KA-T and factory fuel setup???

[uncle_louie83]

ok...heres the thing...a buddy of mine locally has a SOHC t3 turbo....i believe its the IAP stage 1 kit...it is totally bad ***. Well all he has for fuel management is a walbro pump and he used an external FPR and bumped the stock fuel pressure up 3psi over base and he has been boosting for awhile now...no safc...no bigger injectors...its all stock other than the pump and 1:1 FPR. He said that the stock ecu will compensate for up to 7 to 8psi of boost with just a pump. i believe him cause ive seen it with my own eyes but does a 93 DOHC do the same if it were a small turbo and say 6 or 7psi of boost?

lewis

[bruinbear714]

You can do it with a FPR and a fuel pump.. the stock MAF will run out at about 8psi of boost, so if you run at 6psi and back timing off a couple of degrees you will be fine.

[:: orion ::]

You can do it with a FPR and a fuel pump...

But it's going to take more than "3psi over base" fuel pressure.

270c cinjectors can support ~190rwhp. 3 more PSI of fuel pressure will get you to maybe ~195.

So if his setup is lame, and he's only making ~195rwhp at 6-7psi...then OK. But you WILL NOT Have the same results with your car...you motor will blow.

You could *maybe* do 3psi form a T3/T4, or 4psi from a straight T3 on completely stock fuel system (or even with a high-flow pump)...but any more, and goodbye KA.

- Brian

[hannibal]

Yeah, stock base fuel pressure is 3bar (43.5psi). Maybe he's running 4bar base pressure. That would make the 270cc injectors act like 312cc. I'd say thats enough fuel for 210-220whp.

[uncle_louie83]

well im just trying to figure things out....money is tight...the lady is pregnant...buying all this other home & baby stuff is taking a chunk away from the badass boost project and i know once the baby arrives i wont be able to do that. I was just going to trade off a few of the badass things i have for a small sr setup and boost 6 or 7psi and no more. i know id want more but atleast id have some sort of boost....ill prolly just do my safc and a walbro pump....cause i have an safc in the car now wired up and working.

anywho....his car runs rich...really rich...he has the walbro 255HP pump and an aftermarket FPR 1:1 and runs 3psi over stock only and that car runs rich at idle and runs 12:1 AFR all the time in boost with a t3 turbo...its mean and runs awesome..but his is the SOHC and i know there ecu is different and there programming is different. I was just wondering if this could be done with the DOHC also

[hannibal]

I dont know the differences between the SOHC and DOHC ECUs, but if this setup runs as well as you say it does, it should be good enough for the KA-DE. Although the ECU doesnt have anything to do with it. It cant sense boost and it's controlling the stock sized injectors.

But something just doesnt sound right about what youre describing. As orion said, 270cc injectors can only supply enough fuel to run 195whp safely. Are you sure he's not using increased base pressure or a rising rate FPR??

[Import_Ant]

Thanks for the kind words lewis I'll try and iron out some of the gaps here.

I'm running an upgraded fuel pump (Walboro 255 lph) According to Mark at IAP (Gofast1 on here) the increase in volume 'should' hypothetically be enough to increase the base fuel pressure by about 2-psi. I didnt think this made sense since the FPR is set at a given amount and is going to cycle the extra pressure through but we had a long conversation about it a while back regarding the capacity of the stock fuel system and basically the jist as I understand it was that the stock fuel pump didnt provide as much volume of gas to the fpr and that increase in volume is enough to step up the base fuel pressure just a tad when taking into consideration the stock fuel lines and stock FPR's ability to handle that increase in volume.

enough about hypotheses here are the facts about my setup.

Stock injectors, Stock FPR, Walboro 255Lph fuel pump, stock ECU.Stock Ka24E motor (8.6:1 compression) stock Ka24E MAF timing set to 15 BTDC (stock for KA24e motor) T3/T4 set to 8~ psi (just a tad over .5 bar)

the differences in compression and capability of the SOHC MAF allow me to run a bit more boost over a KA24DE with a 9.1:1 compression motor and with a KA24DE MAF. As Orion said I'm PROBABLY hitting around 200rwhp. im just able to do so because of my motor's 'mild' setup from the factory. Also I believe the DOHC motor runs at 20 BTDC timing and that's got to cause a bit of difference as well.

I have heard rumors that the SOHC MAF is capable of reading a higher amount of airflow than the DOHC anyone care to confirm/dispute that?

I'll try and check back later if anyone has any other questions or things I forgot to mention.

-Aaron

[Nismo_Freak]

Do it right the first time

[uncle_louie83]

we know that nismo freak...were just trying to solve this mystery here...ive seen it with my own eyes on the SOHC...for example import ants car...its impressive for the setup. I guess i can see how it works but at the same time its confusing. maybe the maf reads the more air coming in and the ecu compensates with more fuel...because he isnt maxing out the maf yet..hasnt reached 250whp. he does have the equipment to do a more reliable setup but that isnt going on until next season. I enjoy talking with aaron about ideas and new things about the 240 world. the guy is smart

all im trying to figure out is...can this be done on the ka and if so how many psi ?

i know a guy locally who has an s14 with a small t4 and he is pushing only 7psi...only upgrade he has is a FMU...and thats it. He has been running this setup for 4 years now. the whole car is stock...suspension and all...just an old guy named bill who works for a local motorsports shop and that car is impressive too....its truly awesome how the stock fuel/ecu can work with boost here.

WDracing has shown his stock fuel pump is good for 14psi....well can the stock s13 fuel pump do this too....or what is the limit for the stock fuel pump...

im trying to collect data here...so if you know the stock fuel pump limit? please chime in if anyone does

[Florida240sx]

Tell you what guyz...I'll answer all your questions and guesses tomorrow night or the following.Got my Radiator fixed.My wideband and test pipe should both be here by Wednesday. We'll see what the lc-1 and xd-1 wideband tells us.

[Nismo_Freak]

we know that nismo freak...were just trying to solve this mystery here...ive seen it with my own eyes on the SOHC...for example import ants car...its impressive for the setup. I guess i can see how it works but at the same time its confusing. maybe the maf reads the more air coming in and the ecu compensates with more fuel...because he isnt maxing out the maf yet..hasnt reached 250whp. he does have the equipment to do a more reliable setup but that isnt going on until next season. I enjoy talking with aaron about ideas and new things about the 240 world. the guy is smart

all im trying to figure out is...can this be done on the ka and if so how many psi ?

i know a guy locally who has an s14 with a small t4 and he is pushing only 7psi...only upgrade he has is a FMU...and thats it. He has been running this setup for 4 years now. the whole car is stock...suspension and all...just an old guy named bill who works for a local motorsports shop and that car is impressive too....its truly awesome how the stock fuel/ecu can work with boost here.

WDracing has shown his stock fuel pump is good for 14psi....well can the stock s13 fuel pump do this too....or what is the limit for the stock fuel pump...

im trying to collect data here...so if you know the stock fuel pump limit? please chime in if anyone does

There is no mystery.

You are talking about simplistic modifications that are cheap and readily available. To me there is absolutely ZERO reason why you should even consider running a stock fuel system ghettorigged to barely keep the engine alive.

You are inviting failure.

Brian could have blown his engine trying to find out about the fuel pump's capacity. All for the sake of a $100 shipped part.

Do you want to constantly replace motors, and shell out money just for the sake of knowing when the 100+k mile stock parts will give out? If so you are defeating the purpose of budget building anyways.

[Import_Ant]

There is no mystery.

You are talking about simplistic modifications that are cheap and readily available. To me there is absolutely ZERO reason why you should even consider running a stock fuel system ghettorigged to barely keep the engine alive.

You are inviting failure.

Brian could have blown his engine trying to find out about the fuel pump's capacity. All for the sake of a $100 shipped part.

Do you want to constantly replace motors, and shell out money just for the sake of knowing when the 100+k mile stock parts will give out? If so you are defeating the purpose of budget building anyways.

while it is a cheap part to buy, he was just curious if anyone KNEW of the capacity of the fuel pump. he wasnt asking Florida to test it out to its limit. the PURPOSE of budget building is getting the job done for the lowest cost. Lewis is just trying to discover if there is an option to use what he has to make a setup that flows better than something he's going to have to spend 100$ on. I'm not his lawyer/spokesperson but I do see where he's coming from. while it may be evident to you or I that it might not be a smart choice, that's the purpose of this thread isn't it?

Quote »does a 93 DOHC do the same if it were a small turbo and say 6 or 7psi of boost?lewis[/quote]i dont want to start a war over this i'm just pointing out that he's just doing research at this point. not making concrete plans.

[uncle_louie83]

aaron is right...plans are not set in stone...and yes im just researching. i know that some of the questions i ask arent the right way to do things but i just like to know...thats how i have learned alot over the years by asking questions and testing out products. ive found out that the stock s13 pump cant flow anything...but the s14 pump can do effciantly 12psi..so that mystery has been solved for me.

all i want to know if can the stock FPR and the stock injectors/ecu/maf and everything else say with a walbro pump work ok with 7psi on the DOHC...ive seen it done with a walbro on a sohc....so if you want to test it florida then go ahead but if it breaks then its not my fault...i just thought id ask the boards if they knew the answer.

[Mustangs_Suck]

Do it right the first time

Word. Can't press that enough. I bought my car with crappy parts already on them. This winter the car goes into storage and I am rebuilding my entire motor with forged everything and getting a STRONG manifold, great turbo, redoing all my piping to be solid, getting all guages, and fuel management, and upgrading the injectors.

I will not cut corners in my car....especially after seeing all this "my KA blew" threads...if I don't have enough money to do it by the time weather is nice out..I simply won't have a nice car that summer...

Do it up right...don't try to get as close to certain limits just so it holds...if you can't afford it - wait until you can.