schnellfahrer

Can someone tell by looking at this picture at what boost the Reliaboost is set? (I see no threads). This is how it came from Guru.
Thanks!

turbo951fan

It looks like it is on max boost setting. If its with the standard spring then max boost is around 16 PSI.

Jake951

Yes, it is the maximum boost setting. The more threads that are showing, the less the boost. On my car, the maximum setting produces way more than 15 psi, but I'm not sure if mine has the same spring as yours.

schnellfahrer

If I remove the locking nut I can see maybe 5mm of threads. I just came back from a testdrive with the Guru chips and the Reliaboost. There aren't any long straights nearby, but I did get a chance to see max boost in 3rd. 15-16psi. I also see 15psi in 2nd. I'm waiting on a new wastegate, and I didn't bother to get underneath the car so I'm running the Reliaboost through the CV and stock wastegate. I didn't see any spiking in 2nd or 3rd.
I'll leave the Reliaboost at it's current setting until I get the new wastegate installed.
Thanks for the help!

KLR

That sounds about right. The amount of boost that you get on a given setting really depends on your wastegate's condition. If your wastegate is going south, you won't be able to get more than 12psi or so no matter how you set the stock reliaboost. If you are shimmed, then you can usually get about 15psi in 4th with a couple of threads showing. Without shims and with a good factory wastegate, setting it to max boost should give you about 14-15psi, although it will drop back to 12-ish at high RPMs.

There is variability with every car, so it's appropriate to expect to have to adjust it. When you put the new wastegate in, be sure to back it out several turns and adjust from there.

schnellfahrer

Thanks for good tips!

toddk911

You can also change out the spring in the reliaboost.

schnellfahrer

I recorded the boostgauge with my cellphone a couple of times while doing some 2nd gear pulls. I get 15psi rather late (~4000rpm) and it drops quickly to 12psi (~4700rpm). I also seem to get boost in stages. Feels like I'm getting a kick at ~3200rpm and then another at ~4000rpm. Could this be because of weak WG or not bypassing the CV?
I think the boostcontroller Danno sells are set up for 18psi.

KLR

I assume from your reference above to "waiting for a new wastegate" that you have not shimmed the old one. I am in the same boat. I ordered a new wastegate Monday, so hopefully it will come in next week.

With the stock wastegate, falling to 12psi in the upper rpms is typical, as is much slower spool up. I'm not managing to get above 12 psi at all, even with the reliaboost fully tightened. I believe that this is either due to my wastegate being toast or the fact that one of the four studs that connect the small crossover pipe to the wastegate is broken. I think that this is a relic of the clutch job that the car got last year before I bought it, as the three bolts that attach the other side of the pipe to the crossover are brand new. A very reputable shop in Metro NYC left it this way, which is another good argument for DIY. So is the bill for $4500 for the job (also included a steering rack and other miscellany).

In any case, I get the stairstep effect as well. I think that this is due to the car stuttering a bit as it runs rich due to the improper boost level. Your replacement wastegate will likely make this go away.

schnellfahrer

Good info KLR. I have not shimmed the wastegate. I'm waiting on a Guru modified wastegate. Should arrive within a couple of days. I thought that the Reliaboost more or less made up for a bad wastegate. That it doesn't send any air to the wastegate at all untill it reaches its preset. I guess the fact is that the wastegate bleeds pressure all the time, regardless of being fed air from the Reliaboost or not.
This actually means that I can expect even more power from my set up than I have now! The car is scary fast as it is. The roads are wet outside now and the car is more or less useless. The tires brake loose in every gear (except 5th).
I just love this car......

Danno

"I thought that the Reliaboost more or less made up for a bad wastegate."

No, the Reliaboost controls only 1 of 2 variables that determine when the wastegate spring opens. It only controls pressure on the diaphragm and the other variable, exhaust-pressure on the valve head is controlled by the spring. It's the sum of these two forces diaphragm-pressure and exhaust-pressure that opens the valve. We have to manage both of them in order to get a flat boost -curve. By increasing spring-tension over 2x stiffer than stock, we reduce the contribution that exhaust-pressure makes to the overall sum of opening force on the valve (thus more weighting on the Reliaboost).