Being my combo just did not come to realization this year due to some vendors taking way to long and my travel schedule, I have decided to for the most part decided to step back and rethink my combo.

My current combo when I use Desktop dyno to get a estimate of power produced peaks @ 7500 rpm and drops only 17 hp by 8000 rpm. It says it makes 628 @ 7000 & 629 @ 7500.

That is using the generic sequential intake template.

When I put on a single plane setup (again, generic setup), it adds roughly 50 hp at those levels...quite a bit of difference.

So obviously, my combo is going to NEED to shift high to get the numbers I want (9's)...which brings me to a dead end because of the stock computer and it's inability to go higher than 7200 rpm.

So what I am curious about is how much of a difference in ET/MPH by simply using my stock computer/fully ported LT4 intake and shift @ 7200 opposed to like 7800'ish with a FAST or equivelant system? I have some guesses, but I am curious to what others might think?

 

Not nearly enough info. What cam are you talking about? What kind of a TB on the single plane? What single plane? And so on.

Rich

 

This is going to get into a whole can of worms here....

 

I was thinking along the lines of a 1300 cfm TB and a converted to EFI unit from Bret.

My current list of mods....

Topend:

AFR 210 heads
2.200" intake valve / 1.620" exhaust valve
Solid roller springs with 300 lbs closed, 680 lbs open
Stud girdle, lash caps, everything else that goes with this.
Completely ported LT4 intake(with optional distributor hole already there...for future plans and opened for a Mono-blade).
Every bolt on you can think of...58 mm tb, cai, wp, Delteq, etc...

Heads flow:

-Lift---INT---EXH
.100--100.3--61.4
.200--165.2--115.9
.300--222.5--154.4
.400--262.5--209.3
.500--289.2--221.9
.600--301.4--235.8
.700--307.5--251.0

Cam:

Very aggresive ramp rate solid roller 104 CL, .657/.657, 257/261 duration
solid roller lifters and everything that goes with this.

Engine:

LT4 block with 4 bolt mains with Milodon billet main caps
Callies Dragonslayer 3.875" stroker
5.850" Lunati Pro rods
Diamond pistons - 1/16", 1/16", 3 mm
custom rings gapped for nitrous
Canton oil pan with correct pickup
Melling oil pump

Exhaust:

Kook's 1-3/4" to 1-7/8" stepped headers...custom dual x-over 3" exhaust with turndowns before the rearend.

Drivetrain:

TH-400, t-brake, spragless, TCI trans-shield, TCI flex-plate shield
Neal Chance converter, 4300 rpm on motor, 5000 rpm on spray
Mark Williams 4" driveshaft
12 bolt, ta cover, 33 spline, c-clip elims, etc...

Suspension:

BMR k-member, a-arms (upper & lower), KBDD subframes, BMR drag sway bar, BMR xtreme LCA's, Spohn custom TA

Fuel:
50 lb Delphi injectors
Racetronix in tank and in line fuel setup

Power adder:
NX 150-200-250 hp shot system with bottle heater

 

It seems to me most of the gain would be higher rpm. Your cam is gonna want to rev high. IMHO the single plane would shine up where the cam is gonig to run but the stock PCM won't take you there and will be a serious limitation. But I defer to someone like Bret who has more experience with that kind of combo though. It would take a more sophisticated simulation than DD to model this kind of thing.

Rich

 

This is a 396 stroker right?

I can tell you this much... I have very intimate knowledge of a 406 small block with a cam verrrrry similar to yours, super vic, afr 210's with very similar flow.... peaks with ~600hp at 6500 rpm. I can't see a 396 going 7500rpm with a cam this size. The heads are IMO too small to breathe up there.

Not trying to burst your bubble but I'd plan on seeing a peak somewhere before the PCM cuts you off.

-Mindgame

 

More to your question... sorry if I missed it...

I think the LT1/LT4 intake has a few hundred rpm (peak HP) on the single plane carb intakes. The single plane conversion is going to be worth more HP though.

While we're on that subject.... have any of you guys seen the Holley EFI intakes? Found it kinda cool that they went the next step & built one for the 23º raised runner guys.

I'd like to hear any opinions... not to get off course here but I think it might tie into what you're trying to do Canton.

Good luck.

-Mindgame

 

Alternatively, I could defer to Mingame, who also knows more about these combos than I do.

Rich

 

Thanks for the replies.

About the software...what would you recommend?

 

Engine Analyzer Pro.

Rich

 

Hmmm...bunch of things I have read about there....now to get the information there I need.

I do a quick setup though....633 hp @ 6700 rpm & 517 tq @ 5700 rpm using basic info though.

My DD shows it pulling much higher....very interesting...you have a lot more options to toy with.

Thanks.

 

Ok....

Those must be king kongs lobes because 300 seated is a ton of pressure.... I'm not going to get into that all now.

Luckily you have the huge valve in there, which is a good thing on this setup. The motor with that lift and valve will be happy to 6700rpm, after that it's not going to make any more power or peak higher. Just seems like there is more duration in there than their has to be, and more overlap than the stock computer can handle so tuning is a beotch.

Now I hear guys say that the Super Vic is only for high RPM.... but I've never heard them say why. Which doesn't suprise me. You are going to have more cross section with the Super Vic, but also longer runners. We can debate on that all day but its not the worst thing in the world, the Accel SBC single plane is not a bad way to go either, I've converted one of those as well. The thing that is lacking on the combo now is the plenum volume and runner length. Which a single plane will fix. The big thing is that it's going to make more TQ, and probably make that cam a little more usefull, but also screw up the intake to exhaust ratio.

Bret

 

Yep, and lots of experience with it if you want "PROfessional" results.

 

I just want to get the thing actually running and see what it does instead of all this internet dyno...

Tuning wise, yeah, I imagine it is going to be a bear and run rich I.

My big hold ups are to much gearing for the n2o & the low stall on the motor.

 

Just finished mine. Dyno numbers next week.

http://www.afbforums.com/index.php?showtopic=16900

Tony Shepherd