2.3L Whipple owners in Houston

[StangLoveR]

I'm guilty of posting this here in hopes that in the high traffic someone on my side of town will see it.

Is there anyone near Pearland that has a 2.3L Whipple that is around this weekend? I'm suspecting my bypass valve as the cause for an issue I'm having and wanted to see what the valve feels like on another whipple (how it feels as it moves through its entire range of motion). This is a 5-second engine-off check.

Anyone around?

 

[NickSezz]

What issues are you having?

 

[StangLoveR]

I'll note first that this issue only started happening after I swapped from the 525hp Whipple/FRPP injectors/pulley to the 3.375" pulley and ID1000's:

When I tip into the throttle, even gently, there's a delay or lag before the throttle gets to where it should be.

Tune-wise things are looking good, so I'm suspecting the bypass valve not operating correctly. When I move it through its range of motion, it has a rough spot or two toward the end of its range. I loosened its mounting screws and manipulated it a bit but regardless of how I mount it, the throw of the lever is not smooth throughout, and if you let go of it just right it can actually hang without closing. So I'm thinking that might be the issue.

And that's why I want to check out someone else's bypass valve.

As for the valve keeping vacuum, I did a rough test by rotating the valve all the way open and plugging the nipple with my finger and it holds just fine (from what I can tell from this test anyway).

Finally, to check whether it was the assembly within the blower itself is rotating freely, I unbolted the bypass from its mount to eliminate the spring's effect, and sure enough it rotated nice and smooth.

A question I'll surely have for this weekend (I'm having shipped a new valve just in case to swap this weekend) is how do you actually replace the valve? I'm planning on calling Whipple but might as well ask here! I assume I need to remove the blower completely - yay.

That's actually not the worst thing in the world since my gauge is telling me its making 6 lbs of boost whereas with this pulley it should be making ~10 lbs, so in eliminating possible problems removing the blower will give me an opportunity to reach the lower intake bolts to make sure they're still torqued properly, etc.

This is pretty frustrating........

 

[NickSezz]

Honestly is sounds like this might be related to who calibrated the car after the injector swap. A relatively easy way to tell would have been to swap injectors and try the old tune and see if it fixed the problem. The pulley size is really not a factor here.

The way you are describing the movement on the bypass sounds normal. There should be a slight preload on the lever arm when its mounted and adjusted properly.

There are tables in the tuning software for throttle delay that may need some tweaking. You will get a lagging effect if this delay is too long or if the throttle opens too fast. When these tables are changed fuel timing also has to be changed to come in quicker/slower depending on the adjustment.

As for only hitting 6psi, that is lower than what I would expect. Did you take this reading before or after you messed with the bypass? We normally re-rout the vacuum line for the bypass to see boost. That way when under pressure it ensures that the valve stays closed.

Good luck!