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M35 Boost Increase Findings

BoostdR
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BoostdR Mentor

BoostdR

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I monitored my std boost and found it spikes to 16psi then drops to 10psi. I have raised it up and it now peaks @ 20psi and drops to 15psi. I did hit boost cut this morning in the cold so have dropped it a little. I have seen some dyno read outs and am suprised to see the boost spike is common. I am wondering if the standard bleed solenoid is causing the erratic curve. It may be the normal setup and it does feel great coming up on boost but feels boring up in the rev range. Has anyone else experienced the same?

My Trans is also letting me know its not happy with the extra power as it groans when changing from 1st to 2nd. I will get the filter changed and check it has the correct fluid...Is the a common fault??

Other mods are only a catless front pipe and filter.

Matt

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scotty nm35 Grand Master

scotty nm35

Posted
Posted

The trans issue will be wrong fluid from compliance most probably.

The boost issue? You will have one soon if you go down that path. The ceramic wheel will not handle it. You are looking at big bucks for a rebuild due to the labor involved. The drop off is due to the tiny turbine size more than anything, just be happy with the huge midrange right where you want it. :)

Bis-e Bee Mentor

Bis-e Bee

Posted
Posted

or go a high-flow rebuild...

one of these days I will get a gcg high-flow, at the moment my turbo (touch wood) seems to be fine, i'm close to the mystical 100,000km's though so anything can happen i spose.

when it goes, it needs to be replaced, so i don't know if that would be a good or a bad thing.... wait for it, probably will happen now lol

BoostdR Mentor

BoostdR

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Posted

I am also under the impression the compliance fluid is not the Nissan Matic J that should be in it. I have been very careful and only pushed it enough to hear the noise a few times. I will change the fluid and check the filter before leaning on her again. I will let you know how I go. I have found a boost level where I am not hitting boost cut. My next plan is to stick my wideband on and find out what mix of E85 gets me a nice AFR. I can report the M35 will run on 100% E85 with some loss in power off boost(to lean) and acceptable on(still abit lean) My Stag loves anywhere between 30-45% E85. It does make a noticable increase in power. Currently It turns all 4 tyres coming on boost in first. Again I'll let you guys know what I find on the AFR side and what fuel combo at my boost level 13-14psi(up top) gives the best AFR. I expect 100% BP98 would have her running rich(in the low 11:1)

Matt

scotty nm35 Grand Master

scotty nm35

Posted
Posted
I am also under the impression the compliance fluid is not the Nissan Matic J that should be in it. I have been very careful and only pushed it enough to hear the noise a few times. I will change the fluid and check the filter before leaning on her again. I will let you know how I go. I have found a boost level where I am not hitting boost cut. My next plan is to stick my wideband on and find out what mix of E85 gets me a nice AFR. I can report the M35 will run on 100% E85 with some loss in power off boost(to lean) and acceptable on(still abit lean) My Stag loves anywhere between 30-45% E85. It does make a noticable increase in power. Currently It turns all 4 tyres coming on boost in first. Again I'll let you guys know what I find on the AFR side and what fuel combo at my boost level 13-14psi(up top) gives the best AFR. I expect 100% BP98 would have her running rich(in the low 11:1)

Matt

Definitely fit a wideband before you try that again... The factory ecu is good at remapping for different fuels but not THAT good.

If you fitted 20 percent larger injectors and a better (read not plastic impeller) fuel pump, then played around with the fuel pressure with an adjustable reg, you could get the afr's close enough. I would still rather the logging and ease of a p1ggyback of course.

I found the problem to be the timing is all over the place. E85 requires fairly advanced timing due to the slow burn properties, especially off boost. At idle the factory ecu drops the timing to -1 for some reason causing the ethanol to burn in the exhaust not the cylinder, this makes cold starting a bitch and it is really noisy. That is the reason for the drone at 2000 revs too I think. I have been playing with the low rev timing to try and pep up the soggy takeoff but the Emanage can only add or subtract, not set, and the timing varies wildly in that area.

The noise you hear, does it sound like there's gravel in the box? I have a noise like that which I think is the transfer case struggling with the torque. After 100 power runs on the dyno and lots of fun on the street I have come to the conclusion it is slip in the transfer clutch plates but it hasn't failed yet... I wonder if the pressure to the plates can be increased?

iamhe77 Grand Master

iamhe77

Posted
Posted
I am also under the impression the compliance fluid is not the Nissan Matic J that should be in it. I have been very careful and only pushed it enough to hear the noise a few times. I will change the fluid and check the filter before leaning on her again. I will let you know how I go. I have found a boost level where I am not hitting boost cut. My next plan is to stick my wideband on and find out what mix of E85 gets me a nice AFR. I can report the M35 will run on 100% E85 with some loss in power off boost(to lean) and acceptable on(still abit lean) My Stag loves anywhere between 30-45% E85. It does make a noticable increase in power. Currently It turns all 4 tyres coming on boost in first. Again I'll let you guys know what I find on the AFR side and what fuel combo at my boost level 13-14psi(up top) gives the best AFR. I expect 100% BP98 would have her running rich(in the low 11:1)

Matt

Don't waste your time looking for a trans filter, there isn't one. You can flush out what is in there and replace i with either Nissan Matic J or Nulon 100% Synthetic ATF.

I have found that the trans is very smooth and quiet with the Nulon stuff in there (even more so than with the Matic J).

Out of curiosity regarding using E85, what ECU are you running (if any)? Have you changed out your fuel pump for something without plastic internals? What injectors are you running?

(sorry for all the questions :thumbsup: )

  • 5 months later...
wailiam Enthusiast

wailiam

Posted
Posted
I monitored my std boost and found it spikes to 16psi then drops to 10psi. I have raised it up and it now peaks @ 20psi and drops to 15psi. I did hit boost cut this morning in the cold so have dropped it a little. I have seen some dyno read outs and am suprised to see the boost spike is common. I am wondering if the standard bleed solenoid is causing the erratic curve. It may be the normal setup and it does feel great coming up on boost but feels boring up in the rev range. Has anyone else experienced the same?

My Trans is also letting me know its not happy with the extra power as it groans when changing from 1st to 2nd. I will get the filter changed and check it has the correct fluid...Is the a common fault??

Other mods are only a catless front pipe and filter.

Matt

I have the same problem with groans in between gear changes when under high load. Redlining doesnt cause it because the torque has dropped off by then. Can it be fixed? I had the trans fluid changed by nissan and it made no difference.

Turning on the A/C helps due to the loss of power.

Jetwreck Grand Master

Jetwreck

Posted
Posted
I have the same problem with groans in between gear changes when under high load. Redlining doesnt cause it because the torque has dropped off by then. Can it be fixed? I had the trans fluid changed by nissan and it made no difference.

Turning on the A/C helps due to the loss of power.

may not be the gearbox....the groaning could be the turbo!......you still have the standard turbo? how many km's?

PetroDola Proficient

PetroDola

Posted
Posted (edited)

i noticed spiking on a totally different car after a GT25 BB highflo for a corolla .. did exactly the same thing.

spiked to 18 then flatened out at 10-12ish.

I worked out its bleeding air from the boost T and required cable ties on the boost t's actuator end as over 12psi it would vent through the hose to atmosphere on the connections.

just something to check i guess.

no boost cut or detonation either.

but most likely unrelated.. just read stock turbo

Edited by PetroDola
KiwiRS4T Grand Master

KiwiRS4T

Posted
Posted

Transfer box problems seem to be rare even at high power levels.

For an expensive ecu solution if some one were keen and rich enough you could use a Link or a Vipec wire in version as a second ecu and control all the engine management functions with that and leave the stock ecu to run the auto.

wailiam Enthusiast

wailiam

Posted
Posted
may not be the gearbox....the groaning could be the turbo!......you still have the standard turbo? how many km's?

Could be but I've only done 48000ks!

Seems a bit early to be replacing the turbo... thinking of upgrading to a series 2 with the 3.5 L NA engine...

I dont wanna put in a high flow that will be laggier than stock and replacing the turbo with a standard one seem like a waste of $ with very little to be gained.

PetroDola Proficient

PetroDola

Posted
Posted (edited)
Could be but I've only done 48000ks!

Seems a bit early to be replacing the turbo... thinking of upgrading to a series 2 with the 3.5 L NA engine...

I dont wanna put in a high flow that will be laggier than stock and replacing the turbo with a standard one seem like a waste of $ with very little to be gained.

it wont be laggier than stock by a long mile.. unless you go too big of an exducer wheel on the exhaust side of the turbo.

im going to go 2860rs gtbb hiflow for my spare turbo thats coming and see how it works out.

if it turns out too small.. ill build the original up to spec for a 30/71

Edited by PetroDola

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