12cm turbo housings

[Jim Curry]

I am wondeing if anyone of my 1st Gen comrades can convey there experiences and opinions on using of a 12 cm turbo housing on a 1st gen truck. Info on waste gated vs non waste gated. How it effects egt's, boost ( low end & high end) , over-all preformance and weather or not you would recomend one or perhaps a 14cm version . I am running a 16 cm now as you can see from my sig. along with the other mods I have listed. Look forward to your input and suggestions.



Thanks Jim

 

[fastmark]

I may not be a good example, but here goes anyway. My stock 92 service truck with an auto runs fine. I do not have boost guage. My new crew cab has a 12 cm on it. It does not run very good. I had to turn up the fuel just to get 1/2 way decent performance. It only builds about 16 lbs of boost in 5th floored. I did not run it with the original turbo so I can't compare before and after. I am still looking for hp.

 

[drives mopars]

my 93 14 makes 28

i like the 14 , w/ pw's pump up

open pipe . gets 28 psi



about 215 hp at rear tires

 

[Jim Curry]

Thanks for the input guys. I am getting up to 29 # of boost at wot but it is still alittle slugish at take off.





Jim

 

[NeedMoPower]

The 12cm housing did alot for my truck. I was really trying to find something that would eliminiate turbo lag and improve throttle response... . the 12 was the answer. With all of my mods listied in my signature i'm making 35 pounds of boost and my egt's are controlable, but can get into the 1400+ range under full throttle up hills. I'm glad I decided to make the move to the 12cm housing. The truck runs alot better and I love the sound it makes when I shift gears!

cody

 

[Jim Curry]

Thanks again for the feed back. Those of you that have replied, are your 12cm housings waste-gated or not. If they are did you have much trouble getting the extra clearance for the waste gated's extra length. Did you loose any top end as a trade-off for the better low end response and where did you get your housing?



Specifically to Needmopower, what housing where you running and what was your boost level with that housing. Looking to see what the net gain in boost was in your case and if EGT's improved when you went to the 12 cm.



Thanks Jim

 

[drives mopars]

what size is the turbo on 2 gen stock

can we use the 2 gen's houseings and or turbo



are they the 14's ?

 

[Jones]

Hey Jim,

I had a non-gated 12cm on my Cummins/Ramcharger for a while but I took it back off and put the stock non-gated 18cm on. As light as the Ramcharger is, it launched almost too quick and I just about rear-ended two cars the first few days 'cause I suddenly had zero turbo lag. It was a real eye-opener! Also always wondered if it ran out of boost somewhat sooner too, like moving the entire response range down towards the bottom end. If you decide you would like to try it, e-mail me and I'll see if I can't work you a deal. If I try a swap again I'll probably go with something a little tamer, like a 16 or maybe a 14. Might have just shot mself down on the sale but it seems most guys are happy with a 16cm, at least for general driving or towing... for what it's worth.

Hope this helps, Jones

 

[NeedMoPower]

I'm running a wastegated 12cm turbo off of a 97 I believe... . I know it is off of a newer truck. Before the 12, I was running a 16. I picked up about 5 pounds and really didn't see that much of a change in egt's. My egt's flew through the roof with the addition of my lucas injectors and heavy pump tweaking. If you choose to use a wastegated 12, you will have to modify your downpipe, but was not that hard at all. I had no turbo lag after I put the 12 on, but I also didn't I lost anything on the top end... . you just don't have to wait for the turbo to spool anymore.

cody

 

[fastmark]

Well, there must be something wrong with my truck. I turned up the pump and it is a little better, but WOT in 4th or 5th gets me 16 lbs of boost. I think i need to have my timing checked. The 12cm did not do much for me.

 

[J DeMaio]

I believe that the 1994 + trucks came with the 12 cm housing and they were all wastegated. I'm not sure if you can buy an aftermarket 12 cm housing, but i know you can 14 cm.

 

[KEENO]

12 vs 14 vs 16

Hey Jim!



Keeno's Opinion: I don't believe you can make a wrong decision between the (3) housings. They're all better than having the "No Boost" 21cm2 or even the better performing 18. 5cm2 from the '93's.



I believe that the 16cm2 you're currently running is the "Best bang for the Buck" because it just slips right in, performs well and the downpipe doesn't need to be modified by the 1. 5" approx.



The 12 & 14's will both have to the downpipe modified or a new one purchased or bent. Not a big deal... Just a more cash.



I have had both the 12cm2 & 14cm2 on my truck and really seem to prefer the 12 for my driving style in hilly conditions & 2 lane roads. I must admit that I have re-installed the 14cm2 after a few discussions similar to this & to evaluate on my upcoming Western Trip. I'm looking for the 'more relaxed' interstate driving mode of the 14 & 16's (not as much boost) instead of the "High Strung... instant boost" of the 12cm2. I do however believe that I'll miss the 12 once I get to higher elevations & winding roads of the West.



In summary: It's all based on the way you drive & personal preference... There is no perfect housing for all of us.



16cm2 are great & inexpensive to purchase & easy to install.



14cm2 are outragiously expensive (from Banks) and the downpipe must be modified but I believe these might be the best compromise of the (3)



12cm2 are cheap used from our Second Generation Brothers but the downpipe still needs to be modified.



I have (2) 12's in the garage that I plan to reinstall upon returning from the trip, one OEM from a '95 and the other has had the wastegate & actuator completely plugged & welded. I'm a bit apprehensive about messing w/ the welded one but might have to bolt it up to satisfy my curiosity.



My truck produces 27# of boost w/ the 14cm2 & 31# of boost w/ the 12cm2 installed, EGT seems to be similar and max out @ 1150 w/ either housing.

 

[Jim Curry]

Het Keeno;



Living in Florida , I don't have muck in the way of hills to deal with. Around town and interstate travel is the norm. With the 16cm I develope 29#s of boost at WOT and EGT's can easily reach 1250 to 1300 degrees. I do not tow very often at all. I do a bit of street running.



Jim

 

[KEENO]

Looks like you have plenty of fuel...

Hey Jim!



I didn't realize that you had 215 HP injectors installed! You are at the theshold of upper EGT (1300 degrees) because of the injector fueling and going to a smaller housing will just make it worse.



You say, 29#'s of boost @ WOT and its still feeling sluggish?



If this is the case, maybe you need to "Loosen" up the AFC "Star Wheel" to allow the "Fuel Rate delivery Pin" to move sooner.



Check out Dave Fritz's website for instructions. dodgeram.org



Keeno

 

[KEENO]

A second thought...

Hey Jim!



I have just re-read the entire post and now I'm wondering if maybe your "Full Power Screw" might be delivering too much fuel @ lower RPM when combined with the 215 HP Injectors & DD fuel kit.



The reason that I say this, is that in the past when First Generation Brothers installed the "PW" injectors they had to actually 'reduce' Full Power Screw adjustment to get the engine to perform properly. ("Mark93" & others)



I had over adjusted the 'screw' last weekend w/ my BD injectors & JRE enhanced inj. pump and actually lost performance. I re-adjusted it last night and the truck is performing at it's best.



Just a thought... No science involved!



Keeno

 

[KEENO]

Hey Fastmark!



Sorry to hear that the 12cm2 isn't working well for you!



I hate to mention this but are you sure your VE injector Pump is in good condition?



When I originally installed the Banks "Stinger Plus" w/ 14cm2 housing I couldn't get much over 10 PSI boost because of my wore out pump. It wasn't until Ted Jennetty @ JRE installed a rebuilt & enhanced pump on my truck that I finally got the performance I had always dreamed of.....



Keeno

 

[Jim Curry]

Fuel screw is in 1 to 1 1/2 turns. I might try backing off the fuel screw a bit. Response now is good after boost kicks in but still a bit sluggish at take off.

Jim

 

[EOliver]

Just a question about the turbine housings... I have seen a few guys post on here about non-gated 14cm and 12cm housings. I am wondering where to pick one of these things up at? My truck is completly stock at this point (except for K&N w/modified air box and straight exhaust). I am pretty sure my fuel pump is in good condition as it has had fuel additive its whole life and with under 80,000 miles it has never been opened up. I am planning on bombing soon... but I only want to do it one time. This is what I am planning: Lucas injectors, pump tweaks, a 14cm non-gated housing if I can find one, otherwise a 16cm housing, 3. 5" exhaust, DTT '93' TC and VB. What do you guys think? Is this a good combo for the truck? I would like to have a truck with little to no lag and that would be able to at least do a nice powerstand!



THANKS!

 

[Jim Curry]

Hi EOLIVER;



Your list of proposed mods sounds good but you will have to settle for a 91% converter because for the 727/518 trannies that is the highest effcientcy converter DTT has . The 93% is only available for the 94 and newer trucks. Your first mod shopuld be EGT & boost gauges. I would suggest a O- 50 or 0-60 # boost gauge. If you get a 0-30 you may find you will max it out . If you go with the lucas injectors you may not have to turn the pump up very much but you definatly will want to ajust the star wheel and pin & diaphram . With the lucas injectors you will want the Gauges and turbo housing done before or at the same time to take proper advantage of the extra fuel. Watch thoose Egt's though, because with thoose mods you will be developing lots of heat. Keep it below 1300 - 1350 degrees max and then for only short periods of time at thoose temps. 1150 to 1200 might be a better rule of thumb. You don't want to start melting engine parts.



A transmission temp gauge would not be a bad idea either along with a better transmission cooler. This would be adviseable in any case but especially if you are doing a lot of heavy towing.



Thats all that comes to mind right now . Hope this is helpfull.





Jim Curry

 

[fastmark]

One thing I forgot to mention. My exhaust temps are only 600 degrees. I have a BD brake and the probe is in the brake after the turbo. What should my temps be. Keeno, The truck runs and starts fine. I can't imagine the pump being bad. I need to have it timed. How much is the tools to time the pump and where do you get them? I like doing things myself. Mark