I am just glad I wasnt driving it when it happened. All is well now, I cleaned everything up and fixed a few more welds that the tuner didnt do properly so now its back to normal. Car goes on the 18th to get tuned fingers crossed.

 

Tune booked for the 18th of this month so this coming Tuesday over here fingers crossed everything goes well. I have to use a start up spray to get the car started so hoping thats a ECU tune fix rather than a engine problem.

 

I'm on-board with you in hoping it's a tuning issue causing the startup problems.

 

So got it tuned, drove it back all the way (230KM trip each way) home and just as I reach the last 3-4KM to my house its back to running on one rotor Just my luck. The car made a healthy 146HP at the wheels with a beautiful torque curve and everything went great other than now I have the same problem as last time

 

Damn, your just catching Hell with that thing. Was the tuner able to sort out the high idle?

 

Yup everything was sorted out till I neared home. Anyway I have found the problem as the leading plug but no idea why it failed. Anyway the car runs beautifully despite the leading plug intermittently failing.

Making 180HP at the crank so around 140HP at the wheels which is nice in a light car. Manage to light up 3rd sideways and it carries on the drift with ease which is fun since I have a long sweeping corner on my road that I have fun on now. Loving the rotor and the redline is at 7000 RPM since it falls off after that.

 

Kind of curious as to what your final weight is being naturally aspirating. Has to feel good being able to go through the gears after having it down from the conversion for so long.

 

If you still have issues with the leading plug it has 2 be a wiring or ecu issue............a plug wont just fail out of nowhere.

 

I think wiring since the ECU tuned fine and the leads are new Mazdaspeed ones that were never used so its either wiring or a plug. I might throw on another ground as I have just one ground for the coil packs going from the mounting plate to the chassis.

I will weigh the car soon but yes it feels great. The gearing on the MX5 too be honest is too short to me where a little less revs for more speed/top end/final drive would be perfect. Power wise the car really gets moving around the 3000RPM mark onwards and just keeps on going. Videos soon when I buy a decent camera

 

IMG_0824_zps2e968ef9.mp4 Video by sup_dawgTT | Photobucket

7000RPM limit

 

Sounds good. Was that a 5th gear pull?

 

3rd gear if I remember correctly

 

Definitely sounding great! Gratz!

 

nice one.

is the 7k redline temporary?

 

Update time:

Got the one rotor problem fixed by changing the spark plugs again to another new set and its working fine.

The 7000RPM rev limit is set where we saw it dropping power off so if I port the engine maybe it will increase but we saw no point to rev it any higher.

 

Ah! Sounds like you had more room to rev .

 

oh interesting so you guys reckon another gear would have given more power and higher rev limit?

 

Ash, there are several rear end choices for the mx5. If yours is a 1.8 NA, you probably have the 4.1 rear end. A lot of turbo guys swap in a 3.9 torsen for the same reasons you are wanting a little more top end. I believe there are some JDM MX5s that came with a 3.6 as well. But at your power levels I think the 4.1 is a better match.

If you turbo that 13b, your 5spd won't live long above 250 rwhp and you'll want to swap in for the NB 6spd as. Folks start killing miata drivetrains above 250 rwhp.

 

Thats great news seeing as mine is a 1.6L 5 speed 1990 so I have a viscous differential. I dont plan on turbo'ing this motor as I love the feeling of the NA response as I have the Supra for more power anyway. So far I love the engine set up and fingers crossed it doesnt break on me again I will have some in car footage when I save up for a nice new camera

 

For a 1.6 going to the better rear end is a little more involved. Make sure you get the 1.8 axle halves along with the torsen as the 1.6 uses a smaller axle that wint work with a 1.8 diff. The torsen is also much better than the old viscous diff.

Awesome build btw!

 

For sure thank you so much Flying_solo. I have looked into that and I am just trying to build the bank balance back up now that the car is streetable Next would be a torsen diff with the axels and maybe rebuild with high compression rotors. The gearing is great for drifting as the rev range is awesome and it picks up fast so no complaints there, the only time I wish I had the longer 4th and 5th ratio is when giving it full throttle on the road

 

I realized there are too many words and no pictures :P





(Jack holding exhaust up so it doesnt rub on the rollers :p )
(the second to last run, tune is currently 146HP at the wheels)

 

Completely agree, the 1.6 diffs barely stand up to the stock power of the original 1.6's. The 1.8 rear diff would def be worth the money for the safety margin of the beefier gearset (folks are pushing 300-350hp on that diff with no issues). Believe the 1.6 diffs came with 4.30 gearing, so when you swap it will also increase your gearing to 4.10. I wouldn't go any higher in gearsets than 4.10 at your current power levels or it'll feel like a snail.

Really diggin the looks of the swap! Are you planning on swapping out the stock air inlet and going with a cold air intake of some form?

 

Thank you Wildman923. I am chasing a torsen since I want the constant lock up rather than the occasional lock from the viscous but too be honest my viscous has been great too me so far

I am hunting for a alloy elbow that can be bought for the FD throttle body, once I find that I will attach a ducted pipe to a cold airbox housing a filter, that filter is only there as I needed one for the drive home

 

Why have you removed the pictures???