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I just came back from a R31 Skyline dyno day, we ran my Clubman back to back with Michael Coppola's Clubman.

The actual numbers aren't important, its more the variation between them that I'm looking at.

My car is stock, only has the timing bumped up a bit. His is also basically stock, he just has the timing and a K&N panel in a Loch Stewart intake that hasn't had the hole through the firewall drilled.


His made 78rwkw, mine made 69rwkw.


Again, I'm not concerned about the actual numbers, just the variation (and I'm fairly sure the dyno is optimistic, I've never seen so many RB30's register over 100rwkw)... Would a Loch Stewart make THAT much difference? Its like 15%. Other things I was thinking it could be... When my timing belt was done, could they have put the belt on one tooth off, or could my cat be collapsing??

Blocked up cat, plugs fouled or incorrectly gapped, O2 sensor, fouled injectors, dodgy AFM...the list goes on!

Ok, I'll get new plugs on Monday, I'll also see about getting my exhaust fitted and have the cat inspected when they do that, maybe get a s/h Commodore cat or something. Will chuck a bottle of injector cleaner in next tank

are you running the stock air box? Restrictive and sucks hot engine bay air...

I do have the stock box, I'm not really wanting to cut a hole in the firewall.

He has the Lach Stewart but no firewall hole, it just stops a cm or so from the firewall

adam, fwiw, mine when first dyno'd made just under 72.5rwkw with k&n panel filter & a hole cut in the lower part of the standard airbox fitted with a 10cm pipe picking-up air from a hole cut in the engine splash tray/ cover. the vehicle was otherwise standard including timing although it only had a verifiable 50k kms on it. it then made 81rwkw after fitting a unichip. & after the last dyno, 93.3rwkw after further fitting mania cowl cai, stewart hi flow cat & catback system. still to dyno stewart headers & larger nb8 crossover intake pipe. figures were all from same dyno over a period of 6 mths. so taking into account differences in dynos yours may not be unduly low, although the other vehicle's seem optimistic as you suggest for what is presumably the old style stewart cai.

Yes, his has the older fibreglass cool looking Loch Stewart intake.


I couldnt relly care what the actual number is, its just that we ran my car 2 minutes after his and its a pretty big variation. Also he took me for a ride in his before we went on the dyno and it felt considerably stronger, going round corners his felt like it was wanting to oversteer, mine doesnt get anywhere near that feeling on the same corner and his has better tyres than whats on mine atm


I think I may end up having to cut the hole... Might go and knock up an Autospeed intake

appreciate what you mean about the actual numbers, & only offer mine as another indication of standard & modified numbers for a similar vehicle. from my limited knowledge of the old stewart cai as fitted to the other vehicle in this case, i.e. k&n panel filter breathing air from within the engine bay, some advantage would be gained as the k&n filter panel is said to allow slightly better air flow than the oem one while the airbox inlets would be 6cm (oem) versus 10cm(?), but not as much advantage as the dyno indicated. i guess this begs the questions of dyno operator input, unknown mods to the other vehicle, &/ or yours possibly not operating at maximum efficiency, but given his is noticeably different on the road it's probably the latter two. btw, did you get a chance to compare torque figures?

Hang om...if it was a Clubman, wouldn't it also have some sort of custom exhaust? If you did the intake, cat and zorst, I would say that a 8-10rwkw gain wouldn't be out of the question...

mate, dont worry about the max power, how did the torque/power curve look?

They were both clubmans with standard exhausts, his has no mods other than the Loch Stewart and 14 degrees timing.


We laid the graphs over each other, with the curves laying over each other they were pretty much identical, but when we lined the grids up, his curves were significantly further up the graph than mine. I think my torque curve tailed off a bit at the end though compared to his

Adam_NAclubman wrote:They were both clubmans with standard exhausts, his has no mods other than the Loch Stewart and 14 degrees timing.


We laid the graphs over each other, with the curves laying over each other they were pretty much identical, but when we lined the grids up, his curves were significantly further up the graph than mine. I think my torque curve tailed off a bit at the end though compared to his

Ahhh...I thought you meant "Clubman" as in "Lotus Seven" type thing

What did yours and his AFR curves look like?

Unfortunately we didnt get afr curves this time


I did stick one of those enclosed Simota pods that was used in the Autospeed article on it today while I work out lengths for getting the piping to go to the firewall. Tonight we took the car to a main road thats next to the parklands and I stood on the side of the road and got my friend (guy I bought it from and sold my DR30 to) to hammer the MX5 up and down the road a few times.... Oh my god it sounds good for a pod... a really deep loud growl, very happy with the note

Adam_NAclubman:

Oh my god it sounds good for a pod... a really deep loud growl, very happy with the note

if you liked that just wait until you fit the pipe drawing air from the cowl...

if you can't find the appropriate combination of piping, i.e. 10cm choked down to 7.5cm then can recommend the custom made one piece carbon fibre pipe which mania sell - it was $120 including postage as of mid last year. good luck

93_Clubman wrote:Adam_NAclubman:

Oh my god it sounds good for a pod... a really deep loud growl, very happy with the note

if you liked that just wait until you fit the pipe drawing air from the cowl...

if you can't find the appropriate combination of piping, i.e. 10cm choked down to 7.5cm then can recommend the custom made one piece carbon fibre pipe which mania sell - it was $120 including postage as of mid last year. good luck

...which kinda looks like this (courtesy of Zoom-Zoom):



jonno.