Engine/Transmission (1994 - 1998) DDP Stage 4's with Stock Turbo?

[MAllen]

Is it safe to use Stage 4 injectors with a stock turbo until I am able to upgrade the turbo. I have 234000 on my stock injectors and wanting to replace them and while I am doing it might as well go all out. Would egt's be a problem. I do currently have he #12 plate from tst on the truck. I can move that plate forward or backwards as necessary.

Thanks

 

[JGK]

Watch your temps, but I would expect your #12 plate would keep the fueling under control enough that you can live with them until you improve your air input. Just watch your foot use!



-Jay

 

[MAllen]

Jay, I see you have the 3K GSk, How does that affect the performance. Does it make the power band larger? Also, how big of a difference did you see when you put the stage 4's on?

 

[GOlsen]

I was following another thread on here a while back where someone had the same question. Turns out that DDP wouldn't even sell him the Stage 4's until he got a new turbo. When I got my stage 2s, with the stock turbo, I was seeing cruising EGTs about 1000. My peak EGTs... well, I was able to bury my 2000F pyro. Just something to think about.

 

[BTighe]

should be fine as long as your carefull. wont be able to tow much but if your just crusin, you shouldnt see high temps for more than a second or two.

 

[Forrest Nearing]

I wouldn't do it... I'd get a good turbo first.



I ran an sps62 on my last 98 5sp... I ran it with stock injectors for a while and got 55psi out of it with just a custom plate and AFC mods. It ran nice and cool. Then I put DDP4's in it, turned the boost down to 48 due to drive pressure, and made 535rwhp w/ it

 

[JGK]

MAllen,



The governor spring kit is probably one of the 2 or 3 best mods for the buck you can do on a 12 valve. It really wakes the engine up. I've never run the 4k kit, but I've heard it can make the throttle a bit more sensitive which could be an issue if you get into icy conditions in the winter. My truck pulls well past 3000 rpm and on fast accelerations I can see over 3500 between shifts, though I'm way out of the power band by then. It is well worth the money.



As to the DDP4s, they really cleaned up the smoke as compared to my old PDR 370s I had. 2 of those wouldn't even "pop" on a pop test anymore! I didn't see a huge increase in power, but some. Mostly cleaned up the exhaust due to more efficient burning (better spray pattern). I'm real happy with them.



The other thing to consider if you do this is your clutch. If you get your foot into it a lot, not only will your temps get dangerous, but you'll spin a stock clutch pretty quickly.



-Jay

 

[MAllen]

I already upgraded to a southbend clutch about a year ago & noticed it holds good. I'm slowly going to be upgrading as I get the money & just want to make sure in the process I don't hurt anything.

 

[MMcCallie]

GOlsen is right, DDP wouldn't even sell me the stage IV injectors. Said that even with my stock plate all the way back that they would be too much. They sold me stage IIIs instead. Said i would be happiest with them because they get the best fuel economy and could still support well over 600 hp. Had my original stock WH1C turbo ported and it didn't last 3 months.

I'm now running another used WH1C and was told by the shop that i got it from not to expect even a year out of it. I added a second huge water methanol injector nozzle and that is helping. My BD-Power thermocouple quit this summer and a new one is on the way so i can't report on EGTs just yet.

I bought an old HT3B and plan to eventually add it to my setup. I'm confident with enough air i'd be making over 500 hp, that's my goal. Even with the water injection i am unable to totally clean up my smoke on hard acceleration with a home ground plate full forward. Like the others said, you'll want to match your turbo and fuel starting with a turbo to be safe. Guess you'll just have to deal with the lag for a while.

 

[Forrest Nearing]

I already upgraded to a southbend clutch about a year ago & noticed it holds good. I'm slowly going to be upgrading as I get the money & just want to make sure in the process I don't hurt anything.

what model clutch? I was able to blow through a 13" OFE w/ my DDP4/sps62 combo, and I don't bang gears... pure roll-on power

 

[MAllen]

My goal is to produce close to 500 horse. Maybe to do that I need to be shooting to do that with stage 3's. Would that be safer to run with the stock turbo until we can change it?

 

[JGK]

McAllen,



If you're shooting for 500+ hp, you're going to have to do a fair amount to prepare for it first. I wouldn't put my hard earned money on injectors just yet if that's your goal. Get the the foundation built first before you start adding a killer roof. Get the support structure in place (head studs at a minimum). Then work on the internal supports (air: turbo; fuel with what you have: AFC mods, GSK, plate :#10 works great, then start thinking of grinding a custom version). Finally cap it off with injectors and maybe delivery valves (191s).



Each step will provide an added power boost and help you understand what's going on.



If you jump ahead with injectors too soon, you'll overshoot the fuel supply before the rest of the engine can handle it.



I didn't understand your goals initially. Look at my sig (in my first reply above). I didn't do it all at once. I had a #11 plate, then the 3K GSK and a number 10. Had 370's and an HX40 added somewhere in there. Added a cam a few years ago when I had to replace the gear case gasket. Did studs before adding the compound spinners. Only after all that did I add the DDP4s.



-Jay