stock maf maxing out? or fuel pump?

[TT SHO PROJECT]

ok so now with some miles on my turbo sho (freeway and in town) iv noticed that i can take the car upto 4 grand in 1st and a tad over 3500 in 2nd and probably less in 3rd before it falls flat on its face... it kind studders before doing so and boost drops off (ie no hott exhaust gasses spinning the turbo) so im either running outta fuel (stock pump) or the stock maf is maxing out.. what do you guys think? how much hp is the stock maf good till? and how much hp is the stock non sho fuel pump good for?

i dont want to spend money on things i dont need so im hopeing i get some good info here =P if i just need a maf then ill get a maf or if i just need a fuel pump i have a 255lph laying around that i could swap in.

oh yeah and another note is that i think theres oil in my spark plug tubes? cuz i hear a thick boiling after i run teh car that seems to be comeing from teh plugs in back... i cleared out the ones up front so theres almost no boiling... could this be a problem under boost? just a thought.

Thanks in advance.

-Bob

 

[wood_e]

unplug the maf and see if the symptoms are still present.

 

[TT SHO PROJECT]

un plug the maf with a turbo car? is that safe to do?

 

[wood_e]

Well I wouldn't think it to cause harm as its a pretty standard way of eliminating components that may be faulty. I don't have a FI SHO though... so YMMV

 

[TT SHO PROJECT]

Welll i do think i found teh problem... i unpluged the maf just now took it fer a spin... stilll did it... now i removed the maf plumbing so theres nothing at the inlet of teh turbo (stupid to do i know) but the car pulled much harder and i was able to take it to almost 5k rpms in all gears... didnt want to push my luck and try for more rpms.... but the problem i think was that the Very sharp u bend of a rubber flex pipe from teh turbos inlet to the maf was getting crushed by the suction of teh turbo and thus closeing the air to the turbo. so now the sho's gonna be off the road again till i can figure out a better way to place the maf..

Thanks.

-Bob.

 

[Lance Cheney]

No, that's a really really bad idea. The program will run without a MAF, but it will assume a certain amount of airflow for a given throttle position and RPM - it has no way of knowing if you have a compressed intake charge. So instead of 13:1 AF now you're getting 17:1 with just 4-5psi of boost.

Stock fuel pump, combined with higher required pressure at the rail is going to cause a problem. You should hook up at least a rudimentary O2 sensor monitor (a digital multimeter worked well enough for me to tell whether I was grossly rich or lean). Driving around without at least that is really crazy.

The stock MAF & injectors should be good for 300 HP... unless its transfer is significantly different due to your intake plumbing changes. That, again, is something that is easy to see with a DVM. Just route a wire into your cabin and hook it up to your DVM, have a friend watch it while you accelerate and see how close to the ~4.7V max it gets. I ran my car on the dyno and had no issues with the stock MAF at almost 240whp, so I doubt that's the issue.

I would consider, at the minimum, the following upgrades as absolutely mandatory for longevity and driveability:

(A) 190lph fuel pump (only slightly overruns the stock FPR). 255lph has issues - do a search
(B) Tweecer or other tuning device
(C) 36+ lb injectors
(D) 80mm Lincoln MAF or equivalent (400hp + capable)

And if in doubt, pull the plugs. A misfire can cause all kinds of problems.

-Lance

 

[TT SHO PROJECT]

yeah welll i just took it for a quick run... didnt hear any lean knock... but im not doing it again.. even tho it was fun hehe. but yeah i need to make a metal ubend for the maf. so a 190lph would be good enough for how much hp? this turbos good for 350+ i really only want 300 max but i may be passing that with 8psi but i wouldnt know for sure till i get it dynoed.

On another note... i hear you have to mod the fuel rails somehow to get bigger injectors to fit? how do you do this? this is one thing (minus money) thats stoped me from getting injectors.

-Bob.

 

[Off Road SHO]

On another note... i hear you have to mod the fuel rails somehow to get bigger injectors to fit? how do you do this? this is one thing (minus money) thats stoped me from getting injectors.

-Bob.

Most higher flow injectors also have a larger inlet so they wont fit inside the fuel rail. Troy had The Other Woman's rails machined out (by a machinist that knew what to do and what NOT to do) to accept 42 lb Cobra injectors.

If you had a precise drill press, an X-Y adjustable vise, and the correct boring bits and chamfer bits, (don't forget to chamfer the edges so you don't cut your o-rings) I guess you could try it yourself. But gasoline under 40-100 psi is dangerous. Be careful.

Tom

 

[TT SHO PROJECT]

Most higher flow injectors also have a larger inlet so they wont fit inside the fuel rail. Troy had The Other Woman's rails machined out (by a machinist that knew what to do and what NOT to do) to accept 42 lb Cobra injectors.

If you had a precise drill press, an X-Y adjustable vise, and the correct boring bits and chamfer bits, (don't forget to chamfer the edges so you don't cut your o-rings) I guess you could try it yourself. But gasoline under 40-100 psi is dangerous. Be careful.

Tom

ACK!!!!!!!!!!!!!!! hehe why cant someone just sell already modded fuel rails?!?! hehe.

 

[SuperchargedSHOguy]

ACK!!!!!!!!!!!!!!! hehe why cant someone just sell already modded fuel rails?!?! hehe.

The demand is so low...any competitent machine shop can modify your rails for you.

You definitly need a higher rated MAF and a higher flowing fuel pump (lincoln 80mm and 190 lph minimum) and a way to tune that puppy. Just slapping on the appropriate parts without telling the ECU is a bad thing unless you like your CEL, bucking, stalling, ect...

 

[TT SHO PROJECT]

The demand is so low...any competitent machine shop can modify your rails for you.

You definitly need a higher rated MAF and a higher flowing fuel pump (lincoln 80mm and 190 lph minimum) and a way to tune that puppy. Just slapping on the appropriate parts without telling the ECU is a bad thing unless you like your CEL, bucking, stalling, ect...

well it runs good sofar... i slapped a blower... 24# injector a big fuel pump and a 75mm maf on my stang with out a problem at all... well the 255 did over run the stock fpr but thats a 20 buck fix (accell fpr) hehe

tobad they dont make a maf for bigger injectors for teh sho like they do for teh stangs.

 

[SuperchargedSHOguy]

well it runs good sofar... i slapped a blower... 24# injector a big fuel pump and a 75mm maf on my stang with out a problem at all... well the 255 did over run the stock fpr but thats a 20 buck fix (accell fpr) hehe

tobad they dont make a maf for bigger injectors for teh sho like they do for teh stangs.

Thats the difference between the stangs and SHOs. The stangs now a days have MAFs setup for different injectors and are plug and play...as for the SHO...yeah right. Slap on a 80 mm maf and it will run like crap until you tell the ECU via chip/lpm or TwEECer.

You only used 24 lb/hr injectors on a blown stang My 4.6 stroker motor in my supra used 24 lb/hr injectors without the blower...way higher now that I put a turbo on it.

 

[TT SHO PROJECT]

Thats the difference between the stangs and SHOs. The stangs now a days have MAFs setup for different injectors and are plug and play...as for the SHO...yeah right. Slap on a 80 mm maf and it will run like crap until you tell the ECU via chip/lpm or TwEECer.

You only used 24 lb/hr injectors on a blown stang My 4.6 stroker motor in my supra used 24 lb/hr injectors without the blower...way higher now that I put a turbo on it.

remember theres 2 more injectors ;P plus a 12:1 fmu helped... with 12psi it was still pretty damn rich at the redline oh yeah it huffed black down the track at the top end.. so it was all good. it made a tad over 400 hp at the crank. not to shabby. iv seen ppl make more power on stangs with just 24# injectors.

 

[SuperchargedSHOguy]

remember theres 2 more injectors ;P plus a 12:1 fmu helped... with 12psi it was still pretty damn rich at the redline oh yeah it huffed black down the track at the top end.. so it was all good. it made a tad over 400 hp at the crank. not to shabby. iv seen ppl make more power on stangs with just 24# injectors.

yeah, but there are stock stangs that come with 24's from factory N/A...I believe the FMU was what kept you from leaning out. You definitly need to get a A/F reading on your SHO before you hammer on it...buts thats me. I am done taking risks with engines.

 

[TT SHO PROJECT]

yeah, but there are stock stangs that come with 24's from factory N/A...I believe the FMU was what kept you from leaning out. You definitly need to get a A/F reading on your SHO before you hammer on it...buts thats me. I am done taking risks with engines.

yeah i hear ya man... risk can be costly.

 

[NCTaurusSHO]

i have modified fuel rails you can buy. I also ran stock maf and injectors for half a year . The car ran great, I unplugged the octane shorting bar (sprout connecter) that retards the timing 3 to 4 degrees that allowed for 12-15 lbs of boost with no problem. I recently up graded the MAF to 73mm and 30lb. injectors. We never had a problem running it up to the rev limiter under boost.

PS. Still beating the **** out of it every day.

Stock fuel pump
Stock tranny
Stock axle shaft

I would try to elimanate the fmu and try that

You can modify your fuel rails on your own if you want. You need a 9/16 drill bit, take a piece of tape, and hold one of the injector o-rings to the side of the drill bit, the will tell you your depth. Mark it with a piece of tape on the bit. Then drill em out to your tape line. And file the edges nice and smooth. Took about 20mins or so.

 

[TT SHO PROJECT]

cool man cool... i was thinking about unplugging the spout just to be safe.. kinda forgot about it tho hehe thanks for teh reminder... with out the maf (i have to remake the maf plumbing....) it pulls like a sob in 3rd gear hehe. i know its not good to run it like that (overly rich... tho someone said it runs lean.. but every ford i have rran with out the maf defualts to mega rich like eye burning rich in some cases)

on another note...

today i just ran in to my first real problem...(all a part of working out the bugs) after beating the snot outta it fer a lil bit.. i think i burst the oil return hose some how it seems to be leaking right at the turbo,(its just normal heater hose probably why) lucky for me it didnt start leaking till i Just pulled in my driveway! phew that was a close one! didnt even lose a qt. thank god hehe. so imma have to rethink my oil return hose... i have a hose from a fat tender (umm fast food joint deep frier oil cleaner thinger lol.) very high temp hose so i might gank some of that to fix the problem we will see... kinda sux tho cuz i have to remove the turbo to replace the hose.... but i kinda should do that anyways to make me making my new maf plumbing much less of a pain.


-Bob

P.S. oh yeah forgot to ask.... 9/16th drill bit?!?!?! thats one **** of a big hole!!! just about 14mm! =P you sure its 9/16ths? not that i doubt you but liek uhh thats a pretty big hole for an injector.

 

[NCTaurusSHO]

positive that it is 9/16. We have 4 rails here if you need us to do it for ya. Just look at the o-rings on your injector and see how big it is.

 

[TT SHO PROJECT]

turbo sho pic lol well kinda..

sorry got bored.... heres a quick scetch of the my turbo sho... its pretty bad scetch but you will get the idea. i dunno how to use this phto bucket thing so here goes nothing... <img src="http://i11.photobucket.com/albums/a198/jadecreepa/turbolow.jpg" alt="Image hosted by Photobucket.com"> if that dont work then heres the direct link

http://i11.photobucket.com/albums/a198/jadecreepa/turbolow.jpg my friend with teh digi cam couldnt find his damn cam so this is the best i can do for pictures lol.