Help! Car Leans Out Gradually After 5000Rpm..

[rondofj]

thanks bro, let me know, I can pick up, thats very nice of you

[t04z]

Hey mate had pretty much exact same problem with a brand new 040 bosch leaning out past 5000rpm sent it back got a new one and was fine so sounds like a fuel pump to me man

[Pal]

try clamp off your outlet(not full closed though) from the fuel reg and go for a drive, see if that restores some power. if it does, your fuel reg is stuffed

[rondofj]

aaarggh... hoping its not the pump, its a bit of a pain to replace, gud idea about pinching the outlet, hoping my car doesnt choke from lack of of fuel and blow up! !

[Pal]

put it after your fuel reg on the return line to the tank. it wont run out off fuel then

[rondofj]

So I got this pic from someone elses post, just need to know if its correct.. where to connect the fuel pressure tester etc..

[rondofj]

Just had car tuned again today on Dyno with DVS JEZ from SAU - the results are just so amazing on the street compared to old tune - just totally different to drive so smooth and super responsive from 2000 all the way to 7000rpm and can feel the turbo kick a lot more now....just luurrrv it!! Torque was an impressive more-than expected 546NM. I was thinking it would be more like 460ish NM..

Power started from a super low 132rwkw (stock r34 maps) onto a kinda okay 186rwkw (dyno sheet coming soon)..was hoping for AT LEAST 200 plus rwkw with current mods, but I think because I have the stock dump (rest of exhaust is 3", power and boost started dropping later in the rev range at 13.5psi.. We checked the rubber intake hose too, it wasnt sucking shut. It was a Mainline Dyno which supposedly reads a lot lower than Dyno Dynamics dynos, thats what I've been told..

Although the power is a bit disappointing the result on the street is much better than I expected, just crisp beautiful and yes, fast. The air/fuel ratios are almost perfectly straight - 11.7-11.8 afrs - Jez is amazing and takes his time to tune it bit by bit across little rpm bands - I would say big difference to those workshops that just give u a power figure..

Couldnt wind the timing up more than 14degrees because power started dropping at this stage --- is my dump the restriction??? Also my 100cell metal cat isnt welded properly - there is a slightly smaller than 3" extension pipe that sits part way INSIDE the 3" cat opening on both sides and then welded to the flange and cat..I think because it was easier for the exhaust shop to weld it this way - didnt think it was a problem then, but now think other wise??

We found there was NOTHING wrong with my fuel pump and regulator, it was the afr gauge giving incorrect readings on the road ONLY because it was picking up atmospheric air plus the exhaust air, thus leaning out the ratios.. Two different gauges did this. But when we added a short length thin pipe to the end of the exhaust with the afr sensor inside, the afrs went perfect-- no dramas at all.. this might help other tuners and gave us a lot of headaches..please take note!

[rondofj]

Recommend JEZ AAA++ now for all tuning and also mechanical work.. He's one top bloke and also has good prices! !

Jez, thanks heaps mate, today was the best outcome from all the work we did so far..

[rondofj]

still dont believe my torque figure 546Nm - 'Simon-S14' (Orange S14) here with a RB25 NEO makes identical torque with almost TWICE as much power - 358RWKW??? And 'WASN'T ME' (black R34GTT) also with a RB25NEO makes almost the smae power as Simon but with 1000Nm +????

Some funny business going on for sure, sure different dynos give different readings, but not by THAT much..?? These guys' results can be seen on PAGE 33 of the Rb25 Turbo Upgrade thread.

[rondofj]

no comments anyone?

[R.3.2.G.T.R]

don't bother comparing torque figures, take it with a grain of salt

[SargeRX8]

As long as you get punched into your seat, your torque is good. My turbo is on the car, once I finish my install then chuck a high flow cat on it and it's tune time. Your from parramatta, how far was jez from you? I can't drive the car hard at all so a little worried about the drive. Did you take the f3?

[karma_syke]

the injector cleaner that you add to your fuel doesn't do shit, to get them clean you have to remove them and take them to a specialist, there's a thread on here somewhere which demonstrated dirty injectors flowed 20-30% less.

oops didn't read the second page, glad you got it sorted.

Edited June 11, 2011 by karma_syke

[rondofj]

Sarge Rx8 yes i took the f3 and its about an hour to central coast, give him a buzz hes on sau, btw why do u have rx8 as ur sig, u drive one?

[Dose Pipe Sutututu]

that torque figure is probably the tractive force of what is required to move the rollers, not the engine's torque.

[rondofj]

So the engine torque would be even more?? Say another 100Nm??

[SargeRX8]

that torque figure is probably the tractive force of what is required to move the rollers, not the engine's torque.

But isn't that still the torque made by the engine to the wheels? The roller will measure the force put against it, how fast the wheels have pushed and turned the wheels in an amount of time thus giving you a calculation of the torque figure.

My old car made 5600N torque, this is not a unit of measurement which is convertible to nm but I was told it is quite a healthy number for an RB25.

I always understood torque and power as a punch. The torque is how hard, the power is how fast. But to have speed you need torque and with torque should create speed... Its something I am not familiar with. Diesel trucks produce huge torque but don't move, but if you stand them against a brick wall they will tear through it like butter..

[rondofj]

5600N is force - Newtons is force only - torque is Newton times meters