mx5cartalk.com

Somehow you feel your SP just isn't quite what it once was, some call it the SE Influenza. Fortunately your Intercooler won't shrink and their is a cure

Some symptoms, Power feels bleah, Economy is shot, doesn't spool well, has started to backfire even more often than normal, lastly, even a wheezy NC can catch you......

WTF's wrong, most likely this........

NOTE: for those SP owners smiling saying nothing wrong with mine, most of the nuts removed to do the following were tight

Clear evidence of cylinders 1,2,3 and 4 leaking exhaust.

NOTE: centre stud has even managed to unwind itself, here it has been removed for a new one.




Clear evidence of cylinders 1,2,3 and 4 leaking exhaust past the gasket.



Possible reasons for metal on metal shriek some get, Exhaust manifold to turbo housing gasket has faaaaaaaaaaaaiiiiiiillllllllleeeeddddddddd Obviously the stud is not meant to be there, it is to demonstrate how badly the gasket has failed.



Part of the reason for the above failure.

NOTE: original manifold to turbo stud shown on left next to it replacement which is easily 4mm longer, original nut for same lower centre, this nut is capable of the task BUT given the shortness of the stud the two locking tabs come to rest on top of the stud whereas they should be on a few turns and thusly binding onto the stud.



and from a different angle.



Larger nut pictured is the original that held the manifold to the block.

Pretty copper looking ones are the Inkonel Alloy ones, these are designed to go ON and stay ON


Manifold to turbo housing studs being removed for replacement with longer ones.


Nicely machined Manifold.



Reliefs being made into exhaust manifold so it can be bolted on properly.






There's a few more photos to get and a list of what needs replacing to come, so stay tuned.

SPy

A number of SP's have been down this road, its good to have someone document a solution because there is a good chance they will all go through it at some stage.

Newells attacked mine under warranty, I doubt they replaced the stud but I do have some fancy nuts like those that are not original and are certainly staying on ! Either Newells had a turbo savvy mechanic or two that knew how to make a manifold stay on or Mazda themselves issued a TSB on how to approach it, not sure which.

My NA turbo used the manifold from an SP, and we used some rather large studs and nuts, due to this problem being around in a few of the SPs

Fascinating pictures. Who did the work?

Jules

Are the inconel nuts and longer studs OEM update parts or as I suspect aftermarket? Where did they source the inconel nuts from?

Yes, who did the work and how much did it cost?

Any physical signs of leaking (soot around the manifold) ?

CT wrote:Are the inconel nuts and longer studs OEM update parts or as I suspect aftermarket? Where did they source the inconel nuts from?

CT, I sourced a supply of 8x1.25 inconel studs for Daniel/ Mania from a bolt supplier in Penrith (Spinners); however they couldn't supply inconel nuts (doesn't sound like they are too common?). They did supply some deformed nuts that have been brilliant on my turbo housing have not lost one yet (originals were just temporary residents - regularly heard them bouncing under the car...).

Cheers,
Dave

bruce wrote:Any physical signs of leaking (soot around the manifold) ?

At the MX5 dyno day i recall seeing one SP with alot of soot on the firewall directly adjacent to manifold and behind the turbo. Not sure if this is the one that ran lowish numbers on the dyno and claimed a faulty aftermarket boost solenoid as the culprite.

C'mon Blackster, have a go. Goals open

Jules

yup, noone in the forward fifty & you're dead in front mate

blackster wrote:

bruce wrote:Any physical signs of leaking (soot around the manifold) ?

At the MX5 dyno day i recall seeing one SP with alot of soot on the firewall directly adjacent to manifold and behind the turbo. Not sure if this is the one that ran lowish numbers on the dyno and claimed a faulty aftermarket boost solenoid as the culprite.

That was my car!
David and I both thought the boost controller was to blame, but it does seem there was a leak somewhere which is now being fixed.

at least i now understand Darbys wishful thinking about bits falling off NC's...........

Dave wrote:

CT wrote:Are the inconel nuts and longer studs OEM update parts or as I suspect aftermarket? Where did they source the inconel nuts from?

CT, I sourced a supply of 8x1.25 inconel studs for Daniel/ Mania from a bolt supplier in Penrith (Spinners); however they couldn't supply inconel nuts (doesn't sound like they are too common?). They did supply some deformed nuts that have been brilliant on my turbo housing have not lost one yet (originals were just temporary residents - regularly heard them bouncing under the car...).

Cheers,
Dave

Thanks Dave - the SE manifold and downpipe has deformed locknuts on it from Mazda - just wondered if they would suit - 8mm - looks like they may so might be a reasonable alternative.

jules wrote:C'mon Blackster, have a go. Goals open

Jules

There's no need to, the SP owners know how the SE performed on the day.

dave wrote:That was my car!
David and I both thought the boost controller was to blame, but it does seem there was a leak somewhere which is now being fixed.

Good to hear you found the problem and hopefully she will be running healthy again soon.

blackster wrote:

jules wrote:C'mon Blackster, have a go. Goals open

Jules

There's no need to, the SP owners know how the SE performed on the day.

Yes, the scoreboard usually says it all for you. Was that the day you made 150ish rwkw?

Boags