Hey all, I'm going to ask something which is probably pretty simple to understand but I'm not sure how to search for it.


I'm sending my turbo in for a rebuild/upgrade. It's going to be a 25G rebuild most likely. Factory MFI parts. The car is already setup with quite a few parts and tuned to handle them. I'm thinking about using this opportunity to install a new fuel pump and injectors.


What I can't find any information on is how fuel maps work with a fuel pump. Would putting in the higher flow pump put more fuel, or does the computer compensate for the higher flow rate and not pump as much. I'm getting it retuned regardless, but I just want to understand!


Thanks.

 

Putting in a higher flow fuel pump only effects the tune if:


A: the old fuel pump was running out of flow, and the tuner added extra injector on time in the fuel table. A new fuel pump that has enough flow will cause a rich condition.


B: The new fule pump over runs the return system, causing a rich condition. This can usually be fixed by drilling the siphon, and/or installing an after market fuel pressure regulator.


The ECU does not automatically compensate for a fuel pump.
As long as the pump does not over run the return system, your tuner will be able to get you dialed in just fine.

 

So I'm going to drop in a Walbro 255(or some equivalent) with some ~1000cc injectors. Hoping that with the 25G rebuild, the new fuel stuff, and the mods in my sig, I can hit the 400HP mark. I'm getting real concerned about how much farther I want to go on stock internals.

 

you will be fine just watch the torque

 

You can make a bit over 400wtq on the stock internals and be fine with a good tune. 400whp will be no issue...

 

Cool, that's good to hear. I don't think my goals are too crazy. John at Titan Motorsport is charging $600 for a tune so I want to get all the pieces ready or installed before I drop it off. I know it's a couple hundred more than most tuners, but he did it before he raised his prices and it's been solid for over 4 years now.

 

What do ya know! I'm also going a turbo upgrade along with idc1000 and walbro 255 and getting tuned by John at Titan this coming Tuesday! Oh and I believe u get what u pay for! John definitely knows how to tune👍 I live in Mel beach shoot me a pm!

 

I'll do that next time I'm in Melbourne with a working Evo. I live out in Tampa, but my whole family is in Brevard. I'm going to install the fuel pump on my own, but I'm going to have them install the injectors once I drive the car up there. Two hours on a tune not setup for higher flow fuel pump and the slightly larger turbo.


P.S. - If you haven't been through Titan before, they're an amazing shop that does amazing work.

 

Been there definitely state of the art! Getting fuel pump, injectors and mhi 18k installed Monday and than tuned Tuesday!! I can't wait!

 

please please please let me know how it turns out. Your setup is almost identical to mine and I really want to see what your end result is. Are you going e85? what size injectors?

 

Will do! Not going e-85 cause there is only one station that sells it as u know! (Race track on Palm Bay rd) going id1000

 

Does the Racetrack at Malabar and Babcock sell e-85? That gas station is like 1.5 miles from my sisters house and would make the trip back and forth much easier if I switch to e-85. I drive over from Tampa on sr-60 instead of going up through Orlando.


More curiosity than anything. e-85 seems like an extra layer of complexity that I don't want to deal with. I'd much rather built for a pump 93 turn since I can get that almost anywhere in Florida.