Jump to content
SAU Community

Recommended Posts

when are these tuning places going to stop using yellow in there dyno printouts? it makes it so hard to find the line....

Edited by itshimdazza

Another thing to check the wastegate is to hook a stiff spring to the flapper arm and hook it to some where else so the wastegate wont open, take off the vac line and block the end, take it for a spin being very carefull not to over boost and watch the gauge, if it does the same as that graph then its not your wastegate, if it does then you have found the problem.

Edited by W0rp3D

edit, tangles response, yer i think that may be the root off my problem. as far as i know the compression is ok but i havnt tested it since i before the turbo blew a few months ago

thanks for the suggestions

bad compression will kill power but it won't stop the turbo boosting. Your power result looks healthy for that boost anyway.

Ok so now I've got 22psi on gearchanges and 20 at redline. And a possible large leak somewhere.

To help us diagnose this, what did you change to cause this effect?

This is yesterday's events.

I just went for a drive to see if disconnecting the waste gate/ try running without an air filter fixed my boost issue and something strange happened. 1st run(no waste gate lines) hit 30psi. Bad idea, pull over reconnect. 2nd run(as normal) boost drop off isn't constant only in certain gears/load points. Pull over. 3rd run(no air filter) goes as normal untin 4th gear 165/170km/h, bang, miss miss miss miss miss miss etc... Slow down, pull off highway, drives as if intercooler pipe has come off. Pull over. No pipes off. Nothing unusual. Do uturn, big skid, drive home. Possibly slightly laggy response. Still hitting 20psi

This is yesterday's events.

I just went for a drive to see if disconnecting the waste gate/ try running without an air filter fixed my boost issue and something strange happened. 1st run(no waste gate lines) hit 30psi. Bad idea, pull over reconnect. 2nd run(as normal) boost drop off isn't constant only in certain gears/load points. Pull over. 3rd run(no air filter) goes as normal untin 4th gear 165/170km/h, bang, miss miss miss miss miss miss etc... Slow down, pull off highway, drives as if intercooler pipe has come off. Pull over. No pipes off. Nothing unusual. Do uturn, big skid, drive home. Possibly slightly laggy response. Still hitting 20psi

It appears the air box and pannel filter is affecting your boost level. Air required can not flow through that tinny hole on the lid. You obviously had more boost with perfromance gain when the lid and filter is out.

Drop actuator pre-load to normal level, Get a big pod filter, get rid of that air box, or remove the panel filter (Panel filter will also restrict flow) and drill few wholes on the lid. Once done you should get the normal amount of boost and power level, that will also drop your inlet and exhaust gas temperture.

airbox.jpg

You really shouldn't be revving out 4th at 20psi without it actually being tuned at that! could very easily be running lean or detonating and hello dead motor!

I had the wrong intake gasket on the middle of the two halves of my intake plenum, made the boost drop from 19psi to 15psi, wasn't until it started making a noise that I realised, even then it was a huge pain to figure out what it was.

Have you pressure tested the intake yet?

Edited by Rolls

It appears the air box and pannel filter is affecting your boost level. Air required can not flow through that tinny hole on the lid. You obviously had more boost with perfromance gain when the lid and filter is out.

Drop actuator pre-load to normal level, Get a big pod filter, get rid of that air box, or remove the panel filter (Panel filter will also restrict flow) and drill few wholes on the lid. Once done you should get the normal amount of boost and power level, that will also drop your inlet and exhaust gas temperture.

airbox.jpg

I doubt that the airbox and panel filter is the problem. I have made 260awkw with the stock box, snorkel and a pipercross filter. Would be interested to see once the boost problem is solved whether putting the airbox (without all the holes bore in it!) back on kills the power.

I lost 11kws on a 260rwkws setup with 2 holes cut on the side of the lid, So it was removed straight way. How ever I've never thought any one would run stock air box with hard intake pipe.

Lillcrash is trying to gain 3psi up top and it appeared to have some effects on boost level. So keen to see if that did make a difference.

We don't get much of a choice down here with the one intake mod rule. Most of the intakes I make are for stock airboxes to keep the engine bay looking standard.

Police in Melbourne seem to hate pod filters with a passion and will treat you like a criminal even though pods do exactly the same job. I don't understand it, they should be checking your cat isn't collapsed or your o2 sensor is oscillating correctly if they really cared about your emissions.

You really shouldn't be revving out 4th at 20psi without it actually being tuned at that! could very easily be running lean or detonating and hello dead motor!

I had the wrong intake gasket on the middle of the two halves of my intake plenum, made the boost drop from 19psi to 15psi, wasn't until it started making a noise that I realised, even then it was a huge pain to figure out what it was.

Have you pressure tested the intake yet?

It's only occasionally making 20psi. But I deffinately need a new tune. It's terrible to drive.

I have a horrible noise at high rpm. I'm making a 3 inch adapter with an air fitting at the moment so I can test it.

Edited by lilcrash

It isn't it just being bad to drive, you could very easily put a hole in a piston and destroy the entire motor if it is running lean and detonating. All of this playing and testing should be done with a dyno and a wideband so you can see what is going on. If you don't have this find a tuner that can do it for you otherwise this could become a very expensive exercise very quickly.

Get the air leak sorted and then find someone who can do everything else for you.

Edited by Rolls

The noise you get from leaking intake is horrendous. Its even worse when you hear a leak on the exhaust side. Broken gasket between the turbo and the dump created the weirdest screech/squeal I have EVER heard.

Also how do you guys test for pressure drop? On the dyno we hooked up the boost gauge on the dyno between the manifold and fuel pressure regulator. Is this giving us the boost level at the manifold? Both my boost gauges are connected DIRECTLY to my intake manifold(one is the boost controller, the other just a boost gauge running off the BOV vacuum feed line). Should I fit one on the other side, say on the hot side of the turbo but not to the TB to monitor boost on both sides? I'm getting full boost anyhow(19psi at all gauges).

Edited by SargeRX8

I used a manometer to measure my pressure drop. There is really no need to have 2 gauges reading two different pressures, the hot side will always read slightly higher than the cool side.

It isn't it just being bad to drive, you could very easily put a hole in a piston and destroy the entire motor if it is running lean and detonating. All of this playing and testing should be done with a dyno and a wideband so you can see what is going on. If you don't have this find a tuner that can do it for you otherwise this could become a very expensive exercise very quickly.

Get the air leak sorted and then find someone who can do everything else for you.

Nothing has changed since the tune, that's why I'm not worried. If Efi performance is half as good as everyone thinks then I don't have anything to worry about. The horrendous noise was there before and (im assuming) during the tune so that's not an issue until I fix it. $69 for the gasket at Nissan and there is none in Australia.

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

    • I'm back from the dyno - again! I went looking for someone who knew LS's and had a roller dyno, to see how it shaped up compared to everything else and confirm the powerband really is peaking where Mr Mamo says it should. TLDR: The dyno result I got this time definitely had the shape of how it feels on the road and finally 'makes sense'. Also we had a bit more time to play with timing on the dyno, it turns out the common practice in LS is to lower the timing around peak torque and restore it to max after. So given a car was on the dyno and mostly dialled in already, it was time for tweaking. Luis at APS is definitely knowledgable when it came to this and had overlays ready to go and was happy to share. If you map out your cylinder airmass you start seeing graphs that look a LOT like the engine's torque curve. The good thing also is if you map out your timing curve when you're avoiding knock... this curve very much looks like the inverse of the airmass curve. The result? Well it's another 10.7kw/14hp kw from where I drove it in at. Pretty much everywhere, too. As to how much this car actually makes in Hub Dyno numbers, American Dyno numbers, or Mainline dyno numbers, I say I don't know and it's gone up ~25kw since I started tinkering lol. It IS interesting how the shorter ratio gears I have aren't scaled right on this dyno - 6840RPM is 199KMH, not 175KMH. I have also seen other printouts here with cars with less mods at much higher "kmh" for their RPM due Commodores having 3.45's or longer (!) rear diff ratios maxing out 4th gear which is the 1:1 gear on the T56. Does this matter? No, not really. The real answer is go to the strip and see what it traps, but: I guess I should have gone last Sunday...
    • 310mm rotors will be avilable from Australia, Japan, and probably a few other places. Nothing for the front can be put on the back.
    • The filter only filters down to a specific size. Add to that, the filter is AFTER the pump. So it means everything starts breaking your pump even if its being filtered out.
    • Just like in being 14mm too small (296mm) makes it not fit, being 14mm too big (324mm) it also won't fit. You want to find the correct rotor.
    • @GTSBoy Ok so that was the shops problem...they showed R33 rotors on R34 page and i did not know 296 do not fit(and are for R33) Yes i bought "kit" with rotors and pads. Pads are ok(i have GTT calipers front and rear). They have some 324mm but no 310mm. So i dont know if they would fit. I have 17inch LMGT4s So another question. Can i fit those in the rear or they are just "too" big for that?
×
×
  • Create New...