i am planning on modding my pump a little and would like to do one of these two turbo upgrades... I would still like to be able to tow so i am not planning on going too overboard. i currently have the 21 cm housing. my questions..

1. which will cut down on turbo lag more?
2. will changing to the stage 3 compressor (only) cut down turbo lag at all?
3. is anyone running stage 3 with a 21cm exhaust housing?
4. what is the exhaust outlet on the 16cm housing? (and is the 21 cm a 3 inch outlet or 3.5?)
5. does the stage 3 have a turbo whine like the newer trucks?

sorry so many questions... thanks!

 

1- depending on your fueling level, but mostly the 16 will cut down on lag.
2- not sure, but you'll still have the monstrous, laggy 21cm exhaust housing.
3- Greenleaf on tdr, he doesn't tow, and is just experimenting with the big housing.
4- all h1c and hx35 exhaust housings are 3 inch.
5- someone else will have to cover that one.

I'd try to find a used 18.5cm housing off someone, usually can get them for shipping or free. Better than a 21 and has almost the same characteristics as the 16. BTW folks just aren't giving away the 16's. Good luck finding one used for sale. Too much demand for them on our rigs and 2nd gens. I wasn't impressed from going to a 16 after having the 18.5.

 

I noticed a HUGE difference between the 21 and the 16

Good luck,
Michael

 

With the 16cm housing it will spool alot faster and have higher boost numbers.

With the HTT III it will have that awsome sound and flow a higher CFM with less boost, making more power at less boost and less heat.

Personally I think if you are towing and not raceing it you should get rid of the lag first with the 16cm housing. If you plan on adding POD's and alot of fuel I would get the HTT III first.

 

if i don't care as much about lag, with the normal pump mods (but no pods) which do you think would create a larger power change?

bgilbert, hey good call on the 18.5 i will keep my eyes out, i know there would be a big jump from 21 to 16... however i did here that the 16 flows about the same (egt wise) as the 18.5 but with a little quicker spool, is this true?

 

With maxing out the fuel and advanced timing the HTT III would probibly make more power, but make it up high. On the bright side it would sound sweet.

 

the way you make more power is add fuel. If your not adding injectors, especially pod's) your stock turbo will flow plenty of air for the fuel you can add with just pump mods. to get rid of lag you can get a smaller housing or add tons of fuel and with just pump mods you won't beable to add that much fuel to not have any lag. I would get a 16cm housing before the stage III compressor.

As for the turbo whine get a hx-35 or a WH1-c and take the silencer ring out. The whine comes from the map width enhancement slots in the compressor housing. If the stage III compressor housing has these slots it will whine for sure if not it probably won't.

 

i don't think changing housings will change power much, if at all. it will give a nice change in drivability though. changing wheels WILL affect spool though. bigger wheel=more weight=slower to turn. if spool is not an issue for you, i would definitely recommend the stage 3. just my .02.

dave

 

These are the facts!!! If you go to the 16cm housing you will have quicker spoolup, if you just change the wheel you will still have the lag of the 21cm housing but will move more air when it spoolups, get the best of both worlds and get the 16cm housing and the HTT stage 3 kit, you will have quicker spoolup and move more air. Your egt's will be a little higher under hard acceleration with the 16cm housing but really not enough to outway the benefits of the combo. This is the combo I used on my old 92' before I sold it and it really woke it up. I think you will be pleased.

 

I switched to the 16 from the 18.5 the spool was a bit quicker but I lost 2 psi of boost on the top. I stuck with the 16 as hauling heavy loads and the 2-3 upshift is a long way, I needed the spool up.

 

I vote for PDR HX40-16!!!! Ok then too much $$ for ya, then htt stage 3, whatever that is , and a 18.5 housing, pass on the 16, too choked on the highway and top end for me. Should be able to find a 18.5 a heck of lot cheaper than a 16. If I were to do it again, I'd keep my 18.5, which I already gave away.

 

i don't normally see any boost until 1800-2000rpm under hard accel. anyone know when i should expect to see it with
1 the 18.5 ?
2 the 16 ?