First off, Hello. Long time lurker and searcher.

Reading all of your tech and Q&A posts lead me towards finally piecing together my own turbo kit. I was given a T-25 and decided I was going to modify the wastegate to boost 6 pounds max. I've read up and down about needing to upgrade the fuel system with a higher flowing fuel pump and a FMU. I got the FMU covered with the Vortech 12:1 but do I really need to go 255 Walbro HP or even 190 HP?

I searched several DSM sited, mainly this, to see if I could get away with a GS-T pump as long as I stick with my 6 pound limit. The deepest I was able to get with the search is someone mentioning I can use the GS-T pump as long as I also run the 450cc injectors with it. Are the injectors a must? Can I run it with my stock injectors like I would be doing if I just got the Walby?

I'm trying to do the initial turbo kit as cheap and resourceful as possible to show others it can be done with research and determination. So keep that in mind before just telling me to buy the aftermarket pump. I know first hand a lot of my 4g63 buddies swapped out their stocks for bigger injectors and there's a fuel pumps galore for me to go through. Thanks.

Originally posted by christ
First off, Hello. Long time lurker and searcher. Reading all of your tech and Q&A posts lead me towards finally piecing together my own turbo kit. I was given a T-25 and decided I was going to modify the wastegate to boost 6 pounds max. I've read up and down about needing to upgrade the fuel system with a higher flowing fuel pump and a FMU. I got the FMU covered with the Vortech 12:1 but do I really need to go 255 Walbro HP or even 190 HP? I searched several DSM sited, mainly this, to see if I could get away with a GS-T pump as long as I stick with my 6 pound limit. The deepest I was able to get with the search is someone mentioning I can use the GS-T pump as long as I also run the 450cc injectors with it. Are the injectors a must? Can I run it with my stock injectors like I would be doing if I just got the Walby? I'm trying to do the initial turbo kit as cheap and resourceful as possible to show others it can be done with research and determination. So keep that in mind before just telling me to buy the aftermarket pump. I know first hand a lot of my 4g63 buddies swapped out their stocks for bigger injectors and there's a fuel pumps galore for me to go through. Thanks.

Get the Walbro. The stock GST pump will not be able to handle the high pressures needed for boost with the stock injectors. If you opt to go for bigger injectors, you will have to ditch your FMU and get an SFMU or standalone system (Megasquirt).

Easiest, CHEAPEST, way would be to get a Walbro 255lph HIGH PRESSURE pump and use the stock injectors with the FMU.

yeah, what he said^^^. if you try to cut corners, you will kill your engine. ditch the fmu= paperweight and get the 255hp. use the search and look for injector sizes and fuel system setups.

Wally 255 and a 12:1 fmu with stock injectors seems to be as basic as it gets for a mildly boosted 420a.

T25 eh?

I've been trying to get my hands on a friends' out of his gst forever it seems like and he can't part with his riced out and wrecked car. What an asshole. He has no job. You think the cash alone would make him want me to rip it out of the car.

Ho-hum.....

Originally posted by totaleclipse_05
Get the Walbro. The stock GST pump will not be able to handle the high pressures needed for boost with the stock injectors.

^What he said. I tried the stock gst/x pump with stock injectors and it just didn't get the job done at all. I immediately switched out to a wally before killing my motor. 6psi on a t25, you won't need 450's, you're better off just getting the walbro to start and as you continue to upgrade it won't have to be changed again.

Why would you waste your time with a T-25 when you can use a 14-b? It flows almost twice the cfm's. Just thought I would point that out.

Originally posted by 95eclipse420A
Why would you waste your time with a T-25 when you can use a 14-b? It flows almost twice the cfm's. Just thought I would point that out.

Not to come off smug but unless you're handing me a free 14b or pointing me in the direction to a free one, why? I was given the T-25 for free and I only intend to be running 6lbs max. Not saying anything bad about the 14 but come on...free turbo that flows in my already desired boost range.

Btw, Thanks for your guy's responses. I thought it was worth a shot since there's probably so many swapped out GS-T pumps laying around. I'm just going to go with the 255HP and the Vortech 12:1 for this setup.

IMO, the t-25 is a waste of time to try and get going. You will have to get a custom manifold made to run the thing since it doesn't use the usually t3-style flange like most manifolds made for our cars use (Hahn/Star). After you figure out the manifold situation, you still have to mod the wastegate (shouldn't be THAT hard I suppose) and then you will have to figure out the piping. With a t-25, I think it would look like a mess and suck trying to get it all hooked up the best way possible. It all depends on your goals. If you make a t-25 work on your setup, it won't leave much for upgrading down the road, while a t3-setup would be easy to upgrade to a bigger turbo and still be able to utilize your existing piping setup (most of the time, depends on how crazy big your turbo would be).

Thanks for your concern but it would be stupid of me to switch turbos right now since I do already have the manifold for the T-25. Like I said, 14b is a better choice all around but I got it for free and the manifold was 40 bucks. You guys aren't going to sway me unless you can beat that deal.

Originally posted by christ
Thanks for your concern but it would be stupid of me to switch turbos right now since I do already have the manifold for the T-25. Like I said, 14b is a better choice all around but I got it for free and the manifold was 40 bucks. You guys aren't going to sway me unless you can beat that deal.

Manifold from the 4G63? That won't bolt up and can not be used. Unless it was made for the 420a engine, it can't be used.

It was made with the 420a exhaust flange and flanged to use the T-25.

Then it sounds like you have most of the parts you need for a very basic lowboost setup. Go for it and enjoy the boost.