Boost issues

[mapmaker]

Yet another thread about boost issues. I have read a lot and tried a number of things, now I need some help.
Last year I installed a new 60-1 turbo from Bison and a new RJC 3" dp with large puck. I had boost creep issues (shooting for 24lbs, would get close to 30lbs by the end of the 1/4). Over the winter ported the wastegate hole and put in a new PTC 9.5" nlu. This spring I couldn't get over 20lbs of boost. I took the RJC boost controller apart and put in a heavier spring, then shortened the rod on the HD wg actuator. No change. I took the DP off and checked the puck alignment (twice) with a grease smear. One side is only covered by an eighth inch or a little more, but it does match up all the way around.
Last night I wired the wg shut and tried it. It maxed at 30lbs. I was surprised it seemed to have more lag, and I thought I would have to get out of it because the boost would run away.
I would switch back to the stock boost solenoid and test but I cant find the vaccum Y.
Is 30lbs max that my setup can create? When I was grease checking I noticed a small scratch across the puck mating surface on the turbo (barely enough to catch my fingernail) I wouldn't think that's enough to bleed off boost? The last spring I put in the RJC boost controller is so long and stiff I don't think there is anyway it can be activating. Checking my PL files this morning, I notice the BLM up to 142 - potentially a separate issue, but could it affect boost? The ds header has been repaired, I checked it and it looks good.

 

[TTipe]

For a 60-1 turbo 30 lbs max boost sounds like the turbo is all done. Sounds like you have a 31/69 trim exhaust wheel. Remember boost pressure is an indicator of what the engine is doing with what you are trying to shove in to it. What diameter did you open your waste gate hole to? What edges of the waste gate hole did you break the edges for. It sounds the waste gate hole size is too large and the hole is behaving like a diffusor instead of a nozzell and or your waste gate rod is too short so your leverage against the spring is reduced. BLMS of 142 can be hazardous in a combination such as yours. I will bet that the alky is saving your motor but your fuel pump is probably not keeping up with demand.

 

[earlbrown]

When you shorten the rod, you limit the ''curtain area'' the wastegate can open. Try lengthening the rod and using the boost controller to raise the boost.

 

[mapmaker]

To follow up.. Earl was right, I had the waste gate binding up. Added a stock pcv inline with the RJC, put on a rebuilt, machined throttle body, and new silicone vac lines and the BLM's look great.


Sent from my iPad using Tapatalk

 

[1KWIKSIX]

I'd be interested to know what diameter you opened up the exhaust waste gate hole to as well.
Did you radius the inside edges too?

 

[mapmaker]

I couldn't tell you exactly how large i made the whole. I marked where the gate hit and stayed inside. I did bevel the inside edge. Even with a very stiff spring in the boost controller it's difficult to build boost. Last weekend at the trick i wired it shut and it stayed about 28 lbs. Maybe a recipe for trouble - we'll see what happens in OKC this weekend.

 

[Mr.Spool]

no my friend that's how you go fast

 

[mapmaker]

no my friend that's how you go fast

Winter time is almost here - I figure if something breaks it will be a good excuse to let my "accountant" know it will take a set of Champion irons to fix it

 

[trbojo]

check check and check again for exaust leaks....every problem I've ever had building boost ended up being an exaust leak...as far as the blms, I had the same issue stuck at 142....I took a 3/8" bolt, cut the head off and drilled a 1/8" hole through it, put it inside the pcv hose to create a restriction...blm issue solved!

 

[1KWIKSIX]

I couldn't tell you exactly how large i made the whole. I marked where the gate hit and stayed inside. I did bevel the inside edge. Even with a very stiff spring in the boost controller it's difficult to build boost. Last weekend at the trick i wired it shut and it stayed about 28 lbs. Maybe a recipe for trouble - we'll see what happens in OKC this weekend.

Reason I asked is that I had a similar issue earlier this year with difficulty in building boost after porting a waste gate hole too.
Ported my little DBB5857SP's waste gate hole on a bridge port from 0.90" to 1.10" & beveled the inside edges of the opening in order to stabilize the over boosting that I was experiencing.
My THDP has a 1.5" diameter sized puck.
Made sure that there was at least 1/8" or more of puck sealing surface on the exhaust housings waste gate opening.

After doing this I could only build 6 or 7 lbs boost....so installed an adjustable HD waste gate actuator.....still could build no more than 10 or 11 lbs boost, regardless of the tension on the rod.

I removed the factory Y vacuum hose for the waste gate assembly and installed an RJC Boost controller (with only 3 threads done up, so it would produce the least amount of boost).

I backed off the tension on the rod so there was less than 1/8" tension.

Took it out for a spin & found around 15 lbs boost. Tightened up the RJC controller another 1 or 2 turns and now have just over 17 lbs boost.

Seems to have found the cure for my low boost issue.

Maybe give it a try......"Just saying'


dave