I spent most of the day putting a 12 cm housing on my 90 with the HTT hybrid. All I can say is it was a bummer,it spools no faster then the 16cm and now my EGTs go up faster then hesballa rockets! [verymad] im running 28psi boost with the WG hooked up and 38PSI not hooked up it will hit 1000* with out hardly even trying and 1300* before 3 gear on a WOT stab.the HTT has a 60mm wheel, I would think that would pump plenty of air .I also drilled the divider through the WG . [dummy]

anyone want to shoot me some ideas?

maybe ill advance the timing some more.I have a set of piers 180 performance injectors in it maybe they want more timing??

I'll probably get slammed, but when you put a larger compressor on you move more air which will cool EGTs if no additional fuel is added, but putting a smaller turbine housing on restricts exhaust flow and will raise EGTs. When you go bigger compressor Id go bigger turbine. I had a 18.5 stock and put on a 16 and lost 2 psi and ran a bit hotter but I needed a bit better spool for the heavy loads. When I get the pump rebuild I will probably stick the 18.5 back on.

Id put the 16 or 18.5 on and watch the temps drop.

What are the other mods on the '90? Something doesn't seem right. The 12cm should out-spool the 16 by a good bit. What size compressor did you get from HTT? Now that I've dialed things in a bit more, I can't see much over 900 untill halfway through 4th and I've really gotta lean on the 'ol girl in 5th to get over 1200. Re check all your clamps and unplug the wire to your KSB and take a ride...that's the cheap and dirty way to see if 5-7 more degrees of timing will help on a non-ic truck.

I think you have more fuel than the 12 cm can handle. You have an automatic in there, so there's no reason to run the 12 cm unless you're living at 5,000 feet. Put the 16 or the 18.5 back on.

I'll probably get slammed, but when you put a larger compressor on you move more air which will cool EGTs if no additional fuel is added, but putting a smaller turbine housing on restricts exhaust flow and will raise EGTs. When you go bigger compressor Id go bigger turbine. I had a 18.5 stock and put on a 16 and lost 2 psi and ran a bit hotter but I needed a bit better spool for the heavy loads. When I get the pump rebuild I will probably stick the 18.5 back on.

Id put the 16 or 18.5 on and watch the temps drop.




That's way off. I am going to have to agree with wannadiesel on this one. too much fuel, put your 16cm back on. I have a H1E 8 blade 60mm that I hybrided with a hx35, and the 12cm drilled housing is way too small.

OK I have a 12- 16- 18 putting the 18 back on for towing would be my first choise ,but why will an hx35 cool my 01 with mach 1.6s and a smarty but not cool the 12v 90 ...is it because of the lack of a intercooler?

That's way off. I am going to have to agree with wannadiesel on this one. too much fuel, put your 16cm back on. I have a H1E 8 blade 60mm that I hybrided with a hx35, and the 12cm drilled housing is way too small.


Hows that I was dead on? I said to switch to a bigger housing, as the smaller one is keeping spent gasses in. So theres 3 options really, get more into the cylinder to cool it, put a larger exhaust housing to get more hot gasses out faster or turn the fuel down.

I dont look at it as too much fuel, its not enough air or to much exhaust restriction.

Like I said, put the 16 or 18.5 back on....

Hows that I was dead on? I said to switch to a bigger housing, as the smaller one is keeping spent gasses in. So theres 3 options really, get more into the cylinder to cool it, put a larger exhaust housing to get more hot gasses out faster or turn the fuel down.

I dont look at it as too much fuel, its not enough air or to much exhaust restriction.

Like I said, put the 16 or 18.5 back on....


I feel like a tard, sorry, I read your post all wrong the first time. We are all in agreement. you need a bigger housing.

Wow, this thread kind of worries me. I have a 12cm WG housing sitting on my bench waiting to go on. I'd been planning on putting it on my truck when I got back from the Rubicon next week. Its sounds like it may be too small for me becuase I bought this truck for towing my rock crawler . . .

Am I wasting my time installing the 12 when I should just run the stock one becuase it will keep things cooler? I thought that the wastgate would waste any excess exhaust above your set peak turbo pressure?

Or would this 12cm work better with the "Stage III Upgrade compressor housing and 60mm wheel"? WIth this bigger compressor will I be pushing enough air in that the 12cm won't be an issue?

I guess I have to re-evaluate what I bought the truck for. The 12cm housing may not be what I need for towing heavy loads with lots of wind resistance.

Chass
ct

If your only pushing 22 psi i dont think you are close at all in getting to the heat/restriction stage.
I think that you would have to put bigger inj.in, and turn the full fuel screw allmost all the way in, or up!

Wow, this thread kind of worries me. I have a 12cm WG housing sitting on my bench waiting to go on. I'd been planning on putting it on my truck when I got back from the Rubicon next week. Its sounds like it may be too small for me becuase I bought this truck for towing my rock crawler . . .

Am I wasting my time installing the 12 when I should just run the stock one becuase it will keep things cooler? I thought that the wastgate would waste any excess exhaust above your set peak turbo pressure?

Or would this 12cm work better with the "Stage III Upgrade compressor housing and 60mm wheel"? WIth this bigger compressor will I be pushing enough air in that the 12cm won't be an issue?

I guess I have to re-evaluate what I bought the truck for. The 12cm housing may not be what I need for towing heavy loads with lots of wind resistance.

Chass
ct

Chass,

No worries man. :cool: The 12cm comes stock on 2nd gens (which come stock with more HP) so it's not as small as it sounds. You should be fine with the 12cm until you start adding enough fuel to be over 250hp or so.

Altitude also has a direct effect on the exhaust housing size. Gillett's here in SLC (very reputable) told me a 14cm at 5k' is equal to an 18.5cm at sea level. Even my 14cm is a very laggy sob here at 4500-5k'.

The housing will definitely work better with an HTT Stage III/IV upgrade...but that's because it's like a whole different turbo then. The larger 60mm wheels seem to spool noticeably slower than stock, so a smaller housing is just helping to make up for that too. Once they start to spool though it happens MUCH faster. [coffee]

Well, I am at 400 Ft elevation here and usually travel on I5 which varies but is along the valley floors.

My only concern is that this is primarily a tow rig.

I'm not really concerned with fast spool up. When I'm cruising or going up a long hill that thing will have been spooled for hours ;)

I guess its not the end of the world if it doesn't work like I'd hoped. I can just swap it out for a 16 later.

Chass
ct

Hey, in my mind (can you smell the wood burning) going from my 18.5 to a 16 would only be good for somewhat improved city driving.

I am going to see if the gov spring I have ordered helps enough around town to make a 16 unnecessary. If you are mainly pulling heavy loads, the 18.5 is nice. It may be just your personal taste as to which of the housings 16 or 18.5 is best for your needs.

does anyone know where to get a 12cm wG with the divider drilled out?

does anyone know where to get a 12cm wG with the divider drilled out?

Right off your drill press ;)

Apparently its pretty easy to drill it out. You just have to be careful not to screw up the edges of the wastegate port. Like using a center punch, a small bit and then your larger bit.

I have a question, does drilling out your divider accomplish the same thing as grinding out the divider where the housing contacts the exhaust manifold? It seems like you could get a lot bigger hole if you did both . . . or is it necessary?

Thanks,
Chass
ct

OK I have a 12- 16- 18 putting the 18 back on for towing would be my first choise ,but why will an hx35 cool my 01 with mach 1.6s and a smarty but not cool the 12v 90 ...is it because of the lack of a intercooler?Partly that and partly timing.

I have a question, does drilling out your divider accomplish the same thing as grinding out the divider where the housing contacts the exhaust manifold? It seems like you could get a lot bigger hole if you did both . . . or is it necessary?
Yes, you can grind out the divider for about an inch and a half, smooth the leading edge and call it good. On a lightly fueled motor this WILL hurt spoolup. The drilled housing would be less of a problem. Of course, if you're lightly fueled you don't really need to drill the divider anyway...

Yes, you can grind out the divider for about an inch and a half, smooth the leading edge and call it good. On a lightly fueled motor this WILL hurt spoolup. The drilled housing would be less of a problem. Of course, if you're lightly fueled you don't really need to drill the divider anyway...

When you say lightly fueled, do you mean, stock pump, stock injectors or does my pump turned up two turns plus everything else on the list of VE pump mods still qualify as lightly fueled because I don't have injectors?

I may turn up my pump more cuz my idle is only about 500 RPMs which leads me to believe that I have lots more available adjustment.

I don't expect to buy injectors because I'm shooting mostly for good gas mileage. More available fuel means I'll probably use it . . . but stock just wasn't going to cut it.

Chass
ct

I'd expect it to be a little laggier than a normal 12 cm in your situation. It'll still be worlds better than the 21 cm. [yuk] With what you're planning to do you really don't NEED to do anything to the divider. The wastegate will have no problem keeping boost under control using the back 3 cylinders.

did CHASS do this, does any body know?

I did not. I sold the truck to upgrade to a 24 valve.

Chass
ct

while were on the question, i was thinking of trying a 12cm WG for in town/ having fun, not towing, much anyway. what would it do for temps with the 60mm wheel combo, and is there that much performance gain over a 14cm non gated housing?

with the 5spd its great with my over fuel 90 auto it got toasty really fast

won't get to hot with it drilled? i am adding an intercooler and 3 inch pipeing.

Mine doesnt really get that hot... I guess hot compared to the I/C guys, but nothing I would complain about. My smoke screw is in far enough that I have to re-index my throttle plate or whatever that thing is... I would have to floor it through every gear to the end of 5th for it to hit 1300+

Tell you one thing, 2nd gear has a lot more get up and go... It almost gets to 20 psi:cool: (maybe 10 before) Makes for a quick snort through the gear.

Oh, and to rebal, advance the timing! Thatll cool ya right down.

i had to re index my throttle too when i yurned up the fuel screw and with the 14cm i have now i get boost fast but i think it needs to be faster i know its over 20 in 2nd.

big stinky is yours drilled?

Here's my 12 next to an 18.5. I liked the way it ran--would hold non-ic injectors and a maxed pump to 20psi with no problems. 36psi was the happy place.

http://www.dieseltruckresource.com/pics/data/500/medium/18-12_housings_001.jpg

Here's my 12 next to an 18.5. I liked the way it ran--would hold non-ic injectors and a maxed pump to 20psi with no problems. 36psi was the happy place.

http://www.dieseltruckresource.com/pics/data/500/medium/18-12_housings_001.jpg

Thats an interesting way to do it, I took the lazy road and just used my 3/4" holesaw and went right through the stock WG hole through to the other side. Now I just need more fuel, its hard to get over 1,100* in 4th or 5th under 90mph. Over 90mph and the temps start climbing to 1,500* by 110mph.[yuk]

Not drilled yet... I was gonna before I put it on, but got too impatient. Guess i can turn it up a bit more yet huh! Looks like them 12er housings need a bit of work when you look at em right beside the bigger ones! Come to think of it, boost did creep when it was wastegated at the stock number... My poor turbo

BTW i just used 20psi in 2nd as a quick-off-the-top-of-the-head number... I was just comparing it to the 18.5er. I checked the number on the ring gear when i had the rear out too and it told me 3.54 but when i got the rear rebuilt, they put a new carrier in it and on the bill it said 4:10 and up carrier... The things that make you go huh...

On a side note i think my boost elbow is a bit much... need to drill it out a bit. (non adjustable)

i found an hx 35 for 175 so i am going to put the 12cm on the hopped up truck and the 14cm on the hx and put that on the stocker
what should the w/g be set at stock and what is a good place to set it, and i know i will need an adjustable elbow to adjust it.

the hx came off a 99 with 78,000 miles on it.

Stock setting is 22-25 psi. Get a manual boost controller, not a boost elbow. A boost elbow is just a leak. It will let the boost spike but then the boost will drop back to the factory setting once the system stabilizes.

could i use a needle vavle for the manual boost controller?

No, restricting it will just slow the operation and cause a spike similar to a boost elbow.

Most successful MBC's use a simple checkball and spring setup to prevent boost from reaching the wastegate until the pressure is where you want it, then the checkball moves and lets the wastegate actuator see boost.

got it on and the wastegate opens at 15 psi, i drilled the w/g out to 13/16 and cut the divider down and sharpend the leading edge of the divider.

http://www.geocities.com/chmwatson/FAQs/mbc.html
I build one like this. Works great. I would get a few different springs, that way you can tune in the "sensativity". With a stiff spring a turn might be 5-7 psi, while a lighter one maybe 1-2. Put it together, set it with an air compressor, and put it inline to the WG. Pretty easy.

all hooked up made a manual boost controller out of a flow set valve we had, doesn't seem to build boost any faster than the 14 non w/g and doesn't sound cool when you shift, but when the gate opens i do not get boost creap, and it cools off faster with the 12 than the 14cm.

towed a little over 10,000 lbs first time with it today can keep my foot in it untill mid forth then hit 900-950 post turbo and let off then it cools off quite quick and can hit it again if i need to, doesnt seam to spool any faster than the 14cm did, however it runs cooler down the freeway and a hair less boost @ 65 must have ported it well enough for my fueling mods

I have a 91.5 Intercooled. Everything is stock. Truck is a work truck and lives its life towing my trailer around town. I currently have the 21cm housing and have problem pulling up some hills. Was thinking about going to a 12cm or 16cm housing. Which would be better for my application?

Also i know turbo technology starts in diesels and trickles down into cars ect. I know in my race car with a GT4202R with custom billet 76mm compressor inducer and 102mm exducer we really need the T4 divided configuration. Keeping the engine pulses separated really helps to spool a big turbo. Of course to do it right we have to run dual wastegates and dual Blow Off valves but if done right you can gain 1000rpm faster spool up compared to a single scroll design. So it confuses me that you guys are removing the divided setup. Maybe its because the manifold doesnt really separate the pulses in the Dodge's so really there is no true benefit. :(

Can anybody fill me in?

Chris

I think that drilling might hurt spoolup but also we're talking huge displacement to turbo size ratio advantage with the 5.9 over your ricer. The stock 12 spools TOO fast with a lot more fuel than stock and becomes restrictive so the divider is drilled in order to lower EGT and provide better W/G ability to control max boost.

Also take a look at the newest Technology in the he351 holsets on the third Gens. No divider to be found on those ones.

I think that drilling might hurt spoolup but also we're talking huge displacement to turbo size ratio advantage with the 5.9 over your ricer. The stock 12 spools TOO fast with a lot more fuel than stock and becomes restrictive so the divider is drilled in order to lower EGT and provide better W/G ability to control max boost.

Also take a look at the newest Technology in the he351 holsets on the third Gens. No divider to be found on those ones.

LOL.. Thank you for the explanation. We do lose some top end with a divided setup on the so called "Ricer" but nothing that is worth switching back to a single scroll and loosing the spoolup.

BTW my Ricer is a 2.0L 4 cylinder with GT4202R turbo with a redline of 11,000rpms. Its makes 1158 all wheel horsepower and runs mid 8's second in the 1/4 at over 170mph. Not bad for a car weighing 3000lbs. [coffee]
And definitely is not a HONDA i hate those things.

I have a 91.5 Intercooled. Everything is stock. Truck is a work truck and lives its life towing my trailer around town. I currently have the 21cm housing and have problem pulling up some hills. Was thinking about going to a 12cm or 16cm housing. Which would be better for my application?

Also i know turbo technology starts in diesels and trickles down into cars ect. I know in my race car with a GT4202R with custom billet 76mm compressor inducer and 102mm exducer we really need the T4 divided configuration. Keeping the engine pulses separated really helps to spool a big turbo. Of course to do it right we have to run dual wastegates and dual Blow Off valves but if done right you can gain 1000rpm faster spool up compared to a single scroll design. So it confuses me that you guys are removing the divided setup. Maybe its because the manifold doesnt really separate the pulses in the Dodge's so really there is no true benefit. :(

Can anybody fill me in?

Chris

If its an automatic truck, then go with the 16cm, you wont be dissapointed, the egt's may run to hot and may surge with the 12cm housing on it, you'll love the 16 over the 21 [yuk][yuk]. It wont be the same truck.

Sorry i forgot to mention that it was a 5 speed. Would i still go for the 16cm housing?

Thank you for your reply and time.
Chris

I'd recommend a stock 12 CM housing with a stock 5 speed intercooled truck. No need to even hook the w/g up if you're stock and without the 3200 GSK

I traded my friend Travis his 14 w/g for my 12 w/g because he his stock without any real extra fuel to speak of and no 3200 GSK. He loves the 12 CM, and he has a 5 sp too. He liked it more than the 14 so you'd like the 12 more than the 16 for sure. Better around town and won't get too hot for towing stock either.

Cool car too BTW. I wonder what that sounds like at 11 Grand on the dyno with that turbo and all that HP.

5 speed truck, no doubt go with the 12cm. It'll feel like your driving a racecar when you let out of the clutch there will be no turbo lag and will respond almost immediately. 12cm go for it. then fuel mods later :D

THANK GUYS! Appreciate all the help. [guitar]

Chris