Greddy Kit - Road Racing?
 

I bought a 1992 Miata with a Greddy turbo kit and <5k miles on a rebuilt 1.6L engine. I know that it would probably be fine for autocrossing, but how would it fare on a road course since it is a hot air setup and on stock injectors? It has a Walbro 190lph in the tank. Is it a bad idea to run this on a road course or is it fine to run a hot air car at 5psi for extended periods until I decide that I need more power (and have the money) and go with an intercooler, injectors, engine mgmt and some kind of air meter. The car also has no cat and a full 2.5" exhaust and suspension mods.

With a quality synthetic oil and your cooling issues under control (no overheating) I don't see why not? do you have a wideband?

The car will be ran with Mobil 1 (unless someone has a better suggestion on brand and weight...maybe time for a search)

I always keep a close eye on coolant temps. I didn't know how hot the IATs would go under load for extended periods and lead to knock.

I do not have a wideband in the car now, but I will most likely put one in it. It is almost silly not to have one as cheap as they have become.

I ran my greddy unintercooled for a few months with no knock just had the timing set back a little bit, and I run amsoil oil btw. And since you have an NA you can use your oil pressure gauge as knock detector if it starts shaking under boost then its knocking.

regarding that "knocking detection method", that's only true for the earlier pressure sensors, or does it still apply to the post 94, that only have On/Off positions?

he has a 92 though yea your correct though

Good to know about the oil pressure gauge, did you road race/auto-x with your car when it was not intercooled?

Also, I tried to send you a PM but I am new so it won't let me. I wanted to see your setup and don't have a myspace.

Do you even feel the boost at 5psi? ;p

Personally I wouldn't push it very hard on a road course without an intercooler and an oil cooler. Retarding the timing will help, but at the same time it will create alot of underhood heat, resulting in melted brake master cylinders.

Hah, very funny. Drive a stock miata and hop in a boosted one and you can feel a difference. I am used to to Mitsu motors that run more than 5psi stock. I didn't get the Miata to be an all out drag car or to make huge power...I wanted something that handled like it was on rails but it is hard to have fun in something slower than a civic. :)

How would an intercooler and oil cooler help save the master cylinder? I would figure than an intercooler = most boost = more heat on the turbine side = melted master cylinders. It has the little heat shield on it, should I also wrap some heat tape around the master cylinder and the hoses behind the shroud for extra heat protection?

I will do a search on oil coolers to see who has done what and when they are a good idea.

Does 6 deg. of base timing sound right?

I think he was making two separate points. 1> he would not track it w/o oil cooler + intercooler.
2> The underhood temps will be great for bbqing.

Run race fluids, heat shield your engine bay, and possibly consider the NACA duct that many of us are using to get some air into that hood.

Newbsauce understood me.

Running hard on a track with a turbo miata requires some additional cooling, especially if your turbo is oil cooled. You can definately drive it around the track, but I pushing it with out some kind of oil cooling is not a good idea.


The intercooler will allow you to run more reasonable timing advance. Retarded timing causes retardedly high EGTs which melt your master.

6 is probably the farthest you can advance it with no charge cooling or race gas.

The heat created from retarded ignition is much hotter than the heat from alittle more boost.

Just custom make an intercooler setup for like 200 bucks...

I think the added safety is worth it.

It sounds like an intercooler is the next logical step, but the downside seems to be that when I do that I will also need larger injectors and some type of fuel control device.

Anyone want to link me to their homemade intercooler setup that allowed them to keep AC and PC?

Why would you need more fuel just because you add an intercooler?

Because naturally I will be unable to resist adding more boost. :)

oil cooler is a must.

I plan on getting an oil cooler for sure, I kind of just assumed that it would have one stock.

I have an intercooler at 5psi. Just did so i can advance timing a little bit. Since you have some money, do the oil cooler (fo sho), intercooler, godspeed radiator (or koyo), and If you got more money then move on down to water injection.

Im scared to track race (we don't have a track here anyways), i just cant see my self boosting for longer then like 5 minutes.

oh yea for injectors just grab some 1.8 miata injectors, there pnp and there good for 9psi and there not pricey.

Since you have a 190 pump are you still using the vortec.

Are stock radiators not sufficient even if cleaned and filled with water wetter and a 75/25 mix of water and antifreeze?

I don't need any other mods to run 1.8 injectors? Will they cause it to run rich or more difficult to drive around town?

The car does still have the vortec, is this not compatible with the 190?

The 1.8 are just pnp and thats it.

The 1.6 stock injectors are rated like 235cc or something like that. The 1.8 injectors are 265cc. I was running 305cc with the Vortec and stock fuel pump and it idled fine, but since i dont have software to run my EMB i took them out and put back the stock ones. When i get my EMB up and running i will be tuning the car with the 305cc.

you'll be fine on the track. I ran mine at 5psi just fine. put some good quality zipties around the accordian part of the stock crossover pipe to help it from expanding too much. put 100% water in (don't forget to replace when you're done) and possibly put in a gutted thermostat (again, don't forget to replace) and make sure you run both fans all the time, one of yours is only coming on with the a/c. do a search to figure out how. there are three things you can do for almost free.

I did see some high coolant temps and oil temps, which is why I put in an intercooler, and a godspeed radiator. just keep an eye on it.

Yes, you need more fuel when you add an IC. The charge air is cooler, which means denser, which means more oxygen molecules per putt in the chamber. More oxygen needs more fuel. Probably in the range of 10 to 15%.

You're saying a stock greddy kit with noting added except an intercooler will require an extra 35cc of injector (1.8 tan tops) to run 5psi safely?

not necessarily

So if you're running 5psi and drop a IC, you'll loose about 1psi. Then you boost it up to get 5 psi again?

yea there's a little pressure drop through the IC but It makes up for it with the cooler air

no need to crank up the volume knob, because the extra power from cooler air is enough?

No, you'll be slower even with the cooler air until you crank the boost back up to where it was. How much slower depends on the efficiency and pressure drop of the intercooler setup you use.

thx bruce that was my doubt. :)

It will also depend on where your boost reference for the wastegate was. It is was after the intercooler then you would make the same boost as before.

:giggle:

When I get my betamax player in...

That's why I asked the question. My wideband on basically the setup stated earlier shows the stock injectors and fuel pump are perfectly adequate at 5psi.