Boost Problem - HELP!

[ProvenPerformance]

Last night I helped my boss install the same Bosch 230/605 plate in his 97 2500 4x4 that I currently have in my 95 (see signature). What the plate did for my truck was raise my stock boost from 24psi to where it is now at 35psi (I've confirmed this reading with two different gauges). It turned the truck into a fun to drive rocket! However, after installing the same plate in his truck, the boost went from a stock 19psi reading to only 22psi. EGT's rise very fast also (to 1200 deg - I should mention he has a 1000lb camper in the back of the truck). There is a definate difference in "seat of the pants" feel between the two trucks. Neither my truck or his has a restrictor elbow in it... so what might the cause be in the drastic difference? I know that his wastegate signal comes off the bottom of the turbo, where mine comes from the back of the AFC housing, but why should that matter? Both plates were installed in the stock location, using the same exact process. At lunch today, I tried putting a "restrictor" in line (in the rubber hose) between the stock 90deg elbow fitting in his turbo and the wastegate diaphragm (0. 040" ID hole in brass stock) and actually lost a couple psi after doing a road test just minutes ago. I thought the theory of the restrictor was to "trick" the waste gate and raise boost pressure. What's goin on? Any thoughts would be greatly appreciated! He's leaving for Canada on vacation tonight and I would really like to get this figured out ASAP!!!

 

[ramman]

slide the plate foward a bit,a few thousandths can make quite a difference. The trick to the boost elbow is to vent some of the signal to atsmophere so the acturator will see a late boost signalpressure,the small hole is through the side.

 

[ProvenPerformance]

Ramman, with the boost elbow, is there still a hole through the fitting where the hose/hose clamp connects to? ... or is there just the hole in the side? Do you know what size hole(s)?



Thanks for the reply... . I really appreciate your help!

 

[Todd T]

there is still a small amount of boost that gets to the actuator. the rest vents to the atmosphere but not much.



maybe his wastegate is stuck or misadjusted. this would bleed off boost too. you can block off the boost hose all together just be careful on your test run not to overboost it, if it will.

 

[ProvenPerformance]

Thanks Todd, that's the next plan of attack... plugging off the elbow completely. That will definately tell us if the hose is leaking, the wastegate is in need of attention, or if the problem lies elsewhere.



Again, thanks for taking the time to reply!

 

[Todd G]

Make sure all the intercooler hoses are on tight. hey may be leaking at the higher boost levels.