Controlling boost

[john saleeby]

I upgraded my 87 GN with a Walbro 340 and hotwire kit. I have a KB chip with KN intake. All else is stock. When I floor it, the boost spikes and knock retard on the Scanmaster goes anywhere from 8 to 20. I don't want a lesson in head gasket installation. I will be installing a THDP and Cotton's SS exhaust system very soon. I was thinking about either buying or making an adjustable wastegate. Any ideas or advice is appreciated

 

[GNguy]

some people would call me crazy because you dont really need it on a basically stock car but I went with a external gate and DP and I have not had any boost problems since then,,,,,before I couldnt control boost for the life of me.....Also the RJC BC is great too......

 

[Danster]

You may also want to consider upgrading the chip. From my understanding, the KB chips had to much timing for pump gas.

Dannyo

 

[SGRIM]

What fuel are you using? What octane is the chip for?

 

[john saleeby]

boost control

91 octane in california. Kenny Bell "Flash " or "Hot Flash" chip if I remember and designed for light street performance. Would I be better served first by installing say the RJC boost controller or getting a chip from TurboTweak?

 

[Danster]

Get both, but I bet the new chip will aid in reducing the knock your seeing.

Time to update!

Dannyo

 

[Sinful6]

I upgraded my 87 GN with a Walbro 340 and hotwire kit. I have a KB chip with KN intake. All else is stock. When I floor it, the boost spikes and knock retard on the Scanmaster goes anywhere from 8 to 20. I don't want a lesson in head gasket installation. I will be installing a THDP and Cotton's SS exhaust system very soon. I was thinking about either buying or making an adjustable wastegate. Any ideas or advice is appreciated

John, your wastegate puck may be too small casuing it to spike/not control boost. The THDP should help, I would think. I would steer clear of an adjustable wastegate. What kind of boost are you running right now on 91 octane? An alky injection system could act as another "layer" of protection against detonation/blown gaskets, and last I checked they're $200-250. Also, you might want to check out this post before you buy a boost controller: http://www.turbobuick.com/forums/showthread.php?t=197464

Feel free to PM me with any more questions.

HTH.

 

[Ormand]

For pure stock, without bigger injectors, the stock puck and hole should be plenty big. And the adjustable wastegate is good for increasing boost, but usually won't give you less than stock. Until you get another chip, you might get by running the hoses "tuner style". Just run one hose straight from turbo discharge, to the wastegate actuator. Don't connect a hose to the wastegate solenoid. (Easiest way to do that is just pull the hose from the solenoid, and plug it with a golf tee. You can use a clamp or a tie-wrap to make sure the plug doesn't come out) Do a throrough check for leaks in these hoses attaced to the wastegate actuator, since a crack can cause overboost.

 

[Turbo6Smackdown]

ormand, when running a pure stock setup, are there any hoses in that area, that with a slight leak, cause overboost?

 

[Sinful6]

ormand, when running a pure stock setup, are there any hoses in that area, that with a slight leak, cause overboost?

Turbo6Smackdown, Yes, the hose that runs to the wastegate actuator will cause overboost if it's leaking/dry rotted.


Ormand, I think adjustable wastegate arms are an "old school" technique and not necessarily a good idea. This is because when you change the length of the actuator rod, you can cause the puck to open prematurely, or stay cracked open all of the time. I'm not saying go out and but a Greddy profec e-01 $500 boost controller, but for the money, a nice ball and spring manual controller is a good investment, especially considering the age of our cars where this scenario is probably already happening in most near stock rides.

 

[JayC]

The HotFlash is NOT a street chip unless there is a toned down version that Ive never seen.

 

[Turbo6Smackdown]

a nice ball and spring manual controller.. would this be something other than say, the rjc hybrid controller? im guessing since its 'manual' its something that you have to go up underneath the hood to give a few cranks for more or less boost? am i right?

 

[Sinful6]

a nice ball and spring manual controller.. would this be something other than say, the rjc hybrid controller? im guessing since its 'manual' its something that you have to go up underneath the hood to give a few cranks for more or less boost? am i right?

Turbo6, You would be correct manual means you have to go under the hood and adjust boost. The "RJC Hybrid" controller is a good controller, BUT!!! you should read this link in its entirety: http://www.turbobuick.com/forums/showthread.php?t=197464 before you buy one. To sum it up, RJC ripped that controller off of "DawesDevices" now "3bar". Who is the original manufacturer of it. It's the exact same controller, just marked up in price $14. RJC even ripped off the same picture that's been on the DawesDevices website for 5+ years and called it theirs. Or, you can try out one of my controllers, same "ball and spring" concept, but a different design to eliminate spiking, and it's adjustable from inside the car so you don't have to pull over and burn your fingers, you can just sit in the drivers seat and adjust while you drive.

Hope This Helps.

 

[87geeinn]

Boost spiking with RJC/3bar controller.

It just so happens tonight that I was on my way to work with the GN and rolled into the throttle. Well, instead of stopping at my set level of 16#, my boost spiked and kept rising to about the 18-19# range before I let up. Check my sig. It says RJC controller, but I indeed bought mine from 3bar. I popped the hood and didn't notice anything out of the ordinary. All of my hoses were still connected and the small pinhole was not blocked. I have noticed this happen on one or two other occassions. I moved the controller, got back in the car and it was working again...rock solid 16# boost. My puck isn't frozen up and the actuator is just as new as the turbo (about 8k miles on both).

So....is there an inherent flaw in these controllers that sometimes causes the above scenario? Sounds like the boost is being blocked from the wastegate thus keeping actuator from opening the puck

 

[GNguy]

u guys f$@ked up....I have an external gate with the RJC and its rock solid....... :biggrin:

 

[JayC]

Almost all external gates are rock solid as long as the gate is big enough. Doesnt really matter how you control them.

 

[Sinful6]

It just so happens tonight that I was on my way to work with the GN and rolled into the throttle. Well, instead of stopping at my set level of 16#, my boost spiked and kept rising to about the 18-19# range before I let up. Check my sig. It says RJC controller, but I indeed bought mine from 3bar. I popped the hood and didn't notice anything out of the ordinary. All of my hoses were still connected and the small pinhole was not blocked. I have noticed this happen on one or two other occassions. I moved the controller, got back in the car and it was working again...rock solid 16# boost. My puck isn't frozen up and the actuator is just as new as the turbo (about 8k miles on both).

So....is there an inherent flaw in these controllers that sometimes causes the above scenario? Sounds like the boost is being blocked from the wastegate thus keeping actuator from opening the puck

I would disassemble your controller and check to see if there are any hang-ups inside(slag, lips, etc) in the metal that could cause either the spring of ball to catch on something. This should have been part of their quality control?

 

[Turbo6Smackdown]

yea, i aware of the dawes device deal. was just double checking on what ya meant. so, these little boost controllers, are meant to help what... JUST spool up? or to better control the boost, cuz our stock internal wastegates suck.

 

[Sinful6]

yea, i aware of the dawes device deal. was just double checking on what ya meant. so, these little boost controllers, are meant to help what... JUST spool up? or to better control the boost, cuz our stock internal wastegates suck.

Better control the boost, while having the side-effect of increased spool-up. It's a win-win, which is why I say time and time again that they're the best mod for the money.

 

[Turbo6Smackdown]

ahh i see. so if i may be experiencing crappy boost control cuz of my internal wastegate, this would help the problem?