How much cooler will the car run w/ an aftermarket radiator? The car is pretty much stock, but I'm looking to make it run as cool as possible since from what I can see detonation is the sole killer of these motors. Who makes a good radiator for these cars?

Thanks
Chuck

 

It won't really run any cooler than normal, Chuck, but it should keep it from running as hot during hard use and should prevent overheating in hot climates.

The Koyo and Fluidyne are the cheapest and most popular aftermarket radiators, probably.

 

Cool, well for the money I think we'll do it just for precautionary measures. My whole goal with this car right now is keeping it cool... then work on some more in depth mods. Is that a good place to start? So far we've purchased a Pettit intake, Racing Beat exhaust, boost gauge, and water temp gauge. Next in line will be the radiator and larger intercooler. Think all that will make a noticeable difference on the car? Anything else you'd recomend to pep it up a little?

Thanks
Chuck

 

Aluminum AST.

 

And the water temp won't cause detonation.

 

However, in traffic... Your high engine temps can heat soak the crap out of your intercooler, which could, I guess, lead to detonation...

 

Actually, no. If the motor runs cooler the engine bay will be cooler and the intake air temp will be cooler and there will be less chance for detonation. Basically, yeah I know it'll have little effect... but every little bit helps imo.
What is an Aluminum AST?

Thanks
Chuck

 

Aluminum Air Separator Tank. It's the black plastic thing with a cap on it, bolted to the driver side of your stock intercooler.

 

What's it do? And where do you buy them?

Thanks
Chuck

 

You can get them right here at the RX7 store. It separates the air from the cooling system...It's not an improved process when you buy the upgrade... But heat tends to crack the stock piece causing you to spill coolant, and then you overheat!!

 

Do you have a downpipe yet? If not, getting rid of the precat and adding that will drop underhood temperatures quite a bit. I can't comment on all of them since I've only installed and used a Pettit dp, but I've had mine about 3 years and it's still working perfectly (as it should be), I'm happy with it. With the intake, catback, and downpipe though, you'll want a new computer before you add on the intercooler. If not, there's where your detonation will come in (stock computer not compensating for increased amounts of air, and will run lean). Again the Pettit computer is awesome, just plug it in and go, I loved mine. The Power FC is another good one (what I have now). It works fine on the base maps for some people, others it requires just a little bit of tuning. Those are my recommendations.

 

Yeah, it's got a bigger downpipe. Not sure exactly what brand/size, but the dealer we bought it from (LA Motorcars of Dallas) said it had an aftermarket one...

Thanks
Chuck

 

Since you already have a downpipe, as Rx7even said, do not install that intake and cat-back on your car without either controlling boost to 10 psi (boost controller) or adding an aftermarket ecu. You WILL blow your motor without doing one of those two options.

 

Seriously? So what aftermarket ECU do most go with? Sounds like it starts to get expensive at this point? Is it worth going this far? He'd like to be in the 12's or 13's with the car.

Thanks
Chuck

 

12's on an automatic? Interesting...

Well, you need to look into an aftermarket ECU when you start using boost levels higher than the stock 10 PSI. You could probably get away with running up to 12 lbs of boost, but why trust it? An upgraded ECU is cheaper than a rebuild.

There are simple pre-programmed ECU's like M2, Pettit, GForce and others... or there are re-programmable ECU's like Haltech and Power FC.

It really depends on how much modifying you plan to do to the car. The pre-programmed ECU's are fine until you want to increase injectors or go single turbo.

However, if you plan on getting a re-programmable ECU, you should also plan on having it tuned by a professional, or send it off to be programmed (depending on where you order them, they can be programmed before they are shipped, but I doubt that it's free).

 

Not necessarily. While it is always a good idea to keep an eye on the boost level of course, adding a cold air intake, a downpipe, and a cat-back don't necessarily mean a blown engine. The restriction of the main catalytic converter still remains, and it is removal of both cats that would be the sure ticket to boost creep and dangerous lean conditions without additional fuel. If Boost is peaking above 11 psi, fuel modifications should be the next step before adding any further performance modifications, in conjunction with some method of controlling boost to safe levels.

If you can't immediately upgrade your ECU, there are two ways to increase the safety margin cheaply. One is a rising rate fuel pressure regulator, or "poor man's fuel computer", which will increase fuel rail pressure under boost, injecting more fuel at a given duty cycle than a lower fuel pressure would. This is a bandaid, but if the boost levels aren't excessive (> 11-12 psi), it should be sufficient. The other is a manual boost controller, which can be picked up for $85-120, probably. Installed properly, you should be able to limit boost to stock or just above stock levels without difficulty.

 

Oh ok, so it wouldn't require a complete aftermarket pcm that would need a full tune by a professional. That had me worried. I'll look into the pre programmed stuff.
What are most people w/ cat back, down pipe, cai, and larger intercooler doing for tuning?

Thanks
Chuck

 

For programming your stock ECU, you have several choices, Pettit Racing ($699), M2 Performance ($695), etc. among others. For about $500 more, you can get the A'PEXi Power FC and commander. From there, the price goes up for stand-alone systems. The AEM system has promise, but isn't available yet, to my knowledge, and others have had good luck with the Wolf 3D system.

 

Just FYI, for some places that do pre-programmed ECU's (like Pettit), unless you send them your ECU first and wait for them to send you the new one... There is usually a core charge fee of $650 (which you get back upon sending them your ECU after the swap).

So, if you don't send Pettit your ECU, you'll pay the $699 for the pre-programmed ECU and the $650 core charge up front. After you swap them, you send back your stock ECU and get your $650 back...

 

Allright guys, let me jump in here.

I have a 94FD with Pettit catback, cold air system, and underdrive pulley system. I have ordered a fluidyne radiator, water temp gauge, and
Pettit downpipe.

I talked to Cameron Petit, and he said a ECU upgrade wouldn't be necessary at this point, but he also said take it out in second, and test it to see where the boost goes. He was of the opinion that a lot of the engines fragged by overboost were due to people doing other underhood modifications without an ECU upgrade.

 

I would test it in 4th, where there is more engine load.

 

I would just do the normal boost test:

http://www.scuderiaciriani.com/rx7/boost_test.html

If you are seeing over 11 PSI, then you should look at restricting your boost or getting an aftermarket ECU.

Some people have experienced spikes over the stock 10 PSI with just a downpipe. Each car is different, so just try the boost test and see where you are...

 

The reason NOT to do the WOT boost test in 4th is that in order to complete the test (4500-7500rpm range) you need a straight section of road that will allow safe speeds in excess of 120mph while watching the BOOST guage insted of fully concentrating on the road. This does NOT describe any PUBLIC road in the US that I know of.
second gear allows a complete test at near legal speeds but you do run through the test rather quickly! Third requires higher speeds (than second) but allows a longer time at WOT.

Also the engine load is the same at WOT (the engine will produce its max power regardles of what gear you are in) the ACCELERATION rate is faster in the lower gears because of the mechanical force multiplacation provided by the lower gear ratios. Disregarding Aerodynamic Drag and mechanical friction (however at higher speeds both are significant) it takes the same amount of work to accelerate from 10-20mph as from 110-120mph

 

Cameron Worth is the owner of Pettit Racing, if I'm not mistaken.

Also, keep that main cat in there if you want to keep your motor in one piece. I would also put the car up on a lift and check to see if you have a downpipe--the stock precat has a large bulge versus the straight-through downpipe.

 

I think what we'll do is put on the parts, then make a trip to the dyno and richen the a/f up if needed w/ an adjustable fuel preasure regulator.

Later
Chuck