16cm Turbo Housing

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I have a '92 4x4 ext. cab with 5 spd and 3. 54 diff. I pull a 7000 lb. 5th wheel and about 60% of the 129,000 miles on it are towing miles. The only performance mods are BD monster exhaust, K & N filter, EGT and boost gages and BD exhaust brake. The EGT probe is in the turbo outlet elbow. I am considering changing the 21 cm turbo exhaust housing to the 16 cm housing to see if that helps my EGT. When pulling the trailer against a head wind or up a long grade, I can get to 1000 -1050 degees in 5th gear and about 60 mph (not lugging there). Boost is about 10 psi there. If the rule I've heard (for a turbo outlet mounted probe), that you reduce max allowable temp of 1250 in the manifold by 10 degrees for every 1 psi boost is a valid rule, then 1050 at the turbo outlet with only 10 lbs boost may not be too bad, but I've also heard that 950 at the turbo outlet is the limit. My max boost is about 15-15. 5 at full load and 2400 rpm. Before the monster exhaust and K & N filter, max boost was about 14, so boost is on the low side of the 15 - 19 spec. Downshifting to 4th to lower EGT isn't so bad as it (I hope) also helps keep my Getrag alive, but I still wonder if the 16cm turbp housing will help EGT. The quicker spool-up may be worth the replacement even if it doesn't help EGT as long as there are no serious down side affects. So, questions are: Will it help EGT? Do I have a EGT problem? Any potential bad things as a result of the change? What is the experience out there?

 

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With the modifcations to the Cummins you now have, the 16cm2 hot end housing is the next logical step to lower your EGT, raise boost pressure, and improve performance. It's cost effective also, at $140. 00 to $160. 00 for the housing, gasket, and instructions if you need them. You'll turn up the fuel at the pump, and it's covered in the instructions. Reputable suppliers include Ted Jannetty, and Diesel Injection of Pittsburgh.

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92 CUM'NS/DODGE 5spd. , 4wd, 3. 54 gear, 16cm2 hot end housing, mod. injectors, mod. pump, K&N, 3 1/2 exhaust, pyro/boost gages, 4"H. D. suspension, 305 85R16's on 3000# alum. wheels

 

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My turbo died last week, so I called a highly respected turbo specialist in Salt Lake to let him know that I would be sending it in for a rebuild. I also asked about switching to the 16cm. He told me that if I hadn't asked directly, he would have recommended the upgrade before he sent mine back. His remarks paralleled the last posters comments. ($140. 00 installed)
Don

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'93 W250, CC, 4x4 LE Cummins W/mild mods, K&N, 5spd, 4:10, custom exhaust, 5th wheel, gooseneck, H. D. rear hitch, Lund visor w/lights, aluminum everything, Cobra 148GTL C. B.

 

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I have a 16cm exhaust housing and believe me when I say, you'll smile every time you drive your Cummins Dodge with this simple and inexpensive mod. My EGT at the manifold hasn't gotten higher that 925 degrees. My max boost is 27 lbs. How many miles did you get before the turbo went?

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92W250, 4X4, 3" Trail Master suspension, Gas Shocks, Extended Cab,3 Gauge Ispro pod, 16cm exhaust housing, Flow Master muffler, Turned up pump, Performance Friction Carbon Metallic pads, Corex shoes.

 

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My turbo failed at 138,600 miles.

Old school, you mentioned fuel adjustment after changing housings. Is this mandatory or optional once the housing is changed? My turbo will be returned to me w/the new 16cm housing already on it. My pump is at the factory setting and I really dont have any desire to mess with it until it dies someday, then I figured I'd upgrade the pump and injectors.
Don

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'93 W250, CC, 4x4 LE Cummins W/mild mods, K&N, 5spd, 4:10, custom exhaust, 5th wheel, gooseneck, H. D. rear hitch, Lund visor w/lights, aluminum everything, Cobra 148GTL C. B.

 

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Don D: No, you don't HAVE TO turn up the fuel adjustments. Do I recommend it? Yes. You will now have, I believe, the optimal turbo housing for your 12 valve engine. You will spool up quicker, more total boost, and good moderate EGT. With your exhaust system in your signature as modified (hopefully less restrictive) you are at the point of taking advantage of the increased air now available to your engine. It is now ready for a fuel increase.
You can gain torque, power, increased driveability, and mpg by turning up the fuel adjustments at the pump. IN AS SMALL AN INCREMENT as you want.
Check out the site: http://www.ecpe.vt.edu/~dfritz/technical/DIESEL/more_power/POWER_ve.htm
You should really look at installing a boost and pyro gage, seeing that the pyro installation would be easy since the new turbo is not installed yet.
Post if you want any comments further.....
Regards.

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92 CUM'NS/DODGE 5spd. , 4wd, 3. 54 gear, 16cm2 hot end housing, mod. injectors, mod. pump, K&N, 3 1/2 exhaust, pyro/boost gages, 4"H. D. suspension, 305 85R16's on 3000# alum. wheels




[This message has been edited by old school (edited 01-05-2000). ]

 

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Old School, Don D, and Neilman - thanks for the replies. I guess no negitive results from the 16cm housing. I also was sort of wondering whether or not to turn fuel up. My main interest is reduced EGT even tho I'm not sure it's really too high. I'm concluding that the 16cm housing will reduce EGT even if fuel is not turned up due to better air flow. Of course, it's too tempting to turn up the fuel - I just hope the old Getrag can handle it. Thanks again guys. If anyone has comments on the real EGT limit (considering boost and pyro location etc. ) or any down side to the 16cm turbo, I'd still like to hear from you.

 

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Banjobill. I am convienced that the 16cm is the way to go. I just returned from the "TST" site that "Oldschool" recommended,and while I was there I ordered one. I did send a follow up e-mail to TST asking if everything required to install it is included with the Housing. I can hardly wait to get it in.

Walt

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My '92 automatic 3. 54 had a 16cm housing when I got it, so I can't compare what it was like. I get 15. 5-16 psi boost at full power weather i'm towing or not. I've never touched the pump, and as far as I know it's stock. I just got a pyro for x-mas, and am ready to install. I plan to tinker with the screws. I don't hear anyone talking about checking the timing, I understand there is big tolerance with the TDC pin and is not accurate. I also need an Exhaust system, I'm leaning towards the BD system, but it has no headpipe, any other sources? I only have one weld ring for the pyro. What's the saying? This aint no dress rehersal.

 

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I have been following the "more power" dialogue with great interest and, after having added only a K&N filter to an otherwise unmodified truck, attacked the pump. With the smoke screw turned in one turn and the fuel rate diaphram rotated 90 degrees clockwise the overall driveability of my truck is much improved with no apparent ill effects. I will soon be changing the turbine housing and was all set to buy a 16cm2 when I noticed the ad in issue 26 (classifieds) for a non-wastegated 14 cm2 unit. I use my truck mainly for personal transportation. Would this be the way to go?

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1993 W250 4x4 5 spd, 3. 54, 70,000 km, K&N filter, "just getting started".

 

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Hey Guys: It's good to hear of your rewarding results concerning 16cm2 housings and pump incremental turn ups. I personally think the 16cm2 housing to be the best choice for added boost, and still having a large enough turbine chamber area to be less restrictive than a 14cm2 housing.
About timing: The most accurate method is utilizing the spill port / plunger method with the dial indicator setup, and dial indicators mounted on the #1 cylinder valves. Proper (advanced) timing makes a world of difference toward the enhanced output of the engine.
As a recommendation: don't stop at the TST site, dig into Diesel Injection of Pittsburgh: http://www.dieselinjection.net
And very competent Ted at Jannetty Racing.
Post on... .....

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92 CUM'NS/DODGE 5spd. , 4wd, 3. 54 gear, 16cm2 hot end housing, mod. injectors, mod. pump, K&N, 3 1/2 exhaust, pyro/boost gages, 4"H. D. suspension, 305 85R16's on 3000# alum. wheels

 

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Wayne: I noticed you mentioned a weld ring for your pyro gage. I'm assuming you intend to install it post turbo in the downpipe. I'd suggest you install it pre-turbo, at the hottest point for an accurate hot reading. You'll drill and tap the exhaust manifold just before the turbo... ... ... ... .
Regards.

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92 CUM'NS/DODGE 5spd. , 4wd, 3. 54 gear, 16cm2 hot end housing, mod. injectors, mod. pump, K&N, 3 1/2 exhaust, pyro/boost gages, 4"H. D. suspension, 305 85R16's on 3000# alum. wheels
Classic Long Nose Conventional

 

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There is a very good exhaust system offered buy Percision Power Injection out of Kokomo,In (800-432-7269). It's made of T304 stainlees steel. It's 3 1/2" in diameter mandrel bent. There is also a fitting welded on for a thermocoupler for those people who want the thermocoupler after the turbo, although I agree it's more accurate before the turbo.
Gene Hayford
92 350 4x4

 

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I've decided to go after the turbo because I don't want to chance getting shavings in the turbo. I thought about taking the turbo off and putting the shop vac on as I drill, but I would really want to take the whole manifold off, detail it and send it to jet-hot for coating. This is out of hand for me due to $$ and time. I'm happy just to finally fill the fourth hole in my gauge pod! Someone in the know told me that in extreme use, the tips come off the thermocouples, that would ruin my day if it got in the turbo. Boost on!!!

 

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Diesel Injection is out of the short 14 cm turbo housing. They do have the longer non-wastegated housing (intended to be used on 1994 on). This longer version will require the entire exhaust system to be moved back approx. 1 1/2". I was going to purchase one for comparison but I think I'll stay with the 16 cm.

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92W250, 4X4, 3" Trail Master suspension, Gas Shocks, Extended Cab,3 Gauge Ispro pod, 16cm exhaust housing, Flow Master muffler, Turned up pump, Performance Friction Carbon Metallic pads, Corex shoes.

 

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Wayne M. call and talk to Ted Jannetty about the pyro mounting. He told me today that he has been to the holset(sp?)factory and they literaly pour SAND through the turbo for testing.
Tom

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96 2500 CC 4x4 NV4500 3:54 3" body lift 2. 5" skyjacker class2 suspension lift
Dual steering stablizers dual shocks up front 265/75/16 street tires
36 12. 5 16 swampers for mud KN filter(round style)
turbo silencer in top of toolbox
muffler and res. out back in the shed
3" straight pipe in place

 

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Go with the 16cm2 housing! The 14cm2 will be to restrictive if and when you decide to go as far as you can go with the fuel. When set up properly as in the previous posts concerning the fuel pump it will perform the best all around. I have experimented with the 12cm housings off the new style wastegated trucks and it was a dog. Even with the wastegate blocked. I believe it just ran out of boost to soon and the boost readings were low. The 16 is just right for the early trucks with the rotary pumps. Drill the exhaust manifold before the turbo by stuffing the openings with rags. When you are done drilling and taping, pull the rags out and all the filings come out with them. Then sweep the inside with a magnet just to be sure. We have done this on so many trucks I can't remember. Never a failure because of filings and never a prob failure. I also recomend Diesel Injection of Pittsburg. Bruce Mallinson has been playing with Cummins for a long time and he has had very good results. Go to his site and read everything, even if it does not pertain to the Dodge. Stabco has new housings @ resonable prices.


Jan '89, CC, SB, Extremely Enhanced fuel, 16cm housing, Banks exhaust, Autometer liquid filled gauges, Horton fan clutch, factory tach option, KN filter, Firestone air bags, Chrysler V-twin air compressor, Alcoa LST wheels, 255/85/16R BFG Mud Terrain (33. 2"),Flexsteel seats... ... ... ... ... ...

 

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I have read that you need to be careful where you drill the EGT probe hole as the casting for the turbo inlet pipe has casting supports inside of it and you don't want to drill through one of the casting supports. Is this true? I am looking to pickup a 16cm housing, pyro gauge as well as a boost gauge. I went to the TST site and they have a price off $175 which seems high when I have read quite a few times that people get them for $140. Any suggestions? How about gauge packages, any better than others? I also read that if you put your EGT probe after the turbo, since the air is cooler, you don't get an accurate measurement, and it could be in fact up to 400* different from the air temp going into when compared to it coming out. Any comments on this?

Pat Daniels
91 4x4

 

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Coasty,
If you look in the classified section (all the way at the bottom) on this web site you will find a place called Stabco Repower which sells new 16 cm2 housings for $125 to TDR members which includes new gaskets and shipping. Mine is currently on order from them.
Matt

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90 3/4 ton, 4x4, 5-speed, 3. 54 gears.

 

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Pat the exhaust manifold has a center casting that splits the manifold into two seperate chambers. Cylinders 1-3 are on one side 4-6 on the other side. When you drill the hole for the thermcoupler it needs to be offset from center. So you end up reading the exhaust temp from three of the cylinders if just one thermocoupler is mounted in the exhaust manifold. I installed two so I could check the temps from all the cylinders. They read almost the exact same. I don,t think two are really needed. TST's web site has good instructions on drilling and taping the hole in the exhaust manifold. If the thermocoupler is installed after the turbo the rule of thumb is to add 10 degrees for every pound of boost to get an accurate reading. Good luck.
Gene Hayford
92 350 4x4