A NB8B Turbo progress.

IanR · Postby **IanR** » Fri Mar 27, 2015 8:19 pm

Hey all,

I bought this mx5 2 weeks ago from a mate after borrowing it for a week and had to buy it as it was just too much fun. My other car is a boring family boat.. a WRX hatch with 176awkw...

AVO intake plenum and cooler kit
gt2554
Megasquirt 3 PNP from Demitrios
2 1/2" exhaust
Koni sport shock and springs

Plans are to sort it out and gets some RWD skills.

IanR · Postby **IanR** » Fri Mar 27, 2015 8:31 pm

The 17" wheels had to go because they scrubbed badly and were running on spacers... :roll:

, I picked up some wheels here from Joel...they needed some refurb time and new bolts but they came up pretty clean. These wheels are 16x7 et25. New tyres are Goodyear eagle F1 Directional 5 205/45/16.

Gave the shop the wheel alignment numbers from the Flyin Miata site, they got most of it bang on except the rear toe which was unable to be less than a +1.7mm, not a bit deal at this point and it keeps it stable while I am leaning to hold the slide!

No scrubbing, and much more grip, well unless the tires are spinning from throttle inputs...

IanR · Postby **IanR** » Fri Mar 27, 2015 8:58 pm

The Megasquirt tune was pretty good for general driving but it was only tuned using the "auto tune" function by previous owner, boost and ignition had not been tuned, still pretty cool really.

Off to Nitro Dann for the idle to get sorted out on cold start and a full tune of the MS3...

Turns out the 2 1/2" exhaust is restricting things.

Power now is much smoother and runs hard to redline without fluctuations in boost and mixture. Plus power is much more dependent on throttle position, where before even 1/3 throttle would get 14psi in the midrange, which is not smooth and easily modulated.

Final runs yielded 218 awhp.

IanR · Postby **IanR** » Fri Apr 10, 2015 9:50 pm

Some progress this week.

The car has had very loud flutter from having no compressor recirculation valve aka BOV and a open POD.

So I added the enclosed K&N Apollo filter to make it closer to legal to to dampen the way too loud thunder and lightening that was coming from the pod filter, especially anti social in traffic on boost... not so stealth.

To take the "getting more stealth" things further, this week I re installed the BOV that was in place prior to the car being setup to run Megasquirt. Megasquirt needed the bung which the bov was using to measure the intake air temp... so the previous owner discarded the BOV.

To reinstall a bov system I needed to tap a new 19mm hole and make a bung in the alloy cast intercooler pipe and hook it all up again. With the adjust ability of the spring yields a variety of cool noises at different boost/RPM...

IanR · Postby **IanR** » Sun Apr 12, 2015 8:57 pm

More progress today. Went out the garage of the Pressure Pack racing Team in Clarence Town, Ron and his son Keith who are both mechanics and hold various racing titles (like their garage built Hayabusa powered hillclimb 420kg National title weapon).

IMG_0152a.jpg

IMG_0157a.jpg

IMG_0159a.jpg

Out came the diff, opened up and we swapped the open diff for a Lsd torsen from a SE, swapped the crown gear and reinstalled in the car. Sounds simple but to do this it means removing wheels, driveshafts, 3/4 exhaust, bracing and then drop the diff, remove crown, swap gear, reset the diff tension and calibrate the backlash with fancy tools that measure the 6 thou/inch slack required...) I really enjoyed my small jobs and being involved, I learned plenty.

IMG_0160a.jpg

Full credit to the pair, they did this job flawlessly and conversation never stopped with stories of this and that car...currently they have a competitive NA6 with turbo 1.8 in the super sprint series that they put together in their own way. Dyno sheets and race results have spoken for them.

Enjoyed a brilliant drive back to Newcastle roof down and sunset on full show, plus no more of the one wheel lighting up coming out of corners, it feel so much more planted and the rear just squats down under the new level of traction.

pressure pack · Postby **pressure pack** » Sun Apr 12, 2015 9:47 pm

thanks for the kind words Ian. Love the simmons wheels and red leather. a good looking mx5.

IanR · Postby **IanR** » Sun Apr 26, 2015 8:02 pm

Went to the shops today and picked this jewel up. A gt2860rs with .84 trim... id725 injectors are on the way as well.

Magpie · Postby **Magpie** » Sun Apr 26, 2015 8:57 pm

IanR wrote:the rear toe which was unable to be less than a +1.7mm, not a bit deal at this point and it keeps it stable while I am leaning to hold the slide!

Toe out will encourage turn in at the expense of straight line stability as well as increase understeer. In addition at high speed in a straight line it maybe a bit twitchy.

IanR · Postby **IanR** » Sun Apr 26, 2015 10:36 pm

Magpie wrote:
IanR wrote:the rear toe which was unable to be less than a +1.7mm, not a bit deal at this point and it keeps it stable while I am leaning to hold the slide!

Toe out will encourage turn in at the expense of straight line stability as well as increase understeer. In addition at high speed in a straight line it maybe a bit twitchy.

right, im meaning +1.7 is toe in, I was hoping they would be able to get zero toe, but was happy at least it didnt get stuck at toe out which would be twitchy, its got something going on up front too because under full load lift off at 140 plus is seems to wobble a bit...ill get to sort the koni's out soon enough, possibly they are on different settings L&R which would explain it. thanks for the input.

Magpie · Postby **Magpie** » Sun Apr 26, 2015 11:06 pm

I'm about to try 2mm (total) toe out in the rear so I'll let you know what it is like. You may need to do some investigation into why the toe lacks adjustment. Are the alignment bolts stretched, bushes ok, control arm damaged? Good luck with the build

ManiacLachy · Postby **ManiacLachy** » Mon Apr 27, 2015 7:57 am

I don't know how I've missed this thread so far, but now that it's found I'm liking it!

IanR · Postby **IanR** » Mon Apr 27, 2015 1:35 pm

ManiacLachy wrote:I don't know how I've missed this thread so far, but now that it's found I'm liking it!

Thanks mate, stay tuned there is more on the way soon.

Roadrunner · Postby **Roadrunner** » Tue Apr 28, 2015 5:44 pm

Very neat setup, Love the wheels!
Nice to see another turbo in Newy :mrgreen:

IanR · Postby **IanR** » Thu May 07, 2015 9:41 pm

Highlights of the week was finding the creaking bushing in the rear suspension, was driving me mad...All sorted and without the creaking I can enjoy the drive. Second was learning about the dark arts of dyno magic and the illusion of torque during a visit to Professor of Combustion NitroDann... and thirdly was polishing the dull headlights...

IMG_0271a.jpg

IMG_0272a.jpg

IMG_0273a.jpg