A Few Questions From A New Mk2.5 Owner

General Discussion Forums MX-5 Chat
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Hi Everyone!

1st post here. New to MX5 ownership but had plenty of track car and modifying experience from a previous life in the MR2 scene. I find forums to be a priceless repositry of info and experience so I’m hoping to tap into it :)  Some questions I could use some help with:

  1. I was told my car has a torsen 4.1 LSD and paperwork shows fitting of an LSD not long ago. The quick test for one (wheels in air, rotate one wheel and check rotation of other) was inconclusive. I turned one wheel and the other didn’t move at all. Is this normal for these Torsen diffs or is mine rubbish?

  2. My car will be a track car. I’ve read every post I can find on changing the standard intake box. From what I can tell, the mk2.5 standard setup is basically the same as most aftermarket ones, with the snorkel pointing at the headlight hole and crappy but nonetheless present head shield. People report intake temps on track of 50 degrees plus, so clearly something needs to be done to optimise, but I can’t work out for the life of me what that would be:

-100% of randal cowl pics i’ve seen are not on RHD MK2.5s, I have no free cowl space, it’s all power steering pipes and wiper motor. There’s a hole that goes to the passenger footwell but I’m not sure that’s a good place for an intake

-Run a flexible aluminium pipe down in front of the radiator - I feel this would block rad flow (much needed for track) and make adding cowling round the rad (a job I plan to do at some point) even harder

-extra tubing into the headlight hole - I cannot see how this hole is even vaguely effective at providing enough cold air for an engine

-Add a front facing bonnet vent that seals to the intake when bonnet lid is closed - tricky DIY job to get good seal given bonnet opens

-Remove a foglight and run ducting to the hole - seems most feasible - anyone seen examples of this?

  1. Warning light prevention for bucket seat and harness install - I’ve seen the mk3 is tricked by a 3ohm resistor for airbag, does this work for mk2.5 also? What about seatbelts? I really don’t want that annoying beep to go off! Anyone had issues with the MOT for having removed the airbags (aftermarket wheel for example)?

  2. Gearshift replacement - putting in a short shifter because without the centre consol in, the standard shifter is comically high. I’ve seen mentions of needing some gearbox oil to do this  job - is this true? I don’t understand why that would be the case. And if it is true, can I get away with a splash of clutch and power steering fluid or do I need to buy some 75W90 or similar?

  3. Car has done 110k. Any idea how long the standard clutch lasts? ie will it definitely have been replaced to get this far or could it be on it’s last legs?

  4. Anyone thought their throttle pedal was too soft and tried to stiffen it up? if so, how did you do it?

  5. Any owners meetups in East London? Or any of you in the London Bridge/Canada Water/Deptford area?

Thanks!

 

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Hi Dan, welcome to the MX5OC forum and well done for choosing the best model. However, before spending too much of your budget on track mods, please check your chassis rails. A search on here will show you what to look for. If there is an issue, then repair kits are available to ensure all is safe & solid.  This issue has resulted in some MK2 MX5s being scrapped, so there is a good supply of spares for future mods.

Do you have the standard model with 5 speed box or sport with 6 speed box (there are also limited edition special models which have some of the extras in the sport model)? This affects the diff ratio and would help identify whether your car originally was fitted with LSD (might have have been changed by a previous owner). If you have an original LSD, then bad news is it is not Torsen but Tochigi Fuji type (mine failed and was replaced with Torsen 2 3.6:1 ratio in my 6 speed SVT sport model - at same time fitted stiffer mounting rubbers, new washers, etc - big thank you to Duncan at Furious Five’s for sorting this and many other improvements). Info on MX5 LSDs in this web site https://bofiracing.co.uk/blog/tor-what-viscous-huh-mx5-differentials-an-introduction/. 

I fitted a K&N filter with Typhoon induction, which sounds good, but I think lost some mid range power. The standard air box takes cold air from the wheel arch and might be worth sticking with but replace the original filter element with a K&N or Pipercross element (eg https://www.mx5parts.co.uk/filter-pipercross-mk2-25-p-2053.html)

Sorry I can’t help with your other questions. I had a sloppy change and Duncan fixed with a repair kit. I’m still on the original clutch with 79k miles. I’m in Yorkshire, so too far to meet up, but you could try a post in your local area forum North Thames? https://www.mx5oc.co.uk/forum/yaf_topics152_North-Thames.aspx

I‘m sure others will help with improvements for a track car, as I use my MX5 to get to work on A/B roads and I’m very pleased with the improvements on my MX5 so far (after 10 years ownership), which include MeisterR adjustable suspension, TR Lane roll bar, Kumho tyres and 4 wheel alignment, and she always puts a smile on my face. 

George