Bersaglieri

This is my daily driver, and I'd like it to be a reliable 14 second Cummins with in the next few months. I basically just want a fun to drive truck, that I can toy with ricers, Hemi's, PJ/DMax's, and Mustangs on a day to day basis. I do not currently tow.

My current mods are 4" MBRP, BHAF, Gauges, 100 plate, and everything slid forward. I am putting a Suncoast Triple Disk and Valve Body in the trans next week. The truck is a 1997 Ext Cab Long Bed 4x4 3.55 Auto.

I didnt think I had many mods, but last night I found myself pushing 40psi during a quick WOT punch on the highway. I dont know what the previous owner did, but I didnt think I could hit that with so few mods and no boost elbow. I never went WOT until last night since I didnt have gauges till now. I will say it was with NO airfilter, not sure if that matters.

So what do I need to preserve the turbo while also adding some power? If I could kill two birds with one stone it would be nice. A local guy said not to run over 35psi on the stock HX35, if its a daily driver. So should I find a way to turn it down or upgrade to a different turbo? My buddy and I have some turbo's laying around I could make a compound with, but I dont want to do that till after winter. [HT3B, HX52, HX55]

Would getting the boost down to 35psi and adding something like injectors help me at all? I am running a tighter 91% converter, so I was thinking injectors might help make it more streetable since they would help quicken spool time, correct?

A 3K or 4K GSK wouldnt make the truck faster or more streetable would it?

Any suggestions or help would be appriciated. Thank you.

-Dustin-

HOHN

Caveat: I'm a 24V guy, so I don't know all that much about the 12Vs...

It sounds like you have the tranny squared away, so you need to get your fuel and air squared away.

First, you need to lower the boost levels on your turbo. I highly recommend a Manual Boost controller to manipulate the boost signal to the wastegate. I suspect you have no boost elbow and that the port is plugged to hit 40psi. That stock turbo is costing you power at 40psi. Drop it down to about 32-34psi max.

Do NOT run your truck without an air filter for anything other then a quick idle. Even a little dirt can be really tough on a turbo spinning 80K rpm.

You already have a #100 plate, so you are set in that department. I'd look at some honed 215 injectors, like the DDPs.

I'd set the timing at 16.5 or 17 degrees. You don't want to go too heavy on the timing, because you'll end up with more smoke on bottom and poorer turbo spoolup as well as less power with that tight converter. Tight converters and super advanced timing don't play well together.

I'd look a mildly larger turbo with spoolup in mind-- something like a regular Phat Shaft (not super and definitely not Silver) 62 from Industrial Injection. The Hi Tech version of this would be the HTB2 62 with the 65mm turbine wheel.

Injectors don't always increase spool time. Sometimes they'll only increase smoke-- depending on your existing setup.

That's my amateur stab at what a 12Ver should do.

jmo

Muddin_dude06

Thats a pretty good bunch of advice up there from HOHN, one thing I would say to do is search for the "Mack Gold Plug" and AFC/Rack Travel mods. These will yeild a lot of fuel that you are not unleashing as of now. Since you have an auto a 3GSK is all you really need or a 4GSK with the middle spring removed seems to be getting popular. If you make compounds use the HT3B, the others would be too small and cause it to choke at the upper RPM's. Depending on how soon you want to replace the headgasket I wouldn't go above 17* timing.

Also #1 rule (IMO) about a performance diesel DO NOT go above 10 lbs of boost until full operating temperature has been reached!

Injectors IMO don't do much for spoolup, if they don't atomize great then it may hinder it. On your truck you can't go wrong with a set of stock 215's. Also AFC tuning is a Godsend, don't make it belch smoke like no-tommorrow from the get-go, it just needs to be a haze until the boost is building and then hit hard once the turbo is fully on its way to kickin' it!

rebel5422

what does taking out the middle spring in a 4k kit do whats the diff btwn this and putting in a 5k kit?

BigErksG2

It makes it a 3k. 5k is rarely used in a daily driver. I like the 4k alot.

rebel5422

y is it not really used in a dd just because u can go 5k dont necissarily mean u will constintly right? or does it affect low rpm as well when u put in a 5k my govener is still stock and i have not quite made up my mind as to what i wanted yet 4k or 5k

mainiac

install a 4k kit. make then truck very drivable. make sure your kdp is killed. add some tapered delivery valves or 191's and do not worry about injectors to get 14 sec 1/4 miles. learn how to tune your pump. theres no reason to run the plate or afc housing all the way forward, you'll only create fuel at the wrong time. timing at 17-18 degrees works well and add some valve springs and head studs for insurance. after these mods, wire in a tc lock up switch for fastet acceleration.
with this much fuel, you'll toast your hx35 so plan on a nice 62/71 for great drivability around town but the high end drive pressures that will keep your temps in check when playing.

BigErksG2

A 5k kit will have more fuel down low and have a very sensitive throttle. Maniac, the beginning of the thread was from 2007 and it seems he has his truck pretty figured out.