RX1 carb referencing question

Wheel House Motorsports · Oct 24, 2009

For those of you running the t-rx1's do you t the two float bowl lines together and reference them, and the caps on there own system as well? I have the cap and bowl t'd together for 1/2 fed of the airbox, and also running 3/4 t'd the same way.

leans to the point of no running as soon as boost is built, and my fuel pressure is 1:1 with boost.

Wheel House Motorsports · Oct 24, 2009

i found a large picture close up of one of these bad boys... are the float bowl lines just needing to be T'd in on there own or something?

M5- · Oct 24, 2009

Here's some pics of my setup. I'm a little unclear on what your fuel pressure is. You need to set the fuel pressure at idle to about 4-5 psi by teeing in a fuel pressure guage temporarily on one of the lines going to the float bowls. The fuel pressure regulator varies the fuel volume/delivery by using the boost pressure it gets from the intercooler sensor line, more boost more fuel. So if you are running a Malpassi fuel pressure reg you should have 2 lines going to the carb bowls, a fuel return line going to the fuel tank and a boost reference line coming from the intercooler.

M5

Wheel House Motorsports · Oct 24, 2009

my question isnt about how to get referenced fuel to it, i have 1:1 fuel hooked up to the bottom of the bowls, my question is about the line that goes from the two billet t's in the front of mine, heres a modded version of your pic, where does this line hook to? heres how mine is setup as well

Givemeaboost · Oct 24, 2009

You have that all screwed up. The two hoses on the backs of the carbs should run to the intercooler and should go into two seperate locations on it . Don't tee them together and run one line from the intercooler or the carbs won't open evenly. Those are what opens the slides to give it more air which yours is running out of. The two front ones should be teed together and hooked to one line on the intercooler that comes off the pressure side just before it goes into the carbs. I'll pm you my phone number and you can give me a call.

M5- · Oct 24, 2009

Just like Givemeaboost says the line you have marked on my pic goes to the intercooler on it's own barb. The other two you have teed together need to be taken off. The two from the billet tee's tie them toegther and they become the line you asked about on my pic. The other two lines from the back of the carbs go to the intercooler each on its own barb just like Givemeaboost said. When you do those two lines make sure you keep the lines the same length so the carbs get boost at the same time. Make sense?

M5

Wheel House Motorsports · Oct 25, 2009

alright... well, no test ride today, wasnt able to get it all done last night, and testing in the middle of the night isnt very nice to the neighbors!! BUT, got the 2 slide lines hooked stright up into the stubs on my airbox, equal length tubing as well, and im putting a barb in for the billet t line so i can run those down to there own.

thanks for the help, and a HUGE thanks to givemeaboost for the advice on the phone last night!

Wheel House Motorsports · Oct 25, 2009

well, this didnt solve me issues. i tapped a fitting into my airbox right off the angle part so its getting a nice blast of compressed air, and it runs alright up in the air till about 5psi of boost, if i ease on the thing really slow, afr sits at right around 10.5-11 until it starts to build boost, sitting low 13's at 5 psi then if you go over it she starts to lean pop, thats any way i can hit it, wot, low throttle. any thoughts. im all ears

and please dont respond to this one, if you could come over to my carb tuning thread in performance mod that would be awsome, just trying to consolidate info.

Turbo11T · Oct 25, 2009

jets

maybe a dumb answer but why not try bigger main jets?

Wheel House Motorsports · Oct 25, 2009

from a few people i have talked to, the 130's i have may be a tad lean, but not popping like nuts under little load lean... in my thread in perf/mod there was a guy talking about his did the same thing until he got a good signal for his float bowls... like as soon as it hits higher boost its not getting the right fuel pressure.

M5- · Oct 25, 2009

My sled when I first built it I used 127.5 jets and it was super lean 16+ AFR at elevation. Now I run 132.5 and I have 12's, thats only 2 jet sizes so why not slap in some 135's and see what it does. Your jetting will change dramatically at elevation I never nut mys sled at home 3000 ft cause it's just too lean.

M5

Wheel House Motorsports · Oct 25, 2009

hmmm.... a good thought, i guess i could try some 135's or something and see if it doesnt make it better... just seems bizzare, but right now jets are cheap and easy to do, so may help me get closer... and i need it to be safe at 4800 as I unload at 4000 when im not at college... 4500-6000 is our main elevation there, so i need to be setup good for here.

M5- · Oct 25, 2009

Depending on how your air intake is setup your sytem could be getting a ton of air and making it way lean.

M5

Wheel House Motorsports · Oct 25, 2009

refering to under boost or with no resistance(open carbs?

your thing about larger mains could very well be, it will pull a bit of RPM... a tad bit of boost before it goes lean, it gets lots down low, just high demand SLAYS it, once the turbo starts cookin it falls down fast... if this was all just a jetting issue i may punch myself in the face for jumping around it so much.

I wonder if not having an intercooler and such as small charge tube, i get SO much air so quickly to the motor it needs a lot of fuel, vs a setup that comes on slower and is not pushing the cfm's at the same airflow... My setup is very short and affective, so as soon as that thing gets building boost, there is a LOT of air moving at the motor.

zebiraross · Oct 25, 2009

Have you looked at your fuel pressure to make sure it is rising 1:1? If you have your static set at 4 psi you should be seeing 14 psi of fuel pressure at 10 psi of boost.

Turbo11T · Oct 25, 2009

zebiraross said:
Have you looked at your fuel pressure to make sure it is rising 1:1? If you have your static set at 4 psi you should be seeing 9 psi of fuel pressure at 10 psi of boost.

I think he meant. If your set at 4 psi at idle you should see 14psi of fuel pressure at 10lbs of boost.

Sounds like you have some other issue that you need to get fixed first so your not chasing your tail.

zebiraross · Oct 25, 2009

Turbo583 said:
I think he meant. If your set at 4 psi at idle you should see 14psi of fuel pressure at 10lbs of boost.

Sounds like you have some other issue that you need to get fixed first so your not chasing your tail.

Oops, thanks!

M5- · Oct 25, 2009

Ski-Dooin it said:
refering to under boost or with no resistance(open carbs?

your thing about larger mains could very well be, it will pull a bit of RPM... a tad bit of boost before it goes lean, it gets lots down low, just high demand SLAYS it, once the turbo starts cookin it falls down fast... if this was all just a jetting issue i may punch myself in the face for jumping around it so much.

I wonder if not having an intercooler and such as small charge tube, i get SO much air so quickly to the motor it needs a lot of fuel, vs a setup that comes on slower and is not pushing the cfm's at the same airflow... My setup is very short and affective, so as soon as that thing gets building boost, there is a LOT of air moving at the motor.

Try it it can't hurt, an intercooler does offer up some resistence from the turbo.

M5

Wheel House Motorsports · Oct 25, 2009

Im gonna go yank my airbox and give it a rip with no resistance to see what it has to say about it.

and yes. my fuel pressure is rising 1:1... another question I have is, should i be set at 4-5psi with motor off, or 4-5 under vaccum at idle? i have mine set to 5 just pump switched on so that also oculd be part of it, but im diving down into the mid to low 11's when i hammer on it down low, so its getting a LOT of fuel down there.

also, this thing is a pig on rev up.. its pretty dang slow down low, once it builds boost it revs fast, then dies, maybe im just to worried on a part of the throttle swing that dont matter when riding.

Wheel House Motorsports · Oct 25, 2009

Im gonna go yank my airbox and give it a rip with no resistance to see what it has to say about it.

and yes. my fuel pressure is rising 1:1... another question I have is, should i be set at 4-5psi with motor off, or 4-5 under vaccum at idle? i have mine set to 5 just pump switched on so that also oculd be part of it, but im diving down into the mid to low 11's when i hammer on it down low, so its getting a LOT of fuel down there.

also, this thing is a pig on rev up.. its pretty dang slow down low, once it builds boost it revs fast, then dies, maybe im just to worried on a part of the throttle swing that dont matter when riding.

RX1 carb referencing question

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