maximum boost i can safely run with some fuel upgrades

[2DaTrakNow]

I have a walbro 255 fp, and an aeromotive fpr. I am curious to how much boost i can run without any tuning devices or other fuel upgrades. Right not my turbo is just the stock t-25, but hopefully soon i will be getting something bigger. Also, any advice on rewiring the fuel pump? I can tell a huge shortage of power getting to it, as it makes a "surging" noise when i turn on my blinkers, or even press my brakes!

 

[SRiz]

even with 1000cc injectors DSM Link and a supra fuel pump a T-25 is only effecient up to about 16-17psi... after that its a hair dryer , also any higher and u might blow an oil seal mine blew at 19psi

 

[2DaTrakNow]

even with 1000cc injectors DSM Link and a supra fuel pump a T-25 is only effecient up to about 16-17psi... after that its a hair dryer , also any higher and u might blow an oil seal mine blew at 19psi

Haha, well actually the oil seal already slightly blew thanks to a dumb@$$ attack i had when doing a leak down test. I wasnt necessarily asking about the T-25's maximum boost that it can reach, but more towards my fuel systems maximum psi that it can support.

 

[president95]

I didn't think a t25 could even go past 16psi

 

[2DaTrakNow]

I didn't think a t25 could even go past 16psi

Haha, well the guy i bought the car from said it was set at 21 psi...
Now i know that that isnt true....or even close to being true(because i hooked up a my boost gauge and it registered about 11), but there have been people that have gotten slightly over 16 psi on the T-25. I would assume though that their T-25 was slightly new, or in very good shape to reach the 17 or 18+ marks. Also, i know this really isnt something to "brag" about, but i spiked about 22-23 on my T-25 once due to a very faulty ebay MBC which is no removed from my car and sitting.

 

[oldman]

Haha, well the guy i bought the car from said it was set at 21 psi...
Now i know that that isnt true....or even close to being true(because i hooked up a my boost gauge and it registered about 11), but there have been people that have gotten slightly over 16 psi on the T-25. I would assume though that their T-25 was slightly new, or in very good shape to reach the 17 or 18+ marks. Also, i know this really isnt something to "brag" about, but i spiked about 22-23 on my T-25 once due to a very faulty ebay MBC which is no removed from my car and sitting.

Let's put this with the other discussion we're having in the other thread. You can boost the T25 well beyond 16psi but the reason you shouldn't is because T25 becomes extremely inefficient at 16+psi so it will just end blowing hot air (hence air dryer), hot air means less dense air/less air (knocking aside). Now put the two threads together and you should have a better understanding of the relations between pressure, temperature and air flow.

but more towards my fuel systems maximum psi that it can support.

You will still be limited to the stock 450s, how much psi will it support varies from turbo to turbo. In the case of the T25, you will most likely run out of turbo before you run out of fuel.

 

[2gGSX]

With your fuel pump you would be able to play with your fuel pressure in order to compensate for your injectors actually. Assuming the rest of your fuel system could keep up (such as lines and fittings for example) you could bump up your fuel pressure significantly to increase the effective flow of your injectors.

For example, if you raised your base fuel pressure from 43 to 58 psi then your injectors would flow approximately (58/43)^.5 x 450 = 522 cc/min. This equates to 3.5 lbs/min of fuel, which would support approximately 38.5 lbs/min airflow assuming pump gas and 11:1 AFR. At the same time, assuming you boost up to 20 psi to reach this airflow your fuel pressure at this point would be 78 psi, and your fuel pump would flow approximately 178 lph (number from a regression based on previously collected data on fuel pump flow), which will undoubtedly support your injector fuel flow (125.28 lph if they do in fact flow the 100% IDC of 522 cc/min).

In short, if your lines and everything else is up to it you could feasibly increase your fuel pressure to compensate for your injectors. 38.5 lbs/min is more than most people will even hit with the Evo III if that's your next choice of upgrade, although once you nearing this number you should definitely consider actually upgrading your injectors and buying fuel control.

I'm not necessarily telling you to go out and raise your base fuel pressure by 15 psi, but informing you that this may be a viable option for you (whether or not you go through with it is in the end up to you). The theory behind it however is outlined above. Let me know if you have any other questions about this.

A disclaimer by andymoraitis:

The math makes perfect sense, but the problem with such a large fuel pressure bump up is that it will drown the motor in fuel while not under boost. It's a bit of a bandaid when you start running into high IDC's and correct it with fuel pressure, since the real solution is to run a larger injector (of course you know that).

Keep in mind that in off boost situations, running too much fuel pressure will be like running a 255 without an AFPR as it'll wash fuel past the rings. If you want to recommend this, do so as a "track only" method so that people don't start diluting the oil and punting rods through the block.

 

[2DaTrakNow]

Alright, i understand now. Thanks for clearing everything up! The post were great!!!

 

[Eastwood95]

I'm confused.............so you bought and installed a 255 fuel pump and FPR? Doesnt make much sense to me. Are you getting a bigger turbo next week? Why didnt you get a new boost controller, downpipe, BOV, or intercooler piping?

 

[2DaTrakNow]

I'm confused.............so you bought and installed a 255 fuel pump and FPR? Doesnt make much sense to me. Are you getting a bigger turbo next week? Why didnt you get a new boost controller, downpipe, BOV, or intercooler piping?

Well in order to support a larger turbo, you will have to have those mods anyways. So i figured that since i need them, i might as well buy the supporting mods before buying the bigger turbo. I also looked at it as extra safety on my engine. If i boost my T-25 up almost to its max i would always rather be safe than sorry and have the extra fuel there just incase. And i do have a BOV if you looked in my profile.

Also, do you honestly think i would be better off supporting my car with a downpipe and intercooler piping over fuel upgrades?????WTF And yes, i will get a different downpipe, intercooler piping, intercooler, and everything else once i get my bigger turbo. I just wanted to worry about the reliable aspect of my car before i tried to sqeeze every little last hp out of my car.

Then for the turbo, yes...i will be getting a bigger one within the next 2 or 3 weeks. Then since i have my larger intercooler sitting in my bedroom, i will get the IC piping and install the IC, IC piping, and larger turbo as well as my custom made downpipe/exhaust all at one time. That way i dont have to take something off, then reinstall it later. It's just nice knowing that i already have the $100 fuel pump installed, and the $200 FPR kit intalled and wont have to worry about the hassle or expense of those parts later. Plus knowing that i wont run out of fuel also makes it nice.

Make sense to you now?????????????????????????????????????????????

 

[Jeremoose]

Depending on what turbo you'd be upgrading to (14b) you might not have needed the fuel upgrades AT ALL, is what he was saying. So why not upgrade the IC piping/turbo/intake etc so you know what you'd need for fuel support?

I think that's what he meant to say..

 

[2DaTrakNow]

Depending on what turbo you'd be upgrading to (14b) you might not have needed the fuel upgrades AT ALL, is what he was saying. So why not upgrade the IC piping/turbo/intake etc so you know what you'd need for fuel support?

I think that's what he meant to say..

Well even if that was what he meant to say, it would still be safe to have fuel upgrades. Also, i wasnt planning on getting a 14b. I am going to get a turbo that i can make quite a bit of power with, and fuel upgrades will be a must. That is why i wanted to take care of the fuel first. The reason i havnt done anything with my downpipe or intercooler is because it will be so much easier doing everything at once, when every part is removed. I will need fuel support, no if's, and's, or but's about it, so why not get it done and over with now and just not worry about it later? And as i have heard, the stock fuel system starts to max out at about 16-17 psi on the T-25. If i run about 18 or 19 on a 14b, wouldnt that be pushing it??? So again, i would rather be safe than sorry.

 

[Jeremoose]

Yes I understand, I wasn't trying to argue I was just trying to clarify what he was saying a little bit. Sorry no offense

 

[oldman]

I see nothing wrong with doing the fuel pump and AFPR first at all.

 

[2DaTrakNow]

Yes I understand, I wasn't trying to argue I was just trying to clarify what he was saying a little bit. Sorry no offense

Its ok, none taken! I like getting the opinions of others!

 

[Eastwood95]

well, i did read your profile twice and i didnt see that you had a BOV, i was actually gonna ask you to update it in case there were some things you had that were not on the list.

Do you know what specific turbo you are getting? I'm not retarded, I know you need more fuel with a turbo upgrade or if you're turning up the boost, but your not gonna outflow your stock fuel setup on a T-25.........I was just wondering about your timeline of upgrades. Speaking for myself, I cant go out and buy a FMIC, Fuel pump, FPR and then three weeks later buy a new turbo, downpipe, intercooler piping etc. I was thinking you installed the FPR and pump and you were gonna run it like that for a few months. Then get a bigger turbo and run the stock downpipe. But if you're gonna buy everything and then install everything at once, thats a different story.

I look at it this way, the pump and FPR are supporting mods, and so are downpipe's, intercooler pipes, FMIC's etc.................some people do their supporting mods in different stages. The way the Stage I mods are set up in our tech section is the best way "in my opinion" to start upgrading.....

no hard feelings man, just my opinion.....good luck!

 

[2DaTrakNow]

well, i did read your profile twice and i didnt see that you had a BOV, i was actually gonna ask you to update it in case there were some things you had that were not on the list.

What do i have that isn't in my profile? It says Blitz bov for the fourth thing!

Do you know what specific turbo you are getting?

Im not 100% sure yet. I am considering the Evo III 16G from SBR, or possibly something from AGP because i have a buddy that works there.

...Speaking for myself, I cant go out and buy a FMIC, Fuel pump, FPR and then three weeks later buy a new turbo, downpipe, intercooler piping etc. I was thinking you installed the FPR and pump and you were gonna run it like that for a few months. Then get a bigger turbo and run the stock downpipe. But if you're gonna buy everything and then install everything at once, thats a different story.

I can't go out and buy all of the stuff at once either. I curently have some of the parts as i somewhat mentioned earlier. The reason i havn't bought a downpipe yet is because i want to see what turbo i go with, and i want to see how i am going to do the rest of my exhaust. Also, since everything will be done at once, it will be easier to do the downpipe and IC piping with the turbo and other accessories off. Also, i will be having quite a few things "custom made" that i wont have to purchase from a store or anything. That is one reason why i bought some of the stuff you kind of have to buy, and that you can't just make, such as a larger fuel pump.

I look at it this way, the pump and FPR are supporting mods, and so are downpipe's, intercooler pipes, FMIC's etc.................some people do their supporting mods in different stages. The way the Stage I mods are set up in our tech section is the best way "in my opinion" to start upgrading.....

I will not argue that the way it is set-up in the tech section is bad at all. It may possibly be the best way out there. The only thing is, like i mentioned directly above is that the exhaust and stuff will be easier to do, and a lot of it is going to be custom, so again, i want to wait until i have the turbo and surrounding parts off.

I know that I skipped a few steps, and i see exactly where you are coming from. I just knew/know that some stuff would have to be bought down the road, so i went ahead and got some of the more expensive things, and the stuff that i would need no matter what, out of the way. In other words, i won't regret getting the fuel upgrades, all because i know that i will have to have them. The exhaust/downpipe, IC or IC piping can easily be regreted. I could get all of that done, then after a week or so wish i would have done something different due to a certain set up that i would have.

no hard feelings man, just my opinion.....good luck!

Its ok! Same to you, i was just doing things alittle bit differently than what the tech section recomends all because in the long run, for me personally i think it will work out better. I just dont want to do anything, then wish i would have done it differently, so i want to wait and make sure every part goes with each other.

And sorry, i know that when i started this thread it may have sounded like i wanted all of the fuel upgrades for my T-25, but that wasnt the case and I tried clearing it up in the past few post. I do respect your opinions though, and can't blaim you for following the recommended steps the this sites tech section. I am just doing it in a slightly different order to benefit me in the long run.

 

[talon1g-tsi]

I have a 1992 talon tsi , i have upgraded the manifold,turbo and the wastegate,i have an fmic and aftermarket bov . the wastegate is a 50mm . I wanted to know how much boost i could run after i put a new hot wire to the fuel pump and what other small things i could do to run higher boost than stock.
Thanks
MIchael
P.s I am new so if i done this wrong ,i am sorry

 

[winterftbl]

Well first off you need fuel injectors. Second you need something to control them with, example dsmlink or safc or dsmchips. Then you should be good to go my friend.