any 1st Gen CTD people in Charlotte? ...or basic boost question

bigwaylon

bigwaylon

Well-Known Member
Joined
Mar 22, 2005
Location
Charlotte
been doing some work on the turbo...nice rebuild by Jon (StudNuts), and a new wastegated housing and compressor upgrade...

BUT, it's not pulling as strong as when it was stock...

I didn't have any gauges in it stock, so I have no baseline, but it's not getting over 20PSI with the new 12cm housing (used to be 18.5cm) and the HTT Stage III upgrade (60mm wheel, stock was ~50mm)...

most of the guys I've talked to on DTR say I should be seeing 25-30PSI...

with those two upgrades, it out to be pulling more air, and building the boost faster...

I rigged up some piping today and drilled the end and installed a valve stem...and clamped it onto the intake side of the turbo...in an effort to try to build pressure and find a possible boost leak...

hooked it up, sprayed soapy water over several areas, and no bubbles...just a nice lemony smell...

anybody around Charlotte ever messed with the 1st gen (non-IC) setup? or anybody else just have an idea as to what it might be?

Thanks.
Greg
 
20psi is about right for the stock wastegate to open...

Disconnect & cap the "vacuum" line to the WG actuator and then go for a drive.

The 60mm compressor will take more time to spool up, but it should be more than offset by the smaller turbine housing.

IMO, you need more fuel to take advantage of that bigger compressor wheel.. Stage 3 is for ~300rwhp trucks and is what I'm running.

But disabling the wastegate will most likely give you the performance back that you're looking for, but a bigger turbo by itself won't really give you more HP unless you needed one before (over-fueled / under-turboed)

YMMV.
 
I understand your logic Rich...but something just ain't right...

I don't even have the wastegate hooked up right now (hose is just plugged off)...so that's not the issue...plus, it's a Banks Big Head, so it probably would open later than the stock unit anyway...

the reason I'm thinking it's not more fuel that's needed, which I failed to mention in the original post...is that it was hitting ~1300F before (again, I have no idea what it was doing stock)...and that it didn't pull near as well going to Mountain City this past weekend as it did to Crozet back in July...

to me, that high of an EGT means too much fuel, not enough air...but I won't claim to know much (if anything) about proper diesel operation...

"in theory"...to me...the smaller exhaust housing will make it spool faster...and with the shaft spinning faster plus a bigger compressor wheel, I should be seeing more boost in my situation...

I'm going to try to put a little more preload on the wastegate actuator linkage tonight...in the chance that it's sitting there right now slightly open...just enough that it'll hold 20 PSI but not anything more...

when I first hooked it up, it wouldn't run more than 5-8PSI...due to the linkage...so I "fixed" it to the shape it's in now...

Thanks.
Greg
 
bigwaylon said:
I don't even have the wastegate hooked up right now (hose is just plugged off)
Click to expand...

Ya didn't mention THAT.. :lol:

is that it was hitting ~1300F before (again, I have no idea what it was doing stock
Click to expand...

Yeah, that's never good.

I'm going to try to put a little more preload on the wastegate actuator linkage tonight...in the chance that it's sitting there right now slightly open...just enough that it'll hold 20 PSI but not anything more...
when I first hooked it up, it wouldn't run more than 5-8PSI...due to the linkage...so I "fixed" it to the shape it's in now...
Click to expand...

AHA!!! My money is on that. Don't forget, it's got to hold back 20 psi of force to not open.. that's more than it sounds... it's got quite a bit of pressure against it when I took mine apart.

Keep us informed!
 
OK...unhooked the wastegate...turned the linkage in about 3 full turns, to the point I couldn't hook it back up after trying for at least an hour...

got out the trust CO2 tank, and set the adjustable regulator to ~30PSI, and had the wife give a couple short burst into a hose attached to the wastegate...which allowed me to hook up the linkage...

still didn't hook the vacuum hose back up to the wastegate...just trying to make sure it is sealed...

truck runs exactly the same...

pretty much think that rules out the wastegate...

now, I'm completely lost...

Greg
 
Do you get black smoke out the exhaust? If so, how much?

Could you have an exhaust restriction, like crappy stock pipe and muffler?
 
thecarman said:
Do you get black smoke out the exhaust? If so, how much?
Could you have an exhaust restriction, like crappy stock pipe and muffler?
Click to expand...


it's not much...but there is some on startup, some when on a WOT take-off, and some under full load when towing...

I do have the stock muffler (maybe?), but it's cut off after that...

I plan on cutting it off and straight-piping it...so maybe I'll go ahead and cut it off pre-muffler and put a turn-down on it...

I bought the truck in May from the original owner, with ~255K on it...so it may be the original muffler, but maybe not...

if anybody gets really bored...here's the whole thread on DTR...starting back when I was deciding which gauges to buy:

http://www.dieseltruckresource.com/dev/showthread.php?t=100810

I'm going to go add your comment and let them bounce that around while I'm at work...

Greg
 
I wasn't paying attention to the fact you have no intercooler... Oops.. that would certainly make for higher EGT's!

Timing advance would lower EGT's, as would freeing up the intake & exhaust flow.

With my HX35 60/14, I've found best EGT control is ~40 psi +/- 2 psi, so don't worry about overspeeding the turbo.. beyond 35psi on a stock HX35 is just blowing hot air...

Since your fueling is still stock, 20psi or so seems about normal... But the EGT's do seem abnormally high..
 
bumping up the timing is the suggestion I just got on DTR...

ditched the muffler at lunch today...just took off the clamp where the downpipe ends and replaced everything back from there with a small turndown...:D

sounds like a dump truck...:D

intake is a BHAF and 4" exhaust pipe...about as free as I can get...

Greg
 
so did it help?
 
Rich said:
so did it help?
Click to expand...

it seemed to run just slightly different...

but, without a trailer hooked up, I can't tell how it tows...

it ran 850F in 5th at 75MPH and 2500RPM and 13PSI down the interstate on a very slight incline...just as a baseline...

that's the point it gives no more fuel...

all the recommendations I'm getting right now is to advance the timing 1/8"...which will lower the EGT's...

also, go with the fuel pin and 3200 spring install that I was holding off on...which would allow me to run in a different gear at higher RPM's which should keep the air pumping and EGT's down...

it'll probably take a week or two before I get around to doing all that, so I'll post up results when I can...

some good into in that DTR thread over the last couple days trying to help me out...

it's almost like everything is OK...but I didn't "finish" the mods, hence the poor performance at the moment...

Greg
 
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