too much power

[ppe2500hd]

I recently put the PPE accelerator and well i need to get an trany upgrade kit i was wondering if anyone knows of a shop that does that kinda stuff i need the trany to be able to withstand about 700 hp and around 1000-1100 pounds of torque

[madmatt]

if your making that kinda HP you need a complete sun coast and prolock converter. What all you running to make those numbers.

[ppe2500hd]

Well all im running right now is a programmer from PPE (Pacific Performance Engineering) the programmer give me 340 additonal hp, and later were getting propane injection

[madmatt]

Have you had it on a dyno? I afraid you'd be heartbroken. I've seen a couple LB7s w lots of mods and drugs make those kind of numbers,,,,,but not for long :eek:

[ppe2500hd]

no i havent dynoed it yet ut as soon as i get the trany kit mine kaking the truck to irwindale and run the quarter and the 1/8 mile and then put it on the dyno i am wondering whats it pushing to the wheels. i mean ive et an evo, wr,mustange. so its pretty high

[David Proske]

:confused:
What did he say??

[Nix]

Is the PPE adjustable on the fly, or do you have to turn the truck off to change programs? IIRC the other programmers of this type don't allow that degree of adjustability. Their advertised claims are impressive, but I'd like to see some dyno numbers. How long will a Duramax last making that kind of power? Opinions on how much HP you can add with a programmer or Edge type(on the fly adjustable) and still be streetable,ie unloaded,assuming intake,exhaust,full performance trans,etc and reliable? How about a head-to-head with the Hot Juice?

I'm a skeptical about a 2500HD with the stock(?)trans beating a Lancer Evo or a WRX. Mustang, sure but if the guy in the Lancer or the WRX has a comparable reaction time you're history. Doesn't the Evo have something like a 4.9 0-60 time? I haven't heard of too many stock trannies making it into the upper 12-lower 13 range,at least not around here. IIRC PPE is claiming 11's,but I doubt that truck is running a stock trans.

[ 05-07-2005, 09:41 PM: Message edited by: Nix ]

[madmatt]

I've seen D MAX's make that kind of number, but not for long. One made four runs on the dyno then let loose on the way home and the other had to be pushed off the dyno after it's second run. The pistons and rods give up in a bad :eek: kind of way. I've currently got a couple different MFGs coming up w/ some prototype rods, pistons, and we're working on some head mods(ie valve work, cleaning up the ports and some o-ringing.

[Jim Brzozowski]

madmatt I'm curious. Did the pistons fail structurally, deformation from overstressed condition, or did it just gaul up on the cylinder walls and grind to a hault?

[madmatt]

pistons seized sending the rods looking for more room to move. They added some real nice auxillary crankcase vents in the block :eek:

[Nix]

madmatt,do things like extrude honing and port matching apply to diesels as well? It seems logical,but when in doubt ask someone who knows. Any idea when high performance aftermarket pistons,rods,bearings etc. will be available? Just curious.....

[madmatt]

yes the honing and port matching do help some, although not as much as in a non turbo application. I've been doing some work w/ the heads trying to clean up the flow path. the factory bearing seem to hold up great and I currently have a couple sources working on some prototype pistons and rods.

[Jim Brzozowski]

madmatt, Thats what I suspected. The factory clearances don't allow enough expansion room when generating really high temperatures like what was done. I'd be willing to take a chance on the stock metallurgy, but it needs to be opened up a little to allow more expansion room between cyl. and piston. If you are lucky it gauls over the rings and looses compression first before siezing. Guess this time no such luck. Good luck with the rebuild.

[madmatt]

I also plan on trying some "exotic" piston coatings That have proven somewhat successful in other applications.

[Jim Brzozowski]

Yes, I used them a few years back. Incredible increase in relibility under extreme conditions was my experience. Even had to change fuel settings due to thermal coating reducing the piston top temps. They really do work. Its just the same ole question its always been. How fast do you want to go? How much money do you have? I should clarify my experience was not burning diesel, but was 100%Methanol. I'm confident the diesel will keep the fire lit because the computer will be telling it give me more fuel, won't it?

[Nix]

Also, what about larger exhaust manifolds? The stock ones look awfully small for that many cubic inches. Are they small to increase the velocity of the exhaust gases entering the turbo? Is it like a volume vs. pressure type relationship like amps vs. volts? I've been wondering for quite a while how freer flowing exhaust manifolds would affect power and turbo response....

[madmatt]

I don't know about bigger manifolds , but I have opened the inlets on mine up some w/ a die grinder and a nasty azz burring bit.

[Nix]

What do you think about shortening the stroke on a dmax? I know, I know why would you want less than 1200 lb/ft of torque from a performance tuned dmax. I have never heard of a short-er stroke diesel, but wondered if it would bring the horsepower/torque ratio a little closer together and make for more top end RPM. Sounds like something that would be cost prohibitive, but it was just a thought. BTW, did you notice a difference with the opened up inlets?

Also I seem to recall that the dmax has induction hardened cylinder walls. If this is in fact the case, how much meat can be taken out when rebuilding? Is it possible to bore out the cylinders enough to sleeve them?

[Jim Brzozowski]

Aww Come on, your not suggesting anyone is turning the Dmax high enough that they would have to consider shortning the stroke. I don't think that would be worthwhile. Torque is why one buys a diesel. Torque is what accelerates the vehicle, and unless you are operating in a high rpm range all the time it wouldn't be worth it. Ideally you want your torque to come in a early as possible to start the acceleration process and to have it stay there the longest time possible for the best acceleration before you have to shift to the next gear because you ran out of rpm's and had to shift.

[madmatt]

I don't know if it helped or not. I done it just for the hell of it while I had'em off doing some other stuff.

[Nix]

I was just wondering about the short stroke thing...If all that reciprocating mass has less distance to travel, doesn't it accelerate more quickly :confused: ? It seems that most diesel engines in pickups have roughly 2x more torque than horsepower. If you make the ratio a little closer say 700 hp and 900 lb/ft instead of 600 hp and 1200 lb/ft and have a (strictly hypothetical) 1000-1500 higher rpm redline, isn't that still a lot of torque? Could you use electronic engine management to control the torque curve as well? Like I said I was just wondering....

[Jim Brzozowski]

Nix, you do ask good questions. Yes of course shortning the stroke would move the troque up higher on the rpm curve which would help the horspower number after all in any racing application you always have to stay within the sactioning bodies rules. So they limit engine size, etc. the only place left to go and make any appreciable difference has always been in the rpm part of the horsepower equation. The more power pulses per minute you can generate the more horsepower you can produce. The problem with that specific thinking is that traditionally the higher peak power number you can generate the peaker(probably not a word) the engine gets. What I mean by that is that the usable power range gets shorter and shorter so you have to have more gears to keep the engine rpm up on the curve where it can make that power. Most really high horsepower engines are dogs if you bog one down to low rpms. Hope that helps a bit. The key is to winning races is always build the engine to match the conditions the vehicle will encounter during the race. The one who gets the most power to the track the longest period of time should win, all else being equal. Course it seldom is. Not everyone tells their secrets and not everyone uses the same approach. Makes it interesting though.

[Nix]

SoTxPollock, I just want to make sure I understood you. Does shortening the stroke narrow the powerband? Is that what you mean by 'peakier'? Kind of like having a huge turbo on a little Honda Civic engine?

I'm just curious also how the bore/stroke relationship works in a diesel, that is if it is the same as in a gas engine. I try not to assume anything about this stuff. I also know that electronic fuel management has come a long way. I recall several years back reading about a Monte Carlo that had a 500 c.i. engine with (IIRC) 700 horsepower that was still streetable. I probably think about this stuff way too much, but I think it would be cool to have a high-revving diesel that could still have massive low end torque....