MX5 SP Mods

[Marador]

Hi

I am planning my first 2 sets of mods for my SP which I bought a few months ago from my auntie and uncle who resides somewhere on here.

As im getting a little clutch slip at the moment, or a lot depending on what ive been doing... im going to replace the clutch and possibly put in a lightened flywheel at the same time. As i have never put a lightened flywheel in a car before, can i expect much of a gain ?

The second mod i want to do is a boost controller. I am looking along the lines of an AVCR here so that I can keep the boost the same in 1st and second and then increase it through 3rd-6th. But that leads to a few questions...

1. Can the SP safely had the boost increased without a larger cooler, fuel pump, injectors etc ?
2. Does anyone have any experience with boost controller options at this end like the AVCR, EManage or the turbo smart one ?

Once these two mods are done i will be looking to do a few basic suspension mods, although she already goes around corners pretty well

Thanks for any info

[green_comet]

Light flywheel, will make the engine rev alot faster, and drop revs alot faster, you will feel it mostly in during acceleration. It wont really give you much gain at all, it will just make the engine behave differently.

As for boost i have no idea, i would just leave it. The SP is fast enough as it is, all you will be doing is making it easier to loose your liscence.

[Boags]

I imagine that controlling boost per gear is not as simple as you might think. Obviously it would require some sort of switch to tell the computer which gear you are in for starters. I think you would need to go to a full stand-alone ECU to get funcionality like this.

I'm sure those who are better informed will be able to correct me if I'm wrong.

Oh, and I agree with what G-C said about lighter flywheels.

Boags

[ampz]

I wouldn't bother to lighten a flywheel on a turbo car...

I've never seen a gear dependent boos controller, but from this website.
This is what they show:

INSTALLATION
Installation was completed by Mercury Motorsport. Call Mercury Motorsport on 1300 558 650 for cost of installation and tuning.

- The red wire should be connected to power.
- The purple wire should be connected to engine RPM if you want to use Self/Learning and RPM based settings
- The purple wire can be connected to the injector signal wire to monitor fuel injector duty cycle
- The grey wire should be connected to the throttle The white wire should be connected to the vehicle speed signal
- The black wire should be connected to ground
- The yellow/green wire should be connected to ground

I am curious how they would work.
Maybe a speed versus RPM signal would be the determining factor of the gear you're in?

Edit: Further down the same page:

Gear Judge
In order for the AVCR to determine gearing, the Gear Judge feature must be set.
Choose the gear you want to set, on the right side you'll see the ratio (RPM/Speed) which the AVCR uses to determine which gear its in.
- Choose which gear you want to see using the Up/Down keys. Press the Next key to choose that gear
- Drive the car in that gear at a moderate speed. Press Next to set that gear
- Press the Left key to return to gear selection and repeat for the other gears in your car speed.

[Woo]

The AVCR I have in the blue beast is great, top points to Apexi for producing a top class unit.

The only drawback I have found is that is designed for 5 or less gears.
Therefore when you set it up you have the same boost setting for two of the six gears (5 & 6 in my case) and due to the RPM display being intrinsically linked to the speed display it is incorrect in one of those gears. In my case I just ignored 5th and know that when I'm in 5th the display is wrong. But then again 5th is a brief visit on it's way to 6th anyway.

The setup is a bit entailed but once setup is trouble free (just jot down your settings as a battery change will clear it's memory).

The AVCR far exceeds the features of say the E-boost but at a cost of course.

Running more boost in higher gears doesn't reduce the motor load but reduces the on/off impact that happens in the lower gears.
IMHO don't run more that 1 Bar .... definately not 2 Bar as I did (220 kW for 4 days )

Cheers
Wòó

[Benny]

If you increase the boost by more than 1 or 2 lbs, you will need bigger injectors, or plumb in a 5th one.
Good stand alone ECU's will allow you to have different amounts of boost in different gears, but most of them require you to put switches on the gearbox so that the computer knows what gear you're in.

Don't go over 10 or 11 lbs unless you put in some good pistons and rods.
Your engine won't last long otherwise as the engine is running high compression - which is why they drive so well off boost.

[Marador]

Thanks benny, thats exactly the kind of info regarding increasing the boost i was after.

Based on the info above i am not going to go with the lightened flywheel either... if your on the gas you dont spend much time in each gear as it is...

[KIJIMA]

Even at standard power output wouldnt you be wanting to put in an LSD at the same time you whack in a clutch? That, coupled with the $2 mod would totally transform the car and the way it drives, and would be ALOT cheaper to.

[Marador]

Where can i find more details on this $2 mod ?

I assume its replacing boost pipeing with new piping that doesnt have restricters ?

[Boags]

At the moment your turbo takes the boost reading for the actuator from the turbo side of the intercooler piping. This means that after the boost drop of the intercooler the manifold does not see the boost level for which the actuator is set.

By putting in a tee piece in a vac line from the manifold you can get the boost reading after the intercooler - and after the pressure drop. This reading will be 1-2 PSI lower than before the intercooler, so won't open the actuator until later. You are effectively upping the boost by 1-2 PSI, or whatever the pressure loss is across the intercooler. You are still technically running \"stock boost\" because you have not tampered with the actuator.

I hope that makes sense???

Boags

[Boags]

Where can i find more details on this $2 mod ?

Here.