Need some whipple 4.0 help please

[12gt500]

Hey guys I was considering getting a 4.0 Whipple. And I had a couple of questions concerning boost. And my question is whit stock cams and stock heads what is the least amount of boost I can make with a 10% lower. The reason I'm asking my fuel system is a dual wallboro 465's and injector dynamics 1300's on e85. And I want to make sure if I get a whipple 4.0 my fuel system can handle it.

So so in a nut shell what's the largest upper pulley I can run. And how much boost will it make with a ati 10% lower.

 

[1320 Junkie]

Let me first ask this.. stock bottom end?

 

[12gt500]

No. I have a built short block. I built it last year you posted a few times in my thread. I was actually hoping you would chime in. Because I thought you went to a 4.0 from a 3.6 right? I am only asking because I am concerned if my fuel system is enough to support it on e85. I know when I put on my kb 3.6 Lund didn't want my 23-24psi pulley on. Said my fuel system wouldn't handle it.


So that's why I am here.

 

[stkjock]

10% OD and a 4" pulley should make around 20-21

Mine made 24 with a 10% and the 3.75 IIRC

lLund felt u would need more pump?

Now mine is stock damper and 3.875 making 20-21

u have a stock hood? Lowered motor?

 

[12gt500]

Cervinis cobra r good. But I think I am going to lower engine to put stock hood back on.

Yes Lund wanted a triple 465 to run more boost. That being said I never finished tuning with him to know my pump or injector duty cycles.


I know the 10% lower adds 3-4 psi on the kb. Does it not add as much to a whipple? Also stkjock I have stock cams can that be the difference in boost numbers on your engine?

 

[stkjock]

it could be a bit of a factor, I also have Kooks, o/r X and 3" Magnaflow cat back

 

[12gt500]

I have dynatech 1 7/8's and o/r x.

 

[serickson1]

I must be missing something……your current fuel system was not enough to support a 3.6KB on E-85 (you need a triple hat to support E-85 with 1300's) and your thinking of spending money on a larger blower WITHOUT upgrading your fuel system…..you have this all backwards….fuel system FIRST…bigger blower second…….you will make tons of boost with stock cams and 1 7/8" headers with a 4.0…..22-24 range with 4" upper and 10% lower...

 

[12gt500]

Well that's what I was asking in my op. Which i still need some help on. Is my fuel system good enough? And what amount of boost/rwhp will it support on e85. Also my feed is -8 and return is -6 I believe.

 

[serickson1]

Lund already told you it wasn't sufficient with your 3.6….unless I missed something…so…NO…its not sufficient for a 4.0 at ANY boost level….replace it with 3 pumps, AN10 and AN8 lines….otherwise keep what you have on low boost…..your fuel system is the MOST important part of your big blower, built motor, set up…..treat it as such or your motor will go BOOM...

 

[stkjock]

If the man who has more experience with these cars than nearly anyone else tells you you need more fuel..... Why would you question it?

 

[serickson1]

Exactly….

 

[1320 Junkie]

Triple 465's for sure... -10 feed...-8 rail lines...-6 return ..that's what I run along with 1700's now bud....along with fore rails.

Any other questions let me know.