iwantcheese5's Mazda RX-8 231 Watch

JC.
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#61
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#61
(Original post by iwantcheese5)
Best bit has to be that it pops on the over-run now
Just means you've cocked up one of the mating surfaces somewhere. Cold air is being drawn into the exhuast through a hole adding oxygen to the exhaust gasses.

Drop the exhaust and try re-mounting it with fresh gaskets. If you do each part up gradually the mating faces should pull down nice and snug with no leaks onto each other.
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iwantcheese5
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#62
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#62
(Original post by JC.)
Just means you've cocked up one of the mating surfaces somewhere. Cold air is being drawn into the exhuast through a hole adding oxygen to the exhaust gasses.

Drop the exhaust and try re-mounting it with fresh gaskets. If you do each part up gradually the mating faces should pull down nice and snug with no leaks onto each other.
Surely it's the sound of the car backfiring? No fire because it gets stopped by the cat of course. With a de-cat the rex can manage to pop flames out the back.
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JC.
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#63
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#63
(Original post by iwantcheese5)
Surely it's the sound of the car backfiring? No fire because it gets stopped by the cat of course. With a de-cat the rex can manage to pop flames out the back.
Cat isn't going to last very long then, is it?
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warrenpenalver
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#64
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#64
(Original post by JC.)
Just means you've cocked up one of the mating surfaces somewhere. Cold air is being drawn into the exhuast through a hole adding oxygen to the exhaust gasses.
not necessarily. my old racing puma used to do the same on the overrun as do all of them. Quite a few sports cars do it too.
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JC.
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#65
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#65
(Original post by warrenpenalver)
not necessarily. my old racing puma used to do the same on the overrun as do all of them. Quite a few sports cars do it too.
Our TR7 does it. Doesn't mean it's right.
Old cars still draw through fuel through the carb modern cars don't draw any fuel through when the throttle is shut so it shouldn't pop and fart at all.

Nothing else has been tweaked on the engine. It shouldn't be doing it otherwise it would have demonstrated the same symptoms on the previous system.
There's a leak.
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MissSBx
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#66
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#66
Cheese is cheesy and smelly assumption
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iwantcheese5
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#67
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#67
(Original post by JC.)
Our TR7 does it. Doesn't mean it's right.
Old cars still draw through fuel through the carb modern cars don't draw any fuel through when the throttle is shut so it shouldn't pop and fart at all.

Nothing else has been tweaked on the engine. It shouldn't be doing it otherwise it would have demonstrated the same symptoms on the previous system.
There's a leak.
The larger piping means you can hear what it was always doing I think. If you look at the exhaust videos for the RX-8 on youtube they all making popping noises on the over run.
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warrenpenalver
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#68
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#68
(Original post by JC.)
Our TR7 does it. Doesn't mean it's right.
Old cars still draw through fuel through the carb modern cars don't draw any fuel through when the throttle is shut so it shouldn't pop and fart at all.

Nothing else has been tweaked on the engine. It shouldn't be doing it otherwise it would have demonstrated the same symptoms on the previous system.
There's a leak.
erm not right either. some sports cars deliberately overfuel on the overrun just to get that sound. and a lot of it is down to the exhaust system itself.
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JC.
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#69
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#69
(Original post by warrenpenalver)
erm not right either. some sports cars deliberately overfuel on the overrun just to get that sound. and a lot of it is down to the exhaust system itself.
I'm sure you know best...
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iwantcheese5
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#70
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#70
Borla flames, one day I'll get a decat and be able to make flames :pinch:
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warrenpenalver
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#71
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(Original post by JC.)
I'm sure you know best...
its not that i know best....

But i do know very specifically that for example the ferrari F40's exhaust and engine management was tuned specifically to sound that way in addition to the obvious performance reasons surrounding the basic design.

same with the ford racing puma which they again modified the exhaust design for just such a reason. I know this because i have spoken with people on the original cars design and development team....

so yes in some cases it could be an airleak, but in others it certainly is not.

the phenomenum of overfuelling on the over run is not uncommon even on so called super fast processed modern ECU's.

Then of course you are forgetting various specific race/rally car features that deliberately overfuel on the over run and in fact many other areas of the engne cycle for purposes such as launch control, anti-lag, anti-stall, full throttle gear change etc etc etc
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JC.
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#72
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Our '80 MGB GT complete with home brew ECU sprint car used to do it - that's just how it was. I accept some cars do it because of the nature of how they are designed.

Anyway...It's all very well citing loads of race cars with hundreds of pounds thrown under the bonnet but at the end of the day we're talking about a cheap n cheerful road car with a seccond hand exhaust. It didn't do it before, it shouldn't be doing it now.

I'm not about to get drawn into an argument over something I could care less about. Like I said, I'm sure you know best...
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warrenpenalver
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#73
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the standard puma didnt do pops and farts until a uprated exhaust was fitted to it....
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iwantcheese5
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#74
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#74
J.C. are you suggesting that every RX-8 on youtube has their aftermarket exhaust fitted wrong? Every example I've seen on there can make popping noises on the overrun.
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iwantcheese5
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#75
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#75
Well now that I've done an expensive modification to the car it's time for another cheap bit of customisation. The silver trim bits which run along the transmission tunnel were looking a bit worn in places and I fancied making them a bit more exciting...



I still had a load of stickers left from the Stickerbomb book which I'd been wanting to use for something interesting. Being able to completely separate the area to be attack from the rest of the car made the game a lot easier than it would have been otherwise.

Trim after I'd raped it...(used sticky-back plastic for the finish rather than lacquer this time, worked much better)


Arty close-up...


Adding stickers to the little bit of trim round the gear stick to tie it in with the other pieces:


Really quite happy how neat it looks:


Some pictures of it in the car:





I know I'm likely to get a lot of flack for this but I like how it's different from the other RX-8's I've seen! Plus it was a cheap way of making the car more mine. Anyway I hope there's someone out there that likes my strange taste!
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warrenpenalver
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#76
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#76
its different i will give you that!

just dont copy the "rat look" scene and paint strip your bonnet while sticking a stupid roof rack and old rotten suitcases to your roof......
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Mazty
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#77
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#77
The cost of insurance + the mpg = no thankyou.
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iwantcheese5
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#78
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#78
(Original post by warrenpenalver)
its different i will give you that!

just dont copy the "rat look" scene and paint strip your bonnet while sticking a stupid roof rack and old rotten suitcases to your roof......
Haha don't worry I won't be doing that, I would kinda like a carbon fibre bonnet and boot lid eventually. My plan for them would be to have a pair of velocity red stripes (colour of the car) on them offset from the centre and leave the rest so you can see the carbon fibre. I need to get photoshop on the case really to see if it would look any good...


(Original post by Mazty)
The cost of insurance + the mpg = no thankyou.
Insurance - £900
MPG - 25 combined, probably about 30+ on motorways

Rotary engine + good chassis = Brilliant to drive
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chaz1992
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#79
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#79
I'd recommend an open intake, no resonator box - like a K&N FIPK intake. Also a lighter flywheel (counted as an engine mod so your insurance may rocket) would be good (this will allow you to gain and drop revs much faster).

Have to say, not a fan of your trim mod but whatever bloats your boat xD. All in all, fairly impressive.
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LandyJon
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#80
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Gotta say Cheese, I do like your Mazda. The stickered trim's a brilliant idea!
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