Tuned two LS3's today, what a difference AI heads and a FAST 102 make.
08-25-2012, 04:38 PM
#1
Tuned two LS3's today, what a difference AI heads and a FAST 102 make. First car, 2010 Camaro, I just finished up for a customer and needed some final results. The other 2008 Vette was built and originally tuned by a shop in Texas I believe. Their graph read 483/447rw. I will get to that in a second.
2010 Camaro:
AI 275cc heads, stock compression
Comp grind 232/238 .615/.615 113+3
BER ported FAST 102
NW 102 tb
1 7/8" lt's with cats and stock mufflers
UD pulley
Vararam
YT UL's
TR6's
MSD's
20" rims with 315's
504/462rw cut outs closed
514/471rw cut outs open
2008 Vette:
Stock heads and compression
Comp 227/242 .605/.615 115+4
Ported LS3 intake and TB (unknown porter)
1 7/8" LT's no cat's and dual 3" with x all the way out
UD pulley
CAI
TR6's
MSD's
20" rims with 305's
460/430rw
The graph that came with the car said 483/447rw. Two pulls revealed that it was only making 440/417rw on my dyno. After tuning it made 460/430rw. Needed to be leaned out and the timing bumped.
I just thought these were really interesting results considering it was the same dyno on the same day with in ten minutes of each other. The cams are similar and I realize the Camaro has the intake advantage. I have a graph that I will try to get up in a bit. Have to scan it and upload it.
Do we still have to block out non sponsor dyno/shop info?
2010 Camaro:
AI 275cc heads, stock compression
Comp grind 232/238 .615/.615 113+3
BER ported FAST 102
NW 102 tb
1 7/8" lt's with cats and stock mufflers
UD pulley
Vararam
YT UL's
TR6's
MSD's
20" rims with 315's
504/462rw cut outs closed
514/471rw cut outs open
2008 Vette:
Stock heads and compression
Comp 227/242 .605/.615 115+4
Ported LS3 intake and TB (unknown porter)
1 7/8" LT's no cat's and dual 3" with x all the way out
UD pulley
CAI
TR6's
MSD's
20" rims with 305's
460/430rw
The graph that came with the car said 483/447rw. Two pulls revealed that it was only making 440/417rw on my dyno. After tuning it made 460/430rw. Needed to be leaned out and the timing bumped.
I just thought these were really interesting results considering it was the same dyno on the same day with in ten minutes of each other. The cams are similar and I realize the Camaro has the intake advantage. I have a graph that I will try to get up in a bit. Have to scan it and upload it.
Do we still have to block out non sponsor dyno/shop info?
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08-27-2012, 07:27 AM
#9
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Awesome power on that camaro. Those ls3's are quite the package for a small cube motor. Also the cutout closed numbers really suprised me. Those stock mufflers must flow pretty well!
08-27-2012, 12:22 PM
#10
The stock exhaust on both these cars, factory duals, is quite good, so you don't see the monster gains behind the headers like you did with 4th gen f-bodies. Headers, of course, are still game changers with no downside (other than noise) and bigger is better with the LS heads.
Seems like the heads are the big deal here, given the modest gains from FAST LS3 intakes and consistent big results from AI. I also find the cam difference interesting. The first looks kinda like the SpinMonster cam and the second like a cam I had in my LS3 98Z28. Interestingly, my setup had almost identical output to the vette though with 17" hoops, y-pipe, and unported intake tract.
Can anyone comment with experience on the difference these two cams may make and how they work in concert with the better heads/intake?
Seems like the heads are the big deal here, given the modest gains from FAST LS3 intakes and consistent big results from AI. I also find the cam difference interesting. The first looks kinda like the SpinMonster cam and the second like a cam I had in my LS3 98Z28. Interestingly, my setup had almost identical output to the vette though with 17" hoops, y-pipe, and unported intake tract.
Can anyone comment with experience on the difference these two cams may make and how they work in concert with the better heads/intake?
08-27-2012, 07:09 PM
#13
Did someone take down a post? Got an email notification about the FAST being responsible for most of the gains and not the heads. I would say at most that a ported FAST 102 on a motor like this is only going to show 10-15rw over a ported LS3. Maybe 20+ over a stock manifold. I know on Katech's engine dyno the BER ported LS3 intake made with in 1hp of the FAST 102. There was a guy that pickup 20/18rw with a BER ported LS3 intake. Although the porter of this particular manifold and TB is unknown to me. I would guess the heads were worth 25rw or so which is steller considering how good these heads are stock and no bump in compression. It is hard to make more power with an already over sized head for the motor it is on. You have to consider also that 99% of the port work is done in the chamber and bowl area. Not much of anything, if anything, is taken out of the runner. Not on AI's nuts but you have to give credit where credit is due. I just think the Camaro has an over all better combo. A little tighter split, less lobe sep, the heads and intake and TB came together for some pretty good results.
09-14-2012, 01:46 AM
#16
On The Tree
Free bump for Tooley... 
Just bolted on some of his hand-worked TFS 235s tonight (after 9 months of indecision, saving, and planning).
Pray thanks for posting this up - it is nice to see the range of LS3 potential from the SBE 6.2L.
Compare this thread to the SBE 7.0L LS7 Heintz put together (also AI heads, PATTERN! cough cough) that made 620whp and 535wtq NA on pump gas, and it becomes readily apparent that strokers are NOT always the answer.
Big bore/medium stroke paired with some high flowing heads and a wide rpm range is still the magic ticket on these little pushrod mills...
Don't believe me? Go look at the 402-408ci stroker dyno thread (all 11 pages of it). Most of those have 6.6-6.8L and are not posting the results of that well-planned H/C/I LS3 in the Camaro.
Hurts to see (as a LS2 stroker owner) but is also very impressive how far GM has taken the "basic mills"...
-Michael
Just bolted on some of his hand-worked TFS 235s tonight (after 9 months of indecision, saving, and planning).
Pray thanks for posting this up - it is nice to see the range of LS3 potential from the SBE 6.2L.
Compare this thread to the SBE 7.0L LS7 Heintz put together (also AI heads, PATTERN! cough cough) that made 620whp and 535wtq NA on pump gas, and it becomes readily apparent that strokers are NOT always the answer.
Big bore/medium stroke paired with some high flowing heads and a wide rpm range is still the magic ticket on these little pushrod mills...
Don't believe me? Go look at the 402-408ci stroker dyno thread (all 11 pages of it). Most of those have 6.6-6.8L and are not posting the results of that well-planned H/C/I LS3 in the Camaro.
Hurts to see (as a LS2 stroker owner) but is also very impressive how far GM has taken the "basic mills"...
-Michael
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Rich2342 (02-01-2024)
09-15-2012, 07:19 PM
#17
I think that only with a 4.065 or larger bore that the LS3 heads become a viable choice.
Anything under that and the large intake valve and port just becomes too lazy and doesn't keep enough port velocity even paired with a long runner intake.
I do think a camshaft with a good bit of overlap can help a smaller bore with these large heads by helping to scavenge the intake port/valve with the rush of exhaust exiting the exhaust valve while they are both simultaneously open during overlap periods, but that the intake duration should be kept in check as to not lose too much dynamic compression or try and make a stock style intake make high rpm power where they just wont.
This is a good combination of parts that the end result shows impressive results. Nice package Pray.
Anything under that and the large intake valve and port just becomes too lazy and doesn't keep enough port velocity even paired with a long runner intake.
I do think a camshaft with a good bit of overlap can help a smaller bore with these large heads by helping to scavenge the intake port/valve with the rush of exhaust exiting the exhaust valve while they are both simultaneously open during overlap periods, but that the intake duration should be kept in check as to not lose too much dynamic compression or try and make a stock style intake make high rpm power where they just wont.
This is a good combination of parts that the end result shows impressive results. Nice package Pray.
09-16-2012, 10:08 AM
#18
Thanks Martin and Mike. I wish I could have raised the DCR some, actually a lot. To bad the stock pistons don't have valve releifs like the LS7's.
Driving around/under the curve did suffer a little on this car but I think that lends it's self to the large all around top end. It is not bad by any means but customer stated that if felt softer no matter what I did to the tune. I am not sure what a stock manifold would have done for the bottom end. I did also go against the grain a little with the cam choice. Possibly a little more split would have picked up some but I wanted a solid driver that would rip up to 6,500. The cam was actully still pulling up there but was running into the speed limiter. I raised it to 250 which I thought was in mph. Upon closer inspection it is in KM which is exactly where it hit. So raising that may have showed a few more pony's. I would shift this car at the track at 6,700-6,800 for sure.
I was doing some reading on these LS3 heads and they seem to be modled after the nascar thinking of around a 76% intake valve to exhaust valve ratio IIRC. The idea is to get as much intake valve as you can then make up for the weak exhaust with duration and lift in the cam. Sounds good in theory. But again, I wouldn't run these things on any bore smaller than the 4.065" like Martin said. I actually think that is a little small. It just seems to me that a 270+cc runner on anything below a 427 is just too large. I think a cathedral port set up on the 6.2l would stomp the LS3 heads down low and equal if not surpass it up top. Now if the after market can get some stuff to flow in the 360-380cfm range with a 250-260cc runner it would really be a great all around head. I would also like to see the valves sunk or raised and some smaller chamber designs to get DCR up and some more cam in these things. Lastly, I don't think we will see the true potential of the LS3 head untill there is a manifold capable of keeping up with them (that fits under the hood). I think that is why the cathedral stuff is still keeping up. I can't see the plastic intakes we have now flowing much more than 320-330cfm. So all that air you gain at the cost of velocity with the larger runner is lost due to the intake. The engine will only see as much air as the largest intake restriction will allow.
Driving around/under the curve did suffer a little on this car but I think that lends it's self to the large all around top end. It is not bad by any means but customer stated that if felt softer no matter what I did to the tune. I am not sure what a stock manifold would have done for the bottom end. I did also go against the grain a little with the cam choice. Possibly a little more split would have picked up some but I wanted a solid driver that would rip up to 6,500. The cam was actully still pulling up there but was running into the speed limiter. I raised it to 250 which I thought was in mph. Upon closer inspection it is in KM which is exactly where it hit. So raising that may have showed a few more pony's. I would shift this car at the track at 6,700-6,800 for sure.
I was doing some reading on these LS3 heads and they seem to be modled after the nascar thinking of around a 76% intake valve to exhaust valve ratio IIRC. The idea is to get as much intake valve as you can then make up for the weak exhaust with duration and lift in the cam. Sounds good in theory. But again, I wouldn't run these things on any bore smaller than the 4.065" like Martin said. I actually think that is a little small. It just seems to me that a 270+cc runner on anything below a 427 is just too large. I think a cathedral port set up on the 6.2l would stomp the LS3 heads down low and equal if not surpass it up top. Now if the after market can get some stuff to flow in the 360-380cfm range with a 250-260cc runner it would really be a great all around head. I would also like to see the valves sunk or raised and some smaller chamber designs to get DCR up and some more cam in these things. Lastly, I don't think we will see the true potential of the LS3 head untill there is a manifold capable of keeping up with them (that fits under the hood). I think that is why the cathedral stuff is still keeping up. I can't see the plastic intakes we have now flowing much more than 320-330cfm. So all that air you gain at the cost of velocity with the larger runner is lost due to the intake. The engine will only see as much air as the largest intake restriction will allow.
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Rich2342 (02-01-2024)
