before replacing my ex.housing:boost 20max, egt 1150max(after advancing my timing!)

Just got thru replaceing my.. stock? ex.turbo housing with my new 16cm housing and when i go them side by side, i can't tell the diff between them!

How do you tell the diff? my stock holset has a part # on it, can any one till me for shore what housing i just took off?(3519410)

After housing install, ..well the seat of the pants don't seem much diff? Maybe slightly at bottom end
egt and boost are the same??

 

Just got back from my test sec. of the road that i have been using sence i first start mods!(5th gear pull from 1500 up the the land mark that i picked out!)

The 16cm housing has made no inprovment!(veriboles of test:#1 first test was in 40* temp, today 60*#2 just filled my tank before the test!)

shore would like to now what housing i took off!!!

 

The number is cast into the housing all by itself, away from any other numbers. It'll be on the side of the housing that faces the firewall. You should have had an 18.5 cm on there stock. You'll see 18.5 on the back of that housing somewhere. Put a little grease on you thumb and rub it over any marks that you can't read--the greas will bring the casting relief out so it is easier to see. You won't notice much seat of the pants difference going from the 18.5 to the 16. Are you auto or 5-speed?

 

Its a 5sp gess i have better up dated my sig.

 

Didn't I tell ya so before?? 16cm housing is for the 21cm owners. 16cm = money maker for vendors. You might need a wire brush and brake cleaner to clean off the old exhaust housing, it will have 18 on the outside with all the other casting numbers. 92 IC'd models I believe are the only ones that came factory with 21cm housing. The rest all have 18.5. Then again maybe a previous owner swapped in the 16.

 

Ya had allready buy it! so i thought i'd try it and sea if it whould lower my egt...No such luck but, the avance of the timing, i felt and lowered the egts by allmost a 100*

Just realy don't wanta start the pump mods untill the egt is safe enuff to put some more heat in it! I no, I no that cummins said that the safe limit is 1250* but i would like two get it down to 1050-1100* before i start mods,probly dreaming but would really like to have a safety net in case some thing was to happen causing the heat to rise....say in rush hour traffic and pulliing my trailer!
Thats when i would be relying on cummins statement!
its a trailer puller not a racer....Well most of the time

 

Has anybody with an AUTOMATIC transmission changed out a 21cm. and put in a 16cm.housing and if so did it make much of a difference with EGT?

 

Yep sure does. I lost 25-50 degrees cruising at 65mph unloaded and lost 100 degrees WOT pulling my boat. Spool up and throttle response is noticably quicker and there is less smoke when I drop the hammer. As a matter of fact, the difference was not being able to turn the tires with the 21cm and burning rubber with the 16cm all without holding the brake while waiting for boost to come up. It was well worth the bucks in my opinion.

 

Anyone with a 21, auto or manual would benefit with the 16cm housing, no doubt.

 

I went from a 18.5 to a 12. I sure noticed a difference :0)

 

Still curious as to were the measurement it taken???16.18,exc????..cm,
when i had the two housing in my hand I did some measurement but just couldn't fig it out

Any insight would be grately apresh

 

I believe it's inside square area. If you removed a 16cm housing, you'd probly be able to see the 16 cast on the housing easily as it probly doesn't have a 100k miles on it. If it's a stock 18.5 housing with a ton of miles and years of heat cycles and rust on it, then it's gonna require some wire brush and brake clean work. Mine was so old and rusty I could hardly see ANY casting numbers.

BTW when you hold a 16 next to a 18, visually/outside they look identical.

 

On measurements I can't help you but on the back side of the housing that bolts to the exhaust manifold(faces the cowl) there is a number cast into the housing,mine is a 21 which if I understand it right is used only on intercooled trucks in 1992.I guess we are just lucky.

 

If you look in the flange that attaches to the downpipe, you will see the slots that the exhaust flows through to get to the turbine. The area of those slots what is measured.