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Dyno Day : 4th July 2009

BLISTC
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BLISTC Experienced

BLISTC

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well it made more power than a stock 350z, but not with a bad issue....

my car seems to be leaning out at the lower and higher rpm. the midrange seems to be ok. i will try scan the dyno graph. 1st run made 162kw 2nd run made 158kw but leaning out even worse than before.

what could be the cause of this? the dyno tuner said that most possibly the fuel pump may be on the way out.

i have recently just installed the plenum spacer, the cf intake and the grounding kit. i did an ecu reset as well.

what else could contribute to very bad AFR? an air leak somewhere?

-mark

V35_Paul Veteran

V35_Paul

Posted
Posted
well it made more power than a stock 350z, but not with a bad issue....

my car seems to be leaning out at the lower and higher rpm. the midrange seems to be ok. i will try scan the dyno graph. 1st run made 162kw 2nd run made 158kw but leaning out even worse than before.

what could be the cause of this? the dyno tuner said that most possibly the fuel pump may be on the way out.

i have recently just installed the plenum spacer, the cf intake and the grounding kit. i did an ecu reset as well.

what else could contribute to very bad AFR? an air leak somewhere?

-mark

Make sure your plemun blots are tight and use some lock tight on them. Double check your intake for leaks. Even if you reset your ECU give your car some time to adjust to your mods. A few hours running time and not just idle but go drag some XR6's and a few SS's :teehee: . But if you have had your mods for a few weeks then there sould be no problems with ECU.

Touge Kyousou Experienced

Touge Kyousou

Posted
Posted

Hrmm yeah check round the intake and make sure nothing is pinching from the plenum spacer installation (eg. the oil fill rubber grommet/neck thing).

But you said it felt faster than before install ?

My car runs a tad (13's) lean as well. I'll try and scan sometime if you want but overall it's quite good.

BLISTC Experienced

BLISTC

Posted
  • Author
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yeh i did use the loctite on the bolts and the plenum spacer install seems to be A-Ok. all tourqed up to specific settings.

The thing is i dont think the pelnum spacer will cause a problem with AFR as the air is being sucked in, not let out hence the pressure is the othere way

yes when i did the install i made sure the oil filler thing is not pinching when i installed it.

andy65b Veteran

andy65b

Posted
Posted

Have you changed you PCV on the right bank of the motor.

I have been told that these are ofter replaced on the V35. The service manual recommends at each major service which on these would be around the 80k mark.

If it is clogged up or faulty it can be letting in air into the manifold after the butterfly.

Cheers

Andy

Touge Kyousou Experienced

Touge Kyousou

Posted
Posted

Good news, glad to see nothing is wrong with the car! How'd you determine the car was fine ?

Do you know who did the dyno run at ISMR? I've been there for a few years and never had any issues, including dyno runs.. not much required for a power run, just set the parameters, then floor it!

The first time my V went on IS' dyno, it only posted 130kw atw.. it's fixed now though :thumbsup:

BLISTC Experienced

BLISTC

Posted
  • Author
Posted (edited)

have u got the dyno graph for that?

here is my graphs:

Old - car stock:

V35%20Dyno.jpg

Recent - after mods:

3710641540_61b5045045.jpg

and this is what the guys over on the us forums had to say:

OK, what ever that is, its not real. There is no way your car would run at that AFR. Its way too high and way too erratic.

What ever it is, its not your car. It would run like complete garbage (or not at all) if it truely was at 19+

At this point I'm thinking it was the dyno AF sensor or something similar in nature.

and ideas guys? also on the first run it made 162.8rwkw though..... the 2nd run made even less????

Edited by BLISTC
Touge Kyousou Experienced

Touge Kyousou

Posted
Posted

o.0 !!

Omg what on earth..

Yeah what the US guys said, if your AFR was really up there, you should be pinging and the motor probably would've said byebye awhile ago. Maybe it is the AFR sensor on the dyno like you said. However, did you check to see if any of the cars run after you had ok AFR readouts ? That should give you some clues..

Your stock afr readout is about right. Pretty much the same mapping my car is running but with the mods in my list (just simple breather stuff).

Even with everything you've heard/read from forums and mechs...if my car was posting an AFR like that...i'd take it to another dyno just to make sure everything was actually ok. GL.

danielb Newbie

danielb

Posted
Posted (edited)

hey mark

it's daniel here with the blue 350z at the ISMR day.

the reading is due to the sensor they place in the exhaust not being placed in all the way, hence the strange AFR readings. It was happening with quite a few cars and on a few occasions i saw them remove the sensor and Indy himself placed it back in to get a proper reading. Dyno KW readout itself however shouldn't be affected by that. The ISMR dyno is renowned for reading a fair bit lower than other dynos around, and i wouldnt really bother comparing graphs from other places together!

Edited by danielb
BLISTC Experienced

BLISTC

Posted
  • Author
Posted

hey daniel

thanks for the heads up

thats good to know because i got the fuel pump checked out today and the fuel filter and it is all in pristine condition.

its all working fine which is a relief. yeh considering your car is stock and mine isnt, and made a few extra kw with the mods installed it is about right. i heard people say the ISMR dyno was reading up to 20KW lower than what it used to read.

Touge Kyousou Experienced

Touge Kyousou

Posted
Posted

Glad you got to the bottom of it all. Yeah ISMR's dyno is a conservative reader.

Interesting on their afr sensor not working properly..i only dyno'd there not long before the dyno day you guys went to but my afr readout seems to be ok. On the printout below, you can see my 130kw run and my after run.

gallery_56118_3384_23685.jpg

Touge Kyousou Experienced

Touge Kyousou

Posted
Posted

130 was when i first bought the car and it had a problem. 170 was only a few weeks ago. Indy simply printed an older run on the recent printout for comparison. As you can see, the afr's are quite decent i think.

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