What does Crankin the star screw in and sliding the afc plate in do exactly?

 

your going to have to go witha bigger housing at least. injectors and delivery valves are way too much for a stock turbo

 

Look at the 94 in my sig. Delivery valves make a big difference on a 160 and 175 pump. This truck is right at the 350hp mark, beware, you are making well over a 700 ft/lbs when you are crankin' out 350hp. My 94 smokes a fair bit until it gets some boost - then look out! If I launch with 10 psi it will blow the wheel clean off - no need for a brake torque. It will take care of a hemi in the 1/4 and murder it on the highway.

Don't push a #10 full forward without an egt guage - it will get hot very fast.

I have been grinding stock plates to roughly the shape of a #10 and blocking the waste gates on some CTD's around here and these things fly but I always tell these guys to get an egt guage because you just can't tell how far forward is too far when you are mucking with plate position without the guage.

 

CTD Nut what housin are you runnin?

Also why don't I need a waste gate?I really don't understand what the waste does or when it opens but like I said a 16cm nonwaste gated housin is only a 150 bucks from but a waste gated one is I believe 600.

Ok I also have 2 more questions.

First what turbo came on a 94-95 Cummins Manual?I was think is was the Holeset HX35 or is that wrong?

Second, the bigger the housin the slower it spools so there's a lose in low end.So how much would spool would I lose if I went from the stock 12cm housin to a 14cm housin?What about if I went a 16cm housin?

I'm all about low to mid range power, I don't like to rev the crap out of stuff other my Honda CR but it's good to 13,000 RPMs.That and in my friends trucks it seems the Cummins motor is only good to about 3k.After that it just falls flat on it face and it ant worth over reving it.

 

If you are looking to make 350hp you should have a 14cm housing - at least. With all the extra fuel you really won't see a difference in spool up. The truck will pull even harder off the line than a stocker with the 12 cm housing with all that extra fuel.

I do not advocate my setup as the best for making 350hp. It really should have a HX40 or similar turbo to really work well. My turbo overspeeds badly (46 psi ) and I have to keep a watchful eye on thye egt's because of it. There is alot more fuel to tap into but there is just no point with the HX35 still on there.

I would use a wastegate with the properly sized turbo. I don't bother with the HX35 because it is too small to limit peak boost and only slows down spool up.

I would go with the 16cm wastegated housing and you should be good for an easy 350hp without going into a fit of egt paranoya.

1) You have a 12cm HX35

2) If you have the fuel to support the larger turbo down low then you should not notice slower spool up. It's only the trucks that are making the big top end power that have to run a much larger turbo that noticably hurts spool up.

 

Ok thanks.

Ok so now the plan it:

Gauages (EGT, Boost)
#10 plate
3000 GSK springs
Cold Air intake
4 inch straight pipe exhaust
Slide everything forward
16cm non-waste gated turbo housin
Delivery valves (I'll probably try and find a used set of 180s)
South Bend Clutch

It seems like the delivery valves are what pushs everyone over the edge so I think if I stick with the 180s over the 191s I don't think I will have as many problems.I said I wanted 350hp but really anything from 300 and above is fine with me I just hate to put down all that money for a new turbo or is there other things I can do to HX35 to help it out.

Ok I know you said you would go with the waste gated Housin, why?I mean I'm still not understandin how the waste gate works.I mean I think it's set so it opens at whatever booost but I see alot of people on here blockin off there waste gates.How much is over boost on a HX35 with a 16cm housin?

O one last question.What does the AFC spring do?I heard it was smoke control but to me the more smoke the better.

 

Check this site out and see if answers your questions about the waste gate.

http://www.dodgeram.org/tech/dsl/FAQ/turbo_faq.htm

 

Ok that was very helpful.

So the HX35 can support 44 pounds of boost.How much boost can the 12v motor take?

Ok now I have a question.That article says the stock HX35 is good to 32 PSI so is that where the wastegate opens?

He says I need a waste gate or don't block the factory one but I see alot of people runnin the 16nonWG housins.

Like I said what else can I do to my stock turbo to make it work better.I've heard somethin about machinein the shaft out but I'm not sure what they were talkin about.

CDT NUT, I read that again and you said you were over boostin (46 pounds) in that chart it says the HX35 should have a max boost of 15-18 pounds and the waste gate opens at 17 pounds.Does that sound right?I thought I've heard more than a few people say they were runnin somethin like 25 PSI with no problems.

 

the motor will hold about 50lbs ,the boost elbow that you can get with the plate will bring your boost from 17 to 34,the waste gate opens at the pre determined setting bypassing the turbo no more boost.its a safety thing.when you are talking hp numbers there is fly wheel hp and rear wheel hp.there is about a 20% difference.

 

Safely? For how long?

Thought it was more along the lines of 35 psi if you plan on getting a lot of miles out of it?

 

after about 35 the stock turbo is no longer real eficient

 

Ok new question.

Stick with the stock housin and the turbo elbow or go with the 16cm non wastegated housin.

I read the link again it said they ran a motor on the Dyno with and without the wastegate and the power was the same the only thing is, I have to have enough to boost to go with the fuel to control EGTS.I'm gonna do all this and then be able to hammer it down so if I need lay off of somethin (I thinkin I should run the stock DVs and be happy) cause new turbos are expensive.

Also I know the different in HP but it's been know that diesel don't lose as many HP as a gas burner does through the drive train.

A read a from a link in Geno's Garage.I'll try to post a link.

 

Provides more fuel at low boost.

 

Blowby: The difference between 180 and 191 dv's is negligable. 180's are stock in a 215 pump and nobody seems to see much of a gain when they swap out 180's for 191's. If you can get a hold of a used set of 180's, then go for it.

The stock turbo efficiently produces boost to 35 psi. After that much of the additional boost is coming from superheated air that is generated from an overspeeding turbo. What you really need is enough cool and efficient boost to control egt's. Overspeeding a small turbo to get more boost to burn the additional fuel will do the opposite - it will put egt's through the roof because of the excessively hot air charge.

It is safe to say that if you want a truely usable 350hp, you will be in for at least a housing swap. Wastegates can also be helpful in stopping a turbo from overspeeding, therefore controlling an excessively hot air charge fromk happening.

Depending on who you talk to, stock head gaskets seem to hold up to 50 - 55 psi.

15 -18 psi will NOT support fuel for 350hp. Even simple plate swaps require an increase in boost to burn the extra fuel. Depending on what plate you use, the boost elbow that is usually included will be wastegated for up to 32 psi.

IMO, 35 psi is no problem for a 12cm HX35.

 

I have a 94 2500 4x4 auto CTD with the 160 pump. I had a city diesel plate when i got 246hp/635 torque with nothing else but a drop in K&N and a straight pipe. I now have a cone K&N, gauges, a 3K GSK, and a cut stock plate. I was wondering about this. I had just the right amount of hp/torque out of my city diesel plate before i put in the 3k gsk to keep from slipping the converter, but still have the most power possible. When i put my 3k GSK in, it KILLED my power with the TC locked up, but helped a bunch when it wasnt locked. EGT's had never been a problem, and i hit 36lbs of boost every time in 3rd gear with the TC locked. I traded with my buddy his cut stock plate for my city diesel just to see what happened. He has about the same power he had, and with the cut plate full forward, i had more(too much because it slipped the converter), but my egt's when the converter was unlocked would pull plum to 1500 deg. before i hit 65mph. I moved it back just barley, and i dont have hardly as much power as i had before the 3k gsk in lockup, but still a lot more with the TC unlocked, but now my EGT's are WAY down, and i can stand on it probably as long as i want now, and not worry. Also, it wont slip my converter now. When it was full forward, it hit 39-40lbs of boost every time i kicked down on it. Now, it hits about 35lbs when i stomp on it. Anyway, my question is:
Why did it KILL my power with that plate when i installed the 3k gsk. The plate is very close to a #5 TST i think, and dynoed about the same.

Also, why did my egt's go through the roof with the plate full forward, but when it was just slightly back, they are fine? Why did they jump that much with that slight movement of the plate? Was it because i was making 40 lbs of boost that was getting it hot, or the extra fuel it was getting? Im pretty happy with the way my truck runs now, but its just kind of confusing as to why it did this stuff.

Thanks for any help.

Eric