Turbo Flange Red Hot

[CerebralAilment]

So, I decided to do a 2.5" exhaust on my 1989 Volvo 744T.

It sorta makes a nice high pitch ringing noise now when you start it (wondering if my bearing is going or if its the alternator). Last night i drove it home with no O2 sensor because we forgot to swap them over. After we put the 2.5" pipe on with a thrush turbo exhaust the car seemed to sound like it was miss firing.. had way less power (than open down pipe) and when I plugged the O2 sensor in didn't seem to do anything. I unplugged it nothing happend. Wasn't sure if the car had a 'limp mode' or something that its set on right now? I thought at first maybe we might have unplugged one of the plug wires so I went through and unplugged them all one at a time and each one made a difference..

The waste gate moves open & close - but doesn't appear to work. I'm thinking the diaphragm is messed up? I bent it too one accident messing with it on the vice

on the way home after some heavy acceleration when I pulled into the driveway I noticed that the flange the turbo bolts to was glowing red hot (is that normal?)

Here's a video of the ping/squeel noise I hear:


here's the exhaust.



Uploaded with ImageShack.us



Uploaded with ImageShack.us

I went with just straight pipe but it was still very loud - so i added the thrush turbo & it seems to quiet it up a bit.

[Lando]

Originally Posted by CerebralAilment

So, I decided to do a 2.5" exhaust on my 1989 Volvo 744T.

It sorta makes a nice high pitch ringing noise now when you start it (wondering if my bearing is going or if its the alternator). Last night i drove it home with no O2 sensor because we forgot to swap them over. After we put the 2.5" pipe on with a thrush turbo exhaust the car seemed to sound like it was miss firing.. had way less power (than open down pipe) and when I plugged the O2 sensor in didn't seem to do anything. I unplugged it nothing happend. Wasn't sure if the car had a 'limp mode' or something that its set on right now? I thought at first maybe we might have unplugged one of the plug wires so I went through and unplugged them all one at a time and each one made a difference..

The waste gate moves open & close - but doesn't appear to work. I'm thinking the diaphragm is messed up? I bent it too one accident messing with it on the vice

on the way home after some heavy acceleration when I pulled into the driveway I noticed that the flange the turbo bolts to was glowing red hot (is that normal?)

Here's a video of the ping/squeel noise I hear:


here's the exhaust.



Uploaded with ImageShack.us



Uploaded with ImageShack.us

I went with just straight pipe but it was still very loud - so i added the thrush turbo & it seems to quiet it up a bit.

The flange shouldn't be getting red hot. It means you are too lean. In your case, the condition was probably caused by driving with out the O2 sensor. I have also seen retarded ignition timing cause this.

The noise you hear on start up is probably caused by poor exhaust fitment. You probably have a section of the exhaust that is close enough to the frame, cross member, rear axle etc. that rattles when the engine starts.

[CerebralAilment]

Originally Posted by Lando

The noise you hear on start up is probably caused by poor exhaust fitment. You probably have a section of the exhaust that is close enough to the frame, cross member, rear axle etc. that rattles when the engine starts.

Nope that video was made before I touched the exhaust - sorry I should have made that clearer in the video. I'll have to put the brown tops in tomorrow & find a working O2 Sensor & get it on there.

[Group A]

Glowing is normal. Especially after long drives or spirited driving. Part of the reason your are supposed to let a turbo car idle before shutting it off.

[ghost civic]

it must have been crazy loud before...if the thursh muffler quieted it down! The thrush I had put on the 850T was stupid loud.
I would think running without an O2 (or having a bad one) would effect the power.

When my new turbo comes I will pull the exhaust system I have out and paint it...and take pics. Its 2.5 turbo back with a single muffler. Not loud, but has a nice tone.
Wish I had a shop and some of the tools you have!

[JohnLane]

You've got......... Ready for it? A *gasp! .......... Slipping alternator belt!! It is noisy for it. Common. I like to take a little wire brushy to the belt to deglaze the belt as it idles.... This will often help if the belt is properly tensioned and not worn-out junk.

Exhaust should be noisy now! Glowing exhaust....... Have a peek at it at night after you've been a savage.... pull over and let it idle.... take a quick peek..... That ish is pretty damned hot!

OP no exhaust Kittah.....

[CerebralAilment]

Originally Posted by JohnLane

You've got......... Ready for it? A *gasp! .......... Slipping alternator belt!! It is noisy for it. Common. I like to take a little wire brushy to the belt to deglaze the belt as it idles.... This will often help if the belt is properly tensioned and not worn-out junk.

Exhaust should be noisy now! Glowing exhaust....... Have a peek at it at night after you've been a savage.... pull over and let it idle.... take a quick peek..... That ish is pretty damned hot!

OP no exhaust Kittah.....

I just replaced the belts like 2 weeks ago - its not that. The tension is correct - but before I replaced the belt I did happen to get by by rigging up a smaller belt than I should have - which in turn may have warn the bearing or w/e in the alternator - if its nice out tomorrow I will take off the alt belt quick and see if that's the squeal problem. I hope it is, but it sounds like its coming from the engine.

I'm not happy with the power loss from the 2.5" exhaust as opposed to open down pipe or w/e is causing the power loss it sucks.

Ghost - that's not my shop its one of my buddy's who works for me. I thought maybe I put the thrush turbo on backwards or something but I read online there reversible so I guess not. It does say 'classic sound modern power' so maybe I have a different one than you did?

[JohnLane]

Often you will get to deglaze the pulleys. sandpaper. Careful with your fingers!

[CerebralAilment]

Originally Posted by JohnLane

Often you will get to deglaze the pulleys. sandpaper. Careful with your fingers!

I could see the pulley's needing to be deglazed - they had a power steering belt that was slipping for 3 months from p/o.

No kitty for me - its track car now =D

[ziddey]

Watch your o2 sensor output with a voltmeter. It sounds like you are running lean if your exhaust is heating up that much. Severely retarded ignition timing would do that too, but I don't think that should happen normally with EZK. Nice to see the work you're doing to it, but from your other threads, it seems like you've got a lot of "stage 0" work to do before getting into mods. Would be money better spent.

I'm assuming you don't somehow have your exhaust flow obstructed with the new exhaust.

Were you riding the turbo hard before you noticed it glowing? Or was the turbo fine, just the exhaust manifold glowing? You able to boost? Wastegate able to open?

[CerebralAilment]

waste gate does not open - it spikes to about 12 psi now with the exhaust on & settles at 10psi.. open down pipe it would go straight over 15psi & hit fuel cut. (knock knock its the kool-aid man!!)

I was riding it hard alright - very hard. I let the car idle till the glow went away when I got back. I'm thinking the exhaust might be restrictive based on the down pipe I had to rig up out of the 850 exhaust. Tomorrow I might go to the junkyard & pull a 740T down pipe & o2 sensor see if that works better.

[ziddey]

That does not sound right. Either the wastegaste is opening (creeping perhaps) or you've got a pretty bad exhaust obstruction. With the wastegate signal unhooked, you should be able to hit fuel cut easily on a stock exhaust...

Does it make power at 5000rpm? Is it even able to get to 5000rpm?

[CerebralAilment]

Originally Posted by ziddey

That does not sound right. Either the wastegaste is opening (creeping perhaps) or you've got a pretty bad exhaust obstruction. With the wastegate signal unhooked, you should be able to hit fuel cut easily on a stock exhaust...

Does it make power at 5000rpm? Is it even able to get to 5000rpm?

it gets to 5000 rpm? it will go all the way to the popper..

[ziddey]

If you're sure the wastegate is not functional (is the signal hose unplugged?), and it's only able to hit 10psi, you've got a boost leak.

[CerebralAilment]

Im pretty sure its not functioning? I'm not positive though and I'm not sure how to check.

[vlvman]

Check the wastegate using a tire pump with a gauge connected to the waste gate. It should be fully open with less then 10 psi.

[ghost civic]

you made the 1st part of the exhaust from 850 pipe?
I thought it looked odd. That unessesary bend may not help. But then at 2.5inch I wouldnt think it would make a huge difference that there is now 2 bends there.

[CerebralAilment]

So, I'm thinking it makes a huge difference - or else my motor is blown. I'm gonna do a compression test when I get the chance. But I installed the brown tops today - and my mbc. The MBC does make a difference so obviously my waste gate does work.



adjusted the base fuel - which I might ad was a pain in the ass!



And then I installed my MBC (it was boosting 10psi - put the mbc in - it spikes to about 14 - settles at 12-13 psi).

Then I raced my buddy in his N/A 1992 Nissan 240SX - and he walked me hard. It was pretty sad honestly. I'm not sure why my car has such a power loss but its very evident. I'm not sure if the pipe I welded up is super restrictive with my funny bends right off the turbo - or if I did some damage to the motor. I need to do a compression test, and I pray they're still reading 170 across the board. But if not that's probably my problem.

[Bensin]

Originally Posted by CerebralAilment

I'm not sure if the pipe I welded up is super restrictive with my funny bends right off the turbo -

The best that I can see, which isn't well, that first bend looks over 90 deg. - that certainly could be too restrictive: imagine the constant blast of turbo driven exhaust trying push through the first bend but can't fully escape, so back pressure is created going back to turbo. that's a bend for a header instead of a down pipe... (strictly armchair opinion, not based on experience!)

[CerebralAilment]

Yeah - if I do a compression test and it comes back good im pulling a stock 740 down pipe tomorrow.

[ghost civic]

that bend could be causing backpressure....so even tho you see boost of 14psi the air could be soo hot that its not able to make power.
Remeber how i said when I first got my car it was boosting over 20psi...but that at anthing over 15psi it actually dropped in power, it was mostly cause the air was way hot. Lots of volume...no density.

I just ran my replacement 13c @ 8psi for several hard runs and the pipes were not glowing or red at all.

The 1st bend in my downpipe is less probly only 60-70 degrees and is 2.5 diameter.

What is the inner diameter of the downpipe you are using?

[CerebralAilment]

stock

[CerebralAilment]

So I'm happy to report that the compression is good - it actually went up in one cylinder (or else the gauge was reading funny - it was having issues sorta) but 165-180 is what I got for readings across the board - went back and re-tested 1 of em (the 165) and it was 170 (gauge was funky) - so I'm not sure what to think.

Plugs looked good too - so I'm thinking maybe its a rich problem? Or the turbo restriction or the turbo in general. I'm going to try and get that 90+ manifold & get the 15g I have on their. That or find another turbo.

Any ideas on things to check for power loss?

[ghost civic]

Originally Posted by CerebralAilment

So I'm happy to report that the compression is good - it actually went up in one cylinder (or else the gauge was reading funny - it was having issues sorta) but 165-180 is what I got for readings across the board - went back and re-tested 1 of em (the 165) and it was 170 (gauge was funky) - so I'm not sure what to think.

Plugs looked good too - so I'm thinking maybe its a rich problem? Or the turbo restriction or the turbo in general. I'm going to try and get that 90+ manifold & get the 15g I have on their. That or find another turbo.

Any ideas on things to check for power loss?

this is the kinda situation I wish I (we) could afford nice gauges. I quality wideband o2 gauge would come in handy!
I am fairly certain that my car is running VERY rich....as the MPGs its getting are terrible. I just drove to augusta today and back and uses over 1/4 tank (according to the gas gauge)

Your current lack of power developed AFTER the exhaust install right? I would replaced the 1st section of pipe and see if that makes a difference. Since the power output seemed to come right after the change it stands to reason the new exhaust setup could be to blame.
Plus, pulling the pipe and putting a different bend should be like a 1 hour job (tops) for you and could make a huge difference.

[CerebralAilment]

Originally Posted by ghost civic

this is the kinda situation I wish I (we) could afford nice gauges. I quality wideband o2 gauge would come in handy!
I am fairly certain that my car is running VERY rich....as the MPGs its getting are terrible. I just drove to augusta today and back and uses over 1/4 tank (according to the gas gauge)

Your current lack of power developed AFTER the exhaust install right? I would replaced the 1st section of pipe and see if that makes a difference. Since the power output seemed to come right after the change it stands to reason the new exhaust setup could be to blame.
Plus, pulling the pipe and putting a different bend should be like a 1 hour job (tops) for you and could make a huge difference.

Yup - I really need a wideband. I'm debating on going 3" straight pipe now - I don't reallly like the sound of my thrush its like a quiet exhaust leak lol. I'm thinking about buying one if I can keep making money but I havn't found any summer jobs yet and MNJNKYRDS is slow at the moment.

This car hates me haha