Where oh where did my boost go? - ScottR or Lawrence....
 

Hey everyone - long time no type.

I was at the track last weekend for 3 days here in St. Louis and had intermittent boost problems.

I have a VDO guage along with the stock guage on the dash cluster. I ALWAYS have gotten a strong 15psi in every gear. Last weekend I would fluctuate between 10 psi and 14 psi all weekend. Strange thing was it seemed to be related to gravity and what gear I was in. Coming out of one right turn in 2nd or 3rd I would loose boost and then the next left in 3rd I would get my 15psi but the same turn in 2nd I would get only 10psi. Totally frustrating (especially when some guy in a C5 is keeping up with me)!

I have Autothority Stage II chips, Forge Wastegate and all of my vacuum lines are zip tied at the t's or connections (except for the cycling valve). Checked everything and even replaced a couple of hose clamps that were not tightening like they should when new.

I am thinking wastegate but have never had one go bad. I checked the turbo rotor out and it looks great and spins nice and free. Are these wastegate symptoms?

Thanks in advance!

-g

How is your boost regulated; stock setup with modified banjo bolt or do you have some sort of boost controller?

Yes, I have the same question as above, also is your cycling valve still being utilized?
Ahmet

Same question, do you still have the cyclic valve in line, is this a MBC setup?

Sorry about that.

LBE and modified banjo bolt that came with the Autothority chips.

Stock wastegate no boost controller. The cycling valve is inline - just could never get to it when I zip tied all the other line connections.

all you need is the lbe and stock banjo bolt, eliminate the cycling valve completely. The lbe is a manual boost controller.

You have 3 things manipulating the boost pressure, make it simple with just the lbe set at 15#'s, then see if you have the same problem. I'd get new hose to run all the way from the banjo bolt to the lbe then all the way to the wastegate; the old factory hose to the w.g. will be brittle.

Lindsey Racing has an excellent procedure with pictures on how to eliminate the cyclic valve here is the link: (it's actually on how to install their dual port wastegate, but it shows what to remove to get the valve out of the loop.)

http://www.lindseyracing.com/wginstal.htm

Thanks for the info. I will try the suggestions and see what happens.

-g

Not to take away from this post, but does anybody have a stock cycling valve?

Geofbaltz, you shouldn't use all 3 boost control methods, inline. If you have the LBE (which is a check valve type boost controller itself), then you certainly don't want the restricted banjo bolt.
Ahmet

Not I, mine was cracked when I purchased the car.

Ahmet-

I replaced the Autothority Banjo Bolt with the stock one when I installed my LBE. Forgot about that - it was a while ago.

So I need to just follow the directions on Lindsey's site about the wastegate install when they address taking the cycling valve out of the loop?

BTW, my LBE is set at 10# as suggested by Lindsey when running 15# of boost.

Something doesn't add up...

If I follow the instructions on removing the cycling valve then I am unplugging my LBE on one end. Where does this go then? Directly to the wastegate with new hose? Then should I re-adjust the LBE to 15# instead of 10#?

-g

Yep!

Ahmet, I have a few good ones if you're needing one

you've got mail!
Ahmet

hmmm, didn't get it, $27.50 including shipping via UPS ground

How much would you want for both?
Ahmet

$50 is fine; if paying via paypal, I request an additional 3.25% to cover their fondling fees. let me know if interested. Needing anything else?Jared 417-850-1863

Since we've adequately hi-jacked this thread already...

I might be interested in one cycling valve at that price. I'll let you know when these auctions I'm bidding on are over! What else do you have?
Ahmet

anything and everything 951 related, lightened flywheel, cheater turbo, knife-edged/lightened, perp-drilled, allen-screw plugged, and balanced crank, misc. int. and suspension, body, hatch glasses, mirrors, 8 valve 3lt turbo head, stock 951 head, rebuilt n/a head, stock afm, stock turbos, wastegates, exhaust manifolds, x-over pipes, catalytic converters, forged rods, etc. I've been playing with the 951's for the last 10 years so I have a ton of stock misc. parts that I need to get rid off.