Jump to content
SAU Community

Recommended Posts

Hey Everyone,

i thought i would see what everyone else thinks on this issue with my GTR, since its the weekend all the shops are closed so i cant take it anywhere until next week :(

This is the problem i am facing, since last night my car hasn't been boosting properly (going to 0.4 bar when it normally goes to 0.8) my exhaust note inst as loud as it normally is when your pressing the accelerator. It all happened when i hit max boost and high revs (7000rpm) it just cut out on me, boost was down and exhaust note was very different all of a sudden. The engine still revs but its very doughy and you can hear the turbo spool a little but not as much. could it be a possible blocked cat? not sure what else it can be, i look at the hoses on the intake and BOV and all seem to be fine.

Any ideas where i could take the car on the gold coast if its not a cat issue?

Link to comment
https://www.sau.com.au/forums/topic/361085-possible-cat-blocked-on-my-r34-gtr/
Share on other sites

my car is still making power (0.4 BAR boost) but the car is just struggling to get there and the exhaust is very quiet, if it was a turbo wouldnt it make no boost?

Edited by K33P UP

also another thing to add is that both inlet pipes are sucking and the main hose to the plenum is making a fair bit of flow. so the motor is getting air.

if it was the exhaust wheel in the turbo's the intake should be producing flow correct? also there doesnt seem to be any oil usage just alot of fuel dumping out

Edited by K33P UP

my car is still making power (0.4 BAR boost) but the car is just struggling to get there and the exhaust is very quiet, if it was a turbo wouldnt it make no boost?

Well if you've only blown one turbo then the other one will still be boosting.

Check cat first, quick and easy.

Well if you've only blown one turbo then the other one will still be boosting.

The second turbo will spin, but wont make any boost as the air blows back through the compressor of the dead turbo.... So since OP is getting boost, its not an exploded turbine.

Load up the car on a dyno or going up a hill and see if the cat starts to glow red. If so its a blocked cat, had same issue with mine when it was stock

lol wouldnt it be much easier and safer just to drop the cat and look? if a turbo is half rooted (also being ceramic) the last thing u wanna do is spin the engine at 7000+ rpm

lol wouldnt it be much easier and safer just to drop the cat and look? if a turbo is half rooted (also being ceramic) the last thing u wanna do is spin the engine at 7000+ rpm

Probably not, loading up meaning 2500-3000rpm up a hill in 4th, so its under load, if the cats blocked doing this for about 10-15 seconds will make it glow, seems easier than jacking the car up, and taking the cat out...

Probably not, loading up meaning 2500-3000rpm up a hill in 4th, so its under load, if the cats blocked doing this for about 10-15 seconds will make it glow, seems easier than jacking the car up, and taking the cat out...

each to their own, im just saying if theres any chance it could be the turbo i wouldn't be boosting it. when i did my standard turbo the bearings went causing the impeller to spin out of balance (very slightly) causing it to just nip the sides of the housing which chipped tiny bits of the blades off, mind you as soon as it blew i didn't boost it at all on the drive home but if i did im sure it would have just smashed apart the impeller wheel completely and if it were a GTR theres a good chance it will go through the intake side.

yep it was definetly the a blocked cat, here is a picture of what it looked like from the front. pretty impressive i must say.

post-57129-0-87488200-1303271335_thumb.jpg

so now i have a new stainless high flow 200 cel cat, the car has never run so good..... makes me think the cat has been blocked since i bought it. best $300 i have spent yet!

thanks for your advice everyone :)

Regards,

Dom

Edited by K33P UP

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

    • For once a good news  It needed to be adjusted by that one nut and it is ok  At least something was easy But thank you very much for help. But a small issue is now(gearbox) that when the car is stationary you can hear "clinking" from gearbox so some of the bearing is 100% not that happy... It goes away once you push clutch so it is 100% gearbox. Just if you know...what that bearing could be? It sounding like "spun bearing" but it is louder.
    • Yeah, that's fine**. But the numbers you came up with are just wrong. Try it for yourself. Put in any voltage from the possible range and see what result you get. You get nonsense. ** When I say "fine", I mean, it's still shit. The very simple linear formula (slope & intercept) is shit for a sensor with a non-linear response. This is the curve, from your data above. Look at the CURVE! It's only really linear between about 30 and 90 °C. And if you used only that range to define a curve, it would be great. But you would go more and more wrong as you went to higher temps. And that is why the slope & intercept found when you use 50 and 150 as the end points is so bad halfway between those points. The real curve is a long way below the linear curve which just zips straight between the end points, like this one. You could probably use the same slope and a lower intercept, to move that straight line down, and spread the error out. But you would 5-10°C off in a lot of places. You'd need to say what temperature range you really wanted to be most right - say, 100 to 130, and plop the line closest to teh real curve in that region, which would make it quite wrong down at the lower temperatures. Let me just say that HPTuners are not being realistic in only allowing for a simple linear curve. 
    • I feel I should re-iterate. The above picture is the only option available in the software and the blurb from HP Tuners I quoted earlier is the only way to add data to it and that's the description they offer as to how to figure it out. The only fields available is the blank box after (Input/ ) and the box right before = Output. Those are the only numbers that can be entered.
    • No, your formula is arse backwards. Mine is totally different to yours, and is the one I said was bang on at 50 and 150. I'll put your data into Excel (actually it already is, chart it and fit a linear fit to it, aiming to make it evenly wrong across the whole span. But not now. Other things to do first.
    • God damnit. The only option I actually have in the software is the one that is screenshotted. I am glad that I at least got it right... for those two points. Would it actually change anything if I chose/used 80C and 120C as the two points instead? My brain wants to imagine the formula put into HPtuners would be the same equation, otherwise none of this makes sense to me, unless: 1) The formula you put into VCM Scanner/HPTuners is always linear 2) The two points/input pairs are only arbitrary to choose (as the documentation implies) IF the actual scaling of the sensor is linear. then 3) If the scaling is not linear, the two points you choose matter a great deal, because the formula will draw a line between those two points only.
×
×
  • Create New...