How to soften the low-end hit on a 434" w/Whipple 3.3?
#1
How to soften the low-end hit on a 434" w/Whipple 3.3?
I'm thinking of doing a side-mount, A2A-intercooled Whipple 3.3 on the 434 SBC I'm building, but am a bit concerned about the instant off-idle torque blast. Either I pulley up and limit total boost and power or figure out how soften the hit a bit.
The 434 alone is going to have some traction issues. I'm already planning to change the rearend ration from 3.73 to probably a 3.23 gear.
Any other ideas? Comments? Please - No 'do a turbo setup' comments though - that's not happening.
Thanks,
Jim
PS This is a G-body project with a built 4L80E. Target is a great all-round driver that also holds its own up with anything to about 150mph where my Malibu 'barn-door' aerodynamics will really kill me.
The 434 alone is going to have some traction issues. I'm already planning to change the rearend ration from 3.73 to probably a 3.23 gear.
Any other ideas? Comments? Please - No 'do a turbo setup' comments though - that's not happening.
Thanks,
Jim
PS This is a G-body project with a built 4L80E. Target is a great all-round driver that also holds its own up with anything to about 150mph where my Malibu 'barn-door' aerodynamics will really kill me.
#6
My vote is to use a very late IVC. This will kill some low-end and increase top-end, without affecting idle quality or fuel mileage.
Most performance cams use an IVC between 40 and 50 deg ABDC. You could go to around 55-60.
Mike
Most performance cams use an IVC between 40 and 50 deg ABDC. You could go to around 55-60.
Mike
#7
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I say re-learn part throttle if at all possible... you're in a better position than us turbo guys that are losing traction: you can kinda roll into the throttle, while we have to try to get the turbo spooled with initial WOT and then pedal back just enough to keep traction.
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#9
Don't have a lot of experiance with this but how about using an auxillary output on your ecu to crack open the bypass on the supercharger? Could be as simple as a solenoid with adjustable mount and 12v switched power.
#10
Thanks - some good ideas. The bypass valve one is what I was thinking - I do have a couple ECU Aux outputs. Definitely expecting to learn new throttle control
Not a problem I ever expected to be thinking about! The past ten years have opened up so much more in performance it's just just stunning. What a cool time to be into cars...
Mike - I already got this new solid roller to try with the Vortech, so I'm gonna give it a try on the Whipple and see what happens: 9.5:1 CR, cam is 242/248@.050" on a 115lsa, .60x/.61x net lift). I think it's too short to qualify for your idea, eh?
Jim
Not a problem I ever expected to be thinking about! The past ten years have opened up so much more in performance it's just just stunning. What a cool time to be into cars...
Mike - I already got this new solid roller to try with the Vortech, so I'm gonna give it a try on the Whipple and see what happens: 9.5:1 CR, cam is 242/248@.050" on a 115lsa, .60x/.61x net lift). I think it's too short to qualify for your idea, eh?
Jim
#11
You could put it in 4 deg retarded. That would put IVC at 60 ABDC.
#12
I mentioned this thread to one of my co-workers earlier today with a works 2.3L Lightning and his reply was "why doesn't he just put a bigger tire in the back?". Had a hard time not smacking him, I realize sometimes people arn't willing to tub a car and there are space limitations. Must be nice to fit a 30x16.5-16 slick out back without any modifications
#16
Why change the powerband all over when you can just effect everything below whatever RPM you want. If DeltaT wanted to get fancy with it he could use this as traction control also if he uses the ECU/stepper motor. Honestly while retarding the cam is easier it seems ignorant. There's plenty of other good ways to kill power down low other than messing with cam timing.
*edit* 4 degrees of cam timing is A LOT. I could understand this approach if it was just effecting the intake but not when all the lobes are on a single cam.
*edit* 4 degrees of cam timing is A LOT. I could understand this approach if it was just effecting the intake but not when all the lobes are on a single cam.
Last edited by Drew04GTO; 02-16-2008 at 03:08 AM. Reason: bleh
#17
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I know it was mentioned already... but alot of the guys have been playing with lower gear ratios... like 3.23 and below.... there are some turbo guys that are runing 2.70's on the board but I dont know how that would translate to an S/C application...
#20
Why change the powerband all over when you can just effect everything below whatever RPM you want. If DeltaT wanted to get fancy with it he could use this as traction control also if he uses the ECU/stepper motor. Honestly while retarding the cam is easier it seems ignorant. There's plenty of other good ways to kill power down low other than messing with cam timing.
*edit* 4 degrees of cam timing is A LOT. I could understand this approach if it was just effecting the intake but not when all the lobes are on a single cam.
*edit* 4 degrees of cam timing is A LOT. I could understand this approach if it was just effecting the intake but not when all the lobes are on a single cam.
Also, wouldnt changing the opening or closing of the valves (intake or echaust) cause u to lose some torque down low perhaps?