Walbro 190 vs. 255

[mini zilo]

Here's my question:

I will be running a setup of: small 16g, 650s, safc as far as fuel/tuning. Now, I know EVERYONE is going to say that you can't run a 255 without a afpr. Now, I would really like to not here ANYTHING about the whole 255/afpr issue in this thread, because if I get a 255, I will NOT be running with one. My brother's car ran just fine for over 2 years with a 255 and no afpr, and when his car was tuned by AMS, they told him the AFPR is not neccesary for the 255 unless you are producing over 500 hp. Back to the question, is it a good pair to use 650s with the small 16g and 190? Or is it a better idea to just go for the 255?

 

[silvah_gsx]

Umm you're not going to get much help from anybody if you ask a question and then tell people not to answer...there's a good reason everybody says you need an AFPR, which is that the stock FPR gets overrun by a 255 pump! Would you bolt on a 50-trim with an 11-year-old stock clutch?

 

[silvah_gsx]

Oh and with a 16g, you can run a Walbro 190 just fine

And you don't even have to go to an AFPR

 

[mini zilo]

Umm you're not going to get much help from anybody if you ask a question and then tell people not to answer...there's a good reason everybody says you need an AFPR, which is that the stock FPR gets overrun by a 255 pump! Would you bolt on a 50-trim with an 11-year-old stock clutch?

I didn't ask a question I didn't want answered. I just wanted to know how the 650/small 16g/190 or 255 combo would be. I listened to AMS on the 255/afpr issue. If they tell me it's not needed, I don't need it. They know what they are talking about. And my brother listened to them, and he ran just fine with a 255 with no afpr. But that's not the question.

 

[asexton6969]

In my Opinion:
I would run with 550's, 650's are a lil overkill for a small 16g UNLESS you plan on upgrading later on. Same with fuel pump 190 is fine UNLESS you plan to upgrade. Feel free to post your thoughts and I'll get back.

 

[DGajre777]

You could seach the already existing threads about an AFPR and 255 and the fuel overrun issues a 255 causes without the use of an AFPR.

If your goals don't exceed 400whp, just get a 190 pump and be done with it. Forcedperformance.net states that the 190 is good for 400whp.

 

[hopwoodp]

You could seach the already existing threads about an AFPR and 255 and the fuel overrun issues a 255 causes without the use of an AFPR.

If your goals don't exceed 400whp, just get a 190 pump and be done with it. Forcedperformance.net states that the 190 is good for 400whp.

DGajre777: What is the difference between the High presure and Low pressure 255lph fuel pump? I thought one was ok to run without the AFPR but, If it were me I would use a AFPR for any pump that flows more than the 190. Thats why I rewire my 190 for my setup (1000cc injectors and TD06 20G).

 

[fwdeclipse]

I didn't ask a question I didn't want answered. I just wanted to know how the 650/small 16g/190 or 255 combo would be. I listened to AMS on the 255/afpr issue. If they tell me it's not needed, I don't need it. They know what they are talking about. And my brother listened to them, and he ran just fine with a 255 with no afpr. But that's not the question.

I can tell you right now I had a 190 and upgraded to the 255hp, I did not have the money for the afpr yet so I said screw ill throw it in. The car ran like crap. It idles like it has cams and sputters a bit. I bought the afpr and problem solved. If your going with the 16g the 190 will be fine. I would also go for the 650s also.

 

[DGajre777]

DGajre777: What is the difference between the High presure and Low pressure 255lph fuel pump? I thought one was ok to run without the AFPR but, If it were me I would use a AFPR for any pump that flows more than the 190. Thats why I rewire my 190 for my setup (1000cc injectors and TD06 20G).

You can't run either the regular 255 or the 255HP without an AFPR. The difference between the low (regular) and high 255 is that at high boost pressures the 255HP flows more fuel. At 43psi base fuel pressure on a 2G the fuel flow is very similar.

Here is a table with fuel flows - http://www.roadraceengineering.com/fuelpumpflowrates.htm

 

[oldman]

My brother's car ran just fine for over 2 years with a 255 and no afpr, and when his car was tuned by AMS, they told him the AFPR is not neccesary for the 255 unless you are producing over 500 hp.

1. The extra fuel cost due to fpr overrun in two years would have bought your brother several AFPRs.

2. AMS is worng, what they said doesn't make sense. You can tell AMS we said that then link this thread to them so they can explain their statement if they wish to do so. FPR overrun occurs during idle and part throttle, it's a drivability and fuel economy isuue, nothing to do with open loop operations or making 500whp. They are probably talking about using an AFPR to raise the base pressure in order to get more fuel out of the injectors, at that point with the amount of increased base pressure to make 650s flow enough to support 500whp, you will need more than the 255 to keep up.

 

[mini zilo]

I would really like to not here ANYTHING about the whole 255/afpr issue in this thread

Guys, come on... Stop telling me about that. I just wanted to know what pump would be better for the setup I stated

 

[DGajre777]

Guys, come on... Stop telling me about that. I just wanted to know what pump would be better for the setup I stated

As I mentioned in post number 6, the 190 is good for 400whp - your setup with a small 16G, 650ccs and SAFC will not be anywhere near 400whp.

You could also look at a used Denso fuel pump out of an EVO, they are cheap and flow a little less than the 190.

 

[tkelly27]

If you never ever plan to upgrade or get a bigger turbo, go for the 190. If you see yourself going crazy with the boost later on, or would just like to know you have the extra umph should you need it, go with the 255. Personally, I always pick the 255 because it's the same price

Do whatever you please with your fuel pressure regulator, it doesn't affect me at all

 

[delta448]

My brother's car ran just fine for over 2 years with a 255 and no afpr, and when his car was tuned by AMS, they told him the AFPR is not neccesary for the 255 unless you are producing over 500 hp.

Was his car a turbo DSM? I think someone misquoted or misspoke somewhere. 500 hp is getting fairly close to the fuel flow limit for a 255. If you go very much over 500 hp you'd need 2 pumps or something a little bit bigger than the 255 to safely tune.

You do understand what FPR overrun is don't you? -The stock FPR cannot flow enough fuel back to the tank to keep fuel pressure from rising uncontrollably, fuel pressure rises and your injectors act larger. The ECU will try to combat this by trimming fuel during closed loop, but stomp the gas and you're screwed. Bottom line: you'll run rich, get terrible gas mileage, and make much less power than you should.

Oh, and your pump choice answer depends on your power goal, like Dee said. Over 400 and you need a 255, but you won't make 400 with a s16g, 650's and no nitrous.

Ok, I said my piece, you can go back to running into that brick wall now.

 

[NewB2dsm]

190 pump i made 340awhp On a 190 with no rewire. I only went with a 255 after i went to 650s and a evo 16g.

I know you dont want it in the thread but i run a 255 just fine with no FPR i know tons of people who have.

 

[dsm-onster]

Definately just get the 190. It will handle whatever that 16g can give it. And 550s will be enough and easier to tune w/ your SAFC. 650s are on the top edge of the comfort zone for most because of the incredible timing advances resulting from the offset.

But then again it's possible to run the safc w/ 850s. Especially if you don't want to run an AFPR w/a walbro 255 .

Was his car a turbo DSM? I think someone misquoted or misspoke somewhere. 500 hp is getting fairly close to the fuel flow limit for a 255. If you go very much over 500 hp you'd need 2 pumps or something a little bit bigger than the 255 to safely tune.

The walbro 255 flows around 205 l/h at 30 psi. 205 l/h = 3.42 l/minute. 3.42l/minute = 3420cc/min. that is the flow of 4 850cc injectors at 100% idc. That's good for over 600 hp!

My brother's car ran just fine for over 2 years with a 255 and no afpr, and when his car was tuned by AMS, they told him the AFPR is not neccesary for the 255 unless you are producing over 500 hp.

My car ran.

Discussing hp potential and fuel pressure overrun is apples and oranges. Just see how you like the fuel economy. If it smokes and runs poorly off idle then re-evaluate what ams told your brother. Running fine and running correctly can be quite different. I have a 4 cylinder and I wasn't satisfied that I was getting poor mileage.

You can get an n/a fpr and retune and it will possibly cure the likely result. He!! maybe you'll get lucky and like NewB2dsm.

So keep opec happy. Boost on!

NewB2dsm, what's your idle fuel pressure? What's your mileage? If I boost plenty I still get 28-30 mpg.

 

[dsm-onster]

Was his car a turbo DSM? I think someone misquoted or misspoke somewhere. 500 hp is getting fairly close to the fuel flow limit for a 255. If you go very much over 500 hp you'd need 2 pumps or something a little bit bigger than the 255 to safely tune.

The walbro 255 flows around 205 l/h at 30 psi. 205 l/h = 3.42 l/minute. 3.42l/minute = 3420cc/min. that is the flow of 4 850cc injectors at 100% idc. That's good for over 600 hp!

The 190 flows 75% of the flow of a 255. It is good for 450 hp.

 

[NewB2dsm]

You can get an n/a fpr and retune and it will possibly cure the likely result. He!! maybe you'll get lucky and like NewB2dsm.



NewB2dsm, what's your idle fuel pressure? What's your mileage? If I boost plenty I still get 28-30 mpg.

Dont know my pressure no guage hooked up. Mileage, city around 20mpg, highway more around 25-28mpg. But again this is a 255, 650cc injectors (havnt even takan more fuel out than when i ran the 550s, so i know i can get a bit more), cams and low boost of 18psi 1.2bar spring in wastegate. (always run at least 20 though)

Idle i noticed a little ruffer idle but nothing major, driveablity is still fine as well.

 

[mini zilo]

Alright, cool. Thanks for the input on the fuel pump... But seriously...stop with the AFPR stuff... I KNOW. I knew exactly what everyone was going to say, so I said not to.

 

[DGajre777]

Alright, cool. Thanks for the input on the fuel pump... But seriously...stop with the AFPR stuff... I KNOW. I knew exactly what everyone was going to say, so I said not to.

Seriously, if you really KNEW, you wouldn't say, "if I get a 255, I will NOT be running with one (AFPR)".

If you come on here for advice, fellow tuners are going to give it to you - even if it is something you don't want to hear. It's your car, in the end, do what you want. Hell, if you want get a 255HP, re-wire it, 950cc injectors and try to run it with an SAFC for a Small 16G, it won't cause problem for anyone on here, except YOU.

 

[hopwoodp]

You can't run either the regular 255 or the 255HP without an AFPR. The difference between the low (regular) and high 255 is that at high boost pressures the 255HP flows more fuel. At 43psi base fuel pressure on a 2G the fuel flow is very similar.

Here is a table with fuel flows - http://www.roadraceengineering.com/fuelpumpflowrates.htm

Ok, thanks for the info. I know that there has been some mis-conception (at least on my part) about the differences between the two 255lph fuel pumps.

So, let me see if I can make some sense of this. The regular 255 pump is for let say 400 - 500 hp? So, for the High pressure 255 pump - so, instead of having to get the TTSupra pump you could use this one instead and pretty much flow close to what the supra pump puts out. I don't recall the specific flow range off the top of my head but, I am guessing it would be able to flow above 600hp.

Let me know if I got this right.

 

[delta448]

The walbro 255 flows around 205 l/h at 30 psi. 205 l/h = 3.42 l/minute. 3.42l/minute = 3420cc/min. that is the flow of 4 850cc injectors at 100% idc. That's good for over 600 hp!

The 190 flows 75% of the flow of a 255. It is good for 450 hp.

I was referencing the RRE page Dee linked, -it lists the 255 as flowing 262 lph at 14 volts, 8 amp draw and 43 psi. If you see a real-world value of 205 at 30psi, won't flow be less at higher pressures unless the pump draws more current? I imagine 205l/h on a 255 is a little more optimal than most of us will see unless the fuel feed line is replaced with some larger diameter line. Also, if FP says the 190 is limited to 400, I'm inclined to believe them.

I personally would try to keep idc below 85%, as most fuel injector vendors recommend. That doesn't change the pump's output but it does mean the 850's would be flowing 2720cc/min at 85% idc.

 

[dsm-onster]

I was referencing the RRE page Dee linked, -it lists the 255 as flowing 262 lph at 14 volts, 8 amp draw and 43 psi. If you see a real-world value of 205 at 30psi, won't flow be less at higher pressures unless the pump draws more current? I imagine 205l/h on a 255 is a little more optimal than most of us will see unless the fuel feed line is replaced with some larger diameter line. Also, if FP says the 190 is limited to 400, I'm inclined to believe them.

I personally would try to keep idc below 85%, as most fuel injector vendors recommend. That doesn't change the pump's output but it does mean the 850's would be flowing 2720cc/min at 85% idc.

I know that 850s shouldn't be pushed to 600 hp. But That's an easy way to see hp potential for total fuel flow.

I cant say that the fuel rail/lines are capable from first hald. But I have seen a single walbro 255hp and stock fuel lines go beyond 500whp.

FP is going to be conservative. Its the reason why you AND I trust them.

 

[dsm-onster]

Ok, thanks for the info. I know that there has been some mis-conception (at least on my part) about the differences between the two 255lph fuel pumps.

So, let me see if I can make some sense of this. The regular 255 pump is for let say 400 - 500 hp? So, for the High pressure 255 pump - so, instead of having to get the TTSupra pump you could use this one instead and pretty much flow close to what the supra pump puts out. I don't recall the specific flow range off the top of my head but, I am guessing it would be able to flow above 600hp.

Let me know if I got this right.

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It depends on the boost you're setup requires to reach your goal. If you have a great flowing (high VE and/or high displacement and/or high revving setup), then a 255 will be plenty. But Most of us have to pour on the boost. The HP pump flows more at high boost, but flows the same at lower boosts.

 

[dsm-onster]

Dont know my pressure no guage hooked up. Mileage, city around 20mpg, highway more around 25-28mpg. But again this is a 255, 650cc injectors (havnt even takan more fuel out than when i ran the 550s, so i know i can get a bit more), cams and low boost of 18psi 1.2bar spring in wastegate. (always run at least 20 though)

Idle i noticed a little ruffer idle but nothing major, driveablity is still fine as well.

You haavn't adjusted base fuel for 650s from the 550s? or you havn't gone back and retuned at the rpm intervals.

A good WOT tune (11.5:1) won't do that much for fuel consumption vs. an ok WOT tune (10.5:1).

I know some people have gotten the 255HP to run fine w/ a stock FPR. I'm doubting you. I just want to know why some have and others havn't. If we can figure it out once and for all, then we'd save over 100 bones per DSMer .