RobSpec

I am glad I found this forum. I have been running the following setup for 3 years now and have slowly been working out the kinks. I think I am down to the last one and am hoping WI is the solution. I have built and tuned this car myself and the setup is as follows :
1996 miata
Flying Miata 2 kit, intercooler, Link programmable computer
Huge radiator, coolant reroute, huge fans, oil cooler, hood louvers
Wideband O2 sensor and monitor
Running 93 octane fuel
12 psi boost
Fairly rich mapping = 205 RWHP
Toyo proxes RA-1 225/50/15 tires on 7 inch rims
Spec miata suspension
Wilwood big brake kit

I run the car in Florida for track events only. It is not a street car. It is caged and stripped and loaded up with track suspension, tires and safety gear. The car is a blast and runs extremely well. I have the water temps under control at a max of 200 F and the oil temp is manageable at a max of 230 F on the hottest 95 degree days.

Ok ...my problem has been that after a few laps, 4-5, in the summer at tracks like Sebring and Homestead the car falls on it's face. I believe that the intercooler gets saturated and can't handle the load. The intake air temps must spike causing detonation and the Link computer responds by retarding the timing to the point the boost drops to 8 psi and the car feels like a dog. With the Link I have the capability to datalog the intake temps but forgot last weekend when I was at the track. I will do this before and after installing WI so I will know the impact.

Has anyone installed a setup like this on a similar car? Flying Miata sells a kit , AquaMist, that picks up and injector signal and manifold pressure but want $940. I like FM but that seems very costly. Any advantages to the Aquamist versus this system?

With the setup I have what parts would I need? I would likely go with a system that I can adjust to fine tune.

I assume that the injector would install between the intercooler and the intake manifold? There must be an intake manifold tap for boost pressure as well. Would I install the injector before the Flying Miata air temp sensor? I would think so the Link computer would then be getting an accurate air temp.

Thanks for the help. Anyone in the Florida area that wants to check out the car can find me at most Chin Motorsports events.
Rob

jayc72

iTrader: (14)

I wouldn't install the nozzle before the AIT probe. Spraying water on it would likely give you an artifically low reading wich could cost you more than some HP

If the link doesn't hear knock it shouldn't retard the timing. WI will help prevent the knock by cooling the charge. What I don't think WI will really help with is cooling the IC. Another approach would be a CO2 or NO2 intercooler sprayer ... or even water.

MiataNuTca

Water injection would definately help your setup. If your link is using a knock sensor to retard timing, it would make a huge difference. If the link is using IAT to retard it would probably best to put the water nozzle before the IAT sensor. You would want to go with the DO progressive kit and get a map sensor (0-5v) to run the progression off of your boost. 205rwhp seems low for 12psi. I know your saturating the fuel, but it's not a good thing to do this with water injection. Here's a couple of articles on a/f ratios in turbo applications with and without water/meth injection:

http://web.archive.org/web/200601030...rinjection.htm

http://www.innovatemotorsports.com/resources/rich.php

magnamx-5

iTrader: (7)

lean it out toss out the fmic and go from there stop pulling so much frigin timming probably as well. i have no problem running stock timming map at 13 psi with only WI and fuel. running about 12.5-1 AF on a simple on/off setup. Making closer to 240-250 whp

RobSpec

You gotta remember that this is not a street car or a drag strip. When I track the car I am on boost for long periods at a time and run for up to 40 minutes continuously. Sebring is a 3.7 mile track with several very long straights. Even in the turns I am mostly on full boost. I run rich on purpose.
If I do go to water injection in addition to my intercooler I will definately cut back on the fuel as I will not need it. Right now if I cut the fuel and added timing it would be a recipe for disaster.
Anyone else do road course track events and WI to help out the intercooler??
Thanks Rob

Ben

iTrader: (33)

Rob, what turbo and what dyno?

You might want to check out some of those cool drag racing intercooler cores. Some have the ability to run chilled water or CO2 or NO2 to keep the core cold. You could then fire the CO2 with a system based on MAP, CLT, and maybe even RPM. Or even a momentary toggle on the dash, and hit it every time you hit the start/finish or something. I don't know if the water setup would heatsoak, it may.

RobSpec

Hi Ben,
I believe the FM kit uses a Garrett GT2560R. I used a Link system to "virtually" evaluate the hp. No actual dyno numbers so it a rough estimate at best.
I have considered spraying water on my intercooler to see if it helps. I could simpy reroute my windshield tank to some squirters in the nose. It's worth a try as it is cheap and simple.
If I get some replies that give me confidence in a WI system I would give that a try as well.
Thanks again
Rob

Ben

iTrader: (33)

OK, starting to come together.
The HP guestimate program i DLL is hardly accurate.
FM does offer different turbos, if you had a 2554 and ran on a stingy (aka "accurate") dyno I'd understand. 205 from a 2560 blowing 12ps isn't right.

Me thinks you should go to a dyno tuner and tune your car up on a load dyno. You don't want to go too far advanced with timing, but you also don't want to retard it too far either. That would be good use of a few hundred $$.

Spraying water on the IC has been done before. People pick up Rainbird sprinklers from Home Depot. Soflarick just did so, for his Florida based track car.

WI wouldn't be a bad idea either. You can pick up a progressive devils own kit for $300 IIRC, and you'll need a tank. The washer bottle isn't going to cut it for track use. You might want to try something with dual nozzles, a small one before the ic, and another at the intake mani. Someone (aquamist?) also makes a nozle designed to spray through the turbo.

magnamx-5

iTrader: (7)

My 1.5 gallons of water works out to be 30+ minutes of boost past 4 psi. And yess i have run that out in 35-40 damn near it might not be a sanctioned track like yours but it was still reamed pretty damn hard on a daily basis. What ever you do never run a nozzle pre intercooler this is a recipe for pooling in the IC. If the air intake heat is not high enough the water will not stay suspended and you will not see optimal results. GL man

MiataNuTca

Ya, I would be looking at a 3-5gph nozzle with at least a 2 gallon tank for racing. My 1 gallon will last me a week of "normal" driving.

After going WI myself for a month now, I would never look back. I'm lovin it. All the benefits of boosted power without all the drawbacks of heat issues. My RX-7 intercooler would get heatsoaked after a couple of 4-5 second boosted runs, now my car doesn't flinch. I actually was able to get away with 91 octane gas and retard my timing by 3 degrees in my upper rows.

RobSpec

Thanks for the help,
You are correct, I have not been to a dyno to do heavily loaded tuning. I may be able to replicate in 12 minutes of near full boost conditions on a dyno but am not sure. This would correlate to 4-5 laps at Sebring. It sounds like I need water injection as even with perfect tuning for max HP I am going to continue to heatsoak the intercooler fairly quickly in the Florida heat and regardless of the fuel and timing maps not be able to keep from detonating. I am fairly sure I have decent mapping right now if this were a street car, very conservative (rich) but acceptable. For the first 2 laps or so it pulls like a freight train. If It were strictly a street car I would pull alot of timing and lean it out as I would use a limited amount of short duration boosts. I would definately get more HP that way.
I am not too worried about maximum horsepower, I am more concerned with not blowing up the engine, eventhough they are very inexpensive and easy to replace.
It sounds like the WI will cool the charge thus keeping it from detonating. That may be my solution to heatsoak of the intercooler.
Thanks again
Rob

RobSpec

One more question please,
What signal/signals does the Devil's own kit use to determine when to begin pumping water? I see a lower boost **** and a upper boost limit ****. Does it also use intake air temp? How about injector pulse width/load.
I would think the best setup would be one that picks up injector pulse width (to determine flow rate requirements), intake air temp (to only flow when a temp limit is reached), and manifold pressure (lower and upper boost settings for on/off).
The Aquamist system appears to use injector pulse width and manifold pressure.
Thanks Rob

magnamx-5

iTrader: (7)

mine just uses a simple on/off pressure switch. works fine. I think you are trying to overcomplicate this dude, a simple system will work just fine.

Kelly

iTrader: (6)

Either one of the Devils Own kits will solve the heatsoak as well as detonation issues. You may even gain some power as an added bonus . I would install the nozzle just after the nozzle just after the intercooler outlet. A progressive system with 2.5 gallon tank would run you about $330 shipped. You could use the Links map sensor to send a boost signal to the progressive controller.

Kelly

iTrader: (6)

Dude...FMUs work too. It gets the job done but its not dialed. Same with the basic vs progressive. Quit telling people to take their intercoolers off.

RobSpec

Thanks WOT,
That is the info I needed to know. I will likely mount the water/alcohol tank in the trunk on the passenger side for weight balance. With this setup does the pump mount in the back with the tank or up front in the engine bay? Either way I would need additional tubing, it just would be different by mounting location by high pressure or low pressure tubing.
I re-read my LINK information last night and the system does retard timing and alter fuel at a set intake air temp. It does this gradually. The LINK also seriously reduces timing when it detects knock via the knock sensor.
So, I would have to install the nozzle as you suggest right after the intercooler outlet and before the intake air temp sensor. Otherwise the intake air temp sensor would still be reading a higher temp than what would actually be entering the combustion chamber and the fueling and timing would be falsely modified. Hopefully the water/alcohol being injected does not damage or cause erroneous readings on the intake air temp sensor.
So a 2.5 gallon tank with programmable system would be $330. Does this include the proper connections and/or regulators to hook right up to the MAP sensor for the LINK via a splice? I could not find the actual output of the MAP sensor and ramp rate in the manual.
What nozzle would I use? The FM 2 system runs at 12 psi, with 550 lb injectors.
Thanks again
Rob

magnamx-5

iTrader: (7)

Yes it is. the pump as i have mine in the trunk, just above where the jack used to be. Also FMIC has killed many motors to WOT. Dont trust a big hunk of metal obstructing your rad. Its true wether you admit it or not

Kelly

iTrader: (6)

A fmic has killed a lot less motors than stupidity has.

UofACATS

iTrader: (1)

Are I/C sprayers even "legal" at the track?

Many dragstrips they are not.. I/C sprayers suck anyways.



Magna, you have great sucess w/o an I/C, you've done a great job for your application. This guy runs for extended periods of time under heavy load, but says:

Thus, ridding himself of the "big hunk of metal obstructing your rad" for cooling purposes doesn't make much sense.


Personally, I love the idea of W/I. However, the problem remains of A: injecting it before the AIT and possibly getting inaccurate readings (per jayc72), but I've heard of this as well. It's always "don't inject before the temp sensor!" (*I'd like Wideopen to get in on this* please ) Or, B: Injecting it after the AIT sensor, cooling the charge, but the software does not know this, and continues to act in the same manner. If there is someway around this, I think that's the best option because the fact that your car does fall on its face when it heatsoaks is actually a good thing, you don't want to jeopardize that safety factor.

In theory, if you can prevent your I/C from heatsoaking, you can have your "first lap" performance last the whole time. Some inject pre I/C to help prevent heatsoak, but bad things happen there as well, such as water build up.

Continuing with my ramble, perhaps injecting far enough away from the AIT would prevent inaccurate readings. Perhaps a test is in order. It would seem rather obvious (I'm purely guessing) if the AIT started going haywire, and you were seeing 36º intake temps on an 85º day, for example.

Joe Perez

iTrader: (8)

It's been done both ways. My setup uses a 5 liter tank in the trunk (opposite the battery) feeding the washer bottle via a transfer pump, and that bottle feeds the main pump which is mounted up behind the front bumper.
The pump placement: https://www.miataturbo.net/forums/showthread.php?t=6932
and the new tank: https://www.miataturbo.net/forums/showthread.php?t=9256

If your rules permit, what about putting a 1 or 1.5 gallon tank in the trunk, and then another one on the floor in front of the passenger seat, then mounting the pump on the passenger footwell? Assuming the lower tank can be sealed and the upper tank vented, gravity and suction should take care of moving fluid from the upper tank to the lower as demand requires and give you a three gallon capacity.