Region: NASA-SoCal
Car #: 23
Year : 1995 Posts: 912
Status: Offline
posted
o·ver·dog (ō'vər-dôg', -dŏg') One that has a significant advantage.
Not sure if that's the definition you were looking for, but that's what google says.
Most guys run with hardtops because it's better for aerodynamics, so you can get higher top speeds down the straights. Plus, it keeps your helmet from scraping on the ground when the wrong side is facing up.
I've never personally seen anyone run open, but I know a few guys do.
-------------------- Rob Gibson RJ Racing 2010 NASA Nationals TTE Champion 2008/2009 WERC Champion 2007 NASA SoCal SM Champion rjracing.net Weekend-Racer.com
Region: 11
Car #: 09
Year : 99 Posts: 143
Status: Offline
posted
I am new to the forum and the class, but have been involved in motor racing for over 25 years. I am looking to build my own SM and have several questions.
Donor cars - Can I use say a 92' chassis with a 94' engine? Seem to have many cars in the area that have received engine swaps. Given that I will be mostly running in the SE, Sebring, Daytona, Homestead, Moroso, Roebling and Road Atlanta, is there a preferred year order? I seems the 98' is being avoided or not talked about. I would lean towards a lighter car being that I weigh under 170lbs an I hear arguments for later cars for heavier drivers.
Gearbox - How difficult, costly, time consuming , reliable is an automatic swap for a manual? Seem to be many available autos in my area.
Engine - What is an OK compression ratio on a used 100K plus engine?
OK I'll say. The first thing you need to do is read the GCR which is the rule book and covers many of the important issues. It is available as a free download from the SCCA web site. Answers can also often be found by doing a search on this website.
To answer your first question, you can not do the the engine swap. A 1.6L car keeps a 1.6L engine. 1.8L cars are split by years. The GCR covers it.
Here is the other priceless nugget. It's cheaper/easier to buy a car already built.
Region: NASA-SoCal
Car #: 23
Year : 1995 Posts: 912
Status: Offline
posted
quote:Originally posted by cpdenis: Donor cars - Can I use say a 92' chassis with a 94' engine?
No. 94 cars have a 1.8L engine and 92s have a 1.6L. It may be possible to put a 93 engine into a 92, cause they both had 1.6L. Same with 94-95 (same engine) and 96-97. But not a 96 in a 95 or 94 because there were slight differences in the 1.8L between those year ranges.
quote: Given that I will be mostly running in the SE, Sebring, Daytona, Homestead, Moroso, Roebling and Road Atlanta, is there a preferred year order?
Read the FAQ. There are a LOT of things to consider when choosing a year. I went with a '95 1.8L because I'm over 200 lbs, but also because with 90-93 being the only years with 1.6L engines, whereas the 1.8L was used from 94-05, I figured parts would end up being more plentiful for the 1.8L.
But basically, 1.6L is lightest with least power, but smaller brakes. 94-97 1.8L has a little more power, a little more weight, and bigger brakes. And the 99-05 have even more weight, and with the changes in the chassis, I've heard that you need to be a little smoother driving them.
I've noticed that there aren't many 96-97 cars out there, and that may be because the mods to that year's engine were mainly to allow a higher compression ratio at the stock timing, so they have a smaller opening in the restrictor. But since timing settings are open, you can advanced it on a 94-95, and end up with a similar compression ratio to the 96-97, except the 96-97 still has the smaller restrictor opening. So theoretically, a 94-95 would have more power than a 96-97, but with the same weight. [I'm sure what I just said about the engine differences isn't completely and technically accurate, but you get the point.]
quote: I seems the 98' is being avoided or not talked about.
Probably cause there are no 98 Miatas that were built in the U.S.
quote: I would lean towards a lighter car being that I weigh under 170lbs an I hear arguments for later cars for heavier drivers.
170 isn't heavy, but it's not exactly light when you consider how light the Miata is (2325 lbs with driver for 1.6L)
quote: Gearbox - How difficult, costly, time consuming , reliable is an automatic swap for a manual? Seem to be many available autos in my area.
I personally wouldn't do it, if only cause there are too many manual cars available that won't require the extra work.
quote: Engine - What is an OK compression ratio on a used 100K plus engine?
Dunno.
-------------------- Rob Gibson RJ Racing 2010 NASA Nationals TTE Champion 2008/2009 WERC Champion 2007 NASA SoCal SM Champion rjracing.net Weekend-Racer.com
quote:Originally posted by Rory: Here is the other priceless nugget. It's cheaper/easier to buy a car already built.
You seem not to know very much about the Miata in general, so familiarize yourself with the car and the rules first: model years, engine revisions, restrictor plates req'd, allowed mods/backdating, minimum weight, etc. Take in a few races as a spectator first. Ask a lot of questions and take pictures of as many cars as possible (with the owner's permission of course. We won't bite. But we love fresh meat. If you think you can hack it, get your license then rent a car. If you still think you are into it, you will know what to do next.
Region: 11
Car #: 09
Year : 99 Posts: 143
Status: Offline
posted
OK, I've taken all the suggestions as above and I am looking at a 93' car. I am interested in the build myself, and will pass on the already built SM. I'll probably regret it later.
1- How can I tell if a hardtop is original or aftermarket? 2- The car has the Vin number and stickers on the door jamb, and front fenders, but most of them are painted over or just erased. Does it matter? Chassis is straight, never crashed. 3- The radiator is leaking, I am planning on replacing it and I am assuming the engine will need a complete set of gaskets and probably a water pump rebuild or replace as well as new belts.
What are the mechanical replacements or rebuilds, brakes, engine, that should be undertaken during the build and the approximate parts cost?
Region: WDCR - 042
Car #: 75
Year : 93 & 95 & 99 Posts: 3727
Status: Offline
posted
quote:Originally posted by POWERSS: Why is there a difference in restrictor plate size between 94 -95 and 96-98 model years when nothing else seemed to change?
Also, why is there no penalty to >2001 even though the compression ratio was increased by .5?
Can 1999 and 2000 run the 10:1 compression ratio?
2001+ = VVT. They do not seem to run as well as the '99, '00 cars.
'94-'95 are OBD1 cars while '96-'97 cars are OBD2 cars. The OBD2 adjust timing to warrant the smaller plate. Some argue because the replacement crate motor is the same.
'99-'00 are 9.5.1 cars.
-------------------- Mike Collins MEATHEAD Racing http://www.SHEETZ.com The MEATHEAD Racing 2010 Calendar is up!!!! www.MEATHEADRacing.com SMAC Member WDCR-SCCA SM Drivers Rep. ALL OPINIONS ON RULES OR SPECIFICATIONS ARE JUST THAT, MY OPINIONS!
Region: WDCR - 042
Car #: 75
Year : 93 & 95 & 99 Posts: 3727
Status: Offline
posted
quote:Originally posted by cpdenis: OK, I've taken all the suggestions as above and I am looking at a 93' car. I am interested in the build myself, and will pass on the already built SM. I'll probably regret it later.
1- How can I tell if a hardtop is original or aftermarket? 2- The car has the Vin number and stickers on the door jamb, and front fenders, but most of them are painted over or just erased. Does it matter? Chassis is straight, never crashed. 3- The radiator is leaking, I am planning on replacing it and I am assuming the engine will need a complete set of gaskets and probably a water pump rebuild or replace as well as new belts.
What are the mechanical replacements or rebuilds, brakes, engine, that should be undertaken during the build and the approximate parts cost?
Looking forward to the suggestions.
CP
1 - Hardtop and Snug tops (aftermarket) are the most common. The best tell tale (not a guaruntee) is if you see a one inch tab at the top center of the back glass where the weatherstrip meets it is a OEM top. If the weather strip comes together at the bottom center with no tab it is most likley a Snug Top.
2 - You need to read two vin number by rule. I could teach how to beat that, but that would not be in the "spirit" of the rules. Your best best is that the vin on the firewall needs to match the vin on the dash.
3 - Replace everything that holds fluid.
What you replace is up to you. That is primary difference between a pro built $40,000 SM and a $7,500 SM back yard special. I've seen back yard specials just as fast as pro built cars, but not often and they certainly don't last as long.
-------------------- Mike Collins MEATHEAD Racing http://www.SHEETZ.com The MEATHEAD Racing 2010 Calendar is up!!!! www.MEATHEADRacing.com SMAC Member WDCR-SCCA SM Drivers Rep. ALL OPINIONS ON RULES OR SPECIFICATIONS ARE JUST THAT, MY OPINIONS!
Region: 11
Car #: 09
Year : 99 Posts: 143
Status: Offline
posted
I was under the impression that aftermarket tops were not allowed in SM. Am I mistaken? The dash is cracked from sun exposure and chipping away, how do I save the VIN tag?
Region: WDCR - 042
Car #: 75
Year : 93 & 95 & 99 Posts: 3727
Status: Offline
posted
You are not allowed to use an aftermarket top. It is near impossible to tell the difference between a snug top and OEM one the latches are removed. THe only visible difference is in the rear window gasket, but if you replaced the glass in your OEM top it would look like a snug top.
The VIN tag is held on with two rivets. Drill it out and move it to a new dash.
-------------------- Mike Collins MEATHEAD Racing http://www.SHEETZ.com The MEATHEAD Racing 2010 Calendar is up!!!! www.MEATHEADRacing.com SMAC Member WDCR-SCCA SM Drivers Rep. ALL OPINIONS ON RULES OR SPECIFICATIONS ARE JUST THAT, MY OPINIONS!
Region: WDCR - 042
Car #: 75
Year : 93 & 95 & 99 Posts: 3727
Status: Offline
posted
cpdennis, where do you live? I think you need to go visit someone near you. The Spec Miata community is full of great people willing to help out. Most of your questions could be answered over a beer in someones garage.
MEAT
-------------------- Mike Collins MEATHEAD Racing http://www.SHEETZ.com The MEATHEAD Racing 2010 Calendar is up!!!! www.MEATHEADRacing.com SMAC Member WDCR-SCCA SM Drivers Rep. ALL OPINIONS ON RULES OR SPECIFICATIONS ARE JUST THAT, MY OPINIONS!
Region: 11
Car #: 09
Year : 99 Posts: 143
Status: Offline
posted
Mike, I live in Miami, I've had a chance to speak to Mr. Drago (briefly), Chip Van Vurst and others at the track. Everyone is always very helpful, but I do not know anyone in my area with the forum's experts. CP
Region: Central
Car #: 1
Year : 1994 Posts: 61
Status: Offline
posted
Compression readings on a new engine should be 192 or so, depending on your gauge. Anything above 180 on a used engine should get the job done. Equal numbers should be what your looking for to get a handle on the engines health.
Region: 11
Car #: 09
Year : 99 Posts: 143
Status: Offline
posted
I'm thinking of ordering the miata cage kit. Can anyone tell me how long the installation should take? Experienced welder, 1st time install, car stripped, 2 person install. Txs
Region: NER
Car #: 46
Year : 1993 Posts: 160
Status: Offline
posted
Mike, I live in Miami, I've had a chance to speak to Mr. Drago (briefly), Chip Van Vurst and others at the track. Everyone is always very helpful, but I do not know anyone in my area with the forum's experts. Chip has a wealth of knowledge and is a great guy. Did I mention fast? I bought my first Miata from him. Worth the trip up from Miami.
-------------------- LTD Racing Chief Of Inappropriate Comments
I've built 7 SMT's with the Miatacage.com kit and found it to be (In my opinion) the best cage out there and Sean is very helpful and he has everything else to complete the car as well.The first cage I installed took a week, working about 4 hours a night, after purchasing a tubing notcher it can be done in a long weekend, assuming all the prep and door gutting is complete and the seam sealer is removed from the base pod area's. The instructions that come with the kit are great and every tube is numbered and again Sean is just a phone call away.
Region: SoCal
Car #: 13
Year : 1992 Posts: 847
Status: Offline
posted
quote:Originally posted by cpdenis: Gearbox - How difficult, costly, time consuming , reliable is an automatic swap for a manual? Seem to be many available autos in my area.
CP
I did the auto-to-manual swap over a weekend... It was easy and seems just as reliable. I'd recommend it if the costs are SIGNIFICANTLY lower than getting a manual donor to begin with. For instance my auto-donor was a free car!
-------------------- Thanks, John Mueller NASA SM National Director http://www.Weekend-Racer.com #13 "Tiger Miata" - 2009 SoCal SSM Champion
Region: 11
Car #: 09
Year : 99 Posts: 143
Status: Offline
posted
Given Chip's new schedule its hard to pin him down.
Danny99, thanks for the info. Without revealing any trade secrets, when you say a weekend are you saying 18 hours alone. If I gut the car and prep the floor and doors, how much time is there in the positioning of the tubes? I have a tubing notcher. I have not seen the instructions, but can I place and tack weld all the tubes in place then follow with the complete. Welder is very experienced.
John, at the time I was looking for a donor car Auto's were plentiful. Many people discouraged me from making the conversion, but I have a few friends who have undertaken the swap many times. Most of them on Civics, not on a Miata. I finally found a manual.
On my last two cars I had it tacked and ready for the welder in 12 man hours, there are a couple areas that you mock up and bench weld then install in the car due to the tight fit but that will make more sense when you see the instructions. Also many of the main tubes are aleady notched It really is a great kit.
Region: 11
Car #: 09
Year : 99 Posts: 143
Status: Offline
posted
And again another newbie question. I understand the 1.6s changed the size of the crank end in mid 92. If that is correct can you find out through the VIN number if that car has the upgrade or what is the difference visually?
How difficult or costly is an upgrade if the engine is not one of the updated ones?
Region: MidDiv
Car #: 13
Year : 92 Posts: 2873
Status: Offline
posted
quote:Originally posted by cpdenis: And again another newbie question. I understand the 1.6s changed the size of the crank end in mid 92. If that is correct can you find out through the VIN number if that car has the upgrade or what is the difference visually?
How difficult or costly is an upgrade if the engine is not one of the updated ones?
Again thank you for all your help.
You can find out by calling Mazda Motorsports with the VIN. They can pull it all up.
A short nose isn't a bad thing if built correctly. FWIW, I think the short nose was phased out in late 91. My 92 is a long nose on both my motors.
-------------------- ---------------- Z Brothers Racing / East Street Auto
Region: 11
Car #: 09
Year : 99 Posts: 143
Status: Offline
posted
Thanks Casey. Would you happen to know if their website is interactive? Plug in the number and get the results, or do I have to wait for Monday to call? Any clues on the visual, I am looking at a car tomorrow AM. CP
Region: MidDiv
Car #: 13
Year : 92 Posts: 2873
Status: Offline
posted
Get the VIN tomorrow and call them on Monday. You can't do it via the website. Ask for Tim Buck. He is a fellow SM racer and will give you the skinny on the chassis.
If it is a 92 you should be okay either way. Post your location and you may get a SM guy to help you take a look.
Region: chattanooga
Year : 1991 Posts: 54
Status: Offline
posted
I recently found a problem with my 1600. I had a noise that sounded like noisey lifters (a rattling sound -- almost tinney like loose sheet metal vibratine. It went away at ~2000 rpm. Since this engine had 160,000 miles, I decided to replace it with a crate. Upon removal, I found the bolt to be almost finger tight (Less than 10 lbs of torque)! I had this happen with an old chevy S-10 and should have recognized the noise. I haven't torn the engine down yet, but I have been advised that it is probably not worth rebuilding since cranks are over $500.
Anyone running a 90-91 small nose crank would be well advised to check the torque after every weekend, and if found to be loose, replace the key and bolt as described in the above link. Wish I had seen it last year. Frank
Region: 11
Car #: 09
Year : 99 Posts: 143
Status: Offline
posted
Ok, finally acquired a 99'. I have begun to strip the interior, and I wanted to clean, pressure wash the engine, suspension and undertray. Any suggestions or items I should watch out for. Of course I'll be doing this in the most eco-friendly way (disclaimer). Thanks CP
Region: WDCR - 042
Car #: 75
Year : 93 & 95 & 99 Posts: 3727
Status: Offline
posted
Don't spray anything electric.
-------------------- Mike Collins MEATHEAD Racing http://www.SHEETZ.com The MEATHEAD Racing 2010 Calendar is up!!!! www.MEATHEADRacing.com SMAC Member WDCR-SCCA SM Drivers Rep. ALL OPINIONS ON RULES OR SPECIFICATIONS ARE JUST THAT, MY OPINIONS!
Region: 11
Car #: 09
Year : 99 Posts: 143
Status: Offline
posted
Mike, thanks I was really careful, I brushed the engine bay with a detergent and littly rinsed with water and wiped down. I WD-40d everything, let sit for a few minutes then started right up. I let the engine heat dry the rest. Haven't tried under load, but no misfires. The radiator has a very small crack (that I wasn't sure about or didn't want to know) and is leaking, so that is a top priority on my upcoming parts order. The car came with what I believe and was told is an OEM top engine strut bar. Does it have to be removed if it came with the car? CP
Region: WDCR - 042
Car #: 75
Year : 93 & 95 & 99 Posts: 3727
Status: Offline
posted
The engine strut bar is not allowed in SM.
-------------------- Mike Collins MEATHEAD Racing http://www.SHEETZ.com The MEATHEAD Racing 2010 Calendar is up!!!! www.MEATHEADRacing.com SMAC Member WDCR-SCCA SM Drivers Rep. ALL OPINIONS ON RULES OR SPECIFICATIONS ARE JUST THAT, MY OPINIONS!
Region: Houston
Car #: 91
Year : 1991 Posts: 2171
Status: Offline
posted
quote:Originally posted by frank g: I recently found a problem with my 1600. I had a noise that sounded like noisey lifters (a rattling sound -- almost tinney like loose sheet metal vibratine. It went away at ~2000 rpm. Since this engine had 160,000 miles, I decided to replace it with a crate. Upon removal, I found the bolt to be almost finger tight (Less than 10 lbs of torque)! I had this happen with an old chevy S-10 and should have recognized the noise. I haven't torn the engine down yet, but I have been advised that it is probably not worth rebuilding since cranks are over $500.
Anyone running a 90-91 small nose crank would be well advised to check the torque after every weekend, and if found to be loose, replace the key and bolt as described in the above link. Wish I had seen it last year. Frank
Cranks are quite a bit less than $500 if you join Mazda's competition parts program. You get a BIG discount!
-------------------- Do I turn my 99 Hard S into a killerfast SM or seek a donor?
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