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Hi,

I think I just wanted to clarify absolutely necessary mods vs. 'nice to have' mods. Car is 'squirted

I'm turbo - 12.5psi and I do not have:
- COPs
- Coolant reroute
- Oil cooler
- thick core rad (i am running an auto rad however)
- uprated clutch (running 1.8 stock)

I am also running 315cc injectors. So far, never more than 90% duty (@ redline).

In sweaty QLD, I expected my car to melt and die. But it's sweet, and has been FI for 2 years out here (3 in UK).

Correct me if i'm wrong, but there's a fair amount of marketing at play here.. I don't see all the bells and whistles as absolutely necessary.

Or, am i REALLY lucky?

Paul

Your particular usage plays a massive part in whether the above is needed or not..

Run the car for any decent time on the track and you'll almost definitely need all the above or it wont stay together long.
Just daily driving with the occasional squirt through the gears and you prob wont need any of the above.

Its the sustained high revs that usually causes heat issues, and requires the above solutions.

I've done several track days.

However, the qld raceway circuit isn't exactly flat foot all the time!

I'll have to do some data logs, but never seen >90 centigrade coolant. it's a cheap ebay auto rad.

Perhaps the 1.6 generates less heat? would seem logical to assume so. I have however noticed the turbo setup (over supercharged) produces more heat.

Do you monitor oil temps?

but never seen >90 centigrade coolant, if this is on the track then your cooling system must be awesome!

What are you using for data logs? Where are your sensors located and have they been calibrated?

315cc injectors @<90% and a stock 1.8L clutch that is coping with your power output for the past 5 years... You have somewhere around 160whp if I had to guess.

A nice clean auto rad may just be able to handle that on a good day.

How many Kms on the stock 1.8 clutch?

I'm running a stock SE clutch (SE turbo - 164 HP) but i'm assuming its only a matter of time before it gives up.

SE clutch in mine did over 127,000kms in total, at least 80,000 of them with 174rwkw = 230bhp. It was not worn out when I replaced the motor. Only replaced it because it was convenient. I'm as gentle on clutches though as I'm vicious on brakes.

In what way are COPs needed on the track?

davekmoore wrote:In what way are COPs needed on the track?

In my case for reliability reasons.

I fried 3 coil packs before I switched to COPS and have had zero issues since.

Think it was the 6-7 cycles each track day of getting everything super hot from a session on track then parking the thing between sessions, where the heat just wafts up and heat soaks the coil packs.
I know lots in the club have no issues at track days with std coilpacks, but for me, three in 6mths (and theyre not cheap) was the last straw. So I put in toyota COPS and have never looked back.

Assuming you have an aftermarket ecu the toyota units are actually cheaper to replace then the mazda coil packs.

Word of warning though, I've been through 3 sets of eBay ones. Gave up and purchased used toyota ones from the wrecks and not a fault since.


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To the OP,

As someone who has built, tuned, dríven and maintained dozens of turbo mx5's, Id say you drive very conservatively.

In your head this may not seem right, but im absolutely certain you drive very conservatively compared to a lot of people.
As was said right away, its about the use and horsepower not the boost pressure. While you may find your car adequate all of the time I guarantee Sebastian Loeb (Or even Mark Hellmun) can fry your clutch, brakes, coolant, oil, and almost definitely your wheel bearings in 3 or 4 laps of a fast circuit.

As a quick example, I routinely fit inconel stud and nut kits to cars, which is 4 studs and 4 special nuts costing >$150 alone to hold the turbo to the manifold. We also machine the flanges and run no gaskets to eliminate the gaskets from failing, on top of this the manifolds and turbos are machined and tapped to fit studs with 55% more cross section for 55% more strength which are held in with a special ceramic locking compound which costs $200/bottle, because even the near 50 dollar each stud and nut combo in OEM 8mm diameter sometimes isnt enough.

For those not reading between the lines, grade 12.9 bolts with locknuts, locktite and metal gaskets isnt enough to stop the turbos literally falling off many (including street only) cars which are dríven very hard.

Dann

Here is one shot of a car recently outfitted with the Resbond, Inconel, Stage8, no-gasket combo.

This is a fully street dríven nissan silvia using a genuine HKS manifold with stock turbo, OEM studs and locking tabs, with a metal gasket. It lasted <1 month until the turbo was held on with one nut which was on about 5 threads. The genuine HKS manifold also had 3 cracks in it, although Im not sure how long they had been there.

This is a good example of the difference between drivers, OEM nissans with average drivers last the lifetime of ownership without the turbo falling off, but one 22 year old, a few weeks and a few sets of tyres and the turbo is literally only in the engine bay because of 5 threads and the oil lines holding it in.



Dann

A full breakdown of these parts and when they need to be fitted.

Paulus wrote:Hi,

I think I just wanted to clarify absolutely necessary mods vs. 'nice to have' mods. Car is 'squirted

I'm turbo - 12.5psi and I do not have:
- COPs
Typically past 14psi, OEM coils have spark breakdown at higher boost levels, the car literally misfires during boost.
- Coolant reroute
This allows the car to be tuned for more power (happy to explain why) and helps cool cars dríven hard for prolonged periods
- Oil cooler
On cars dríven hard enough for prolonged periods this prevents premature wear due to oil no longer protecting as well as it should, outside of its rated heat range
- thick core rad (i am running an auto rad however)
Again, a 500whp drag mx5 could probably do without a radiator as it only has to be dríven for 9 seconds, its about how hard and how prolonged (and duty cycle) of power use.
- uprated clutch (running 1.8 stock)
This comes down to torque, many turbo setups on stock clutches literally slip and the car freerevs to redline without accelerating, this typically happens at 8-10psi, but depends on total torque put down.

I am also running 315cc injectors. So far, never more than 90% duty (@ redline).

In addition, these injectors and duty cycle tells us you are unlikely to be making a lot more than 160whp, which is 100whp less than some stock engined turbo guys are making, this is also a significant difference in the cooling and clutch mods required.

In sweaty QLD, I expected my car to melt and die. But it's sweet, and has been FI for 2 years out here (3 in UK).

Correct me if i'm wrong, but there's a fair amount of marketing at play here.. I don't see all the bells and whistles as absolutely necessary.

Or, am i REALLY lucky?

Paul

I hope this answers a bunch of questions.

I think it's good to dispel myths when we can, based on experiences. Save people money. My experiences are pretty different to the suggestions on the internet – I think majority due to driving style and the 1.6 motor.

Datalogs- megasquirt, sensors; OEM. I’ll upload after my next track day, unless it melts.

5 years supercharged. 6 months turbo - allegedly ~180bhp supercharged (i say that because i've had different dyno results). let's say 170bhp. 10.5psi, regularly revlimiting on the track. I’ve wound the tubby up to 12.5psi, no idea of bhp but was shocked to feel the 1.8 oem clutch hold the torque. I only went upto the torsen because of the internet.. the 1.6 open wasn't exhibiting any issues.

Let’s deal with each item separately; the purpose is testing the null hypothesis that all these mods are required

Clutch – actually ‘used’ 1.8 clutch (!!) bought off a guy in wales (UK). I think 20k miles. Well established knowledge that torque kills… correlated to driving style (a la, slip that thing and it dies). If I continue to ‘delay’ power until revs are match and no slip possible, I’ll extend it’s life.
Likely upgrade needed for the slipper and more aggressive gear changing.

COPS – legit, I don’t see the need on the 1.6. no spark blowout and no reliability issues. 1.8, different story.

Injectors – depends on duty cycle. But I seem to be ok on 315cc. nice idle for the smaller size. Next dyno I’ll let you know

Rad and coolant re-route. For street, in my experience auto (two cores?) is fine. Track, fine supercharged.. but will have to report back now turbo. Re-route? Turn on the heater. Turbo I can feel a sh*t load more heat, so yes.. this one may be needed.

Oil cooler- no idea why needed for my use. But I don’t monitor oil temps, relying on coolant temp being the symptom. Competitive track, more likely.


The point is… don’t spend $$$ if you don’t have to. Monitor your temps and decide yourself.

rascal wrote:Your particular usage plays a massive part in whether the above is needed or not..

Run the car for any decent time on the track and you'll almost definitely need all the above or it wont stay together long.
Just daily driving with the occasional squirt through the gears and you prob wont need any of the above.

Its the sustained high revs that usually causes heat issues, and requires the above solutions.

Dead right.

Magpie wrote:but never seen >90 centigrade coolant, if this is on the track then your cooling system must be awesome!

What are you using for data logs? Where are your sensors located and have they been calibrated?

I may revise that to 95 degrees!! haha. no calibration, just listening for boiling water and comparing sensor reading.

I'll verify/prove myself wrong next track day

NitroDann wrote:To the OP,

As someone who has built, tuned, dríven and maintained dozens of turbo mx5's, Id say you drive very conservatively.

In your head this may not seem right, but im absolutely certain you drive very conservatively compared to a lot of people.
As was said right away, its about the use and horsepower not the boost pressure. While you may find your car adequate all of the time I guarantee Sebastian Loeb (Or even Mark Hellmun) can fry your clutch, brakes, coolant, oil, and almost definitely your wheel bearings in 3 or 4 laps of a fast circuit.

As a quick example, I routinely fit inconel stud and nut kits to cars, which is 4 studs and 4 special nuts costing >$150 alone to hold the turbo to the manifold. We also machine the flanges and run no gaskets to eliminate the gaskets from failing, on top of this the manifolds and turbos are machined and tapped to fit studs with 55% more cross sectional area which are held in with a special ceramic locking compound which costs $200/bottle, because even the near 50 dollar each stud and nut combo in 8mm diameter sometimes isnt enough.

Dann

Good points, maybe i need to push the car more.. or maybe i shouldn't. No inconel here, just bunnings.


This is just a street car with track usage once every 2 months. Suggest we calibrate our advice to suit usage.

Absolutely. I start 90% of customer interactions by asking goals, intended use, and honest driver experience.

Your injectors will not support the HP you think you have, btw. Physics.