Intercooler - TPS - and Upgrading

[tugboatphil]

Here I go again... .



I'm looking to try and get my 90 back on the road. Due to money, it won't happen until about this time next year. But I've been seeing a lot of parts for sale, as folks are upgrading their own trucks. Here are my questions;



1. If the TPS causes so many problems, why did they put it on the pump? Is it just for the O/D? Does it have anything to do with the intercooler (didn't these two things appear at the same time?)



2. Is there any problem with installing an intercooler on a pre-91. 5? Is it just a matter of getting the hardware, or does it need the computer box in the engine compartment?



3. The inlet hose on my 90 turbo is considerably smaller than the 93. Would I need to change compressors?



4. Has anyone done this and what would change your mind from doing it again?



Thanks for any input.

 

[BushWakr - RIP]

Hey tugboatphil,



The TPS controls the 3-4, 4-3 shift only. It is located on the pump AFC housing because it takes input from the throttle shaft on the pump.



You can install an intercooler but I believe that there are some mods needed to get it to fit. Double check this..... maybe some of the guys who've done this can jump in here.

You shouldn't need top alter/install a pcm for this. It is really nothing more than a radiator for the charge air so that the air temps are lowered prior to entering the intake manifold.





Pastor Bob.

 

[tugboatphil]

Thanks, Bob.



Was there any connection between adding the O/D and the intercooler at the same time, or just coincidence? Is there a difference between our coolers and the 2nd gen?

 

[BushWakr - RIP]

The second gen coolers are a bit larger than the 1st gen one's...

The intercooler was added to help with emissions. . at the same time the pump timing advance was reduced, pump/line pressure increased, injector size decreased as well... . pretty much all in the name of clean air...



Bob.

 

[Thierry]

If interested contact me off line and I can give you some ideas on the installation as I have done it both on my 89 and 1 85 crewcab, and yes I would do it again and again and again.



Best thing overall is that I dont overheat any more.



I will be doing it on my 85 Crewcab as soon as I have the time.

Good luck



Thierry

 

[dpuckett]

Tugboatphil,

If you can find one, and can afford it, I'd go for a 2nd gen cooler. I'd also recommend upgrading to a HX35 turbo, preferrably a hybrid from PDR, et al. I have a PDR HX35-12 on mine, and love it. Even with the stock housing, I lowered my peak EGTs 150 deg.

For the intercooler, you will need to do some trimming on the grille. I have the 91 grille, and the HX35, so I'm just going to put a 2nd gen cooler in when the time comes. I have to cut and drill anyway, why not go for the bigger intercooler? You may also have to get a new plate for the intake manifold. It will definitely be a custom job if you go with the 2nd gen cooler.



Daniel

 

[tugboatphil]

Dan,



When you say that the newer intercooler requires trimming the grill, do you mean shaving some from the inside? So the newer one is thicker? Does the bracket not line up either?

 

[dpuckett]

I'm not positive about the brakcets lining up. I do know that on the 89-90s, with their flatter grille, you will have to trim no matter what one you go with. Yes, the trimming is from the inside (back side?). I picked that up here along the way, along with most everything else I know about these beasts. THe newer coolers are quite a bit bigger, volume wise. I got the measurements from here. I took the tape measure out, and it will work on my pickup, but I also have a 91. If I think of it, I'll look up my chart, or the thread with the specs, and pst here this weekend.



Daniel

 

[JLEONARD]

I'm not positive about the brackets lining up



The early trucks (like mine) don't have any brackets. The 2nd gen intercoolers will fit, but you will need to do some disassembly and fabricating. I think it was Paul Herouix (spelling?) who installed one of these. You might try to pm him if he doesn't see this and post.



3. The inlet hose on my 90 turbo is considerably smaller than the 93. Would I need to change compressors?



The intercooled turbo has a larger intake turbine and a larger housing that the turbo on the non-intercooled trucks. I'm sure you could adapt to your turbo, but I don't know how much of an effect the smaller turbine will have on performance.

"By the book" you will get a 2 - 5 psi pressure drop across the intercooler, so perhaps you will need the larger volume to make up for that.



Good luck and keep us posted on your progress... . I have a 2nd gen intercooler that needs a repair and I have been hesitant to go thru the work to install it in my truck. (I'm not convinced that the benefits are worth it for the kind of driving I do. )

Jay

 

[tugboatphil]

Thanks, Jay. Have you ever pressure tested an intercooler? I'm looking at making a set of caps to clamp on, with an air valve on one. I guess a radiator shop could repair one???

 

[JLEONARD]

Yes, I believe that radiator shops can repair an intercooler.

I've never pressure tested one, but I would do it as you are planning... caps, and an air valve. Put perhaps 40 psi in and see if it leaks down, or put in a water container, swimming pool , or bathtub (send the wife/girlfriend out of the house first) and look for leaks.

Jay