Re; Ported Intake Manifold
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Race Director
Joined: Mar 2005
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From: Austin Texas
Re; Ported Intake Manifold
I just recieved a used "Formato Ported" Intake Manifold from a Forum member. Some interesting measurements since I have both on the bench.
Intake ports on the heads vary a lot, crude dial caliper measurements show variations of 0.091" on the ports. They vary from 0.934 to 1.025. Definitely not CNC.
The stock intake manifold ports overall are smaller than the ports in the heads. They vary from 0.900 to 0.957.
The ported intake manifold varies from 1.030 to 1.099.
The "after" Dyno should be interesting since the smallest head port doesn't match the smallest ported manifold port and the largest head port doesn't match the largest manifold port.
BTW; It took me an hour and a half to pull the intake manifold (hey,I'm old). The Helms manual is a JOKE, one of the first instructions is to drain the cooling system!
Intake ports on the heads vary a lot, crude dial caliper measurements show variations of 0.091" on the ports. They vary from 0.934 to 1.025. Definitely not CNC.
The stock intake manifold ports overall are smaller than the ports in the heads. They vary from 0.900 to 0.957.
The ported intake manifold varies from 1.030 to 1.099.
The "after" Dyno should be interesting since the smallest head port doesn't match the smallest ported manifold port and the largest head port doesn't match the largest manifold port.
BTW; It took me an hour and a half to pull the intake manifold (hey,I'm old). The Helms manual is a JOKE, one of the first instructions is to drain the cooling system!
Tech Contributor
Joined: Mar 2003
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From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
LG's after dyno:
the power difference is documented by LG:
In the above graph the only difference was the manifolds. 9rwhp and 17rwtq is the difference if you mistakenly reduce the numbers to what is at peak. The power differences in the midband are staggering by comparrison to peak numbers. The top line is the FAST and LG headers with a tune and the botom is a ported LS2 with no other changes. The cost is roughly 80-90 bucks per HP so H/C guys looking for more will opt to say that the difference is worth it. If you are doing only a few mods and dont care about getting to the best attainable than I guess the values you hold to will be evaluated differently. Money aside there is a difference.
Keep in mind as posted about previously, peak power doesnt tell the story about the FAST manifold. The gains in the midband are much more impressive but still the difference for the uninformed customer will still unfortunatly be the peak only numbers. They will still say the difference is "only 9hp" when in reality the above graph tells a very different story at 5000rpms being more than 20rwhp over the LS2. A ported LS2 is an accountant's choice, a ported FAST is a mechanic's choice.
In the above graph the only difference was the manifolds. 9rwhp and 17rwtq is the difference if you mistakenly reduce the numbers to what is at peak. The power differences in the midband are staggering by comparrison to peak numbers. The top line is the FAST and LG headers with a tune and the botom is a ported LS2 with no other changes. The cost is roughly 80-90 bucks per HP so H/C guys looking for more will opt to say that the difference is worth it. If you are doing only a few mods and dont care about getting to the best attainable than I guess the values you hold to will be evaluated differently. Money aside there is a difference.
Keep in mind as posted about previously, peak power doesnt tell the story about the FAST manifold. The gains in the midband are much more impressive but still the difference for the uninformed customer will still unfortunatly be the peak only numbers. They will still say the difference is "only 9hp" when in reality the above graph tells a very different story at 5000rpms being more than 20rwhp over the LS2. A ported LS2 is an accountant's choice, a ported FAST is a mechanic's choice.
Tech Contributor
Joined: Mar 2003
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From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
porting the LS2 isnt free unless you do it yourself which I'm guessing you will do. The differences above a ported LS2 are still 20hp and 20rwtq in the midband so if you intend to ever do another mod beyond the ported LS2 then it should be noted that if it doesnt accomplish 20hp and 20 rwtq for the same cost as the FAST then the approach is flawed.
In either event I did specify throughout my post that the values (even financial) will be a consideration for this mod. If one does an air cleaner before the FAST then I question the wisdom since 400 bucks yeilding no power increase hardly qualifies as a bargain compared to 700 for what is minimally 20-25rwhp from the manifold. It is a power bargain even compared to headers unless you mistakenly only look at peak numbers which is where FAST haters like to point when they say how bad this part is.
In either event I did specify throughout my post that the values (even financial) will be a consideration for this mod. If one does an air cleaner before the FAST then I question the wisdom since 400 bucks yeilding no power increase hardly qualifies as a bargain compared to 700 for what is minimally 20-25rwhp from the manifold. It is a power bargain even compared to headers unless you mistakenly only look at peak numbers which is where FAST haters like to point when they say how bad this part is.
Last edited by SpinMonster; Mar 17, 2007 at 12:23 PM.
Le Mans Master
Joined: Mar 2006
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From: New York
porting the LS2 isnt free unless you do it yourself which I'm guessing you will do. The differences from there are still 20hp and 20rwtq in the midband so if you intend to ever do another mod beyond the ported LS2 then it should be noted that if it doesnt accomplish 20hp and 20 rwtq for the same cost as the FAST then the approach is flawed.
In either event I did specify throughout my post that the values (even financial) will be a consideration for this mod. If one does an air cleaner before the FAST then I question the wisdom since 400 bucks yeilding no power increase hardly qualifies as a bargain compared to 700 for what is minimally 20-25rwhp from the manifold. It is a power bargain even compared to headers unless you mistakenly only look at peak numbers.
In either event I did specify throughout my post that the values (even financial) will be a consideration for this mod. If one does an air cleaner before the FAST then I question the wisdom since 400 bucks yeilding no power increase hardly qualifies as a bargain compared to 700 for what is minimally 20-25rwhp from the manifold. It is a power bargain even compared to headers unless you mistakenly only look at peak numbers.
Would you bother having the FAST intake ported?
Safety Car
Joined: Jul 2006
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From: Objects in your mirror are losing , Long Island, NY
St. Jude Donor '08
porting the LS2 isnt free unless you do it yourself which I'm guessing you will do. The differences above a ported LS2 are still 20hp and 20rwtq in the midband so if you intend to ever do another mod beyond the ported LS2 then it should be noted that if it doesnt accomplish 20hp and 20 rwtq for the same cost as the FAST then the approach is flawed.
In either event I did specify throughout my post that the values (even financial) will be a consideration for this mod. If one does an air cleaner before the FAST then I question the wisdom since 400 bucks yeilding no power increase hardly qualifies as a bargain compared to 700 for what is minimally 20-25rwhp from the manifold. It is a power bargain even compared to headers unless you mistakenly only look at peak numbers which is where FAST haters like to point when they say how bad this part is.
In either event I did specify throughout my post that the values (even financial) will be a consideration for this mod. If one does an air cleaner before the FAST then I question the wisdom since 400 bucks yeilding no power increase hardly qualifies as a bargain compared to 700 for what is minimally 20-25rwhp from the manifold. It is a power bargain even compared to headers unless you mistakenly only look at peak numbers which is where FAST haters like to point when they say how bad this part is.
Drifting
Joined: May 2000
Posts: 1,952
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From: Palos Verdes Peninsula California
Those are nice gains. Too bad I didn't do more research into the FAST before I had my stock intake ported.
Out of curiousity, which would be better to buy for an engine with stock internals, the 78MM or 90MM FAST?
Out of curiousity, which would be better to buy for an engine with stock internals, the 78MM or 90MM FAST?
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Safety Car
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From: Corpus Christi Texas
Tech Contributor
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From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
no application is better with a 78mm. Your car comes with a 90 so why switch it.
Tech Contributor
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From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
Cost of a FAST (- minus) Cost of ported intake = the cost of the gains seen in LG's comparrison.
example: FAST ($705-texas speed) - (250? 350? ported manifold) = $350-$450 for 20 rwhp and 20 rwtq in the midband (not talking peak numbers)......Is that worth it, is the value question. I know someone will say that the FAST port will cost money but the sale of the LS2 will help which obviously you cant sell if you are porting and keeping it.
The two of you do realize that the graph I posted was a comparrison of ported LS2 to a ported FAST? It wasn't stock vs. FAST.
Last edited by SpinMonster; Mar 18, 2007 at 12:52 AM.
Safety Car
Joined: May 2005
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From: Corpus Christi Texas
My post had nothing to do with your post. I was simply stating what my results were regardless of what your dyno graph said. But yes, I've seen that graph and know what the comparison was between.