Converting a SM to a full ITA ride "build"

[iambhooper]

So the last few times I've been on track, I've ran the SM in ITA. I'm really happy being back in IT, and want to convert the car over to full ITA spec car (as budget and time allow). I know the 1.6 isn't ideal, but it is what I have.

The car is a tiring crate 1.6, with a nice header on it. Other than that, it is full SM. I've finally got all the electrical bugs worked out, so that's not an issue, but I do need to go back and strip out the ABS wiring from the harness.

It has one issue, that I need to figure out a fix for... under heavy straight line braking, it feels as if it "hops" in the front. I'm thinking the bilsteins are worn and causing the hop. If that's the case, can I use the SM coilovers with Koni's, or do I need a new setup? If so, what's a good spring rate to start with?

As for the motor, does removing the emissions vacuum goodies do much, or should I even bother?

Is there a good enough gain with a Megasquirt PNP? If so, from what I've read, it's possible to eliminate the AFM from intake. Is that something allowable, doable, worth it? If not, what cold air intake do I need to look for?

Thanks!

hoop

[gran racing]

Is there a good enough gain with a Megasquirt PNP?

Yes.

As with most cars, you're going to hear a lot of different opinions. It also depends on your driving style. I'm sure Andy will chime in as he had one of the best built ITA Miatas out there.

[jwasilko]

It has one issue, that I need to figure out a fix for... under heavy straight line braking, it feels as if it "hops" in the front. I'm thinking the bilsteins are worn and causing the hop. If that's the case, can I use the SM coilovers with Koni's, or do I need a new setup? If so, what's a good spring rate to start with?

Is there a good enough gain with a Megasquirt PNP? If so, from what I've read, it's possible to eliminate the AFM from intake. Is that something allowable, doable, worth it? If not, what cold air intake do I need to look for?

Thanks!

hoop
I had Ohlins shocks in my old car, and I'm going to move back to them this winter. There's lots of options for spring rate.

The Megasquirt is a good aftermarket ECU, and you will pick up power (and have the ability to adjust the redline, which helps, too).

Keep in mind the rules regarding the AFM state:

"On cars so equipped, the air metering/measuring device (i.e. air flow meter, air mass meter, MAF) must be operational and shall not be modified."

-jeff

[iambhooper]

I had Ohlins shocks in my old car, and I'm going to move back to them this winter. There's lots of options for spring rate.

While I have no doubt they are nice, $3000 "may" be out of my budget for this car (or any). Hence, why I was aking about using the SM coilovers on Koni's.


The Megasquirt is a good aftermarket ECU, and you will pick up power (and have the ability to adjust the redline, which helps, too).

Keep in mind the rules regarding the AFM state:

"On cars so equipped, the air metering/measuring device (i.e. air flow meter, air mass meter, MAF) must be operational and shall not be modified."

-jeff

I thought that was the case, but a fella can whish. :D

[jwasilko]

Might be worth looking at ISC's suggestions:

http://iscracing.net/miatasuspension.html

[Greg Amy]

"On cars so equipped, the air metering/measuring device (i.e. air flow meter, air mass meter, MAF) must be operational and shall not be modified."
Note that the intent of that rule is not that you have to use its signal, it's to keep you from modifying its mechanical "operation" -- and thus air restriction. Other regs allow you to install a MAP (if not already equipped) to properly work with the Megasquirt.

We've debated this back and forth, but no one has yet to come up with a good verbiage to replace that, without allowing some level of intorturation of the MAF.

- GA

[iambhooper]

We've debated this back and forth, but no one has yet to come up with a good verbiage to replace that, without allowing some level of intorturationof the MAF.

- GA

Googleing that word didn't provide me with a definition, instead it provided me with http://tgadrivel.blogspot.com/2012_11_01_archive.html

For which I will need to find some time to read. :D

Nonetheless, I believe I understand the idea behind the "word". Either way, if/when I do a Megasquirt, it would be a good idea to let someone who know's what they are doing do with it what they will.

[JLawton]

A good portion of the guys run their ITA Miatas with the SM set up. That's probably the best/cheapest way to go. The biggest bang for your buck is getting more horse power. Magesquirt is a good start just make sure you know someone local who can tune it.

[Ron Earp]

Check with Ron M, he had his MS conversion done by Peter Florence as did Jeff Young.

[Andy Bettencourt]

Sell the 1.6 SM, buy a 1.8 SM for similar money and THEN do a conversion to ITA.

Then call me.

[iambhooper]

Sell the 1.6 SM, buy a 1.8 SM for similar money and THEN do a conversion to ITA.

Then call me.

:D If I sold the car, and was dumb enough to buy another, it would be a FWD somethinorother. Hence, I'm trying to patch up what I got. We've been competitive in ITA, but I'm always looking to improve things.

[mossaidis]

I know Andy is biased and probably justifiably so. On the other hand, folks think a full prepped 1.6 ITA Miata at LRP would do very well, if not, get close to the lap record set by Andy's 1.8 ITA Miata before weight was added. Bruce Perry's 1.6 ITA Miata is living proof that that car can kick ass at WGI as well (2.17's if remember correctly).

[Andy Bettencourt]

I ran the same time as my track 2007 record at the 2012 NARRC Runoffs with teh extra poundage...the only thing holding the car back is a fresh driver. Getting on the track once a year just isn't good enough from a driver skill standpoint. It's a mid 1:00 car there. It's been 1:00.8 with less power.

I do think the 1.6 could be a fine LRP car but that is an anomaly of a track. Trust me when I say that a full-tilt 1.8 ITA car at WGI is a low 2:16 car all day long. All you need to have is a 'Leverone' who will drive anything anywhere to validate. :)

The biggest advantage is the torque output and curve of the 1.8. Something I highly value.

If you want wrong-wheel drive, go for it! Just make it an ITR car!

[iambhooper]

I ran the same time as my track 2007 record at the 2012 NARRC Runoffs with teh extra poundage...the only thing holding the car back is a fresh driver. Getting on the track once a year just isn't good enough from a driver skill standpoint. It's a mid 1:00 car there. It's been 1:00.8 with less power.

I do think the 1.6 could be a fine LRP car but that is an anomaly of a track. Trust me when I say that a full-tilt 1.8 ITA car at WGI is a low 2:16 car all day long. All you need to have is a 'Leverone' who will drive anything anywhere to validate. :)

The biggest advantage is the torque output and curve of the 1.8. Something I highly value.

If you want wrong-wheel drive, go for it! Just make it an ITR car!

Even though I've never driven it, I know well enough to know that VIR and LRP are 2 entirely different tracks.

Am I wrong in thinking that the only difference between a 1.6 and a 1.8 is the motor and dash? If so, couldn't I just do like I did with the carbed ITC CRX and convert it over? The GCR allows for this.

[mossaidis]

There's a thread somewhere here on making a 1.8 ITA out of a 1.6 in ITA. It's more work than you think. Just ask Jim Alley.

[Andy Bettencourt]

There's a thread somewhere here on making a 1.8 ITA out of a 1.6 in ITA. It's more work than you think. Just ask Jim Alley.

+1

[Chip42]

hoop - make sure you still have the 1.6L rear end in that car, 1.8L parts are legal in SM And NOT in ITA.

the 1.6L doesn't have a throttle position sensor "really". it has a button that tells the ECU "yup, It's open". mazda did the same on the S4 engine RX7s - maybe even later. ITCS allows you to add or replace a TPS. do so - it will pay big dividends with the ECU, and an MSPNP can be made to work with just about any TPS.

I think the 1.6L properly done should be a reasonable A car. have fun.

[Andy Bettencourt]

the 1.6L doesn't have a throttle position sensor "really". it has a button that tells the ECU "yup, It's open". mazda did the same on the S4 engine RX7s - maybe even later. ITCS allows you to add or replace a TPS. do so - it will pay big dividends with the ECU, and an MSPNP can be made to work with just about any TPS.



Both of those cars came with the flapper-style AFM. Later cars had the MAF.

[jwasilko]

There's a thread somewhere here on making a 1.8 ITA out of a 1.6 in ITA. It's more work than you think. Just ask Jim Alley.

I'm glad to have picked up that car :-)

[UNCbigM]

Interested to hear/see what you're doing here Hoop. I just picked up a 1.6 after renting a friends this past season and I'll be converting to ITA sometime after 2014. I'll be running in ITA in SM trim through May, then I gotta be busy as a baby daddy so that'll give me the rest of 2014 to be better prepped for ITA.

See ya on the track!

[MSPERBER]

Miata Miata Miata, stop hitting the easy button and build something different, I need something I can draft with, all these little dam miatas.:)) rebuilding my focus after one long year and I am already behind.

[DaveOH32]

Miata Miata Miata, stop hitting the easy button and build something different, I need something I can draft with, all these little dam miatas.:)) rebuilding my focus after one long year and I am already behind.

How 'bout a CRX?

[XelderX]

Miata Miata Miata, stop hitting the easy button and build something different, I need something I can draft with, all these little dam miatas.:)) rebuilding my focus after one long year and I am already behind.

Hold your horses. My Protege is at the fab shop getting the cage put in it. I'm hoping the suspension for the autoX car shows up in a week or two so I can move the old Konis back onto the Protege.

[UNCbigM]

ITA is going to be so much fun this year! Take your time Sperber ;-)