junito1

I was told that if you get a good fuel pump and bigger fuel lines from tank to rail will make a huge difference. High flow fuel filter as well.

gxl90rx7

iTrader: (1)

upgraded fuel pump is necessary, but i would say the stock lines should be fine for any BNR setup.. Ive ran my stage 3 at 15psi, with 750cc/1000cc injectors at 90% duty cycle and fuel pressure is steady as a rock ~55 psi to redline on stock lines, stock fuel filter, stock FPR, walbro 255

Bryan@BNR

iTrader: (1)

No need to upgrade the fuel lines. Not until you make around 500 RWHP. As for injectors on a stg2 I would run 4 720's. But 550-720 and pump combo should be good for 300 RWHP. After that you must atleast do 4 720's.

junito1

I have mentioned this before and got bashed but my puerto rican uncle tuned my car with an aeromotive fpr. I have 720 secondaries and a walbro 255. Those are my only fuel supporting mods. He worked magic with the fpr and ran 14 psi with my BNR stg 4. And never ran lean. in fact it never leaned out more than 11.0 afrs

I personally have not ran 14 psi. But he had already tested the car out several times.
He is not just a ghetto mechanic neither, he is a certified mazda master mechanic/ tuner in puerto rico.
And my motor has lived through 3 years of my drifting/drag abuse. So say/think what you want.

Bryan@BNR

iTrader: (1)

550-720's with the base pressure turned way up is high risk. It works sometimes, but injector failure is definately a problem running them over 100% dutycycle for a constant amount of time. If they were all side feed injectors, it would be no problem running them at 100% but they are top feed. Top feeds will overheat and tend to want to stick open/closed then your engine is toast.

'87snail

ok guy's got two questions for ya,
1.) i am running a turboetnics 60-1(8-12 psi.) , 720cc injectors(4x),stock lines& pump, tial wastegate, custom Cat-less turbo back exhaust, 2" i/c to intake piping,2.5 greddy intake to throttle pipe, corky 20"(guesstimate)x 8"fmic , fluidyne alu. radiator. hks pfc-fcon, "wild" street prt, 2mm apex seals, and 93 side seals. I am running really fat at the moment and am having a boost issue, on top of needing a basic tune up, any who once i get my **** properly tuned and tuned up and the boost issue sorted out how much do you guys think i will be putting down?

2.) i am hitting full boost at 4.5k and this is unacceptable for my road racing/brutal street driving intenstions. so i found a pair of 98 supra twins for dirt cheap with 0 miles on them, at most i will be boosting to 18 psi so i think the pair is sized about perfect how much do you guys think i will make at 18psi with the proper tune, and proper fuel system w/ stand alone?

boost_its_what_for_dinner

supra twins will not help you...

DC13B

how much did you make on this set-up? ans what was it tuned with?

'87snail

why not the supra is moving a similar amount of cfm plus the supra twins are sequential which i know will be a bitch to get running properly which is part of why i am doing it plus if you get the j spec turbos they have ceramic turbineswhich in itself will lead to faster spool times

boost_its_what_for_dinner

dont ever go with twins unless your running like twin gt28's or bigger... and then you would do just as good as a single gt37+

TweakGames

iTrader: (3)

u dont have enough fuel with the 720 x 4. You will run out of fuel at 80% duty, at around 270 rwhp.

gxl90rx7

iTrader: (1)

i had it dynod at 12psi = 308whp, but not at 15psi. the butt dyno indicates there is a noticable difference though heheh rtek 2.0

'87snail

but you are still not giving me any concrete evidence as to why the set up is a bad bidea cause from the papers standpoint its a very logical choice for a road car

'87snail

ps i am only shooting for like 420whp max

boost_its_what_for_dinner

why watse the time? oooooooooohhhhhhhhhhhhh you will have 2 turbos big deal. just do a good single like the gt32 or similar would be like a bnr 4 but ball bearing and high boost ready

DC13B

cool, thats almost the exact smae set-up ill be running. im on rtek 2.0 right now too. but will upgrade to 2.1

lovingthefc3s

iTrader: (2)

87snail..............you need a Fuel Pump!

'87snail

yea i know bigger injectors too thanks though

jsnow82

iTrader: (3)

i need help. i have a bnr stage 4 series 4 turbo with a big streetport and all manifolds ported to match. I seem to have a big problem with boost lag. Im not seeing bull boost untill close to 5k. 1st and 2nd gear are even lousy to get to boost. I have checked for leaks with a smoke machine and everything is ok. Im starting to think that the wastegate is not staying closed. I have ready through this thread and have not found an answer. I have a racing beat 3inch exhaust. I also have 3 intercooling piping which could potentially be a cause too, but i doubt it would cause that much lag. thank you everyone

2Lucky2tha7

iTrader: (3)

^^ yeah, his car has been acting funny lately with that turbo. It's been lagging real bad. Although, he has mentioned that it will hit 16+ psi @4k, but now it's not till like 5k+ like he said. He's also using a Hallman MBC

junito1

I have never had the power to use 3" intercooler piping. But i doubt a bnr stage 4 will need that.

You could try using your stock intercooler. This will Let you know if its the piping/intercooler setup or not.

WHo ported the motor? Maybe a bad port job.

2Lucky2tha7

iTrader: (3)

Well, I can tell you that it's def. not the porting. We were both surprised at the prior port job from when it was 1st rebuilt a few years ago by a certain well known company that I will not mention. The secondary ports were "passable", but the primary ports were just horrible and irregular. The worst I've ever seen, lol. It had to be rebuilt because the front iron cracked. Stronger (dowel area) s5 front and rear irons were bought and ported, along with the intermediate iron and rotor housings being re-shaped/ ported.

jsnow82

iTrader: (3)

lol. thanks brian. i did the porting on the housing and i know for sure that i did a great job on them. car was getting good boost response for awhile until i lowered the boost to tune the 6-8k area. i then put the boost back to where it was and noticed the boost lag. wastegate def is working and holding boost. im starting to think maybe the boost controller but why will I still make 18psi and hold it throught the rpm range?

htkingswood

Have you checked your turbine wheel? Damaged turbine wheels cause severe lag.

Clipped turbine wheels increase lag but still make boost and hp so it's possible you may have a damaged blade or two causing similar symptoms to clipping turbine wheels. Just a thought.

Your exhaust housing could also be cracked.

I hope you sort out your problem, I can image how frustrating it must be.

SmogSUX

iTrader: (12)

Check your blow off valve? I read someone had a similar issue and the bov leaked and needed to have the spring tightened.