From garage queen to time trial dream - '92 TTD build
 

Well hopefully my driving skills are better than my poetry skills!

I introduced myself here, but I have a '92 Miata that I am planning to build for NASA Time Trial.

One thing that I didn't mention is that I want to keep the car street legal and reasonably comfortable. Here in Houston that means the air conditioning has to stay and, with a dyno reclass, I will probably need to carry enough weight to keep the full interior.

The first step is to make the car safe and reliable for the track. It is low mileage, about 35K, but old of course.

Pre-track maintenance

1. Replace all fluids - what are the recommended synthetics now days for the transmission and rear diff? I have the VLSD by the way. I did like Redline on the Camaro.

2. Replace all belts and hoses, including the timing belt. Are there better than factory recommendations for these?

3. Replace brake fluid and pads. I am a Castrol SRF fan (set it and forget it!) and although I think that I could nurse the stock compound pads through a track day or two, I am afraid of the age. Will almost certainly go with Carbotech so that I can swap street pads back in if I have a couple of months between events (see the street legal comment above).

4. What am I overlooking?

Pre-track upgrades

Before the first track day I plan the following hardware upgrades:

1. Aluminum radiator - I want to stay with one of the thinner ones to keep the weight off the nose because of the a/c. I would also like one with a completely stock inlet and outlet because of the coolant reroute.

2. Coolant reroute - the full blown versions like 949racing seem like too much work to me, so I will wait until I have overheating problems to go to that. I found and ordered the racer coolant reroute kit from Bell Engineering and will hope that is enough. Besides, it is Time Trial, one lap is enough, right?

3. Braided brake lines - just good insurance because I never felt the difference when I put them on my 2007 Mustang. Maybe it has something to do with sliding calipers and or that the calipers on the Mustang possibly flexed.

Actual build

I will go into more detail later as all of the TTD cars in Texas seem to have disappeared this year. So my plan of 150-160rwhp and a race weight of 2380lbs or so has changed.

I am not sure whether to go up to TTC with more hp or down to TTE with more weight. There are about 8 TTE cars signed up for MSR Houston this weekend. Maybe I can get the car down to 140rwhp with a restrictor.

- Wayne

Edit to add: I know, search nOOb and I will, but if there are definite forum #1's I wouldn't mind if someone answered here.

And since it seems that pictures are a good idea in build threads, here are a couple:


2007 Mustang GT that got me started

https://www.miataturbo.net/attachmen...ine=1421381869

(Those magnetic numbers were great until one flew off at about 110!)


1998 CMC Camaro

https://www.miataturbo.net/attachmen...ine=1421381869

(I think the white color and those BBS wheels are what let a Ford guy since high school buy a Chebbie!)

1992 Miata c-package

https://www.miataturbo.net/attachmen...ine=1421381869

(Poor thing, sitting all those years in the garage, doesn't know what is about to happen!)

- Wayne

Welcome Wayne!
Coming from those past cars, when you get the braking system sorted and you're on a set of stickies this car is going to blow your mind in the braking zones.

Here are some notes:

None of us are great poets, but after a few drinks we sure think we are... works the same for driving! No, wait... ;)

No Redline. Yes Amsoil.

Gates Racing timing belt is good.
If you are going to keep your power steering, consider fire sleeve on the lines. Most track cars yank the PS, and a burst line is a common cause of on-track fires (for all cars, not miata specific)

Stock pads won't last a day. Carbotech XP10/12, Hawk DTC-60, PFC 01... Be aware that Carbotechs are very sensitive to transfer layers on the rotor, so you need a set of dedicated rotors to go with the pads if you're swapping between track/street use. I did this for a while, but later switched to the Hawks which are not sensitive to this.

Safety items

Sounds about right.

I personally choose the class that allows more freedom in changes to the car and more speed. However, the sensible approach is to go down a class rather than up, so that the budget stays manageable instead of doubling ;)

-Ryan

I would start out with TTE. It is very easy and not very expensive to get the car to a power and weight that is competitive in E. Getting the car finished so that you can get plenty of seat time should be priority number 1, so don't go overboard with engine mods for 2015. Intake, exhaust, and ecu will easily get you to TTE power levels. Use 2015 to set up the suspension, scope out the local competition in E/D/C, and to become a better momentum driver, then start adding power next winter if you still think you need/want it.

We have some really useful threads here for TTE and TTD setups. Make sure you read through those before spending any money.

All sounds like your well on the right track...only thing I would add is that coming from big cars with some power/torque the drive experience may not initially be very exciting....but out braking and cornering around those big cars is a LOT of fun!

Is this guy getting trolled? No one has commented on the Begi RACER re-route yet?

not by me, but I've never heard of the begi racer re route...presumed it was viable...?

increased HP decision
 

I did my first track day in the Miata at a Chin Motorsports event at TWS. As I expected, it was a totally different driving experience from the CMC Camaro. There were a couple of corners that I just breathed on the brakes because I couldn't avoid slowing the car down too much if I got on them fully.

I have spent 100's of hours on this and other websites trying to decide the best way to increase HP for NASA Time Trial. I couldn't find the best thread to ask my question, so I will just throw it in here and hope for a few replies.

I would like to change the RWHP from 135 to 150 easily so that I can move between TTE and TTD as the number of entrants change:

1. 1.8 swap

Pros - lowest cost ($1500)
Cons - most work, cannot easily change RWHP

2. DIY turbo

Pros - low cost ($2000)
Cons - no fab skills, ECU required, no experience

3. FFS

Pros - easy install, pulley change for HP
Cons - expensive ($5000)

4. BEGI Shanghai-S

Pros - easy install, low cost ($2300)
Cons - not sure about HP change

There is no way I can justify the almost $3K difference between the FFS and BEGI system, so I think that I will have to go with the Shanghai-S.

Are their any alternatives that I missed? Am I missing something important in general?

Again, the goal is to run heavy with a dyno reclass to keep the car comfortable on the street.

I would HIGHLY suggest not going forced induction anything for a max of 150hp.

Try a VVT swap and different ECU maps for the 15hp swing.

That's basically what a couple of other TTD Miatas that ran at the last NASA TWS are planning. Both have '99 engines with MegaSquirts making 137ish. They said they were planning on tuning down to 130 to make TTE.

I'm points based and still have enough to add an aftermarket ECU and stay in TTE, (when funds become available). You would have to keep a 1.6 to stay points based. You'd have to ask those with more knowledge if 150 is doable with a 1.6.

Not to mention most components of the Shanghai kit are not what i would call "track worthy."

Thanks for the replies. The 1.8 swap was by far my last choice because of the amount of work involved but I definitely need to look more into the VVT motors.

1.8 swap is undoubtably less work than installing a Begi kit.

Don't stress having power do suspension wheels and tires and some safety things and get some seat time. Once you can get around 2.02s at TWS or 1.51's at MSRH then start modding more to fit the class you want to play in.

So, since my last post I've decided that it wasn't worth the effort making the '92 competitive in NASA TT and bought a '99. Then I decided that TT was too much time and money and sold the '99.

I still have the 1.6 Miata in the garage - what about SCCA autocross? It is not competitive in the Street class but very competitive in Street Touring. As I mentioned above, I plan to keep it reasonably comfortable on the street and kept a/c and power steering. With the goal of a locally competitive car I got good tires, coilovers, big front bar, and have now done two years of local events.

It is time to add some power but I'm not ready for an ECU, mainly because I have to keep the AFM. The plan is high flow cat, exhaust, CAI, and timing advance before the January event. Here is my duplicate post from miata.net about a problem with the Racing Beat CAI install:

I'm trying to install a Racing Beat CAI on my '92 and the wire harness will not reach the AFM:

https://farm5.staticflickr.com/4893/...aa6daaea_c.jpg

I followed the instructions "The wire harness leading to the air meter must be carefully
straightened and re-positioned to give adequate length."

The intake seems farther from the brake lines than the Racing Beat example and some photos online:

https://farm5.staticflickr.com/4869/...5a259fba_c.jpg

However moving the bracket so that the intake is much closer to the brake lines still doesn't enable me to attach the wire harness - at least without stretching it a lot harder than I want.

Am I missing something? Should I just massage the bracket until it works?

Finally, I found this online. Will the AFM work properly upside down?

http://www.fagerquist.com/miata/build/tb%2023.jpg

An NA6 should be very competitive in ST/TT6

Yes the AFM will work upside down. It's just a vertical flapper door, so putting it upside down won't hurt anything.

All the I/H/E mods in the world won't make a 1.6 breath well until you ditch the AFM however.

I took a midfield 1.6 spec miata making 120 to the wheels, put a MSPNP1 on it, removed the maf, and added a couple degrees to the base map. With no other changes, we saw a 5hp advantage above 6,000rpm. It was literally a ~5 minute modification on the dyno, back-to-back runs. It was mainly to prove to my boss that there wasn't much more to be had with the 1.6 unless we ditched the AFM.

The "Spec" Miata was obviously a race shop built 1.6, I've installed a handful of MSPNP1s, widebands, AITs, and CAIs on 1.6s, usually netting from 110-120 (not bad for 100k+ blocks), which is a very cheap and fun track package, especially because these were probably all 90-100whp beforehand. The MSPNP1s can be had for as little as $300 these days and have plenty of features for an otherwise stock 1.6. This is all a moot point if you're saying you're not allowed to remove the AFM for class reasons though...

...and NASA Texas decided to make a 200TW sub class, which I'm against, but there's that. At least they still count towards class contingency.

Yes, I must keep the AFM for the SCCA STS class.

In case anyone else ever has this problem, I assume the wiring harness is essentially hand made and has some variation. I found a connector to the fender and pulled it out, giving me plenty of slack to follow the Racing Beat directions:
https://farm8.staticflickr.com/7910/...728af26b_c.jpg