crap, my turbo housing says 21 on the back, so that means its the 21 cm housing correct, as far as ive read on here, the only thing i seen about the 21 is about changing it. whats so bad about the 21 cm housing?

 

One word...... LAG
It's called the LAGMASTER for a reason!
Mine, too, has the 21 but I've got an 18 sitting here just itchin' to be put on!


I'm not sure WHY they switched to the 21 at the introduction of the I/C model half way through the 91 model year. They switched back to the 18 a year later after people complained of the lack of power.

 

Dean,I actually liked my 21 alot for top end and highway pulling,the only reason I changed it was after I did some mods+increased fuel I was getting lots of pulsing through the 21 when under load.Also lots of heat
But I would never go back now that I've got an HX-35.jmo

 

Well i dont notice much lag with mine? I mean i hit the gas, and within 1-2 seconds turbo is at full 28lbs of boost roasting the tires off. if it went to say a 14 cm would i gain boost and lower egts?

 

You'd gain boost, and should lower EGTs. But, if you still have the stock H1C, you will be overspinning your turbo, so EGT may not drop that much. Peak efficiency of the H1C is the mid 20s psi.

Most trucks, esp stockers with the Lagmaster, have about 3seconds lag, then it is slow to build boost, and just all around sluggish. It sounds like you are making nearly double stock boost, so if your fuelling is increased accordingly, you will reduce your lag.

Daniel

 

I went from the 18 to the 16 and noticed a difference. I am real happy with the 16. Pulls 10K alot better from a dead stop.

 

I think a 21 works better with a auto than a 5 spd. Once you get it lit, it holds boost through the gears. With a 5 spd. you have to start all over 3-4 times.

 

I went from a 21 to a 12. What a difference. It's a completely different truck.

 

I went to the 16cm. Oh what a feeling.
I was just given a pile of old TDR mags. In one there is this article on the 21cm housing. It seems that it was an attempt to lower boost to reduce NO2 emmision. Go figure.