Can't lower the boost

evil666

Active Member
Joined
Dec 4, 2004
My internal waste gate rod is stretched to the max and my rjc boost controller is at the minimum and the least boost I could get is 20 to 21 lbs on a hot day and 22 to 23 lbs on a cold day. With my old set-up I had the waste gate rod adjusted to 1/8 of an inch to hook it up the down pipe waste gate puck and the rjc boost controller to the max and was able to lower the boost. Is the solution to porte the waste gate hole in the turbo, which I was told will cause more lag? Am I stuck to go the expensive way which means an external waste gate, with an electronic boost controller?

Thanks for any good info,
Marco

This is my new set-up: T-Top 86 Grand Nationals 109 block with weisco forged pistons and 2 billet center main caps, M&A aluminum heads, roller rockers, port match lower intake ,te63 a.r .82, erson 214/214 cam, razor alky injection, 94 octane, hooker cat back with dyno max ultra flow muffers, kenne bell headers, 60 lbs injectors, extender alky chip with 23/21 timing, with a gen 2 with a LS1 maf,thdp, mease 24 row IC, PTC 3200 stall 9 1/2 convertor, Ron Custom max boost brake module, MT drag radials (275/60/15) , rjc power plate, rjc boost controller, zeitronix wideband, HR motor mounts, Weld Drag Lites with skinnies up front, electric exhaust, hr rear sway bar, no front sway bar, 90/10 lakewood in the front and 50/50 lakewood shocks in the rear with energy suspension poly bushings all over, boxed rear lower control arms, Big mouth cold air with an AFE air filt

T-Top 86 Grand National 62000 km)
stock long block, stock suspension, 12 inch red stripe convertor (2800stall), te44, smc alk injection (95 % etanol), 25.5lbs boost,( boost spike 28 psi in 1st gear), 94 octane, hooker cat back with dyno max ultra flow muffers, 42 ½ lbs 009 injectors, turbotweak alky chip with 23/21 timing, thdp, mease 24 row IC, Ron Custom max boost brake module, MT drag radials (275/50/15) 3720lbs race weight with driver. (Torque convertor locked only after car shifted in third), rjc power plate, rjc boost controller, zeitronix wideband, HR motor mounts, comp cam 980 valve springs. Weld Drag Lites with skinnies up front, electric exhaust cut-out.
BEST E/T
60FT=1.53
1/8= 7.25
1/4= 11.48
MPH=120.82
BEST 60FT=1.52

I have a gen 2 with an extender chip and LS1 maf, hr rear sway bar, no front sway bar, 90/10 lakewood in the front and 50/50 lakewood shocks in the rear with energy suspension poly bushings all over, boxed rear lower control arms. MT 275/60/15 drag radials. Big mouth cold air with an AFE air filter. The times above were done with out these parts
 
when porting the exhaust housing wastegate hole....you will only experience additional turbo lag if you over port the wastegate hole to a size that the internal wastegate puck can not completely cover.
 
What type of wastegate do you have?

Didn't see in your sig where you listed the downpipe. Is it a Terry Houston style dp? Integral style wastegate or is it an external style? Is the puck arm swinging freely and not jammed closed allowing unlimited boost. Possibly a failed rjc valve? All there is in the valve is a spring and ball bearing but possibly the spring is jammed in the valve somehow and not letting the pressure through the valve.

Test the valve with metered shop compressed air. Raise it from 10 psi all the way up to when the valve opens (or not) and that would eliminate that as a problem.

If that doesn't show anything up, start checking the wastegate actuator for failure or a busted diaphram allowing it not to move. Could test it with low pressure air too I guess.

Good luck,
Jerry jr.
 
What does the Ron boost brake do?

I've heard of it but have not read much on it. Could it be that messing up? I don't know how that part functions.

Jerry jr.
 
disconnect the wastegate rod from the swing puck.... if you get 20 lbs after that then you need to go external with a nice clean exhaust flow path to it as high speed air doesnt like making turns

if you get little/no boost then the wastetgate you have is working and you need a lower pressure wastegate actuator
 
I have the same problem. I do have the non HD wastegate. The lowwst boost I could get was 15lbs. everything backed our to the limit. had to take it off because I was tuning it and was getting knock before that.
 
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