Boost....and a bit about controllers

[Steve Wood]

I have been helping someone for the past year that was a newb to Buicks...  Got him down to mid 11's on a 5831 turbo or whatever the replacement for the 44 is called (running alky) on default timing with a TT chip.

For months, I kept telling him that it was not normal for his O2s to go to 000 for a second when he stepped on it.  He kept arguing that his car always did it and he had no timing retard on his SM.  I told him that he was going to blow something pretty soon if he did not quit arguing and figure out what was wrong.

Of course, he blew both head gaskets.  Eventually he discovered his maf was bad.  He took out another set of gaskets a week after the first.

Then he starts telling me that he had learned on the Net that 28 psi was where his turbo really came into its own and that he was losing a lot of performance by running at 26 psi.

I explained to him that anyone that would name a sweet spot on a turbo as THE boost obviously did not know what he was talking about because it depended both on the engine combination as well as the compressor map and it could vary a few psi from car to car.

Of course he wanted to turn the boost up.  He went to 27 and it was okay, so he went to 28 but suddenly had 30 instead.  Lifted both heads.  Fortunately, the third set of gaskets he had had put on the car were shims from RJC and the car seems to be fine again back at 26 where I had originally told him to call it good after a good retorquing.

He was using a manual boost controller and discovered they are not linear in implementation .  I thought about this yesterday when someone posted that one turn equalled one psi.  I had the same problem with the Turbonetics regulator valve that would jump from 24 psi to 28 psi with nothing in between.

I can think of several morals to the above story, but, in the end, you will come out better if you take the time to learn how things actually work rather than trying to tune your car by magic numbers you read on the net.

[Forzfed]

Thanks for sharing, Steve!  My controller works really good and does not jump.  That being said, I have it hooked up so there is a low pressure side and high pressure side on the controller.  I've seen guys hook them up and vent to atmosphere, which I could see causing major problems.  Especially when the weather changes.


And as for SM not having any knock, I've been in cars that were rattling there engines and SM didn't pick up any knock.  With it's refresh rate I wouldn't trust it on any car faster than 12's.  And that was with a quick jab of the gas, motor rattles, let off.



 

[Steve Wood]

that is one of the reasons I am a proponent of PL these days...too much can happen in 1.4 seconds as was the case with his maf which he never monitored.

[motorhead]

Another slow learner.

[YGspider]

These cars are such bitches sometimes.... haha I remember the first day I got it and learnt you cant just nail the gas you have to watch the sucker like a Jumbo jet with all the controls and if something's wrong abort !
I've had mine for about 3 months now and I've still never went WOT because I'm chasing stuff down. Once the kinks are worked out I bet these cars are a real fun car to drive. But when a issue arises you must correct it.

[SuperSix]

These cars are such bitches sometimes.... haha I remember the first day I got it and learnt you cant just nail the gas you have to watch the sucker like a Jumbo jet with all the controls and if something's wrong abort !
I've had mine for about 3 months now and I've still never went WOT because I'm chasing stuff down. Once the kinks are worked out I bet these cars are a real fun car to drive. But when a issue arises you must correct it.

Good attitude - you will do well with Buicks keeping that in mind - Tune, tune, and then tune some more.

You will get to a point, if done correctly, where you can beat the snot out of theses cars reliably.

[Jeff]

With my old tr all I would do.is shoot for magic numbers. Now w my new one ive become wiser. Learn parameters and mainly shoot for the safe side. Even now I want a 10 sec car but ive decided to work w what I.have learn to tune and build  slowly. Throwing parts at the car will generally keep.you slower and.also.help break stuff faster and or just more of it..

[tb3]

what is the best boost controller for a street car?

[Steve Wood]

I prefer the factory wastegate solenoid if it is good.  Otherwise a manual boost controller is fine

[phil_long]

You can't vent to the atmosphere with the manual controller from RJC can you? Because that's what I have. I have also noticed, since I have hooked up the RJC controller, with the WG solenoid removed from the puzzle, it just hisses under ANY acceleration. Is this a problem?  I like the sound.  Lol

[Steve Wood]

The RJC is not a bleeder type of controller like factory and there is no need to vent to the atmosphere other than perhaps a vent hole so the wastegate can close fast when you lift off the gas.  There should not be any sound coming out of the controller so I don't know what noise you are hearing under acceleration

It works just like this one internally.  I made a couple of these a few years ago except I sweated a piece of copper tubing in the end instead of hammering the fitting in-still using them

http://www.gusmahon.org/html/boostcontrol.htm

[phil_long]

The sound isn't coming from the controller, it's coming from the factory section that I unhooked.  I believe the ECM is still pulsing the original solenoid, and that's where the whooshing sound is coming from.  I was just asking if that is a problem.  I suppose it wouldnt be.

[Steve Wood]

it should not hiss but it might buzz since it's a relay.  Just unplug the connector

not a relay...it's a solenoid

[daveismissing]

Does Eric suppress the error code?

[Steve Wood]

yes