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I'm sure this one has been debated over and over. What's better? CNC ported heads or afr 205's. Would afr 225 be an option for stock cid. CNC heads seem to be the cheaper route, but I'm interested in performance. thanks.
 

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jason31 said:
I'm sure this one has been debated over and over. What's better? CNC ported heads or afr 205's. Would afr 225 be an option for stock cid. CNC heads seem to be the cheaper route, but I'm interested in performance. thanks.
Jason, not trying to hijack you here..............I cant speak for the AFR's but I do have a set of MTI stage 2e's. MTI hand ports their stuff and seem to be good at it. I have had them about 2 months (bought 1/28/05) and need to sell them. If you take the plunge in the future and you want to talk drop me a pm.

Good luck in you search, J
 

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I'll put in my 2 cents worth. While the AFR flow numbers may not be any better than a well ported LS6 head, it will make more power.
I can ALWAYS add more timing and run it leaner with the AFR head. THe combustion chamber shape has superior burn characteristics. Flow numbers aren't everything.
 

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I like the Torque numbers that the AFR's produce over any other heads. :thumb:

.
 

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jason31 said:
I'm sure this one has been debated over and over. What's better? CNC ported heads or afr 205's. thanks.
Neither. If you are looking for a safe reliable DD then consider CARTEK Stage 2 or 3 h/c :yeadog:
 

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jason31 said:
I'm sure this one has been debated over and over. What's better? CNC ported heads or afr 205's. Would afr 225 be an option for stock cid. CNC heads seem to be the cheaper route, but I'm interested in performance. thanks.
If performance is what you want, then consider looking at the AFR 225's, a BIG cam, and the FAST 90 intake/NW 90 TB. One member here, mjustmike, did this exact package at TTP Performance in NJ and the car made over 490 rwhp, with not the best headers and with the cats on. :jawdrop: I can't speak for drivability, as I think they are still working on the car (changing out the headers and beefing up the drivetrain), but that car is going to be a serious beast when it does hit the road. :thumb:

I have the AFR 205's with a different BIG cam (LG G5X3) and the 90/90 combo, 4.10 gears and the car made 469 rwhp. I like the performance (I'm still figuring out how to handle this level of power on the drag strip :D ) and I drive this car around town locally without issue.

Don
 

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Don Benson said:
I like the performance (I'm still figuring out how to handle this level of power on the drag strip :D ) and I drive this car around town locally without issue.

Don
You and all the other owners of AFR NA 346s.
Eventually the AFR powered cars will run the numbers, but I have yet to see a single AFR NA 346 go into the 10s or a single stroker NA with AFRs go in the 9s (even 10s I think) in the entire country. Not that the AFRs are bad, they make a great head, but out of the box they need more work to go the number.
Remember that a few tuners including us have achieved 500+ RWHP on NA 346s and we have built 600+ RWHP NA strokers with LS6 heads. We have customers that have runs deep in the 10s @ 130+ mph a long time ago with smaller cams than what we can use today with 346s, along with NA runs in the 9.90s with a stroker A4 C5 @ 137+ mph.

The AFR or the ALL-PRO heads would be great for boosted or nitrous applications (with some work) because of their thicker decks and better gasket sealing, but for NA hyd./roller (with out going to the C5R heads because of the special manifolds needed) my choice is still the LS6 head that we port in-house.


Julio
 

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You and all the other owners of AFR NA 346s.
Eventually the AFR powered cars will run the numbers, but I have yet to see a single AFR NA 346 go into the 10s or a single stroker NA with AFRs go in the 9s (even 10s I think) in the entire country. Not that the AFRs are bad, they make a great head, but out of the box they need more work to go the number.
Remember that a few tuners including us have achieved 500+ RWHP on NA 346s and we have built 600+ RWHP NA strokers with LS6 heads. We have customers that have runs deep in the 10s @ 130+ mph a long time ago with smaller cams than what we can use today with 346s, along with NA runs in the 9.90s with a stroker A4 C5 @ 137+ mph.

The AFR or the ALL-PRO heads would be great for boosted or nitrous applications (with some work) because of their thicker decks and better gasket sealing, but for NA hyd./roller (with out going to the C5R heads because of the special manifolds needed) my choice is still the LS6 head that we port in-house.


Julio
I have been saying this for months.

http://z06vette.com/forums/showthread.php?t=78161&page=1&pp=15
 

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Lou Gigliotti runs the CNC LS6 heads on his World Challenge car as per SCCA rules. He HATES them and has blown up numerous sets. Supposedly the castings are too thin where they are ported. I'd go AFR personally.
 

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If all you are wanting is a low 1/4 mile time then no, the AFR 205's are not the best for you one of the ported jobs that flow peak like mad are what you want. If you want the best DRIVEABLE car, then yes, they are the best for you. A 230-240cc head on a street car with only 346 cubes is crazy and killing a ton of mid-range and low-end power.
 

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dmtnt said:
Lou Gigliotti runs the CNC LS6 heads on his World Challenge car as per SCCA rules. He HATES them and has blown up numerous sets. Supposedly the castings are too thin where they are ported. I'd go AFR personally.


Because of SCCA rules he has to use the CNC LS6 heads and we have seen a few fail at the welds near the spring seat area. Our heads are not welded and have had zero problems with castings being thin or cracking. Any head that is ported that thin will fail, especially if they have been welded in those thin areas.

Here is a picture of this type of head failure.

 

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tekhombre said:
You and all the other owners of AFR NA 346s.
Eventually the AFR powered cars will run the numbers, but I have yet to see a single AFR NA 346 go into the 10s or a single stroker NA with AFRs go in the 9s (even 10s I think) in the entire country. Not that the AFRs are bad, they make a great head, but out of the box they need more work to go the number.
Remember that a few tuners including us have achieved 500+ RWHP on NA 346s and we have built 600+ RWHP NA strokers with LS6 heads. We have customers that have runs deep in the 10s @ 130+ mph a long time ago with smaller cams than what we can use today with 346s, along with NA runs in the 9.90s with a stroker A4 C5 @ 137+ mph.

The AFR or the ALL-PRO heads would be great for boosted or nitrous applications (with some work) because of their thicker decks and better gasket sealing, but for NA hyd./roller (with out going to the C5R heads because of the special manifolds needed) my choice is still the LS6 head that we port in-house.


Julio
I am installing the AFRs on my 427 C5R as we speak. I was using Stage III LS6 heads but found a valve stem seal leak was causing excess oil consumption and decided to try the AFRs...Am running a 244/248/114 cam and I'll let you know what the chasis dyno numbers show and we'll resolve this once and for all. I hope.
 

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Don Benson said:
Hmmm...I guess this one doesn't count. :roll:

http://www.z06vette.com/forums/showthread.php?t=70360

Don (still not looking for "the light." ;) )

Sure it counts, being an experienced and awesome racer Lou knows how to get the most out of his combination. In that car he has a dry sump, high compression, built bottom end, low inertia road race clutch and rotating assembly along with other goodies that you would need a military top secret clearance to know about. I don't know what bore/stroke ratio Lou's car has, but some sanctioning bodies will allow a 346 CID engine with a 4.125 bore and a 3.25 stroke instead of the stock 3.898 bore/ 3.622 stroke.. This is a car that was designed for a particular type of racing with components that most street cars don't have.

I'm very confident that higher power levels can be reached with LS6 heads along with all the other components this car has.

Julio
 

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tekhombre said:
Sure it counts, being an experienced and awesome racer Lou knows how to get the most out of his combination. In that car he has a dry sump, high compression, built bottom end, low inertia road race clutch and rotating assembly along with other goodies that you would need a military top secret clearance to know about them. This is a car that was designed for a particular type of racing with components that most street cars don't have.

I'm very confident that higher power levels can be reached with LS6 heads with all the other components this car has.

Julio
Ohh, okay. It's just in your thread response to my reply I saw "but I have yet to see a single AFR NA 346 go into the 10s." I grant you that as far as we know on the "forums" this is the the only one, but it did go in the 10's. And now you come back in to the thread and give many reasons as to why it did...though in my mind, these are just false objections to the facts. So be it, but at least there is a single AFR equipped car to have gone into the 10's. :yeadog:
 

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Don Benson said:
Ohh, okay. It's just in your thread response to my reply I saw "but I have yet to see a single AFR NA 346 go into the 10s." I grant you that as far as we know on the "forums" this is the the only one, but it did go in the 10's. And now you come back in to the thread and give many reasons as to why it did...though in my mind, these are just false objections to the facts. So be it, but at least there is a single AFR equipped car to have gone into the 10's. :yeadog:

Ok Don, you got me. Now I have to change what I said.

Besides Lou's race car, etc..... LOL

I don't know if the AFRs on Lou's car were installed "out of the box", I wouldn't if I owned that car. If you reread my post I stated "Not that the AFRs are bad, they make a great head, but out of the box they need more work to go the number".


Julio
 
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