cumminsdriver635

Allright guys. Ever since i put the Goerend converter in, with it bieng so tight; my truck spools like it has an HX40 or something on it Just seems really slow sometimes. I can powerbrake it, and be fine, but everyday driving it is just almost to laggy. Pulled out of a blind curve a few days ago, and just as soon as i started moving, and it was to late to stop, here comes someone running 60mph or so. Immediatley mashed it to the floor, and clouded the road to the point of not bieng able to see the car at all till it came through the cloud of smoke. It just spools slow. There is no way around it, unless you powerbrake it. So with all this talk of boost controllers and stuff, and installing the converter, i have been thinking hard about going back to the 12cm for now at least. My EGT's WOT settle around 1350* or so. Not to bad really; but i really dont want them any higher at all if i can keep from it, because i haul stuff in the summer, and i usually like to run her pretty good up the hills and stuff. I usually keep my sustained EGT's at 1150* and under while towing(dont like taking chances), and it isnt really a big deal. Max boost is around 36-38psi with this housing. If you guys feel i could put my 12cm housing on, and get my spoolup back, and wastegate it around 34psi or soand not gain ny in the EGT department, i would really like to do it, si im just looking for some input from you all on this. Once you get rolling, the spoolup isnt bad. Its taking off that is aggrovating. Im just afraid im gonna be pulling 16k lbs or so some day and get stopped on a hill, and not be able to take off without completley killing all the mosquitos within a 1 mile radius before i can get it spooled up and took off. Its also hard to take off fairly quick in traffic without smoking pretty good. So any help/ideas is appreciated. If i go to the 12, i might drill the wastegate hole the flap covers as the one thread mentions, and wastegate it at 34psi or so.Do you guys think EGT's will go up? Thanks!

Eric

Cummins4Life

I'd go back to the 12W, drill it out so engine can breathe better and try to adjust your starwheel for either the least amout of smoke or the quickest spool, whichever is more important. However a tighter converter will make any modded truck smoke until boost is up.

I've ran, 12W, 14W, 16, 18.5, and 21 housings on my truck. The only difference between the 12W and 16 housings was that i could hit 50psi with the 16 where with the 12w I could limit boost. I doubt you'll run into any EGT problems with a 35/12 except when you want to.

cumminsdriver635

Thanks for the info! Yeah. I know my truck is going to smoke enough either way, and it doesent bother me much, but with the bigger housing, taking off is a little aggrovating with the tight converter as i said. It just doesent build boost quick enough to suit me a lot of the time, and my tranny shifts pretty quick, so sometimes the shift to 2nd happens before i get spooled in 1st which just lugs it even more when im driving with a light throttle. The main reason i ever changed was because with my boost elbow, it had an allen head screw in the side of it that i thought you could adjust it with, but i couldnt get it under 40PSI, and i didnt realize till i took it out when i installed the 16cm housing that it also had an allen bolt running straight up inside of it, so my wastegate was never opening at all. It was just as if it was blocked off. So now, i think im either gonna make or buy a boost controller after i put the 12cm housing back on, so that i can play with the boost, and set it where i want. I dont want to work the turbo to hard, so i would like to keep it around 34psi where it is about the most efficient. I hope the 12cm will fit back on.lol I made my 4 inch downpipe when i had the 16 on, and where it is shorter, since it doesent have a wastegate, i may have to do some more modifying to get it back on.lol Either way i think i will put it back on. I just think it will suit me better. Thanks a lot for the input!

Eric

cumminsdriver635

Also, how do you like your Valet switch? What does it do for low end smoke? If you mash it from a stop does it still smoke bad or is it much more controllable? How are EGT's, and power? Thanks a lot!

Eric

Cummins4Life

It works pretty good. The main reason I got it was when I had 370's I needed to turn some of the fuel down when towing. I cranked the starwheel all the way back and this let me tow with relatively controllable EGT's. Right now WOT with the 180's I can hit 1300* with it on, then peg out the pyro with it off . It does cut out a good deal of the low boost smoke (depending on where your starwheel is at) but usually a "puff" then it cleans up. You can definately feel the lack of power when you put your foot in it. I like it because it gives you some adjustability.

signature600

Ditto on the valet...I would also go back to the 12cm housing!

Chris

CTD NUT

If more off-idle snap is what you are looking for, consider swapping to 191 DV's and a #100 plate or a #10 if want to limit some top end fueling. You will not believe the difference in off idle torque with this set up. The 160 pump has the tiny 131 DV's that seriously effect low end fueling. I agree about the 12cm housing too......it will help spooling but you will not get around the fact that you will need more low end fueling than what you have to overcome that tight converter. As long as you stay with stock sticks, egt's will be controllable with big DV's and the 12cm housing.

HOHN

Good advice, CTD nut.

I'd go with the 12 housing as well. If you feel the 12 is choking you and causing high EGT, then go with an external gate. 99% of the time, the 12 is going to be a better housing.

On a daily driver or tow vehicle, spoolup is more important than peak EGT control, imo.

CTD NUT

Yes, I agree, this is often overlooked. WOT is used so little on a daily driver/tow vehicle that, IMO, it hardly seems worth it to sacrifice low end torque, spool up and drivabilty in the name of dropping a little WOT egt. With the set up on my 94, the turbo is unquestionably too small for max WOT hp and egt control but it is down-right snappy and has huge off idle torque because of the nearly instant spool-up. One way to look at it is that you can control WOT egt with your foot but the only way to increase spool up is to use a smaller turbine housing. I suggest keeping the 16cm housing around because if you ever go to big sticks like 370's, the 12cm will just be way out of it's range but at that point you can go to a larger housing without losing spool up speed because of all the extra fueling you will have!

swank

i vote for putting the 12 back on and adding a larger compressor wheel. and drilling out the wastegate and continuing the hole through the divider. that will help tremendously with keeping boost in check.

dave

G1625S

Yup, the drilled divider works good for me.

infidel

I've tried 12, 14, and 16.
With the 16 poor spoolup. Went back to 14 wastegated at 40 psi, best of both worlds.

Cummins4Life

ditto

signature600

When I finally get around to installing my twins, this is what I've been thinking about!

It's a 40/B2 setup, but if I can't spool the 40 for towing, I'll switch to either a 12sm or 14cm non/wg (have ATS w/external) and see if that will light like I need.

Just what I'm thinking, at least
Chris

cumminsdriver635

Looks like ill be drilling out the W/G on the 12cm, and building a manual boost controller, and reinstalling it to see what i get. Thanks guys!

Eric