383 rwhp, stock hx35, tons of fuel, what gives???

Maybe something to add, have any of you ever tried to put a T3 spacer between the manifold and charger?

I've never tried this with a 35 but I have with a 40 and it works quite well, it simple actually, one of the worse things about a holset other than them being weak is you can't vent all 6 cylinders when the gate opens so you end up over boosting it.....been there done that!

I know for a fact that a stock 35 with an 18.5 housing make 446 hp, is it hot....you bet, like a plasma torch, add water/meth 50/50 and it went to 496.

Jim
 
My trans won't stop slipping until 3200 rpm lol so i'm fairly certain this is my problem. Afterall, this motor is pretty much done, like just about all non ported head stock cam cummins are, at 3200 rpm. I understand the things said on this thread, but with me having all of this fuel over 30psi should be no problem with this housing when rolling into the throttle. I did an experiment the other day to verify, that was I floored it on wet roads as I knew there would be no load. Guess what, the motor went to 3200rpm with the tires spinning and I saw about 20 PSI. Thanks for the suggestions guys, I'm fairly certain in the next few weeks i'm going to move on a trans and will report back with the impacts it has on boost!

p.s. I've never seen the boost on the hx35 with the stock 12cm waste gated housing either that some have seen. The constant of this experiment was, yep, you guessed it, the stock trans slipping all the way!
 
Jim Fulmer said:
Maybe something to add, have any of you ever tried to put a T3 spacer between the manifold and charger?

I've never tried this with a 35 but I have with a 40 and it works quite well, it simple actually, one of the worse things about a holset other than them being weak is you can't vent all 6 cylinders when the gate opens so you end up over boosting it.....been there done that!

I know for a fact that a stock 35 with an 18.5 housing make 446 hp, is it hot....you bet, like a plasma torch, add water/meth 50/50 and it went to 496.

Jim
Click to expand...

Jim, I never tried the t3 spacer on the stock 12cm housing and understand it doesn't make any difference with a non gated housing like the 21cm I have now.
 
Either way you need a good tranny, so get one if you can swing it. But I still think the boost won't be there even with a built tranny. Hopefully I'm wrong!
 
NickTF said:
Jim, I never tried the t3 spacer on the stock 12cm housing and understand it doesn't make any difference with a non gated housing like the 21cm I have now.
Click to expand...

You right it won't make any difference in your 18, but I posted the info just for G.P.

Jim
 
Im still sticking to the transmission slipping being the main culprit.

Now, what part of that do you disagree with oh great one?
Click to expand...

First off lets get this one right...
I am not a great one nor am I trying to seem like I am better than anyone,like your vainly attempting to put off on me.

Simple math shows me its not his transmission.
His runs show this.....
1-383.45 hp/731.06 tq
2-378.62 hp/737.36 tq
3-363.85 hp/717.09 tq

All runs made max power at or around 2800rpm and max torque around 2700.If his truck would make power in the powerband(hp-2300 to 2500rpm and torque 1500 to 1900 rpm)then his torque would show normal numbers for the fueling he has.Take his best run,383.45 and then move the torque into the powerband where it should have been made and watch the number elevate(383.45x5252 divided by 2000=1006.93).

IF he could have gotten the charger lit and not had the lagtime or slow spoolup he would then be in the numbers that would have shown his truck the same as all the others I have seen.When you look at his dyno sheet it shows no signs of transmission slippage just power made way to late.At 34psi with a 21 housing he has the turbo on the same edge as he would if he was using the 12cm at 50psi and thats out of its efficency map.If he was pushing a 12cm 40-45psi then went to the 21cm you take away 4lbs to the 16cm,2.5 more to the 18.5cm and around 2.5 for the 21cm.That would net you 31-36psi with the 21cm and no more,its all simple math.

You can have all the fuel you want when the HX35 is done and out of air you'll not get anymore out of it.At 34psi I feel he has the charger at the end of the rope and as for his trans slipping,not on those runs,unless Chris posted the wrong sheet up.......Andy
 
Just some constructive criticism here Hamer....

What is the biggest restriction between the turbo's boosted air outlet through the intake system and out to the downpipe just after the turbo. If the worst restriction comes from the turbo and turbine housing and boost is a measure of back pressure, I can believe that a 21cm housing making 34 psi is even to a 12 cm housing at 45 psi. If the worst restriction is the head/ intake valves, I do not believe that a 21cm at 34 psi is equal to 12cm at 45 psi.

It is common knowledge that exhaust back pressure steals horsepower.
It is common knowledge that 45 psi is off the map of an HX 35.

I question that maybe a 21cm housing does not develop sufficient drive pressure on the turbine wheel to develop sufficient shaft horsepower to push the compressor up to maximum boosted air output.

If the 12cm housing is seeing 45 psi boost because the tight 12cm housing is restricting flow and causing a back up in the head and thus a back up of intake air, a 21 cm could be flowing identical mass of air at 34psi.

I for one, believe that 21cm is too big to develop full shaft horsepower and that is why 34 psi is max boost. Without measuring the intake air temp and plotting it vs boost, there is no way to know for certain which housing develops the most mass flow of air. I do know that, although highly inefficent, an HX 35 at 42 psi boost is pushing more mass of air than 34 psi boost. In fact, the faster you spin a compressor, the more mass flow you get, just as efficiency drops closer to zero you get less and less increased air mass and more and more additional heat energy added to the air. A stock charge air cooler can only extract so much heat.

But on our engines, there is obviously a balancing act between exhaust back pressure stealing horsepower, and exhaust back pressure gaining horsepower due to turbo charger output.

And of course real world, there is a balance between turbo charger longevity as shaft rpm approaches 150K rpm.
 
So what I am saying is that it is possible for a 21 cm housing at 34 psi to equal a 12 cm at 45 psi, but it is also possible that they flow different amounts of air.

Until we can assign a value for HP loss associated with exhaust back pressure, and values for what components affect intake boost buildup and how much, it is difficult to ascertain the "ideal" boost pressure for maximum HP.

I went the other way, I have a small 9cm housing on my turbo. I gained HP though! I actually gained more egt control as well; turbo chargers are mysterious if you ask me!
 
I am kind of in agreance with Hammer. I think a lot of it is the turbo, although the transmission is contributing...
 
i agree with andy(hammer), that turbine housing is just too big to make any kind of large boost numbers, if he had the 12cm housing on, then i would suspect that he would see 40+ psi, and then his tranny would really be cryin for mercy.

wes
 
Thanks for the input guys. I will continue to report back my results as I try different things.
 
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I think #1 you need to put in a heavier AFC spring, and #2 you need to have some preload on that spring. That will help a bunch, the way I set my truck up with the AFC junk is to where there is no "roll into the throttle" needed or it will bog down. If I stomp the peddle the AFC does the thinking in regards to how much fuel comes in and when, just like it was intended for. And I also think that the 21cm might be a bit much... lol
 
What do you guys think about black smoke (exhaust) coming out of the seal between the exhaust housing and compressor lol? I have a feeling that may be my problem! Will report back more tomorrow, bout to head out for the night!
 
That's ain't helping.

And I'm with Muddin and Hammer, the tranny may be part of it, but the housing is to big, and taking to long to spool, by the time it does you are out of RPM and the powerband.
 
Yeah.. that makes a sooty mess under the hood and on the passenger side fender right along where the hoot meets it.. You might want to make sure all 4(??) of the bolts that clamp the hot side on are all there and tight...

I think TxDiesel007 said it best earlier in this thread.. Too much fuel!! at least when running a '35 at least. I understand you are building/waiting for bigger air.. and that is fine. But, a 5x16 is too much for any HX35. 370s (5x12) should put you over 400/900 no problem.

Jdog56 (replied in your other thread), he has a 21 and doesn't have trouble seeing 40 psi. His is a stock 215 pump with a 100 plate with stock injectors and my old full cut DVs.. truck drives nice, but does get plenty toasty when towing or just driving silly.

Good luck and PS, ..it was nice talking to you last weekend at TNT.. a fellow 12 valve junkie!!:rockwoot:
 
nick17847 said:
Yeah.. that makes a sooty mess under the hood and on the passenger side fender right along where the hoot meets it.. You might want to make sure all 4(??) of the bolts that clamp the hot side on are all there and tight...

I think TxDiesel007 said it best earlier in this thread.. Too much fuel!! at least when running a '35 at least. I understand you are building/waiting for bigger air.. and that is fine. But, a 5x16 is too much for any HX35. 370s (5x12) should put you over 400/900 no problem.

Jdog56 (replied in your other thread), he has a 21 and doesn't have trouble seeing 40 psi. His is a stock 215 pump with a 100 plate with stock injectors and my old full cut DVs.. truck drives nice, but does get plenty toasty when towing or just driving silly.

Good luck and PS, ..it was nice talking to you last weekend at TNT.. a fellow 12 valve junkie!!:rockwoot:
Click to expand...

Thanks Nick, funny to see a guy with the same fricken truck almost and same damn goals also named Nick, kind of stange almost lol! Your truck looked real strong man!!! I've installed the plate half forward (0 plate made ground by me) and tightened up the starwheel. I've been working on getting the rust taken care of under my doors so I haven't had a chance to take it for a spin and see if it made any difference as I'm still waiting for the paint to dry. I'll report back when I do!

BTW, all four of the clamp bolts were tight as could be. I tapped the compressor with a hammer to see if it went back any further and it didn't. I suppose this is normal when swapping housings???
 
Hammer said:
First off lets get this one right...
I am not a great one nor am I trying to seem like I am better than anyone,like your vainly attempting to put off on me.

Simple math shows me its not his transmission.
His runs show this.....
1-383.45 hp/731.06 tq
2-378.62 hp/737.36 tq
3-363.85 hp/717.09 tq

All runs made max power at or around 2800rpm and max torque around 2700.If his truck would make power in the powerband(hp-2300 to 2500rpm and torque 1500 to 1900 rpm)then his torque would show normal numbers for the fueling he has.Take his best run,383.45 and then move the torque into the powerband where it should have been made and watch the number elevate(383.45x5252 divided by 2000=1006.93).

IF he could have gotten the charger lit and not had the lagtime or slow spoolup he would then be in the numbers that would have shown his truck the same as all the others I have seen.When you look at his dyno sheet it shows no signs of transmission slippage just power made way to late.At 34psi with a 21 housing he has the turbo on the same edge as he would if he was using the 12cm at 50psi and thats out of its efficency map.If he was pushing a 12cm 40-45psi then went to the 21cm you take away 4lbs to the 16cm,2.5 more to the 18.5cm and around 2.5 for the 21cm.That would net you 31-36psi with the 21cm and no more,its all simple math.

You can have all the fuel you want when the HX35 is done and out of air you'll not get anymore out of it.At 34psi I feel he has the charger at the end of the rope and as for his trans slipping,not on those runs,unless Chris posted the wrong sheet up.......Andy
Click to expand...

Interesting theory andy

But how or what could have been done to get the charger lit faster? My dynograph at buddah was very similar... too much fuel too soon perhaps? seems to me thats what killed the run in his case and in mine..

AFC tuning, perhaps a gutted AFC is not the solution either....

Rick
 
TxDiesel007 said:
Interesting theory andy

But how or what could have been done to get the charger lit faster? My dynograph at buddah was very similar... too much fuel too soon perhaps? seems to me thats what killed the run in his case and in mine..

AFC tuning, perhaps a gutted AFC is not the solution either....

Rick
Click to expand...

Use one of your old Govenor springs in your AFC and I bet that will help some...
 
Just some info from my old truck. 93 first gen, 5spd,P-Pumped,full cuts, cut plate,light afc spring,stock gov springs, Hx35/14cm wg,stock 3" down pipe and straight 3" exhaust,16deg timming, 393hp/903ftlbs @ 36psi and 1150deg on the dyno.
 
Coop.. What hp pump was on that motor? and what injectors?.. 370s??

Of Topic; your avatar, That picture is such a classic! ..that was F8taldose's old truck, right? and when was that run, ..Spring 2005??
 
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