1991 ram 250 ctd

[Low Impedance]

I use this more or less for towing and hauling parts but i wouldn't mind some more power out of it. I know some small tricks for the mech. pumps, but what are some other ways i can make some more power? I want to intercool it first and foremost but not sure if the 94 style intercooler will work.

Also where can i source the signal for a trans temp sensor for this auto transmission? Not sure where to read it from.

[turbokid]

An external cooler on those dodge trannys help A TON!
Intercooler from a 94 can work with some rigging.

[mopar2ya]

91s should already be intercooled...

As for power, all you need to do is fcut the crimp off the fuel screw and turn it in all the way. Also, turn the aneroid valve (top of pump) all the way down. You can also bump the pump timing up a little by slightly rotating the top of the pump twards the passenger side.

Be sure to get a EGT gauge aftr doing it, you can make alot of heat. All this adds a big power increase depending on the pumps condition.

If that isnt enough, get a fuel pin and injectors for another 90-100 h.p.

[jonnyb]

Quote:

Originally Posted by mopar2ya 91s should already be intercooled...

Intercooler (and 4spd o/d auto, etc.) came mid year 91, so many 91's do not have intercoolers.

For a direct fit intercooler, find one from a 91.5-93. Grab all the piping AND the intake while you're at it...

[moparzrule]

Yeah most 91's are NOT intercooled.

Although it would be easier, I wouldn't really recommend the 1st gen intercooler in there anyway, it's kinda crappy. The 2nd gen cooler is WAY better and worth the effort.

I don't know anything about the auto's, I had a 5 speed 94' CTD. First I would upgrade to an HX35 turbo, the wastegated 12cm housing with spool way faster than the H1C with the ridiculously large 21cm housing you got on there now. Well, 91 is a toss up year, it could have the 18cm housing, but either way they are junk.
The only real options for the 1st gen is the governor spring kit, I think there's a 3400 RPM kit for the VE pump. And also the Lucas injectors, but I hear that they blow a lot of black smoke. With the injectors, the pump turned up, and the HX35 you should be putting down 200 HP to the wheels. Nothing huge, but stock is 160 at the crank so it's definitely a good improvement. Plus the extra RPM's with the governor spring kit help a lot. The HX35 would help keep the smoke to a minimum since it will spool the turbo a lot faster than the stock H1c.

As for the tranny, I'll let someone else chime in there I'm not expert on auto tranny's at all. All I can tell you is what I hear, an external cooler is an absolute must.

[mopar2ya]

I had the 18 cm housing and swapped for the 16 due to the lag in the 2-3 upshift, but ended up going back to the 18.5 because the loss of boost. The larger housing at least for me lowered backpressure and EGTs.

Good call on the gov spring. Id think with a cranked up pump, fuel pin and injectors the gov spring would be a real nice addition. Just be sure to get a EGT gauge...

[moparzrule]

What were your EGT's getting too? How much boost was it putting out with each turbine?
When towing the smaller turbine will yield you lower EGT's, it's sustained high temps that matter. When you are empty the short bursts don't do anything.
I swapped to the 16cm over the stock 12 but I ended up porting the stocker along with grinding out the divider and putting that back on.

Fuel pin, thats the other mod, I knew I forgot one.

On my 94' I had 325 RWHP on the HX35, 38 PSI boost but EGT's were pegging the 1600 gauge though. The engine can handle up to 20 seconds of 2000 degree's.
Towing is a different story though, no more than 1400 sustained in the manifold max, but 1300 is preferable.
When my 94' was bone stock it never saw over 900 degree's LOL, talk about conservative! I never towed with it though, maybe it would have cracked 1000 LOL.

[mopar2ya]

I dropped 2-3 psi from going 18 to 16. I hauled commercially so everything was sustained loads (1,167,000 miles). Everyone said thats weird as boost normally goes up. Max boost with just a cranked pump was 28 psi.

I know it would get to 1300s in a pull. One hot day I pulled a hill in AZ in the wind with a heavy load and just as I got to the top the engine dies just like I clicked the key off, as I coasted to the shoulder the steam rolled out from the hood, the radiator was blowing coolant right out of the bottle, the manifold looked like a cherry.

After a 30 minute cool down it fired right up with a noticeable tick in it. (galled piston). James Ray told me 1280 was the back out of it point, so I always tried to keep it at 1100 pre-turbo.

[moparzrule]

1100 is cold. Yes 1280 is the real figure for sustained temps, I just say 1300. But those numbers are very conservative, I've never seen anybody else have a problem if they keep it under 1400. Like I said, I daily pegged my 1600 gauge in my 94', but again thats just short bursts empty.
Are you on the turbo diesel register at all? Most of those guys really know their stuff.

What was your EGT when it was cherry red? Honestly it's probably because of your 18cm turbine housing that it got so hot. With the 16 you SHOULD be pushing more boost with it which lower's EGT's in towing situations. Very strange that you lost boost, in fact it doesn't even make sense! As far as backpressure with the smaller housing, any non-gated housing that isn't even pushing 30 PSI means you aren't making enough power for it to be restrictive. Your EGT gain was from the boost loss, which again makes no sense! LOL
A great upgrade, but expensive, is the gated 14cm housing. Most guys with hybrid 35/40's run the 14cm gated housing. Anything under 250 RWHP the 12cm gated housing should be used anyway. You will have way more boost in part throttle situations, which will durastically lower EGT's up hills and such.

[mopar2ya]

I used to get a subscription, but retired for the diesel performance years ago. I had the 16 on when it crapped. Nothing made sense on that truck. James Ray who was a senior tech at Cummins and was part of the LSR truck was there when I swapped it and he was baffled also. What was weird is everything was stock except the muffler was gone and the pump was fueled up. It would run like a SOB, tow 28K decent, idle all night long and do it all again the next day.

The truck even outlasted my wife...um ex-wife..

[moparzrule]

LOL

[Low Impedance]

1400 seems so low. I have pegged my rx7 at 2200

[mopar2ya]

diesels are a different animal than piston gas engines which are different than rotary gas engines.

[moparzrule]

Yeah, all different!

[Mr.Mopar]

Which would be more recommended for towing a 12 cm or the stock housing?

Thanks, Olly