S400 low boost P24v puller

When you are pressure checking your intercooler system are you spraying all the connections, intercooler and intake plate with a soapy water to check for the boost leaks?

Make sure to check the intercooler if running a stock one. I have had multiple coolers have cracks that are not visible to the eye.
 
Lincoln_Diesel said:
When you are pressure checking your intercooler system are you spraying all the connections, intercooler and intake plate with a soapy water to check for the boost leaks?

Make sure to check the intercooler if running a stock one. I have had multiple coolers have cracks that are not visible to the eye.
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Yep I spray over everything including the intake manifold plate. I’m running an aftermarket intercooler also.
 
I had a pretty nasty crack on my intercooler I found pressure testing, all in all it turned out to be about a 4psi loss. On a drag truck and it almost wasn't even noticable in spool or track times. It would have to be a pretty severe boost leak to loose 15psi of boost. And very easy to see on a pressure test, any leak that would require soap to find is nothing. I could hear it loud, and feel it blowing out the grill of the truck.
 
jasonc said:
I had a pretty nasty crack on my intercooler I found pressure testing, all in all it turned out to be about a 4psi loss. On a drag truck and it almost wasn't even noticable in spool or track times. It would have to be a pretty severe boost leak to loose 15psi of boost. And very easy to see on a pressure test, any leak that would require soap to find is nothing. I could hear it loud, and feel it blowing out the grill of the truck.
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I've tested intercoolers that were in running and driving trucks, some wouldnt even hold 8psi amazing the trucks ran. i know what you mean.
 
Yea I found a few tiny leaks by spraying water but there’s no way it’s causing a huge pressure loss.
 
I ordered different valve springs and pushrods so we’ll see if that helps.
I was running stock pushrods and cheap springs so maybe that’s part of the problem.
 
Figured I’d update this. Put the springs and pushrods in and was able to hook it last Saturday. Didn’t seem to make too much of a difference. Boost went up to to around 36-37psi going down the track which I guess is an improvemt.

I also wired in some 5v sensors for fuel pressure and drive pressure so I could data log them and get a better idea of what’s going on. Fuel pressure dipped down to around 45psi and drive pressure pressure was up to around 51psi.

Debating on pulling the fuel back around 400cc and seeing what it does.
 
51psi drive is way to low.
Your not pushing that charger near hard enough. You would see 90plus drive, and 50 something boost if you were maxing out that charger.

Either figure out your injection issues, or go to a smaller charger.
 
The turbo made the same boost and similar drive pressure with a SO VP44 last season. This pump on it now oughta drive the turbo harder unless something is wrong with the pump? Is it at all possible I’m over fueling the charger?

I guess I’m just not sure where to start if it is an injection issue of some kind.
 
Try adding 2 clicks on gov springs, and or swapping them for another set if that doesn’t change anything. I had issues getting a fresh 13mm pump to fuel from a reputable pump shop. Finally sent it to someone else to look at and gov springs was one thing they found.
 
Scattered said:
The turbo made the same boost and similar drive pressure with a SO VP44 last season. This pump on it now oughta drive the turbo harder unless something is wrong with the pump? Is it at all possible I’m over fueling the charger?

I guess I’m just not sure where to start if it is an injection issue of some kind.
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What are EGT's?
 
dmigz57 said:
Try adding 2 clicks on gov springs, and or swapping them for another set if that doesn’t change anything. I had issues getting a fresh 13mm pump to fuel from a reputable pump shop. Finally sent it to someone else to look at and gov springs was one thing they found.
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Hmm ok I’ll try that. I have a few pulls this week so I’ll get a chance to try a few things.
 
More than likely the egts are cooler because your putting in more fuel! Pull the fuel back 100cc and I bet they go up. What I’d try is more timing! The 24v puller I wrench on when it was almost identical setup we ran 38 degrees of timing. Now in 3.0 we run 40. It makes a hell of a lot more power at 40 vs at 35 cause we have tried both and cost us a good many feet. Before you go down grading in turbos try 38 degrees for a pull


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Haven’t checked back in a while but since last post I tried pulling the plate back which is 450cc with timing still at 34*. EGT got a bit hotter down the track as expected (1750* vs 1600*). The truck lost a lot of power pulling the fuel. Smoke cleared up to just a haze and I wasn’t even able to spin out at the end of the track at 500lbs lighter then the truck normally is. Also boost and drive pressure were a few PSI less then before.

Next pull I slid the plate all the way up again and tried lowering the timing down to 26*. Truck was able to get up on the turbo a little quicker but power felt about the same as before. Once again boost and drive stayed about the same.

Decided to try a different turbo thinking maybe that’s been the problem. Picked up a 2.5/87/1.10 S400 and tried it last Thursday. Same fuel and timing as before. No change in boost/drive pressure.


I might try going up in timing but with stock pistons still I’m not sure how safe it’d be. I’m sure I was spraying way outside the bowls at 34* I’m not sure how much is too much.

I’m not sure what else to try at this point. Injectors was my next thought although I couldn’t see them being the issue.
Maybe I’m crazy but I think it should be running much stronger then it is. I should have no power issues with no hanging weight and 4.88 gears?
Gonna be taking the pump back off this winter and having it flowed again.
 
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