Boost question

[Braxton Jordt]

My combo is ta 49 turbo, fmic, stock down pipe, stock injectors, red Armstrong chip, walbro 340 fuel pump, alky control, fuel pressure regulator, 208/208 cams, rjc power plate, rjc boost controller.

The question I have is my car will boost sometimes at 17 sometimes at 20 and will then drop 2-3 pounds, I've checked for leaks and have double checked that everything is tightened in terms of the intake and fmic piping. Is this normal for it to drop?

 

[earlbrown]

sounds like your wastegate hoses are old and leaky, the wastegate puck is sticking and/or you have a chip that scales back the boost at higher gears.

 

[theCATman]

IMO.... sounds pretty normal.

If I try to watch my gauge, it will spike to 23-24, then settle in at 21 and hold. This is especially true in 1st gear.

When I raced it, I had it set for a constant 23 PSI. Then it would do a 25 PSI spike, & settle at 23 PSI.

If you have a TT chip, I'm gonna say it's in the chip programming. Eric programs them for a set boost level, then it's up to you to either leave it alone or tune for more.

 

[Braxton Jordt]

I have the red Armstrong chip right now my next purchase is tt chip

 

[SHADOWII]

I had more of the problem when I went to the H/duty w/g, would spike to 30# from 28# set point.

 

[coach]

IMO.... sounds pretty normal.

If I try to watch my gauge, it will spike to 23-24, then settle in at 21 and hold. This is especially true in 1st gear.

When I raced it, I had it set for a constant 23 PSI. Then it would do a 25 PSI spike, & settle at 23 PSI.

If you have a TT chip, I'm gonna say it's in the chip programming. Eric programs them for a set boost level, then it's up to you to either leave it alone or tune for more.

You can't tune the chip for boost. You set it, and alter fuel or timing. If you want the boost altered...you have to re-burn the chip

A fmic is not ideal for a 49...depending on how big it is.

 

[fastblackracing]

check for any header or crossover pipe leeks i have seen small leaks cause flucuation like yours also the way that the Y fiting is hooked up a difference it is resticted on one side to make a bigger pressure leak to the actuator and the intake pipeing and filter areless than ideal cuasingb isues then the chip can be custom tailord by your chip guy if you give him good info to work with> let us know how it goes Mannie

 

[Braxton Jordt]

I welded my driver side header it had a good crack which wouldn't let it build boost by power breaking. But I believe the front mount is off of a power stroke. It's pretty laggy too do you think it could be the front mount causing major lag?

 

[earlbrown]

That could be one (of many factors)

 

[mgmshar]

Couple of things.

First, your original post says you are running an RJC boost controller. If that is correct and it's installed correctly, then the chip, y-hose, and solenoid are no longer having any effect on boost at all. The RJC uses a check valve with an adjustable preload spring between the compressor and actuator to control boost. I have a similar device on my car, and I sometimes see a boost spike when the turbo first spools up.

Second, I have a TA49 with a big FMIC, and it spools like crazy, faster than I remember with the stock IC. And that's with the larger Precision .85 exhaust housing. The first key is to remove any restriction you can from behind the turbo, such as the stock downpipe and exhaust system. Loose exhaust promotes spool. This assumes you have leak free exhaust between the engine and the turbo. The second key is to have a higher stall torque converter. With the stock converter, even the little TA49 will have some lag. With even a simple restalled stock converter, so called red stripe or orange stripe, the TA49 will spool very quickly. A more modern chip that has spool enhancing features can also help.

My combo is in my sig, it spools the TA49 very quickly, lots of fun with easy 11 second potential.

Good Luck,

Sent from my SCH-I535 using Turbo Buick