legacycentral bbs

I know this has been rehashed many time but I've look at all the treads and tried everything I can think of but I can't get more than 7-8 lbs of boost in first gear. I rallycross the car and would love to be able to pull 12-13 lbs.

I have a turbo xs mbc hooked in to the compressor outlet. I have no problem pulling 15-16 lbs in higher gears. I have the coffee mug mod, front mounted intercooler, new vacuum hoses, FCD, stock turbo.

I did the coffee mug before the MBC so the bottom hose of the stock boost solenoid is still pluged in to the mug. The other connections are plugged.

Any suggestions of what else to try.

The larger 16G has that amount of boost in 1st gear IIRC. You're going to need a larger turbo if you plan on doing 13ish psi in 1st.

I had that MBC too, bleed-style TurboXS - what a rip-off for a controlled leak, I could never get boost to be even across the gears - higher gears load the turbo more and change the dynamics of the leak. I believe a ball-and-spring MBC installed between the compressor outlet and wastegate actuator will allow for what you seek.

You can do 13ish psi in 1st with the wastegate actuator disconnected.... IIRC, you can do 20+ psi in 1st if you want, but its just not a good idea with the VF-10 or VF-11 stock turbos

Heck, I'm going to try disconnecting after dinner. I don't think I can get 20 psi out of the stock turbo at this altitude. Wide open only 12psi on top of the peak (pikes)

I had a ball and spring on it. did the same. That's why I bought the turbo xs deluxe w/ 2 adjustment. It's also got a really little hole on the input nipple.

If the disconnect works it will be OK for rallycross. I'm 3rd in open in CO

Justin, talk to me about your car 290.2337

Gotta eat

I really wouldn't unplug the wastegate on the stock turbo. You'll end up losing way more power. I had my car on the dyno with the turbo overboosting and it had an extremely short powerband. It actually made more power at 12psi than at 15psi. Stock turbo is pretty crappy if you want to pull more than stock levels of boost.

DONT disconect the wasgate hose, the factory turbo is perfect. i had a ball an spring a turbo xs dual stage 2 and there all SHIT.

what you need is a electronic boost controler, HKS, GREDDY, TURBOSMART, thats how you control the turbo at its best. i had a HKS ebc and i could hit any boost psi i wanted in any gear, but i sold it cuz i wanted a new one. now i got a TURBOSMART E-BOOST now this is the shit, total control over everything, an you can hook up a water sprayer and when you reach the boost u want it will turn it on.

Here is the results. I removed the wastegate hose, set my fcd to 15 lbs just in case and made a couple of test runs.

1 st gear boost up to 8 psi. and no higher.

I don't get it.

it wont work, takeing the hose of wont give u full boost it will run at 8psi like you siad, you need a eletroninc boost controller.

i see 15 psi in first gear

? I saw 20+ psi (in whatever gear, yes 1st too) whenever my wastegate was disconnected. In fact, it was how I diagnosed what went wrong. (what blew off).

azn2nr wrote:i see 15 psi in first gear

me too.....should we start the 1bar in first gear club for only the coolest people?

I tried wiring the wastegate closed with the same results in 1st.

So EBC whgould not be the answer I guess.

Anybody else have or had this problem with the stock turbo?

Wierd, man. Overboosting the stock turbo should not be a problem It quite happily spools up way past it's efficiency range any time you give it half a chance.

Maybe you have a VF-10 instead of a VF-11...? Are they that much different?

Edit: Perhaps your turbo needs a rebuild? A kit for the IHI RHB5 VF-11 runs about $95 at a local turbo shop, if you've got one of those nearby. You can get 'em on eBay too.

This is a used replacment dtock turbo. The old one which does need a rebuild did the same.

A flash! the bootom line of the stock boost controller is still going in to the coffee mug mod although the upper lines are plugged. Could this make a difference? How about the pressure sensor. Should that still be hooked. It is. Rally x sunday.


Ben

Clogged cat?

Well gutted cats....no emissions

try running with just the down pipe? pull the rest of the exhaust or hang it up/

Third in open class at the rally x Sunday. Faster than all the wrx's and STI's. Beat by a supercharged honda and a Mazda 323GTX by about 5 seconds a run. If I only had a little more boost in First I know I could be faster

This morning I pulled the exhaust fron the down pipe back. Thank goodness I have a lift. It sounded real loud, but no improvement.

Keep those suggestions coming...

I'm still gonna go with rebuild or replace turbo...

I talked to the guy who tuned Robbie Unser's Pikes peak car last year and he said that the stock turbo was limited by the ECU in first. He said the only way around it was a stand alone managment system or a bigger turbo. I guess as soon as I can afford it I'll pick up a 16G.

Nah, I don't buy that. I used to get around 12-13 psi on my VF-11 that was set to 16 psi in higher gears.

I also had my MBC turned all the way in (instead of out) when I first put it in and did my tune run. The turbo spooled up to 20+ psi quick as shit. I immediatly turned it down obviously.

I think I found a loaner td04 to try. I know its not much improvement but if it i'll boost more in first I can buy it for $100.

Thanks legacy92ej22t for the info. The guy is really full of himself.