Just got a new HG, head bolts, and injectors installed on my 300k 12v CTD motor. The shop is saying they won't warrantee future failures unless I do something about the boost.

All I have done to the truck is a #10 plate, not even moved forward of stock - but I can easily hit 35 lbs of boost, more like 36-37 if I push it.

The shop wants me to limit it to 23 lbs ???

That sounds low to me, but there has to be a compromise since I know 35-37 lbs on a relatively stock motor is not the best idea.

So how can I limit boost? Do I just need to back the #10 plate off some, or is there something else I need to do here?

 

Is the wastegate hooked up? Are you running a boost elbow?

23 psi is pretty low, the HG should hold 30 psi easy.

 

Can they explain why 35 psi is too much for a stock engine? Limiting boost to 23 psi will cause other problems like excessive smoke, high egt, power loss and possibly a mileage drop. If you want to limit boost to 23 psi, you will be best off to limit the fueling too......but who wants to do that?

Why is 35 psi bad for a stock engine with a #10 plate? Whoever suggested this needs to eplain why....

There is absolutely no reason why a stock head gasket won't put up with 35 psi and the occasional spike slightly past that......as long as your timing isn't overly advanced so as to let cylinder pressures become too high, stock head gaskets will accept 45 psi....some guys here have stock head gaskets with twins running at 50+ psi though, the HG is on borrowed time in an application like that!!

FWIW, if you need to have some form of manual boost control, install a Turbo Master....I just posted this pic from USCGtraveler in another thread but it is a great pic of it installed.....

 

Just called the shop and had them check the wastegate (which they should have already checked!) and the verified it is stuck and not operating. They are going to replace it.

The bad news is that now I am not going to be building anywhere near the boost as before, right? Do I need to order the boost elbow and add it (I never got one with my used #10 plate).

 

Get a manual boost controller instead of a boost elbow. The boost elbow will just spike and then drop back to the stock wastegate setting. The controller I use came from Lower Shores Performance off Ebay. I'm happy with it.

I'm running 40 psi with a stock HG.

I ran a Turbo-Master for a while. They work OK until you really put the fuel to them. Then they don't let the wastegate open far enough to keep boost under control.

 

Tell me about a manual boost controller - what is it, what does it do, and what does it cost?

 

A manual boost controller goes in the boost line between the engine and the wastegate actuator. It is a valve that opens and lets boost into the stock wastegate actuator at whatever pressure you set. There are a zillion of them on Ebay, the only one I have tried is this one, and it works as advertised.

http://cgi.ebay.com/ebaymotors/Unive...QQcmdZViewItem

 

I have that same manual boost controller from Lower Shores from EBay. I have yet to spend the time to get it dialed in to 35. I can still spike to nearly 40 psi of heated air on my stock HX35. It works, i just haven't dialed it in yet.

 

Jland, you may have to drill/cut the center divider in the turbine housing to get boost under control. The stock setup only vents the rear 3 cylinders. With a lot of fuel the front 3 will carry the turbo to 35 psi even with the wastegate wired open.

 

Thanks wannadisel - I am gonna look into picking that or a similar device up!

 

CTD Nut is right!
Others have done extensive testing and your stock turbo is within the efficiency MAP at 35 psi... some say your ok up to 38 psi.
Head gasket should hold AT LEAST 40 psi. Many stock HG's are holding up to 50 psi boost! Timing set to high is the only way you will have problems.

RJ

 

I knew it only vented the rear three, I really think I just haven't backed the spring out far enough on the controller, but maybe not. I just didn't think my fueling level was that high yet. But I think I got some crazy-fast Catcher. My stock clutch spun like it was greased and I can hit 40 PSI in a hurry.

 

Truck is back in my posession. I miss the faulty wastegate - it was nice being able to spike the turbo at will. Will be adding a manual boost controller in the near future.

Set the timing to 16*, install 3k GSK, maybe move the plate forward just a hair this time

of course - before all of that I gotta get a trany in there

 

Unless you dont trust the shops work, then I wouldnt worry about limiting boost. The stock HG should easily hold up to 40psi without a worry if its new especially. Just get a manual boost controller as stated, and use that. They seem to work good. Also. Go ahead, and put that GSK in. You wont hurt your tranny with that as long as you dont abuse it. It doesent add power. Just gives you a way more useable RPM range.

Eric

 

A stocker should hold 40 easy unless ur temps(timing ,fuel) are just way out of hand.

Did the shop check the head to see if it was warped ect.

Before I changed exh housings I was seein 50psi out of a 35/40 hybrid and that was overspeedin the turbo and creating alot of heat, and I'm still on the same HG that the truck had when I bought it 2 yrs ago. I still run 45 all the time now with no probs and see 13-1400 about everytime I drive the truck.

Course this is with a 24v from what I understand 12v's are a little more reactive to heat as far as the HG goes, but I would think 40 should be plenty safe

BC