Jump to content
SAU Community

Recommended Posts

Hi guys, just lookign for some input on my current situation.

My stagea autech had N1 Le mans turbos fitted (rated 640hp), adjustable cam gears, 700 injectors, upgrade fuel pump, greddy profec b boost controller and power fc fitted a few weeks back in Sydney and i was a little dissapointed with the result. It made 251kw at 17 p.s.i but was running on 20" rims on a 34 degree afternoon. On the way home afm's started playing up so have since purchased a set of nismo ones and had them fitted and car re-tuned today and still not happy as i was hoping for and told by nearly every tuner ive spoken to that 300-320kw should be what i'de expect to see.

Car made 265kw with nismo afm's at 17 p.s.i with factory rims back on which i think are 16' maybe?

The tuner couldnt seem to work out what is holding it back but said it was just simply a dud lol.

Tried unbolting the cat thinking it may be the issue but it is a catco highflow cat and unbolting it only made a 6kw difference so its not that.

He also said that with a 3 p.s.i increase to 20 p.s.i in boost it was gaining only 3hp so there is a restriction of some sort somewhere. I've read alot of comments on factory airbox and intercooler being fine for the 300kw target but these are the only 2 things i can think of that havent been changed.

List of current setup is:

Power fc

Nismo N1 GT LeMans group A turbos

xforce dump pipes

2.5 - 3" front pipe

Catco highflow cat

3" mandrel bent exhaust and 3 inch highflow straight through muffler

JJR adjustable cam gears

Walbro intank 255l fuel pump

Nismo afm's

factory intercooler and piping

factory airbox and snorkel with K&N panel filter

Greddy profec B spec 2 boost controller

Any suggestions or comments on whether the power figures seem fairly under performing for these mods or if someone has run into the same situation and what was restricting it?

From what i have researched i should definatly be seeing around the 300+ kw mark and its frustrating me having spent the money buying the parts i thought would get me there to fall a good 40+ kw short.

Edited by livewire
Link to comment
https://www.sau.com.au/forums/topic/384616-rb26dett-with-mods-not-making-power/
Share on other sites

  • Replies 75
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Posted Images

Agreed, about 300 is right for those turbs at 20psi. They are pretty crap unfortunately, you would have 350+ with the same setup running -5 of similar instead (and with less lag).

Dropping the zorst was a good call, and the other stuff like intake, cooler, airbox etc would be fine for that power level.

Are you certain the timing is correct, and what cams does it have? Sure there is no boost leak and that the fuel pressure is OK?

I'd do a double take on the walbro...........get a tomei/bosch/nismo and re try. Also see the FAQ section on using a dedicated earth lead for your pump.

Also try taking your K+N panel out and running without it just to check.

Pic of the dyno sheet please.

What are the cam gears set too?

Are the standard intake pipes sucking closed?

Comp tested the motor?

It's running 8degrees on the inlet and 4degrees on the exhaust.

Engine sounds bloody healthy IMO.

Thats crazy. Try backing the intake off heaps. Maybe 4 and the exh to 2.

Did they play with cam timing?

Not today. I believe the previous mechanic/tuner did last week when the adjustable cam gears were installed.

i'd be looking at comp testing the motor.

or possibly setting the cams back to zero and seeing if it makes any difference?

i had a very similar setup to you appart from using -5's and was making over 300kw @ 17psi

the std intercooler is fine for 350kw and i'm still using std airbox at 365rwkw

youre exhaust sounds to be adequate enough for that power, not too sure about the xforce dumps? i have never used them so can't coment on them?

i would do the following:

set cams back to zero and test

check all piping for leaks

comp test the motor.

hopefully that'll give you a reason why such a low figure

When the CAT was dropped, did that mean the entire exhaust was dropped when the run was done?

Ie - Front pipe ONLY connected?

Agree with the others though, check the cam gears belt etc. Most instances of stock-ish cars not making power is when cam gears are installed and they are out, or incorrectly set etc.

Hmm thanks for the input guys. Can only hope its not to do with compression :-/

The guys yesterday checked the cam gears and and said the 8 degree inlet and 4 degree exhaust isn't out of the ordinary so kinda eliminated that. Will see how a compression test turns out I guess. Otherwise its got me beat

Out of the ordinary and not being set right are often two different things.

Not saying they have got it wrong, but too often people have "double checked", only to take it for a second opinion and bam - in 30mins it's fixed with it being checked again.

Hmm true. Getting compression test done asap anyway to get piece of mind or save going all the way back to Sydney for nothing. If compression test comes back ok then I guess its a matter of dropping it off to a workshop with a lot of experience with them to eliminate possibilities. More f!$king money lol. And no doubt I'm gonna be up for a third tune cost too

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • Hey all,   I’ve got an RB25 with a trigger kit that includes a crank wheel, and I’ve hit a wall trying to sort a timing belt tracking issue. The belt either rides right on the edge of the cam/crank pulleys or walks slightly forward once the engine starts. It tracks okay-ish for a moment, then creeps right to the edge—and honestly, it’s stressing me out.   I’ve spent hours removing and reinstalling the belt, double-checking everything:   Tensioner setup is good, checked multiple times Idler pulley and washers are all in the correct places Followed the RB25 timing procedure step-by-step     The only thing I changed was the rear crank washer—I swapped the OEM one for a Neato version, and it made things worse. The belt now sits even more forward than before. I’m beginning to think the crank trigger wheel itself (from the trigger kit) is the issue—poor design or slightly off dimensions.   What’s strange is that with the previous belt setup, it actually ran fine for a couple of years—around 4,000 to 5,000 miles, even with hard driving and high RPMs. But even then, the belt was always riding right on the edge, and I know that’s not ideal or safe long term.   At this point, I’m debating whether to:   Machine a few mm off the crank trigger wheel to bring it back in line, or Replace it entirely with a better-designed unit     Only thing is, I already have the Cherry Hall sensors, bracket, etc.—I just want to replace the wheel only, not the entire kit. Anyone know a brand or supplier that sells just the crank trigger wheel on its own?   Would really appreciate any feedback—especially from anyone who’s run into this exact issue and found a reliable fix.   Thanks in advance.
    • Hi...a little refresh. Is Nistune gonna be enough to run BoV? Or do i need some proper ECU? 
    • Yep that's pretty much what I want to see. Racecars that look and sound like the Group A but with newer tech underneath to make them faster and safer. I'm sure there's enough VK-to-VN commodore, E30 BMWs and Foxbody mustangs shells around to make up a decent number of cars with hopefully a couple of sierras, rx7 and R31s in there too. 
    • Contact Jessestreeter.com/Skevas Racing/JustJap for a new r34 rb gearbox or go a cd00# conversion. No point playing with unknown condition gearboxes.
    • Such a shame places like Amaroo Park have been redeveloped, smaller tracks always make for good racing. Cheers for sharing @PranK there's some good Lakeside video's too. Its so hard with older the cars as parts are so rare and everything was made for a particular chassis at that point in time. Even the V8 Supercar Blueprint era cars are all different between each chassis within a team as they learnt things and made improvements. The COTF cars between each Chassis builder is different too especially motor/oil systems/intakes. The Group A stuff is worth so much too especially chassis with good history. The only way to do it would be composite panels and similar engine drivelines to the original cars. Ford sierra running Focus RS driveline, Commodore running a short stroke LS/LT or a Falcon with coyote and a H Pattern dog box. Could use a standard ecu across all models with a Torque Map and DBW for parity which is not even used in Supercars currently. Hell a TCM is almost a full chassis car these days and the suspension is not even close to standard style in the front running cars.  
×
×
  • Create New...