Like The Title says Im thinking about getting a Walboro 255 fuel pump can i just drop that in and be all good togo? In my 93 Talon I had to get a tune for that size pump what are the benefits from stock to the 255? thanks

 

You should be but you cant just turn the boost up without a tune

 

Yea I know that when I got the car it was set to 20psi thats like what 1 psi above stock so i turned it up to 24 everything runs great not blowing out spark or fuel cut etc. so Ive kept it there its basicly stock besides an exhaust BOV and some couplers. I want to get the Walboro and see if that will give out any gains

 

Um... 24 psi and basically stock and not having a walbro already on an VIII is a combination of disaster waiting to happen...

Is it tuned? From the sound of it at 24psi and not having a walbro already it isnt...

And yes, stock psi is 18-19psi on these cars.

 

My question is kinda of the same. I f i drop in a walbro I know part throttle and idle will not be affected. However, iam curious as to how much I can expect the Afr to change at WOT. I noticed under WOT at 19-20 psi on a cool nite im getting afr's in the high 11's low 12's. To lean for me. They getting progressively leaner after each pull. Will my Afr richen at WOT? Dyno day is coming up.....

Mods: k&n drop in, TBE, MBC at 19-20 psi, Evo ix bov

 

What do you mean not having a walboro is a disaster waiting to happen? my AFR is at 14.3-14.7 idle. It is not tuned I just anted to get the walboro first and see if I hadf to do anything else to run it or what type of gains it gives just by swapping stock pump for walboro

 

Because you will run lean at some point at WOT. The stock pump barely supports stock power. A pump doesnt give you hp gains. It allows you to make gains by giving you the fuel u need. Run to lean and the car will pull timing or worse blow. Idle is not affected as it is in closed loop mode.

 

afr at idle is not as important as afr at WOT...
he's saying that you turned up the boost over factory settings and possibly the tune and there might not be enough fuel at WOT. you need to look at the afr's at wot. the evo 8's have a smaller pump than the 9's. search and you will see.

come on dude.. no one tunes a car by looking at idle and just adjusting idle afr's... they tune it doing WOT runs.

you can drop in the walbro.. there wont be any gains. the pump just provides the necessary pressure to the injectors, the injectors are not going to squirt more fuel because of it. you have to adjust injector duty cycles in the ecu.

think about it. you turn on the water for your garden hose... waters not going to go out until you pull the trigger on the sprayer. the sprayer is the injectors, the water knob is the pump. it just provides the necessary pressure for those instances when you are WOT.

 

Actually the car will run slightly richer due to the increase in base fuel pressure.

 

Get it tuned after a drop in.

 

Its possible to drive your Evo after installing the pump. However, I would suggest a professional tune before going WOT. Also the increase in fuel pressure will cause the Evo to overboost if not tuned.

 

That makes no sense. Boost is not controlled in any way by the FP. Boost in controlled by the Wastegate, exhaust flow, and BC.

 

To everyone who is second guessing what I and re-rx7 are saying you seriously need to go do a lot more reading...

 

gotta love the newbies *trying* to help...sometimes it's best not to say anything at all.

Like i said, get a tune..your car is going to be terrible @ WOT and probably break up due to a/f's being rich as hell

 

Come on dude. Why would you turn up the boost without a tune. Sure it may seem ok, But if you were to datalog you would see that your car is running lean, pulling ignition timing and will also cause knock. So if you want to properly boost 24 psi than get a 255 (the stock fuel pressure regulator will work) and get your car tuned. You will then be amazed at how much quicker a good tune will make your car. Also if the tune is done right you wont have to worry about hurting the engine

Taylor