Tuned R34Gtt

[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!

[Sinista32]

Sounds like a great experience, these are rare.

Good to see your post, the outcome and the pat on the back to DVS JEZ.

So is this a shop I can take my 34 too? PM contact details please

[DVS JEZ]

Glad your happy Ron. Your car definately feels alot stronger than the 186kw it made, goes to show that you can go from 132kw to 186 kw on the same boost just with a tune, your car was low to start with so that shows there is an issue somewhere to start with. the power drops off from 5000rpm more than i would have liked. but there was a fair bit of tyre loss showing on the dyno.

couldnt see the intake pipe sucking shut but the syptoms are similar to that.

with the AFR on the road testing, thats got me stumped. your car is the only one i have ever had lean out due to what we suspect is air going into the exhaust tip and giving a lean reading.

next time when i fit your 3 inch dump pipe i will weld in a 02 sensor bung for increased accuracy.

enjoy your car and we will push some bigger numbers when you get a bigger turbo

[Deano 1]

youve done it again, mr dvs nice work!!!!

[GTScotT]

What ECU does Mr DVS recommend for a 1JZ motor and does he tune these motors?

I like the feedback!

[rondofj]

+++1 for DVS Jez, he is a really top bloke, not only in tuning but other mechanical work too, hopefully we will see a shift away from those overcharging 'give you power numbers only' workshops that 'tune' your car...

Anyways I am also happy to now know that my pump, fuel reg and leaning out is not the issue now. As for the afrs leaning out, my exhaust has a perforated exhaust tip where the sensor sits - it could be this messing with the airflow and blowing more air into the afr sensor.

But 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 as me - 358RWKW?? And 'WASN'T ME' (black R34GTT) also with a RB25NEO makes almost the same 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.

BUT it feels good to know I have that much torque..hurraah! haha..

[rondofj]

Jez, can you ask the dyno shop guy to email me a chart showing the power and torque vs RPM not engine/wheel speed which is what I got. I would like to see what power and torque I made at what rpm which is far more important..

cheers

Glad your happy Ron. Your car definately feels alot stronger than the 186kw it made, goes to show that you can go from 132kw to 186 kw on the same boost just with a tune, your car was low to start with so that shows there is an issue somewhere to start with. the power drops off from 5000rpm more than i would have liked. but there was a fair bit of tyre loss showing on the dyno.

couldnt see the intake pipe sucking shut but the syptoms are similar to that.

with the AFR on the road testing, thats got me stumped. your car is the only one i have ever had lean out due to what we suspect is air going into the exhaust tip and giving a lean reading.

next time when i fit your 3 inch dump pipe i will weld in a 02 sensor bung for increased accuracy.

enjoy your car and we will push some bigger numbers when you get a bigger turbo

[scotty nm35]

with the AFR on the road testing, thats got me stumped. your car is the only one i have ever had lean out due to what we suspect is air going into the exhaust tip and giving a lean reading.

next time when i fit your 3 inch dump pipe i will weld in a 02 sensor bung for increased accuracy.

Any chance theres a leak in the exhaust somewhere closer to the turbo? I have a small leak right at the dump atm causing air to be sucked in, venturi style. The wideband fluctuates badly at certain revs now and I guess my last tune was out a bit because of it.

[KiwiRS4T]

Like you say numbers aren't everything - if it drives better that's a good result.

[SiR_RB]

+1 for Jez, very helpful, top bloke ! Always helps me with any problems I may have with the car

[DVS JEZ]

Any chance theres a leak in the exhaust somewhere closer to the turbo? I have a small leak right at the dump atm causing air to be sucked in, venturi style. The wideband fluctuates badly at certain revs now and I guess my last tune was out a bit because of it.

it would be more likely if we had issues on the dyno too which we didnt, after the dyno we did a check on the road and the AFRs were way to lean, tried my innovate and the shops innovate with the same lean result. then we put in a longer venturi sensor adaptor that sits further into the tailpipe which showed as tuned results 11.7-11.8 on song.

[Dose Pipe Sutututu]

awesome, good to see it wasn't any fuel related issue

at least you now have a spare fuel reg LOL

I prefer to mount my WB O2 on the dump pipe, less chances of sucking in more and more accurate, as post cat the A/F is not 100% accurate.

[DVS JEZ]

thats correct Johnny, always prefer to tune from dump pipe too, unfortunately not everyone wants a bung welded into there exhaust.

the fuel reg was different unfortunately, has the outlet pipe bent at 90 degree's, was the one you gave Ron from a neo motor?

[Dose Pipe Sutututu]

yeah it was, I got it from Dori34 when he sold me the stock injectors & rail. He told me that reg was from a R34, but I couldn't use it because it hit my R33 plenum

[rondofj]

Thanks Johnny, yeah we found that the reg had a 90deg bent hose connection pipe which was modified, and were left scratching heads for a bit trying to figure out if it was the R34 one..

[rondofj]

Does anyone know why this is:

'But 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 as me - 358RWKW?? And 'WASN'T ME' (black R34GTT) also with a RB25NEO makes almost the same 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. '

[SiR_RB]

Anyone got a good rb26 fuel reg they wanna sell me ? Hehe

[DVS JEZ]

Get a new nismo reg. Adjustable so we can just set it at stock base pressure. Think theyre around 150$. Have u asked nissan how much for a new one?

[rob82]

Does anyone know why this is:

'But 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 as me - 358RWKW?? And 'WASN'T ME' (black R34GTT) also with a RB25NEO makes almost the same 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. '

Usually because of dodgy dyno operators.

[Dose Pipe Sutututu]

tractive force, torque to move the rollers vs. engine torque VERY different.