I think I may have a fault with my left hand side turbo, (as I sit in the car) I think it is not boosting for some strange reason.

I suspect that I may have disturbed/damaged something when I grounded the car accidently, catching the left hand side down pipe.

Is it possible to easily isolate each turbo at a time so as to see the function of each one individually?

It's definitely not responding as she used to.

 

Thanks in advance..

Does your boost gauge move past 0 ?

 

 

if so, both turbos are working.

If you have a feeling the car feels slower then normal, chances are it's in safety boost.

Does your boost gauge move past 0 ?

 

 

if so, both turbos are working.

If you have a feeling the car feels slower then normal, chances are it's in safety boost.

 

Hi Lymon,

 

Yes, boost does go past zero.

In fact I can achieve reasonable boost, it's just that in is noticeably slow to respond.

Prior to my little accident, it was nigh on impossible to keep the car out of boost.

Now I have to drive her a lot harder to even generate boost, as if I am only charging pressure on one turbo.

Would this be possible?

if only one turbo is working you won't be able to get the gauge to move past 0 and the lack in power would be very noticeable

 

Maybe first check if you have any ECU error codes which may cause safety boost (eg. code 34 or code 13) or if there are no errors (code 55), you can check for boost/vacuum leaks.

Thanks again Lymon, your advice is very much appreciated.

I will run Data-Scan tomorrow and check for error codes as you suggest.

Do a boost leak test, you've move a lot about.

you haven't forgotten to tighten a hose to the intercooler, knocked one loose when grounding out, knocked of a vacuum hose from the actuators, recirc valves or to safety boost sensor....??

Check every pipe and hose clip you can find.....

Do a boost leak test, you've move a lot about.

 

You are right Steven, definately worth a boost leak test just to be sure I have sealed everything off correctly.

 

- - - Updated - - -

 

you haven't forgotten to tighten a hose to the intercooler, knocked one loose when grounding out, knocked of a vacuum hose from the actuators, recirc valves or to safety boost sensor....??

Check every pipe and hose clip you can find.....

 

As you say Russ, I have disconnected so many pipes and clips I could have easily missed 1 or 2.

Still have not done a boost leak test yet, a bit side tracked with replacing my front cross member.

I will hope to leak test shortly.

In the mean time, I have a question....

 

I have a uk tt, do I have ceramic catalytic converters in both turbo elbows?

The reason I ask is that when I grounded her, I am concerned that I may have damaged them in some way, which in turn has affected boost in some way. Possible?

Over the winter I hope to remove both down pipe elbows, can anyone point me to a thread that may have covered this please? (Hopefully with pictures)

I hear it can be done with the engine and gearbox still in situ, albeit a bit of a pain.

 

Secondly, can someone advise me as to the correct aftermarket decat elbows to go for?

I have stock turbos attaching to Japspeed downpipes that I would ideally need to keep.

I did it earlier this summer with engine in. Battery needs to be removed and also the brake booster, I also removed master cylinder to get enough space to remove the booster. It's tight but doable, think I used some 8 hours spread out over two days.

 

If you have stock turbos you need a four bolt downpipe in either 2.5" or 3" depending on the size of your japspeed pipes.

If you just want the turbo elbows off then yeah, completely do able. In fact I do that before any kinda major work in that area to free up space. The problem is getting them off when they haven't moved for 20+ years, rust, heat cycling etc etc, not fun. If you've got stock elbows and japspeed front pipes I'm guessing you have the NA version with the silencers in them? The Turbo version won't match up. If you google it you will see they are completely different. Virtually all the aftermarket stuff the flange is 45' where as stock it's 90'. Hard to explain.

I did it earlier this summer with engine in. Battery needs to be removed and also the brake booster, I also removed master cylinder to get enough space to remove the booster. It's tight but doable, think I used some 8 hours spread out over two days.

 

If you have stock turbos you need a four bolt downpipe in either 2.5" or 3" depending on the size of your japspeed pipes.

 

Thank you Spiff, glad to know its doable, I'm actually looking forward to tackling them.

As you say, stock turbos, stock elbows attaching to 2.5" pipework.

Any tips on what make and type to look for?

Any further advise would be very much appreciated.

If you just want the turbo elbows off then yeah, completely do able. In fact I do that before any kinda major work in that area to free up space. The problem is getting them off when they haven't moved for 20+ years, rust, heat cycling etc etc, not fun. If you've got stock elbows and japspeed front pipes I'm guessing you have the NA version with the silencers in them? The Turbo version won't match up. If you google it you will see they are completely different. Virtually all the aftermarket stuff the flange is 45' where as stock it's 90'. Hard to explain.

 

Hi Steven, correct, I'm very keen on swapping out the original old down pipes for something more performance related.

As for the japspeed pipes, I haven't any idea as to what the are from mind.

I would be interested in knowing what is the best thing to do now, especially as I am not happy about possibly having a none turbo exhaust system.

Can't be helping things, can it?

I wouldn't worry too much, they are both the same diameter, just a subtle couple of differences. Some people choose to fit the ones you may have to retain a bit more back pressure on the turbos and add extra quietness to the system. The best thing to do is take a few pictures and post them up and then we can can see exactly what you have.

If you've got decats already and jap spec elbows (ie with no precats) then I doubt switching will make a huge difference. Could be wrong though. What makes a good gain is going from stock to full elbows etc. Even that's more about power delivery than power out right.

Thanks again Steven, I will post some pictures.

As for the elbows, they are the original cast iron type with catalytic material inside. (apologies for my incorrect initial description.)

Apologies, edited.

Edited September 13, 20169 yr by Richie K

Cheers Richie K.

 

That's the sort of thing I am looking for.

I need a 4 bolt configuration at the turbo and a 3 bolt at the pipe. (I believe)

Cheers Richie K.

 

That's the sort of thing I am looking for.

I need a 4 bolt configuration at the turbo and a 3 bolt at the pipe. (I believe)

 

You'll need the centre section as well as I found that out at my expense already, these downpipes don't bolt up to the NA decats.

I will have these hopefully off the car in a few days time including the testpipes (decats/centre section)

Edited September 13, 20169 yr by Richie K

Would something like this be the matching setup to connect to my existing system?

Still trying to understand what fits with what.

 

http://www.ebay.co.uk/itm/Turbo-Down-Pipe-Test-Pipe-4-Bolts-300ZX-Z32-Fairlady-Twin-Turbo-90-96-/391346353365?hash=item5b1e0f74d5:g:x1sAAOxy63FS6BWH

Would something like this be the matching setup to connect to my existing system?

Still trying to understand what fits with what.

 

http://www.ebay.co.uk/itm/Turbo-Down-Pipe-Test-Pipe-4-Bolts-300ZX-Z32-Fairlady-Twin-Turbo-90-96-/391346353365?hash=item5b1e0f74d5:g:x1sAAOxy63FS6BWH

 

That would replace from turbo to cat back. So yes it would suit however you'd be discarding your current down pipe/centre section. It's hard to explain the difference other than to say one has a 90' flange the other 45'. Il do you a little sketch if your still struggling. It caught me out when I brought mine some years back.

That would replace from turbo to cat back. So yes it would suit however you'd be discarding your current down pipe/centre section. It's hard to explain the difference other than to say one has a 90' flange the other 45'. Il do you a little sketch if your still struggling. It caught me out when I brought mine some years back.

 

I can't profess that I understand at all really if I was honest, is the 90' flange at end of the stock down pipe and at 45' on non stock?

hence the mismatch?

 

A sketch would be great! I cant afford to get this wrong.

Yeah basically. Give me a sec and il scribble it down.

Appologies for the crap quality, just scrawled it out while the dog was out for his last wee :lol: hopefully you can see how some configurations are coatings and some not.

Thanks Steven, I think I get the idea now.

So I need a 90' to 45' down pipe to mate up with a 45' test pipe?

Just need to be sure that it connects with the existing rear section okay.

I fear the worst somehow.

As per my pm's Dave,

 

TT divorced downpipes and testpipes

 

 

NA decats, these can fit a TT as long as you keep your standard downpipes