-119mph that were made at the same track with DA's between 600+ to 2000+.

My car weighs roughly 500lbs less than yours in it's "track clothes".

So since we are using ricer math that all things being equal, weight, track, DA our cars would be within a .10 one way or the other-with yours probably being a hair faster.

I am glad you are happy with the results.

Me with those kind of hp/tq #'s and for the amount of money spent in comparison I would personally be disappointed with the track times and mph.

 

I know. Running at HRP would have been a lot faster. Unfortunately, HRP is not open for street cars until October 8th and Sealy is not open a week or two after that. We're getting the G8 ready for the Texas Mile on Oct 22-24 so we needed to get to the track before and collect some data.

I am not too concerned about the 11.95 ET. If I were running skinnies and lightweight drag tires, less weight, and more gear, my car would have 60' a lot better. But the 116.82mph in 2706' DA at 4230lbs backs up the dyno numbers so that's all that matters for me. We need to be around 500rwhp to hit our target number at the Texas Mile.

When the weather gets cool, you can expect a string of 119-120mph 1/4 mile trap speeds at HRP.

 

Ok some of the numbers were slightly off thanks Malcom for the SAE,STD,Malcolmized correction to my post..lol


Fellas, truth be told this(display) is still faster than most production or factory cars made today....... So I am not taking anything away from Pat G, this car is fast period........... The only issue I have is when Tony speaks wreckless or not tell the full story about the L92, I have seen this before with concern to the vortecs.... If Tony had not added the kerosine to the controversy, I doubt many of us would even have spoken on the build period... or made a comment and kept it moving......


Tony I can say the AFR 230v2 is a bad azz head, but leave out the comparison to a L92......

 

Yeah I know, ET is more about complete package(suspension,weight,setup,drivetrain etc...)

Its still a bad azz car period...... You know how it goes and have been around for a while. We are a bunch of guys prob at work, not even supposed to be on the internet...lol..... As I stated before, if TF gave me some heads and made me an official spokesman, I am selling out to the man or the establishemnt...lol just kidding.....

 

This.

No doubt Pat's car is badass. But like the one guy above that posted that has all the bolt on's and a cam swap and ran 11.6 at 116 this "conversion" to me seems like a big waste (this is not really the right word) of money.

One could argue that my the 500lbs less that my car weighs is offset and equal to the 50 more rwhp and 40 more rwtq Pat's car makes.

All in all like I said I personally would be disappointed but if you are happy that is what counts

 

I think this is the main point. Stick my 6.0L engine in your car and you can expect to go faster courtesy of the additional 50 hp and 40 tq. The weather corrected mph backs up the weather corrected dyno numbers.

Had I run 120.15 mph in -800' DA (which happens a few times a year at HRP), I'm sure some people would have given more credit to the new combo than it deserves, while running 116.82 mph at 2706' DA draws negative responses from others. The bottom line is they all correct to 119.55mph at sea level. The power the engine makes is the same. The density altitude is what skews the mph up or down. So if anyone still doubts that my car makes in the neighborhood of 500rwhp, I'd like to know why.

 

But you are correct if you ran 119-120 then the dawgs prob would not bark...
but most guys when stating their track times do not state or do a comparison to sea level unless they are in extremely high altitude locations... Or in the case of Malcolm, add a correction factor to sea level to the 11.22 he ran. now we have a 10.9 right... He took it on the chin and rolled....

The real test would be to put the L92's back on and see what the result would be? then we can activley say one or the other.... Whats really striking a nerve with most guys is the marketing about one head over the other.... Thats were the problem lies and if the mamofied parts are worth the swap....

 

Actually, Malcolm stated that he ran 11.22 at 120mph at 0' DA. There is no correction to 0' DA when you run at 0' DA. His 11.22 would not correct to anything faster.

In my opinion, drag racing ETs and mph are much more unreliable for estimating power because the density altitude can skew the results so much. Savvy racers always correct for weather so they can track the gains or losses of their combos.

 

Sorry I should have stated it clearer.

In other words we have somewhat similar cars. Mine weighs 500 lbs less than yours but yours has 50/40 more hp/tq than mine. One could say at the power levels we are at those two factors would cancel each other out. This being said our cars, in theory should run similar times.

The ONLY time my car has run 11.9 at 115/116 is the first time I had ever went down the strip and didn't know what a burnout was LOL. This is also before I did any type of weight reduction other than the skid plate and the spare tire jack out of the back. Next time out with same weight reduction and just more seat time I ran 11.64 at 116mph.

From there there were a few "performance" changes along the way. Yella terra rockers and kooks stepped headers vs 1 3/4 (although neither of these showed any gains on the dyno). Changed out a lot of the bushings, pedders oe height springs and koni adjustables, carbon fiber hood, started taking the back seat out and the fuel tank brace out, and a big and little weld setup. This combined with more seat time for me, has produced a consistent 11.39-11.49 car with mph all between 118-119 with a best of 11.22 at 120.

All of this being said at your current cars weight levels if you aren't running around the above, consistently, once again, I personally would not be happy and would be pissed that my car was somewhat of a "dyno queen".

 

This is what I would like to see but I don't think we will ever see it.

 

You guys are missing the point entirely.

I run 12.65 at 110.17mph (in 278' DA) in my G8 with L92 heads, 1 7/8" headers, UDP, FAST 102 intake, 1.85 Yella Terra rockers, tune.

I remove the L92 heads, remove the 1.85 Yella Terra Rockers, remove the FAST 102 intake, then add the AFR heads, 231/231 .617/.617 114LSA cam, Mamo ported FAST and stock 1.7 LS2 rockers. Then I run 11.95 at 116.82mph (in 2706' DA). Even without adding the correction, I gain 6.65mph in trap speed and drop 7 tenths in ET. That would be a solid gain for a 4230lb trap speed. But when you factor in that I made these gains in 2500 ft worse air, I don't see how I could be disappointed. Remember, we're talking about the real world gains on MY car, not theoretical gains on someone else's car.

 

I am for sure not missing the point. I know you made solid gains-the only thing I am "questioning" or doubting is how much gain the mamofied afr's and fast added vs the L92 setup. Once again the perception from the title of the thread would be you made these gains from a head swap-when in actuality they were made with a cam, head, and intake swap to which a majority of the gain is most likely from going from a non-cammed car to a cammed car.

 

Most cam swaped L92 headed 6.0L G8 only put down 450-460rwhp. With all the goodies (Fast 102, etc, etc, etc).