the mysterious turbo

[FARMERBOB]

Hey all, I have been pondering getting a different turbo. My setup is, 18to1 pistons, high flow injectors,JK chip,mandrel bent exhaust,amsoil filter,'97 cooling upgrades,ceramic coated manifolds and crossover pipe,timing gears,remote mounted pmd,and electronic pump in my '95 truck. Just about everyone I talk to has a different idea about which turbo is best or even telling me there is not an upgrade to the factory unit. What's with all the mystery surrounding this seemingly simple piece of hardware? Also I am going to put some type of intercooling, probably water injection, on this truck soon.What are some of you guys' opinions?

[gmctd]

Call Peninsular - they have 250hp, 300hp, and 350hp (I think) turbos for their 18:1 street motor.

[FARMERBOB]

I guess I should have clarified, I have talked to peninsular, JK, Heath, Banks, as well as numerous rebuilder outfits and engineering businesses

[grape]

It's not magic, there are two peices of the puzzle you know when building a turbo engine. target power and total amount of boost desired to make that power. check the knowledge base at www.turbomustangs.com (http://www.turbomustangs.com) all the formulas are there

[FARMERBOB]

Grape, yes that is a good website for information and with what you said it makes my point. Why all the different answers? If all you need is a couple of basic formulas to figure out what you need, then is the problem that nobody makes exactly what is needed and we're trying to make do with whats available? I've wondered why, like in Peninsular's solution, they're not using a wastegate to produce quicker spool up.

[grape]

probably because they don't sell them. Not to mention a diesel is 10X less critical to hitting target airflow as a gas engine. Diesels dont' get lean and detonate the heads off like a gas engine, the egt just goes down if there is enough oxygen present.

[tom.mcinerney]

Maybe in marine apps acceleration not so important; marine engines generally run at 1/2-4/5 throttle all the time, automotive constantly cycles from coast-accelerate-coast-accelerate.

[willibig]

Hello

I have a Peninsular engine with low comp. pistoons and all the other goodies they offer, I have run four turbos on the engine. a stock GM turbo from 1993 6.5, a Banks turbo, Peninsular I think i asked for the 300 hp version, and a Cummins (holset) turbo from a 1996 with 12cm turbine housing. The safest power came from the Peninsular turbo which seems to be almost the same as the Banks but more upper end boost. The stock turbo, well it is just weak on compared to the rest. If you want all the boost the engine will ever take this is your solution. I was producing 12 psi at 60 mph and my IP turned way down and the waistgate adjusted so it was open at 10 psi. It maxed out at 25 psi with the waistgate open. I decided to take this one off because I don't have an intercooler. But it is another option.

William Nichols

[DogDiesel]

Email me. I have a 8K mile Peninsular non-waste gated turbo for sale. Was mounted on a low compression 300HP 6.5. Power is awesome.
Wayne

[dstoops]

Hey DogDiesel,
I can't figure out how to email you! Interested

[FARMERBOB]

William, Which turbo made 25 psi?, the stock one? With my GM4 still on vacuum it will make 17psi. If it is intercooled and the EGT's are safe is it safe to run 25 psi? Now let me ask the dumb question how do you make more power with less boost, eg. my stock at 17 vs peninsular at 12. Dogdiesel how do I email you?

[grape]

look at some turbo maps.......just because you have two different turbos with the same pressure doesn't mean they are moving the same amount of air. A place to start for 300 hp is a turbo that moves 37.5 pounds of air per minute at any desired boost level you want. Gasoline engines start at 10 pounds per minute for every 100 hp, diesels start at 10 pounds per minute for every 80 hp. Then work backarwards down the left side of the efficiency islands and make sure you aren't going to surge the compressor by moving more air than you have available fuel......or power.

[DogDiesel]

burtonw@bragg.army.mil
Wayne

[willibig]

I was making 25 PSI with the Cummins turbo (holset) That was over boost as far as i'am concerned because i had my IP turned way down to keep the PSI down to that point.

[Mark Bajus]

I'll be putting one of the "mid-sized" penninsular turbos on probably next week, will comment once its done. I'm bumped up on the injection pump now (slightly overfueled, not much, max boost about 17lbs now), any thoughts on how much more I can bump the pump with the new turbo? No intercooler yet.

[FARMERBOB]

Willibig, I was wondering how hard or easy was getting that Holset to bolt up to the exhaust pipe? Also how did any of these turboes compare on the bottom end to stock turbo? Do any of the afore mentioned engines have Peninsular's higher flowing exhaust manifolds? Mark, definitely let me know how your turbo works thats the one i'm mostly considering.

[willibig]

I used a cummins exhaust elbow into a flanged 3" pipe that was short with no muffler. Keep in mind the manifold i am using is a modified 6.5 manifold that places the turbo horizantal to the engine. Also my truck is an old body style. The best of the bunch for torque from the start was by far the Holset, which allowed me to do burnouts with 35" tires!!! i can't do that with the Peninsular turbo or stock turbo.

[FARMERBOB]

Willibig, not being familiar with the Cummins setup, do you think I could fit that into a '95 truck? If I understand you correctly the Holset is wastegated?

[willibig]

anything is possible, it just depends how much money time and knowledge you have. The two big problem areas that i can think of for a new body style truck is with the exhaust routing and possibly clearance with the compressor housing, which is larger than the 6.5 turbo. Although i would not say that it is the best settup even with 18:1 pistons it sure is fun.

To address the exhaust issue (understand i am not 100% sure) you may get away with using the stock down pipe from the holset (I would use a turbo with the shorter outlet pipe) hooked to a 3" elbow, but it would be close.

Good luck

[Mark Bajus]

we'll see how the penninsular works, but that holsett sounds VERY interesting, if the Penn doesnt work that will be worth checking out. The Penn apparently comes with a different elbow, so perhaps one could use that with the Holset. 12cm is one of the smaller housings isnt it? Meaning quicker spoolup? With all the Cummins out there I would think the Holsets would be (relatively) cheap too.

[Mark Bajus]

turbo installed, quick seat of the pants update:
well, I was a little greedy and turned the pump up 1/4 (should have done about 1/8). So, she's a bit of a smoker!


In appearance 2 things jump out: 1)the size of the exhaust turbine housing is WAY bigger, 2) nice smooth radius exhaust outlet pipe.

One thing I wasnt aware of is the turbo has a 2 inch outlet and the intake manifold is 2 1/2", requires a 2" to 2 1/2" transition rubber tube (and some cutting on the intake manifold snorkel as its too long).


Initial performance feedback: there is no initial boost down low: 70 MPH on the freeway used to be 5-6 lbs, now barely cracks the guage. Off the line if you arent careful about rolling on the throttle you will generate lots of black smoke.

Tons of boost in higher RPM: 20 lbs+ with unloaded truck. (used to max at about 17, but a useless 17 as after 2500 RPM backpressure must have been killing it as it just generated smoke). Power used to drop off above 2500 RPM, now it just keeps building and building.

EGT's dont seem any higher in the brief hills I've run so far (my standard couple on the way to work). Accelerating up a hill from 20 MPH to 75+ used to generate 600 post turbo, was about the same with new turbo.

Bottom line is (seat of the pants) TONS more performance. Probably not much if anything right off the light, but from 2200 on up way better. I know, the comparison is not apples to apples, but turning up the pump was part of the whole reason to do this (power!!) and turning up the pump on the stock one would have been a complete waste of time (extra fuel would have gone straight out the pipe).

Hopefully drag the trailer around in the next week, will report on pulling performance, and try to do 0-60 unloaded.


I had the Torqloc installed at the same time, and accidently put on a cummins-like smoke show when I lugged it down a bit far (forgot it was on!!) and hit the go pedal- talk about inpenatrable black wall!!

so far so good, will report further!

[FARMERBOB]

Hey, Mark , thanks for the update that's exactly what i've been looking for is some real experiences with before and after with turbos that are available. If anyone else has any experiences please share them especially if you have an electronic pump