• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

ATT, hood IC or GL4 ?

Do yourself a favor, remove the pass side wheel & inner fender, makes life so much simpler, while you are reworking your intake manifold let studs be soaking with PB blaster

X2 on that, I confirm and stongly suggest you do like Tim suggest.
I'm talking by experience. I did like that, and, even with inner fender still on, removing the turbo bolts was a piece of cake.
You get enough place to work on that.
In my case, the worst bolt was stuck, the one located on the inner side, close firewall. All we had to do was to use a socket with extensions, and a air gun. 30 seconds after it was out :thumbsup:

PB blaster will do fine, the old GM mechanics tip did wonder for me : after your engine has warmed, make a candle melt on studs and bolts... that really helps :D
 
Last edited:
I installed the ATT without removing the wheel or fender. Just stubby wrenches in some places and long narrow wrenches in others. I have a lot of different wrench types and maybe less stuff in the way on my 94.

If you are getting the ATT you better upgrade to 4" exhaust. My ATT did nothing with the Banks 3.5" exhaust with Cat on it. Whereas my GM4 would perform just great. I put 4" straight pipe on and ATT spins up so fast and boosts to 12psi no problem on empty acceleration. I added a chambered muffler and lost a few psi boost. That was just because straight pipe was killing my own ears and neighbors mustnt have been happy. Got the 4" muffler free anyway, was for a Cat Tractor. I have a 5" straight through muflfer I am adapting on next week.

Anyway, 3" exhaust probably isnt going to cut it, so add a few hundred to the list for exhaust when getting ATT. I wonder what the GM4 would have been like with this 4" exhaust, if I fell into a TM for it maybe I'd test that, but not hooking up the vac pump.

Driving at high elevations also threw my ATT for a bit of a loop, good amount of black smoke, even after the exhaust upgrade. Before the exhaust upgrade it couldnt even climb in OD over 40mph up the mountains, any time I tapped accelerator long trails of thick black smoke had to trail the big rigs in 3rd gear at 40mph to prevent the smoke and high EGTs (im talking only above a mile high). After 4" exhaust I was good to maintaining speed at 75mph no problems, with AC on, only bad smoke when getting up to speed. My PCM might not have been compensating for high elevation correctly, but I tried running stock PCM too and no better.

I also have WMI and Propane on mine, the propane I got some power out of it, but the expense is probably only for serious pullers. sometimes the truck would just take off up the mountains with the cruise at 70mph it would go to 90mph from turning on the WMI and propane. I then fixed my solenoids where my Hobbs pressure switches had fried to always closed. The WMI is great though, I would watch GMTDScan IATs fall big time when I switched on the WMI while climbing the mountains.

I have also noticed much lower exhaust backpressure from ATT as discussed in other posts. My ATT whistles so loud I have had more people come and ask me whats under the hood than ever before.

So exhaust would be my first upgrade, then reflash, but if you already bought the ATT, Im sure justification for those two wont be far behind anyway.
 
Never figured our trucks could run so well did you. Nice to have that smooth easy power. Have you done a fuel mileage comparison?
 
I wonder what the GM4 would have been like with this 4" exhaust, if I fell into a TM for it maybe I'd test that, but not hooking up the vac pump.


So exhaust would be my first upgrade, then reflash, but if you already bought the ATT, Im sure justification for those two wont be far behind anyway.

My GM4 with home made TM was good with the 4" exh. with flow through muffler

The ATT has improved pulling and mpg's with reduced EGT's. I also would bet acceleration is better empty.

I would place gauges first, then exh, ATT then chip. The 4" exhaust was a big improvement on my truck. Any way to make these engine breath first before adding fuel will put the least stress on them. IMO

Leo
 
while not mandantory to remove inner fender take it from me it DOES make life easier, I've done it both ways with & without pulling fender. A side benefit is that with fender out you can do preventative maint that side, glows-grounds-starter bracket check, while there also might as well delete the vac pump, with ATT unless a S truck or F with EGR you won't need vac pump anymore.
 
I already have gauges and 4 inch exhaust. I am planning on deleting the vacuum pump, putting a 99.5 belt on and changing the damper while I'm in there. Coincidentally, my passenger side fender has a big hole in it, I recently finished painting a replacement for it so that should all happen at the same time too. That just gives me more motivation to get off my butt and pull the old fender off.
 
thanks! I just placed the order. Did you find it difficult or fairly easy to do? What I've read seems pretty straightforward, but I'll admit I'm a little leery about the turbo bolts themselves. I was going to pull the turbo last year when I did the injectors, but I was afraid the bolts were going to break so I gave up and did the injectors the busted knuckle way.
I know soaking the bolts for a few days with PB is usually a good idea, but I drive it everyday so it'll probably just keep burning it off.

How do you like yours so far?



Love mine so far, Dan. Turbine Doc had suggested taking off the inner fender and it would have made things a lot easier. We used stubby wrenches (good ones) and put a long pipe on the end (perpindicular)and gave it a crack with a mallet and all the turbo bolts came right off. When you're ready, let me know.
 
thanks! I just placed the order. Did you find it difficult or fairly easy to do? What I've read seems pretty straightforward, but I'll admit I'm a little leery about the turbo bolts themselves. I was going to pull the turbo last year when I did the injectors, but I was afraid the bolts were going to break so I gave up and did the injectors the busted knuckle way.
I know soaking the bolts for a few days with PB is usually a good idea, but I drive it everyday so it'll probably just keep burning it off.

How do you like yours so far?

Spray away .... the heat will help it get 'in there' before it burns off... It will help. Soak her up good.

I can't imagine attempting that without taking the inner fender out... Only takes 5-10 minutes with an air ratchet setup. Well worth it for anything behind it...
 
15 minute without air ratchet, anytime I now need to work pass side (turbo side) of the engine the fender comes out, if I had to do a starter, or downpipe, or crossover for 1st time and rusty studs or long time since last anti seize.
 
I have some Wurth pure nickle anti sieze, good for 2500 degree heat. I use antisieze on everything that may have to come apart again.
 
Back
Top