Clucker

Hello All

I got a S300 62/65/12 and put it on my 02 eth with mach 1's and the original MaDD ecm. I replaced an HX35 with the htt compressor upgrade which would do 32psi with manageable egts. Towing 19K gross from Denver to Barstow I had to slow down due to egts but only to 55 on the steepest grades (5th gear)

the S300 will, with the same power, do only 28 with higher egts all around. Thats with the boost fooler screwed all the way in and with the threaded adjustment screwed in 2-3 times. I took out the boost fooler, screwed it into a regulated source of air, and set the WG to crack open at 40psi. The smoke cleans up faster but I believe there is more haze at cruse speed than with the hx35

So Im thinking I need more fuel. I install a PM3 and the boost doesn't change, only EGT's through the roof. So now Im blaming my BHAF...

Thoughts?

Im going to replace my BHAF tonight with new, but I would have thought this turbo would do better than the hx35, OK maybe not with the same fuel, but when I add fuel I would have thought at 1500*..... it would boost more than 30psi. The truck accelerates hard, but running through the gears I can accelerate hard and only get 30psi.

Clucker

O yea.

the truck lives in Denver

Camp

Is it possible that this turbo needs to be able to and can flow more air than the stock exhaust manifold and/or the stock intake manifold can flow? It would seem that with that much heat and the fuel you now have, the turbo should be within its efficiency window and curve, unless there is a flow restriction but, I'm only working in theory on this. I'm looking at it from strickly a fluids flow issue on engineering principle but, I'm sure someone is likely to point out where this is wrong in approach on my part.

BigErksG2

Have you checked for a boost leak? 28psi sounds low. Exhaust and intake manifolds will flow more than enough air. Mine are stock and light twins and keep egts in check while towing at 35psi and 80mph up a mountain and just below 1200 egts on the back 3 cylinders.

Clucker

I have checked for boost leaks

Tonight I pulled the trailer up a small grade (I70 from Morrison to Gennese) the truck would touch 32psi but not for long, I could barely keep 65 in 6th due to egts, I pulled off, pulled the boost fooler elbow out plugged the hole and left the WG hose open to air and went back to do the same pass.

I touched 38 but not for long, the truck would not cruse at 65-70 again due to egts

I backed down to 5th and could hold 70 at 1100*

now with my HTT modded hx35 I could have held 65 at 1100 all day long in 6th

just for S's&G's I turned the tst off and I noticed a power loss, but almost no change in egts

the other odd thing is the truck will not accelerate in 6th with a load from 55, only smoke to black out the interstate, and 1500*. Down shift, burn out all the fuel then stay in 5th because of the grade.

its weird, almost like the Compressor is to big. It will run clean through the shifts and run clean on flat ground, much cleaner than the 35, but no go to use my power

Any one wanna trade for a BD Super B, Anyone have a Compressor wheel and housing for a Super B laying around?

Lil Dog

Sounds to me that its not a 65/12 turbine wheel/housing combo. More like a 71/14 the way you describe the loss of boost at low RPM.

Clucker

just went and measured

62.....

Lil Dog

Not the compression side. I was more concerned with the exhaust side. With the loss of boost at lower RPM leads me to think the exhaust side is too big and doesn't produce enough drive at low RPM/Flow.

dieselfreak21

From what I have been reading the 65 exhaust wheel is no good for towing with any kind of fuel. The boost isnt as much of a concern. You should see lower boost with a Compressor side that is flowing more air. Boost it just how restricted your air flow comsuption is. JMHO but i have been in the market for a towing single and pulling single for my 2 trucks and this what I have learned from alot of reading.

Camp

Some of the boost numbers may be low due to the elevation where he is. My 3rd gen would pull no more than 36 lbs constant at 1250F on the hill he is running tests on, with 16K lbs in tow. I had the same load behind my 3rd Gen coming up the Cumberland Plateau out of Chatanooga and could hold 42 lbs constant at 1150F, with no changes to the truck. That truck dyno'd at 495/1006.

Clucker

Well this afternoon I checked for boost leaks again, none.

I checked the opening pressure os the WG without the adjustable elbow inline, thinking about the drive pressure against the flapper valves helping to try and open the WG, I adjusted the rod ironically until the WG would not open. I drove the truck with the idea I was asking to much of it in 6th gear. Drove Floyd hill from the west to the east. I was able to set the cruse at 2500rpm 70mph 20psi boost and 1000-1100 egt. I had more power available and could accelerate to redline by easing up to the 1200 mark. 6th was almost out of the question. I was able to up shift on the down side of FH and stay in 6th untill I got off at the El Rancho exit to make a call

Im tossed up, I remember pulling 19200 gross to Cali back in march with my modded35 I remember downshifting but only due to loosing speed in 6th......

Im gonna adjust the valves and tow heavy this weekend to see the out come

will post back then

kantdrive55

Bingo, we have a winner... The altitude isnt helping either, but sounds like exhaust side is too big.

Clucker

Ok so other than taking the turbo off, or taking the exhaust brake elbow off, how can I measure the turbine?

I can take the elbow off, but Im not sure I can get my fat head in there to eyeball the calipers while bending over and trying to hover.

is there a P/N on the exhaust housing?

Tate

Something else doesn't seem right. When my truck still had a VP, it had roughly the same size injectors, Smarty and a HRVP and I could pull 45 psi on a 62/71/14. Even if his turbo was bigger than what he thinks he has, this is likely what it would be. If he is blowing smoke and high EGT's, I'm wondering if the turbo spins ok, or if its overly hard to turn.

Camp

I asked the question to him about how free it spins and he said it was free. I'm thinking there is an issue with the waste gate not closing all the way or something.