K20A OR SR20DET

[oztrackdays]

typically these classes.

Class Engine capacity
A 0 - 1600cc
B 1601 - 2000cc MX4 1.8 x 1.7 Turbo Multiplier = 3.06 Litres
C 2001 - 4000cc
D 4001cc & above

MX5 struggle against a Porsche 4.0 Litre flat crank N/A
and 2.2 Litre Turbo EVO motor takes some catching.

Real problem is NA/NB are changing hands Sub $5000 much less for race
cars and few people really wants to spend the sort of coin modifying one
to K series or SR engine swaps.

[speed]

Personally I'd rather turbo the 1.6 then sign a blank cheque to the Honda gurus but saying that, Drea ms are important.
Would be totally awesome if done properly, however I'm sure you've realized that you need to tripple/quadruple your budget.
If the swap is no longer attractive for the price, maybe go for a ride in a turbo 1.6 and see what you think. You might be surprised

[project.r.racing]

In an outright class you can do whatever. Run a space frame, fiberglass panels etc. Some of the quicker cars in my series run supercharged Hayabusa engines. I think if you were going to the trouble of using a B3 bottom end you may as well use something else entirely though.

You cannot do whatever you want with $5K budget. haha

[madjak]

Oh I agree... you can basically only just get a stock car on the track for $3k.
$1k tyres
$250 brake pads
$450 race seat
$180 harness
$40 fire extinguisher
$150 licence
$500 roll bar

I wasn't talking about the OPs option but more general. You're not going to be competitive in outright class with $5k

[StillIC]

You're not going to be competitive in outright class with $5k

Or in any almost any class in an MX5. Unless you have a standard <1.6 litre NA or ND and are up against other standard <1.6 litre cars.

[Dan]

You're not going to be competitive in outright class with $5k

Or in any almost any class in an MX5. Unless you have a standard <1.6 litre NA or ND and are up against other standard <1.6 litre cars.

Very true, the MX5 isn't really an outright competitive car at most levels but even if you aren't winning it's still fun chasing down cars you have no business being near (I've got a pesky Exige in my Supersprint class that I'm getting close to which gives me something to aspire to beat).

That's part of the beauty of the MX5 Club Sprints and the MX5 Cup too, even if you put a turbo on it or go crazy with the car you just end up in one of the highly modified classes against other similarly modified MX5’s rather than big dollar Porsche’s.

[madjak]

I think a well modified MX5 can be very competitive in the road registered under 2000 cc classes. The main competition are much more modern cars that are far more expensive. Given these are daily dríven cars, the drivers tend not to commit into corners so on tighter courses the MX5 can be very competitive even in stock form if dríven close to the limit.

Last year I was competing in my stock 1.6 b-spec against Integra Type Rs, Toyota GT86s and Lotus Exige and Elises and whilst I couldn't get that close on the power courses like the race track and long hillclimbs, on the tighter courses I managed 2nd a few times. The only upgrades to the car where brake pads, a CAI and good tyres. With a 1.8 engine upgrade competition has been very tight between all the cars, all having fairly series built engines. At most events the top 3 in the class are within 0.5 seconds. Now with my intake and some fairly serious power I'm winning class at most events but only by a few tenths.

I think bang for the buck the MX5 is hard to beat. Fun motorsport doesn't have to be expensive and I think the MX5 is probably one of the best options out there for someone starting in the sport as it's a great car to push hard and can be easily and cheaply developed.

[Dan]

Yeah it can be a competitive in the Road Registered <2L class in the right hands against the right competition but lets be honest an equally skilled driver in a similarly modified Lotus or Honda is going to be faster than you as you can no longer succeed in spite of the base car being worse.

To give an example, if I look back the lap records in the NSW Supersprints 2B class I compete in, all of them were set in 2011 by a guy with this S2000 http://www.the-lowdown.com/elliots-s2k/ - 156kw, Moton suspension, air con removed, LSD etc.. It also looks like he can steer because he does a low 1:07 around Wakefield and a low 1:46 around SMSP GP which are times that most people in MX5 race cars wouldn’t be upset with.

If he showed up again everyone else in the class with an MX5 is doomed because he started with a better base to modify on, he’s taken advantage of it (My car inside the regs would be lucky to get within 40kw of him, plus he could go bigger if he did more to the engine or went to E85) and he can steer.

I agree about your point about fun motorsport though, the MX5 can’t be beat in that category.

[sailaholic]

I was following emillo's thread on his k swap. He went the k20 as well but got 3/4 there and realised that IN A MIATA it's just too hard to keep the oil up to the k20 with out a dry sump and ended up having to drop the rev range the were aiming.


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[StillIC]

but lets be honest an equally skilled driver in a similarly modified Lotus or Honda is going to be faster than you

Seconded. And they don't even have to be similarly modified to be faster.

I have seen a barely modified S2000 within a second of the car mentioned above. That is~1.49 at Eastern Creek GP circuit in an almost standard, road registered, sub 2.0L car. Standard 2ZZ powered Elises are barely any slower. Even a modified (NSW Type 2) road registered 1.6 Civic has done 1.50 at EC GP.

But I have yet to see a highly competitive Toyota 86. They are the MX5 of hard tops, but with a higher asking price (not including ND).

[madjak]

I was following emillo's thread on his k swap. He went the k20 as well but got 3/4 there and realised that IN A MIATA it's just too hard to keep the oil up to the k20 with out a dry sump and ended up having to drop the rev range the were aiming.


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I think a dry sump is 100% required in our RHD cars so that the sump can clear the steering rack. I don't know of anyone who has managed to fit the kmiata sump in a RHD car yet. I thought it might be possible with a depowered rack and some heavy trimming on the rack and thats what I would have attempted to do. I'm not sure if it would work though so in my costings I had a dry sump as a contingency. It's one more reason that the price for the K-install is so high.

As for competitive road registered MX5's, I think the lap record for road registered < 2000 cc at Barbagallo is a 66.8. I did a 68.8 two weekends ago on a cold, slightly damp track so I think I could get pretty close to the record on a good day. That record was set in 2010 with an early model Lotus Elise S1 with a built engine. The class is similar to 2B but you have to run full interior and be basically road registered and all mods ADR compliant (except for safety gear). For reference the outright under 2000 class is down in the 63's which would be hard to get near.

[oztrackdays]

Yes it's tough to catch a Carbon Fiber Paneled Lotus with a 9500 rpm K20 in the back.

I spoke with Dave from K-Miata before I did my dry sump, their sump is purpose built for LHD
will not work for a RHD car.