FAST 92 question
I upgraded to a 85mm SLP MAF when I did the 90mm FAST intake. Now I'm SD tuned.
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Just because something is larger, does not make it better. (Unless its on your wife)
Its about what your intake system flows as a whole. And in 99.999% of all instances an 85mm MAF does just fine.
I have a LSx 454 running a ported 92mm FAST, with TFS 245 heads.Its safe to say, my **** flows some air..

I have tested the following on the SAME motor:
Ported FAST 90mm w/ 85mm MAF
Ported FAST 90mm w/out MAF
LME Sheetmetal Intake w/85mm MAF
LME sheetmetal Intake w/out MAF
Ported FAST 92mm intake w/MAF
Ported FAST 92mm Intake w/out MAF
EVERYTHING was the exact same on the car. This was the EXACT SAME MOTOR on both the dyno AND street. As well as data logged the entire time.
The MAXIMUM additional flow I got was 1KPA just before WOT on the sheetmetal w/out the MAF. Other than that, there was ZERO additional flow
As far as MAP graphing went.. They were almost exact at every data point..
So in my opinion, there is ZERO reason to go with the larger MAF. But my opinion is based on FACT..
I am also running a ported LS2 TB with a halltech airbridge and HUGE K&N filter.
Just because something is larger, does not make it better. (Unless its on your wife)
Its about what your intake system flows as a whole. And in 99.999% of all instances an 85mm MAF does just fine.
I have a LSx 454 running a ported 92mm FAST, with TFS 245 heads.Its safe to say, my **** flows some air..

I have tested the following on the SAME motor:
Ported FAST 90mm w/ 85mm MAF
Ported FAST 90mm w/out MAF
LME Sheetmetal Intake w/85mm MAF
LME sheetmetal Intake w/out MAF
Ported FAST 92mm intake w/MAF
Ported FAST 92mm Intake w/out MAF
EVERYTHING was the exact same on the car. This was the EXACT SAME MOTOR on both the dyno AND street. As well as data logged the entire time.
The MAXIMUM additional flow I got was 1KPA just before WOT on the sheetmetal w/out the MAF. Other than that, there was ZERO additional flow
As far as MAP graphing went.. They were almost exact at every data point..
So in my opinion, there is ZERO reason to go with the larger MAF. But my opinion is based on FACT..
I am also running a ported LS2 TB with a halltech airbridge and HUGE K&N filter.
You tried a sheet metal intake on top of heads that can't pass the air along to the engine, so the engine never sees the air flow the sheet metal intake is delivering. Your weak link is the heads. You'll make the same power with 422ci. if you use those heads.
When someone puts together a 454ci, with a sheet metal intake (all the plastic intakes flow crappy comparitively), with a 101mm TB and a 101mm MAF (or no MAF, just go SD tune), heads that flow 400 cfm @ .650, and a medium to aggressive cam......you'll see a 700 RWHP powerplant.
I dont know what a stock maf flows cfm wise, but I still wouldnt believe it would flow enough to feed those heads with a sheetmetal intake.
454ci's need no MAF's (SD tune), 100+mm TB's, than an intake that can flow, then heads that can flow much more than the 245's can, IF you want to be able to properly feed 454ci's.
Its like a guy here I know who has a 427ci LS6 with ported LS1 heads, ported LS6 intake, stock TB and a Z06 MAF. ......Do you think those 427ci's are being properly fed....NOPE!!!! He's got the equivalent of a 383ci breathing OK. His 420 RWHP proves it. He should be way over 500 RWHP with a proper top end.
Last edited by needadvice; Jun 23, 2008 at 01:31 PM.
454ci + sheet metal intake or carb style intake + ported LS7 heads + 105mm TB + no MAF (SD tune) + medium aggressive cam in the low 240's = 650-675 RWHP through an A4, 700 RWHP through an M6.
And don't let the talk about "losing low end torque" by using a sheet metal intake suck you in, its simply not going to be noticable. You'll still be putting down 600+ RWTQ in the mid range rpm's, which is all anyone needs for a street car.
There's a few 427ci F-Body's running around here that some guy in Miami builds for people in his garage at his house, he always uses that cheezy "LS Spyder" sheet metal intake (which still blows away any of the plastic intakes) with 90mm TB's and ported LS6 intakes, and SD tunes them all himself....they're all around 560-580 RWHP, for 4-5 years now. Pump gas, 11.3:1 cr. Its all about the better intake feeding pretty decent heads. Imagine if you had a good sheet metal intake feeding 400 cfm LS7 heads through a big 105mm TB and no MAF??????
Ported LS7's flow about 70 cfm more than ported LS6's, which right there is good for about 105 more HP.(70 x 1.5 = 105 hp)Thats how I see it, but its all about cash. But still 454ci is alot of cubes, you're in big block cube territory, a set of heads that flow 450cfm would even be better because I think even 400 cfm heads still choke the engine some. 400 cfm heads would be the weak link for a 454ci. I think some big block heads flow over 500cfm, so you can see where they are. Cubes are cubes, doesn't matter which block is being used, you still have to feed the cubes. The heads don't know that they are on top of a small block or a big block, their job is the same.
I agree, a stock MAF will be the beginning of a poor top end, especially if you have a 454ci.
454ci's need no MAF's (SD tune), 100+mm TB's, than an intake that can flow, then heads that can flow much more than the 245's can, IF you want to be able to properly feed 454ci's.
Its like a guy here I know who has a 427ci LS6 with ported LS1 heads, ported LS6 intake, stock TB and a Z06 MAF. ......Do you think those 427ci's are being properly fed....NOPE!!!! He's got the equivalent of a 383ci breathing OK. His 420 RWHP proves it. He should be way over 500 RWHP with a proper top end.
Ls7 heads look good on paper, but a bigger runner and port doesnt always make for a better head. The poor placement of the valves and size of the ports drastially kills the velocity.
Find me some threads on here with 427 + ci motors making over 600rwhp with ls7 heads. I could post up three off the top of my head that make over 600rwhp and use TFS heads.
Call any of the reputable engine builders and ask them what they think the best head to put on a 454 is. They'll all tell you a cathedral port head, and probably a TFS head. Vengeance, LME, Etc and there's a reason for it.
Either way, a motor with unported, or even ported LS7 heads, will make just about the same amount of power as a motor with a nice cathedral port head such as the TFS if the motor is built right, and for it.
ANYONE who knows me, knows I have tried EVERY possible combination in my personal vehicle imaginabe. My "Personal" C5 has seen a stock H/C, Forged 347, Forged 403, Forged 404, forged 408, and finally my 454LSX. Not to mention a P1SC, D1SC, F1R, Kenne Bell 2.6, KB 2.8H, FAST 90 direct port, Sheetmetal direct port, and a FAST 92 2 stage. This has ALL been done in the last 2 1/2 years. Ask LME, They build my motors..

If its one thing I do, is test..

It is not difficult to determine wether or not your heads are flowing adequately. JUST because people throw around LS7 flow numbers doesnt mean ****. I can tell you for a FACT, that my heads are not to small for my setup. I can also tell you that a 26x cam with almost .650 lift is no slouch.
You are making statement on a point that has already been done, and proved otherwise. I know, cause it sitting in my garage..
Currently, I've swapped back to a slightly smaller cam, and a TPE ported FAST 92. Why?? Cause i lost 50+rwtq with the sheetmetal...
BUT....The motor got pulled this weekend for some additional parts testing. So if your willing to put your money where your mouth is, I'll put whatever you want on it. The motor will be at LME next week.
I'm willing to bet the title of my car that with LS7 heads and a 100mm TB, we wont hit anywhere near 700rwhp..

, nor will we gain very much more average HP/TQ.You tried a sheet metal intake on top of heads that can't pass the air along to the engine, so the engine never sees the air flow the sheet metal intake is delivering. Your weak link is the heads. You'll make the same power with 422ci. if you use those heads.
When someone puts together a 454ci, with a sheet metal intake (all the plastic intakes flow crappy comparitively), with a 101mm TB and a 101mm MAF (or no MAF, just go SD tune), heads that flow 400 cfm @ .650, and a medium to aggressive cam......you'll see a 700 RWHP powerplant.

