Super Vic Intake v. Fast 90....????

[Fast SVT]

Trying to get some more power out of the stroker because I think my FAST 90 is a bottle neck right now with the ETP 245 Heads.

Is there enough to be gained by swapping to this intake with the ETP 245's. Seems to be varying opinion on this.

http://store.summitracing.com/partdetail.asp?autofilter=1&part=EDL-3847&N=700+0&autoview=sku

http://store.summitracing.com/partdetail.asp?autofilter=1&part=EDL-3847&N=700+0&autoview=sku

[Yooformula]

how much would you sell your fast 90 for?

[SLOWC5]

why not a larger cam?, I dont believe the FAST is your issue

[Fast SVT]

Just put in a larger cam with the same issue. Power is dropping off at 6200.

old cam is 235/240 and new one is 243/251

[SLOWC5]

Whats the compression on that motor? I assume it's a lot lower than an NA motor being they built it knowing your going to spray the car. So on the juice I'm sure the motor is making more power than you might think.

[Poncho]

Isn't it widely known that the L92 stuff has issues breathing beyond 6500?

[Fast SVT]

only thing l92 specific is the block.

Heads are ETP 245's (huge intake runners) and the intake manifold is a ported FAST 90.

Also running 1 7/8th headers.

Really just seems like an intake issue, unless there is something about these blocks that just hasn't been worked out yet with matching an h/c package to the larger bore and stroke.

These LS3/L92 strokers are not making very much more power than the 408's, though they do make significantly more torque.


have not had a chance to get N20 numbers since Speed INC is working through some issues with it, trying to find out if it is a progressive controller issue or wiring.

[forest]

I actually agree somewhat with slowc5 I would lean more towards valvtrain issues. What kind of valve springs are you running? what is the closed seat pressure, open seat pressure at your max valve lift, type of rocker arm you re running, how thick are the pushrods and who made them, what type and brand of lifters you got, what is the size of the valves, and what is the exact grind on the cam. also, comp ratio, bore size, rod length, stroke, how was it balanced, wieghed or spun up? and if spun, was EVERYTHING spun with it? such as balancer, front bolt, rods, pistons, pins, rings, pin retainers, rod bearings, crank, flywheel, clutch cover, and all related hardware? lets get some more details and see if we can determine the issue. Who knows, maybe it is your intake....

[SLOWC5]

last time I checked the LS motors are internally balanced. But definately need more info on the whole engine

[Fast SVT]

I am pretty much dead on power wise with other similar builds, only L92 stroker builds I have seen break 500 are usually manual cars. So that leads me to believe I do not have any valvetrain issues etc...

I just think it is odd that 402/8's are making close to the same peak HP (470-490) as these 416 builds. But with that said the torque is a lot more in the L92's (470-490) versus the 402/408 (440-460).

Why this is the case I do not know, I was hoping for 500-520 rwhp N/A considering the money spent, so now I am trying to find out what component is holding me back....maybe I need to go significantly bigger on the cam?

[BAD LS1]

Good luck getting those kinda #s out of a auto with a unlocked converter. If the car was a 6 speed you would see the power you were hoping for right now. I think thats a pretty good running engine/tune to make those numbers it is now and it pushes that big kangaroo along that fast, there aint nothing wrong with it.

Its a big torque motor... it doesnt need to spin to 7k like a 346 to make more power... big deal if it goes static at 6200 IMHO.

However It does sound like either a valve spring or valvetrain geometry issue to me... or it just so huge of a cam its pushing the outter limits of hydraulic lifters too.

All LS's are internally balanced and dont need anyhting but the internal rotating parts for balance.

[Fast SVT]

Thanks for the input, this is what Speed INC said about the new cam:


The vavle events of your new cam, are almost the same as ours, same intake valve closing point. 50º ABDC

The intake valve opens earlier, which IMO disturbs air flow velocity.

The exhaust valve opens sooner which will work better with nitrous


With that said I do not have any N20 numbers yet (hoping for 650+), they are working through some wiring issues on it and bumping it from 150 to 200.

I also got my new Holeshot Wheels in.......fully tuned on the holeshots I should be seeing low 10's and maybe a high 9 with a great 60.

[forest]

Good luck getting those kinda #s out of a auto with a unlocked converter. If the car was a 6 speed you would see the power you were hoping for right now. I think thats a pretty good running engine/tune to make those numbers it is now and it pushes that big kangaroo along that fast, there aint nothing wrong with it.

Its a big torque motor... it doesnt need to spin to 7k like a 346 to make more power... big deal if it goes static at 6200 IMHO.

However It does sound like either a valve spring or valvetrain geometry issue to me... or it just so huge of a cam its pushing the outter limits of hydraulic lifters too.

All LS's are internally balanced and dont need anyhting but the internal rotating parts for balance.

agreed except when building a motor, you never know what you are getting from the aftermarket company that makes the product, ALWAYS spin the WHOLE assy up just to be sure, it costs no more $$$$ and is worth the knowing its right. But maybe thats just me, I would rather overbuild somthing than stop short based on somthing so simple. to each their own......:thumbsup