How much benefit from a 16cm2 housing on a stock truck?

[HeavyHauler]

Hey fellas, I'm a 2nd gen, 24V guy, but my uncle has a '91 D250 automatic. From what I've read, he has a 21cm2 housing that could greatly benefit from an upgrade to a 16cm2 housing.



Should I recommend that he spend the $150/160 on a 16cm2 housing or is it really worth it on a stock truck? He probably won't be getting bigger injectors or messing with his pump, unless I do it while he's not looking! :-laf



What do you guys think?



Thanks for the help!

 

[pepecat]

I found that going from even a 18cm2 to the 16 with a bhaf and straight pipe exhuast worked wonders on my truck, I had the fuel turned up and I like it bettter with stock fueling, of course mine is non intercooled so I'm not sure what the bennies would be for your dad's.

Nick

 

[paccool]

I don't think you will see much improvement in boost pressure with just the housing change but you will notice the faster spoolup! The boost will come on much faster than the OEM housing will give.



Try to turn the cone to max position if you can sneak in and do it and then a couple of tweaks on the smoke screw and fuel screw and diaphram screw, should make your Uncle smile a little cause the boost WILL increase when you turn the fuel up some! :-laf

 

[BushWakr - RIP]

Depending on the pump/injector situation, we normally see about 2'ish psi boost increase "per housing size" you go down. It can be more or less as noted above when it comes to pump tuning.

You will see a pretty nice improvement in turbo response compared to a 21cm housing I would think... .

Generally the 16cm is really good housing to use on our version of trucks...

If you're not too heavily fueled you can even go to a 14cm WG version as an option. Keep in mind that the 14cm non-gated can get hot on you if you run alot of fuel and don't keep boost pressures in check though... been there, done that, go the video and T-Shirt...



pb... .

 

[HeavyHauler]

Any insight as to why these trucks even had a 21cm2 housing on them from the factory? Was the top end really bad on them prior to this or what? Thanks for the responses - I'll probably let him know about the 16cm2 housing.

 

[JLEONARD]

I say yes change to a 16 as soon as possible.

Mine (non I/C) had a 18. 5 housing, and the change to 16 was awsum. Made the truck much more driveable... . I would say that it lowered the rpm range that boost started by almost 500.....

Jay

 

[Greenleaf]

There is a good/bad/ugly thing with the swap. If the truck has mild pump modifications and your running with the manual transmission, it's a big improvement.



It's by no means a cure all.



-S