supercoolsix

AFR Heads 205/225 vs L92 Heads ..
which one is better?? what would you go with?? let's say you have the chance to choose one of these heads (w/ an intake and stealthy cam)... which heads would you choose and why?

thanks so much in advance!

Kevinmatt

There are also different flavors of the L92 and AFR Heads (Stage 1, 3, 3). I would also like to understand which stage to select for a 1st mod daily driver. What are the best sites to shop for heads?

My tuner was looking at L92 heads and the L76 Intake Manifold for my car. We did not talk about any specific part numbers though. When it comes down to these decisions, it's probably best left up to the tuner to analyze your performance goals and go from there. It should also be noted that only certain intake manifolds work a specific head selection and I am also told that cam selection is also dependent on the heads used as well. Anyone want to expand on this?

I myself decided to wait for heads and intake for my second round of mods. Some folks say do it now and save money.

SpinMonster

For a sreet car with any real size cam the 205's will outperform any of the heads mentioned. On a stroker the L92's are definitely going to shine. Those who used the 225's on stock displacement noted a drop in low rpm TQ and some switched back to 205's including PatrickG on LS1tech.com who got 508 to the wheels using the 205's on a 5.7 liter.

I have the L92's and the car pulls great up top but part throttle is hands down going to always be better with a smaller than 260cc intake runner. When I get a chance the 205's will be on my car unless my old cores can serve as a base for the cartek 4x head.

None of the heads mentioned have ever produced a 10 second time slip on this forum that I am aware of. It doesnt mean it hasnt been done but I havent seen any tuner do it.

LG has used afr's and L92's with great results and could comment. Cartek used 243's for what i beleive is the stock bottom end best at 10.8 in the 1/4 and it doenst sacrifice low end TQ.

While I agree with going with your tuner's advice as posted above, I think it should be noted that the tuner should have had proven track results to back his design and not go by what profit margin is best for his bottom line in selecting parts. That may make selecting your tuner harder than selecting a head.

Evilways

I agree with both posts as to you need to have goals when you mod and a good tuner will lead you in the right direction. For me, wanting to stay stock appearing to all but the trained eye and ear, the L92 combo works great. You'd get a few more ponies from a AFR heads and med. aggresive cam, but you can also easily see and hear the difference from stock. The L92 combo on my car is good for 450rwhp, but unless I swapped a cam, notched the pistons for clearance and added a pully, my combo is pretty much maxxed out ,save for a power adder such as N20 ,turbo or S/C. If you're looking to put down in excess of 500rwhp, AFRs are probally the way to go, but stealth will not be an option.

JFTaylor

Kevinmatt

So Spin, are you saying the 205 AFR's with a FAST Intake is a better way to go if you are not looking to keep that stealth look as Evil indicated in his post? I really do not care if anyone knows that I have my car modified. I do however care about the appearance of the engine. You will certainly know the car is modified once you install that FAST intake! I just bought some airbrushed Fuel Rail Covers and I cannot get too excited about grinding them down to fit the contours of the FAST intake. It looks like FAST would have made their intake compatable with the LS2?? Maybe they could not.

Who are some of the best vendors to go to when shopping for AFR Heads and a FAST Intake? Fast intakes seem to be more readily available than AFR Heads.

For a FAST Intake, I have a few questions:
1.Do you need to order new Fuel Rails with the FAST Intake to modify a LS2? Maryland Speed sells for $195.00

2. Do you need to order a new throttle body with a FAST Intake if you are modifying a LS2? That adds about $444.00 to the order if you do. The FAST manifold itself sells for $729.00 at Maryland Speed.

3. Does $195 (Fuel Rails) + $444 (Throttle Body) + $729 (FAST Intake) in parts sound about to add a FAST? What install charge could I expect?

I'm thinking about just getting Cory to port my stock LS2 Intake and save a bundle and not worry about the appearance change. Hope I did not get off topic - seems like you have to talk about intakes if you talk about changing heads since all are not compatible....Kevin

Evilways

FAST has made zero changes, it's still the same intake used on the LS1 and LS6. If you paint it, you can hide some of the ugly grey, and the engine covers may fit or may not. Myself and others I've talked with that had the FAST could not get ours back on and some do modify them to get them to fit better, but not pefectly. The FAST and stock intake will work with both stock heads and AFRs, but if you go the L92 route, you can, at this point , only use the L76 intake, which, of course, you could have ported if you choose so. You won't need a new TB for the FAST, the L92 comes with all new TB, FI, Fuel rails and hardware and you don't have to cut the car's firewall and patch with a kit or fiberglass. FAST installation is pretty expensive, so take that into consideration.Also, many FAST owners experience a intake drone at almost all speeds, a deep hollow sound, which takes some getting used to. If I had it all to do all over again, I'd have skipped the FAST and waited until the L92 became availible, but thats just me.There's pros and cons to both. Do what makes the most sense to you and that will make you happy. Best of luck in your decision and keep us all informed

Kevinmatt

So you say there is a L92 Intake out for sale? If so, can you send me a link of where to buy one so I can read about it? I always thought the L92 was the heads from GM and not the manifold. If there really is a L92 manifold, will it work with the stock LS2 heads?

I believe you meant to say L76 instead of L92 coming with the TB, FI, Fuel rails and hardware and you don't have to cut the car's firewall and patch with a kit or fiberglass?? I understand from my tuner that the L76 Intake Manifold will not work with stock LS2 heads. What could I expect to pay in parts alone for L92 heads and the L76 Intake? My tuner's part for installation will be $1K. I believe you told me around $1.5K. I saw the L76 Manifold listing for around $528.00 at JEGS today. I believe the heads are $399.99 ea or around $800.00 per pair. I'm sure there is some other stuff you have to buy with this, so $1500 is probably close for parts? So it appears for another $2500.00 I could have L92/L76 heads/intake combo added to my mods.

Evilways

Yes, I ususally just shorten L92/L76 to simply L92 and yes, the L76 will not work with any stock LS2 or aftermarket heads at this point with the exception of the L92s. Geez....always waiting in the wings to catch me in a mis typing..lol. Yes, the L92/L76 heads/intake combo is around $1500.00, all else you'll need is pretty inexpensive" offset rocker arms and stands (8X and 2X respectively), stock gaskets(2X) and get the heads milled .30 to retain stock compression ratio. Much less than $2500.00 total, more like $2K. . Thats less than AFR heads alone cost. Sorry if I wasn't clear earlier...my bad... BTW, the Jegs price you mention for the intake is really good, I've seen it go up in cost elsewhere.

martinblank

Not to get off topic, but FAST is definitely coming out with a new FAST for the LS2 and LS3, with the fire-wall for the C6, among other things, being taken into consideration in redesign. Which is to say, if you’re thinking FAST, you might want to wait.

SpinMonster

You bring up 2 good points I hadnt commented on.

First, the car is super quiet with a simple valvetrain that makes zero noise. I hated the FAST/crane noise level but didnt care since it was fast but it didnt have to be that way. The L92's give up nothing in this department. No spring noise or cam lift noise (at least it was always attributed to high lift cam noise and apparently it isnt from that.)

Second, off on a tangent, the car's exhaust note is exotic with smoother revs and a supersport bike sound to it. I like this change myself. The heads were the only change and the exhaust note was severly affected in a good way so it must have come from them.

SpinMonster

Definitely? Please state the source of this info.

It was 19 months from the article I read on the FAST until it was actually in my hands so waiting will be quite some time. I wouldnt hold my breath. As I have said before its 15 minutes with a dremel to make it fit so what some whine about isnt an issue to others with cutting to make things fit.

Also, the LS3 is just out and has nothing in common with the old manifold design and there are no immediate plans to make a L76 type FAST.

Gerhold315

What heads are coming on the Ls3?

martinblank

SpinMonster,

Yes. And for both the LS2 and LS3. I'm not whining about cutting. If they are making a better one, I want that. They are. I do. My source? FAST. I was getting ready to do the mod, so I simply sent them (FAST) a friendly Email Monday and asked. They got back to me the same day. Also, I didn't ask about the LS3, they told me anyway.

knkali

any hint of an ETA?

supercoolsix

thanks everyone for your input..

my goal is a streetable 460-470 rwhp/ 450tq...

i guess i'll stick with the 205s because my tuner said he's had great feedback w/ the 205s..

thanks spinmonster, thanks everyon!!

any news on the FAST intake ??