190 or 255 fuel pump for 400 hp

[andyo1980]

The next mod for me to get is a fuel pump. I was wondering which one to get, my goal is 400 horsepower to the wheels. Will the 190 be enough or should I get the 255. I want to do this as cheaply as possible and don't want to get a regulator unless I need to. Thanks.

 

[Black_Bullet]

The HP walbro 255lph

then rewire it.
http://www.raktron.com/fuel/rewire1.html
http://vfaq.com/mods/pump-WB-2GAWD.html

People will tell you to get a afpr due to fuel pressure over run.
This is true, so you should get one, but dont let it stop you from getting the pump
fp over run is not as bad on a 2g as it is on a 1g. 2gs run 43psi base 1gs run 37psi base.
The higher your base fuel pressure the less aggressive the overrun will be....
On a fuel pressure gauge on a friends car it showed it over runs the fuel pressure by 5psi
leading to 48psi of over running. I run a non turbo fuel pressure regulator ( tuned w/ chip. )
which starts at 47psi base fp therefore I only see 1psi of over run. You can find them for about 10 bucks in the junkyard... This could be a cheap option
for you as well ( getting more flow out of your injectors as well. )

I dont think a 190 should be the choice to support 400 whp. Id rather here you have tons of over run using
the 255 than getting a 190 trying to make 400 wheel and leaning out. Im sure it has been done though...

If you do get a 190 rewiring is a must; and http://www.lightningmotorsports.com/walbro_pumps_only.htm carrys the high pressure 190s...

 

[Drubble]

I recall reading somewhere in the forums that a re-wired 190 will support your 400 hp goal.

 

[c4uldr0n]

it has been done hitting 400 whp w/ a 190, for extra insurance a 255 is nice

 

[CanadianTSi]

400whp will be pretty close to maxing out the 190, not much headroom left which isn't a very good thing with fuel...

 

[diddy456]

Use a 255 to be safe. It is not that much more to purchase one.

 

[Black_Bullet]

Actually I recall them costing the same amount as Ive had a 190 and a 255 before...

 

[No_Skillz]

The 190 and the 255 both cost the same. The 255 will need a regulator which is ~$150-$200 depending on brand and accessories. From my research, the kit from importevolution is the cheapest and most complete by far. http://www.importevolution.com/default.php?cPath=24_45

The use of the stock fpr with the 255 is pretty beat to death and is analogous to venting your BOV with stock MAF. Sure you can, it might not be noticeable, but it's still not the right thing to do.

 

[high klicks]

Don't go cheap , do it right the first time that way if you want more power later it can be done without changing fuel system and it takes one thing out of the equation when you are attempting to tune the car. For the extra couple of hundred bucks it's worth the peice of mind and if you can't afford it then you shouldn't be going for 400 horse

 

[daren_p]

Think you get the general idea of what most are saying but 400 whp is right around or will be maxing the 190 pump out. Fuel system is not an area to skimp on, or that small amount you saved on the 190 vs a 255 w/fpr won't seem like such a good deal when its costs you a motor. Get the 255

 

[gsxAWDdsm692]

Get the 255 here:

http://www.extremepsi.com/store/customer/product.php?productid=17198&cat=257&page=1&veh=2G DSM

 

[andyo1980]

Ok, 255 it is, can I get the regulator later? I know overrunning the stock one isn't good, but is it ok to do for awhile? What is the downside to overrunning the stock regulator?

 

[Whiteshadow]

JESUS H CHRIST USE THE SEARCH BUTTON..THIS TAKES BEATING A DEAD HORSE WAYYY OVERBOARD

 

[toyotaturbo]

Ok, 255 it is, can I get the regulator later? I know overrunning the stock one isn't good, but is it ok to do for awhile? What is the downside to overrunning the stock regulator?

I wouldn't try it. Your car most likely will not run at all. Actually, it'll run, it just won't idle above 400 rpms. And it won't move. That's the downside to overrunning the stock regulator. In short, spend the extra dough and get an adjustable fuel pressure regulator. You car will love you for it.

 

[gsxAWDdsm692]

You can't really buy one thing without another when it comes to a fuel pump. Get the pump, rewire kit, a regulator and something to tune it with (SAFC) for starters.

 

[gsxAWDdsm692]

heres one brand new.

http://www.dsmtuners.com/classifieds/showproduct.php?product=63604&cat=7

 

[Black_Bullet]

I wouldn't try it. Your car most likely will not run at all. Actually, it'll run, it just won't idle above 400 rpms. And it won't move. That's the downside to overrunning the stock regulator. In short, spend the extra dough and get an adjustable fuel pressure regulator. You car will love you for it.

I dont feel like much of a newbie .
The car will run fine youll just waste more gas between shifts and after any
time you let off the throttle... That is when over run happens. Its not a constant affair.
Worse case scenario it will leave black soot all over the back of your bumper like it did
my old gst and like it does a lot of modified cars ive seen. Or hell you might even get some nice flaming back fires that ricers love. Theres no immediate part failure or anything of the sort from having fuel pressure over run. Im sure half the dsmers with 255s dont have afprs me included. What is this about it not moving and not idleing above 400 rpms, that sounds more like a car that has a blown engine not one with a little excessive fuel after throttle...

 

[andyo1980]

Alright, thanks guys. 255 and afpr it is

 

[oldman]

The car will run fine youll just waste more gas between shifts and after any time you let off the throttle... That is when over run happens. Its not a constant affair.

You're mistaken FPR overrun with a vented BOV, overrun is in fact a constant affair, that is except WOT.

 

[Black_Bullet]

You're mistaken FPR overrun with a vented BOV, overrun is in fact a constant affair, that is except WOT.

Well i suppose I contradicted myself with saying its not a constant affair
but yet when i say it happens everytime the throttle is pulled back since your on and
off the gas during most driving situations it would be. Therefore the amount of gas wasted and over ran would add up and be significant over time and it could lead to
other issues with the stock fpr i suppose? I know a afpr isnt required to run the car though just because a 255 was installed, and i highly doubt it would make the car idle 400 rpms or anything else dramatic...
I didnt realize his bov was vented though.

 

[xtreme-elements]

i have a 255 fuel pump and a 3" maft set-up.. i have no problems with idle or anything.. i have it tuned at 14.7...14.5 at idle and cruising then 11.7 at wot... what is the idle thing they are talking about....

 

[Talesin]

xtreme, have you actually checked your fuel pressure? Likely it's painfully high, and will cause problems while tuning.

The stock 2G FPR has been shown to be able to not overrun on a non-rewired Walbro 190. Definitely not the desired kind of flow you'll want to join the 400 club.
So far, NONE of the people who claim to be running a Walbro 255 on the stock FPR I've spoken to have actually *checked* their fuel pressure. The car just starts and runs, so they figure it's not being overrun.
As far as 'half' the DSMers with a 255, you could make the same argument about the overwhelming number of 2G owners who are atmo-venting on the stock MAS. Doesn't mean the car is running right, just because it runs at all.

There's a difference between doing a mod, and doing it right. And the latter way is seldom cheap.

 

[Eclipse98_RS]

I wouldn't try it. Your car most likely will not run at all. Actually, it'll run, it just won't idle above 400 rpms. And it won't move. That's the downside to overrunning the stock regulator. In short, spend the extra dough and get an adjustable fuel pressure regulator. You car will love you for it.

I had a 255 without an upgraded FPR and I ran just fine.

 

[Syndicate13]

Just to add fuel to the fire my rewired 190 seems to hold up to my 435awhp just fine. Of course I'm not relying on just gas here.

 

[romeen]

I ran my car for a year with a 255 and no AFPR (this was before I joined Tuners so I didn't know any better ). The car ran and at the time I thought it ran fine. As I became a bit more knowledgeable I finally got the AFPR. Car ran much better. I would think that if you are taking the time and spending the money to modify your car that you would want to optimize performance. Each car is different. Your car may run "fine" w/o the AFPR but I would be willing to bet that it will run noticeably better with it.

In addition to the safety factor already mentioned, fuel pressure adjustability can also be a useful aid in tuning the car.

So far, NONE of the people who claim to be running a Walbro 255 on the stock FPR I've spoken to have actually *checked* their fuel pressure.

Hey John. Agreed ^^. Before I installed my AFPR I actually did check my FP with a guage on top of the fuel filter. BFP was right at 50 psi.