ChevyChad

iTrader: (50)

I did explain why it doesn't make a noticeable difference in the first reply.

And yes, a ported fast at 16psi will make more power than an LS6 at 16psi. Problem is, you'd have to up the output of the turbo to get the FAST to 16 psi if it was already at 16 on the LS6. But then, your 'extra power' isn't coming from the ported intake, its coming from you upping the boost on the turbo.

speedracer5532

iTrader: (8)

Maybe for people wanting to go forced induction and don't have a FAST then yes it is alot of money over the LS6 but when you already have a ported FAST then your options are different. I agree with Patrick that I think a ported FAST will make the same power as a LS6 with less boost because it has less restriction.

Patrick G

iTrader: (14)

It's always easy to turn up the boost to make more power, but if you're making a killer pump gas combination, wouldn't you want the most power with the lowest boost possible?

Let's say that if we find that 10 lbs of boost is the limit for pump gas without adding methanol, we would have to turn the waste gate down to 10 lbs right? If that's true, then which combo would make more power at 10 psi?

MIGHTYMOUSE

iTrader: (59)

would the intakes need to be tested again this time pushing air through them rather than drawing air through them?

only when an FI system is totally maxed out would this be a real option to gain output

anything below being maxed out, and well thats the beauty of FI, turn it up! especially with a turbo; its free!

don't forget psi is just a number. you arent really saving your motor from extra stress by throwing thousands of dollars on top end parts to get a lower boost read out. The power and tq you make is the indication of the stress

i'm sure some racing teams somewhere have measured and determined what is acceptable pressure drop across an intake (much the same way as manufacturers have found this info for intercoolers) if not sounds like there are some volunteers here.

keep in mind the size of the piping running up to the throttlebody, for example i have 3" pipe so it doesnt help to have a t/b or intake with a larger opening.

SUPERBOOST

iTrader: (11)

If you were doing a large single setup and had no intake,and if they all cost the same,which would you use?Ls6,ls2,fast 90,victor jr,or gmpp?Lets look at it like that.Opinons?

hellbents10

iTrader: (10)

Right the intake is not going to help make pump gas power. That is a matter of cylinder pressure, tuning, p/r's, and the type of fuel you are running.

black01_WS6

iTrader: (13)

I still like the ls6, given the options and if they were the same cost. I am still waiting on seeing the new weiand intake coming out- it looks promising for FI.

SUPERBOOST

iTrader: (11)

I guess its just the old school in me,I realize f.i. is different but it makes more sense to me to build the best flowing engine you can,heads,cam,intake,etc. and then turbocharge it,Would you not make more power overall?

Patrick G

iTrader: (14)

While I would agree that power equals cylinder pressure and cylinder pressure determines octane resistance, would a manifold that makes the same power with less boost give lower intake air temps? To me, 650 rwhp with 8 lbs of boost would have lower intake air temps than 650 rwhp with 10 lbs of boost (even though the cylinder pressure would be the same). Does lower IATs matter in a pump gas application? I always thought so, but I learn something new every day.

rao

iTrader: (18)

Lower IAT will help in a FI application. The real question here is cost/benefit and on that score I'd bet that the FAST in not in the ballpark for most people.

Patrick G

iTrader: (14)

I'm sure cost effectiveness is an issue for most, but if you already own both manifolds and want to run the one that makes the most power, which would you choose? LS2, LS6 or ported FAST? Again, I asked which one was best, not which one was best for the money.

rao

iTrader: (18)

The FAST is "best" aside from the people who blew them apart Best in this case doesn't mean that the difference will be material or even large.

hellbents10

iTrader: (10)

In the turbo world that turbo is still moving the same amount of air. So the IAT's would not vary that much. Then again we are all still bench racing here, it would be nice to see some solid results. You might be our guy Patrick? It would be nice to see power@boost givin boost level, exhaust pressure before the turbo(s), and IAT's for both intakes. Also what role if any the two intakes would play in the amount of ignition advance you could run on a certain fuel.

Inspector12

iTrader: (29)

Man this is beating a dead horse really. Just do what you want and it's going to make great power anyways LOL! Boost is just a measurement of resistance it has no bearing on IAT's, but what does is the output from your turbo or other means of pusing air etc... If you work it harder the temps will rise and with that so will the IAT's. So what I am saying is if you are looking for a specific boost number then it might matter if you are looking for a specific power output then it doesn't.

kp

iTrader: (34)

More 'boost' doesnt always mean more heat, generally with a compressor more airflow = more heat.

I have switched between a fast 90/90 and an LS6 several times. like anyone else who spends 1300.00 on an intake I wanted it to make more power but I never gained a thing, 'boost' didnt change either. I have a victor JR/elbow/90mm here but I have never got around to trying it, dont thnk with 15+ psi anything much matters except cross section of the runner.

If you have both try it for yourself and see, not something thats really hard to swap..

hellbents10

iTrader: (10)

I agree with KP, if it was me I would have a ls6 intake and TB on it.

HUNTER02SS

iTrader: (24)

If I was to do it over again I would use the ls6 intake if you already have it. I use the vic jr and elbow,but honestly it was more for the cool looking factor.I was concerned about the #7 cylinder also and hoping equal lenght runner's would help that ! Ls6 intake is just fine!

Frost

iTrader: (45)

Meth usually makes IATs a non-issue except in extreme applications. My IATs at 16psi are always well under ambient and the octane is nice too

Tony Mamo @ AFR

iTrader: (13)

I've only got a minute or two (buried today) but my thoughts are this...

FAST manifolds "coming apart" and "failing under boost" are all Internet wives tale just like 90mm FAST intakes are "too big" for stock displacement applications (we all know thats BS....at least the sharper tech guys among us). How many times have you seen that same dribble in every FAST thread that comes up?

Has anyone actually seen a FAST that has failed under boost?? (if so how much boost?).

A manifold that has a superior shape and design, is less restrictive (with a larger cross section), and makes more power N/A due to all of the above will naturally make more power boosted (assuming the same PSI), BUT, part of the boosted equation also assumes camshaft and exhaust system is optimized for the boosted combination or some of the benefits of the deeper breathing intake wont make its way to the rear wheels.

With any boosted application you must focus and place a serious emphaisis on the exhale side of your combination. If your not properly evacuating that cylinder and making room for a fresh intake charge power is going to start to fall off.

Is a FAST (or ported FAST) as important on a boosted applicaition (versus N/A)? I would say no because its all too easy to run a slightly smaller pulley on the blower yeilding similar power....a luxury that an N/A application doesnt have.

I have helped a handful of guys with serious boosted applications and all of them have had zero issues. Most of these guys are in the low/mid teens on boost pressure, with John (speedracer) pushing it a little more at 18 PSI. All of these combo's have made excellent power and while Im sure an LS6 wouldnt have been a huge difference, Im confident the better flowing less restrictive FAST helped them achieve more. It would allow more air to reach the combustion camber (under the same boost level) due to its less restritive superior design, assuming there was room in that cylinder with a properly designed camshaft and exhaust sytem to enable that to happen.

Also, just because your pushing on the air doesnt mean the more restrictive LS6 intake will even the score. The pressure drop across the LS6 will always be greater requiring you to push that much harder on it to get the same amount of air thru (compared to a FAST or any other free flowing manifold design which will allow the same net airflow at lower boost pressure).

Regards,
Tony

MIGHTYMOUSE

iTrader: (59)

OR

either way, 800rw is old news for an ls6, so if 800 is all you want, then using the FAST would be a waste on that particular car.

now if you had a 400 inch motor and were shooting for 1200 at the tires i woud maybe go ahead and throw the fast on if i had it laying around