Scrub

iTrader: (25)

So will doing this mod decrease underhood temperatures? We know it will decrease 60-160 times, but I'm interested to know just how well it helped cool the engine bay versus a vented hood.

-Dan

FDNewbie

iTrader: (10)

Dan, from earlier in the thread...

Scrub

iTrader: (25)

so basically, it hasn't been determined......
thats all you had to say.

dubulup

sorry to report boys...didn't help my heat soak. temps seemed fairly consistant.

I tried to repeat the runs I did previously...but I forgot I had bumped my fuel pressure from 38psi to 43psi, and my A:F's went from ~10.9 (yes, I know its rich, but I don't care for my AITs) to ~10.3. Car felt slower, most likely due to the tune...datalog showed it too

WITHOUT
4760rpm in 2nd to 7340rpm in 4th = 14.6s
WITH SCREENS
4840rpm in 2nd to 7160rpm in 4th = 15.1s

both tests with the lights up.

I wasn't quite in the MPH range axr6 reported the biggest gains...road/traffic constraints. Car felt solid.

couple things I've observed, my boost oscillates about 1.5psi...MBC tapped off the UIM, will change to the charge pipe. My car seems to have no issues suppling the fuel I need, I'm thinking about dropping my pressure lower than before, running a meth mixture for AI (aux inj) and turning down the boost from 17psi.

Before I retune, I will be installing an EGT I will be able to datalog, and thinking about running a hard ZERO split ignition (lose the AMP). Coupled with the meth and ignition, I hope to tune aggressive, and with my bottleneck IC...hope to make a faster car with less boost. now I end my ramble.

axr6

Just to clarify it.

Was the WITHOUT and WITH SCREENS test run under the same tune or was the WITHOUT test run under the leaner AFR? The way I read it that the WITHOUT test was with the previous, leaner AFR. That would make sense in the results.

Also, were there any substantial ambient temperature differences between the two tests?

I would be very disappointed if you tested the car to be slower, even at lower speeds, with the screen. The second test being 0.5 sec slower for a narrower RPM range points to quite a difference. That is probably more than a random deviation.

I was not certain that there would be much heatsoak differences as the screens are way forward of the engine and will not necessarily vent the hot air from the top of the engine. For me the chief benefit appeared from the reduced drag as the high pressure underhood air was able to exit better.

Always nice to have someone, like you, actually willing to check some concrete numbers.

Thanks

Albert

7racer

dubulup,

do you have an oil temp gauge? Just curious if you noticed any difference.

FDNewbie

iTrader: (10)

dubuplup, sounds like you got a LOT goin on w/ your car hehe. Thanks for givin it a shot!

Oh my bad Dan. I'll come straight to the point: READ THE THREAD NOOB!

~Ramy

7racer

oh, the reason I ask about the oil temp is that this might be a good mod to those with single oil coolers. It might be a cost effective way of improving the efficiency without going to a dual setup.

GoodfellaFD3S

iTrader: (213)

Thanks Dr. Bob, I'll pm him

dubulup

Yes, the first run without the screen was run with a base fuel pressure of 38psi. Then I tinker...mod, etc. Put the car back on the road and forgot that I had bumped the fuel pressure to 43psi. Only remember after I looked at the datalog and shocked to see it was longer time...I did two runs and the second was consistant ~.5s slower. I would have done some more runs, but each time I exited the interstate I saw a cop. Not sure how they missed me?!?!? but I dodged that bullet and wasn't going to temp it again. I'll drop my FP and try again this weekend...


I don't have an oil gauge, however if the oil cooling is more efficient the coolant system shouldn't have to work as hard, correct?

I push my car pretty hard...to the point where the engineers designing the "touring/base" models (single oil cooler) would scream.

If 1/3 of cooling is done by the oil, and I have 1/2 the oil cooling as the R2...I have to think I am taxing my radiator to do too much of the work. I'm sure some physics guy can run the numbers...My SMIC sits on top of my "overworked" radiator, soaking up all the hot exhaust air from the fans. If it doesn't have to work as much, shouldn't my IC see some of the benefits??? Why did it take me this long to realize this??? I'm hardheaded, haha!

Before I spent the loot and time to fab an EWP/V-mount set-up, I think its more important to do something about my oil cooling. Only question is, one large single or two smaller ones...and loose my fresh air intake duct? As I've stated numerous times, I am not satisfied with my AIT's.

CantGoStraight

Do you have any pictures of this modifacation as I was thinking about doing this as well. It was my under standing that the side vents were functional and help generate flow through the oil coolers. Thanks, Jack

axr6

Look for pictures on prvious pages of this thread for the screen mods and also for one that shows the ducting to the side vents.

axr6

Ha..ha.. I remember on one of my runs on that same section of the road, I wasn't timing but, took a friend's 12 yr old son for a ride and he asked me to show him some speed. So, I asked him to count off the speedometer readings...

It was mid afternoon, lots of normal traffic on the freeway and I backed off to create a bit of opening in front of us, got on it hard and the kid started reading..;

70..80...90....100......110........120............ 130..............140...............150..

Just as he called out 150 I saw this Highway Patrol standing on the side of the freeway, writing a ticked to some poor sucker who probably dared to hit 75 MPH...

I swung my arm over, in front of the kid's face, pointing at the cop. Our eyes locked for a moment as the cop looked right back in shock. Then, I calmly instructed the boy in my usual wisdom;

"See what you get when you're going TOO SLOW?" - Never forget the boys expression. Needless to say, the cop never even tried... and... needless to say that I never, ever got a ticket for going very fast.. which was very frequently over many years in too many fast cars.


With my old R1, one aspect I never really investigated at depth was cooling. I simply relied on my factory temp gauge. I had no idea that they were that bad, that is something I've learned only recently on this forum. Did not have oil temp gauge either. Still after 2 full years of track racing, there were no signs of engine problems and, as a matter of fact, after having repaired the crashed car and sold it, the present owner still uses the same engine with around 40K miles on it now. I had actually tried to buy that car back last year but, he would not sell.

Having said that I will propose a second or third hand information here. My racing friend, who used to build large numbers of rotary racing engines for anything from NASA Pro 7 to SCCA GT classes, once told me that one of the better known race engine builder claimed (not sure but, I think he mentioned Daryl Drummmond) that 60 percent of rotary cooling was done by oil. I have no way to back this up other than my own racing experience.

When I bought my first GT-3 class car with a 12A big-bridgeport, putting out 245 RWHP at 9200 RPM, it came with a thin standard street radiator and a very wide, heavy duty oil cooler from an RX2or RX3. Water temps were never a problem but, oil temps were at higher RPMS. In subsequent years and cars, I had found the same thing. I could do with relatively small water radiators and have stable water temps but, I needed very large oil coolers for high RPM driving to keep the oil cool. We ran oil pressures over 100 psi to turn over as much oil to cooling as we could.

So, I imagine that with turbo cars putting out far more power the need for oil cooling many increase. The key is how much real high RPM driving one does? In my race engines I had no problem with cooling oil if I only revved to 8000. Going up to 9200 incrased the thermal loading a whole lot, requiring much more cooling.

Guess, what I am saying in so many words that we should have oil temp gauges, if we drive those cars hard for extended periods. I now have a Touring model with the single oil cooler and not sure if I need more. Yet, I think, I will put in an oil temp gauge, just to make sure, even though I have no intention to race this car but, having moved to the Sierra foothills, I do lot of winding road driving with lots of elevation changes, which can test the oil coolers ability at high PRM boost conditions.

As to testing again, next week, be sure that all conditions are very closely the same as before. Section of road, wind, ambient temperatures, tune, etc. That is why I used to go into so much trouble to record my temps, use the same road and make 2 runs in each directions to account for any wind factor. I have had very high conficence in my test numbers as they showed very high consistency with those parameters. I would simply be shocked if you found that the screens did not make the car any faster using your speed range. Seem like you were over 130 MPH where the difference must begin to show up, even if by not nearly the margins that it did on my tests up to 160MPH.

Albert

FDNewbie

iTrader: (10)

Albert, I've heard the same, from one gentleman who professionally races 3-rotors. He was telling me that a common overlooked element is oil temps. He uses dry sump pump and massive oil coolers, as they impart a significant effect on engine temps.

~Ramy

crabcakesyum

oil coolers and vented hoods help out a lot as well

dubulup

HAHA!! that is great!
with a cop out of his car, you have got to have at least 10s to get out of sight, at that speed. 3-4s for him to get back to his car, and another 3-4s for him to call ahead, and probably 2-3s to get someone to respond, then another 10s to try and think and describe what the hell just flew past????!!!!

I actually had the chance to run a wide range 2-4th gear pull today (head lamps down), BUT THE DAMN datalog didn't register!! I did note AIT and coolant temps were about the same. It really felt like the car was moving a lot better, and traffic was thicker so I didn't get the chance to run again...I might try to get up at dawn and try again.

Oil cooling is something that I've overlooked...I think I can fab a system for under a $1000 that greatly improves my cooling. I'm thinking 20 row parallel.

ArcWelder

True, but the title of this thread is, "Want cooler engine bay WITHOUT changing hood." I think it's accepted that a properly vented hood will lower engine bay temps.

HDP

iTrader: (2)

Alabama troopers usually patrol interstate areas in pairs, especially during the day, and they have their radios on them now (the shoulder clip type) so unless you passed 2 cops on the side of the road (sometimes 3) be prepared to encounter another ahead.

GoodfellaFD3S

iTrader: (213)

No need to fab up a kit, the Gotham kit is well under $1000 and comes with dual 19 row coolers....

http://www.gothamracing.com/catalog/...oducts_id=1176

I have the kit sitting in a box waiting for install.

dubulup

Aren't the stock coolers 17 or 19 row? How much improvement can you see with 19rows? Over stock R1? I know my set-up would see drastic changes, but I think I need something more extreme at the moment...small IC, single, lots of boost etc.

But DAMN $750 is a fine price.


with this bit of info, I think I want overkill on my oil cooling system.
I think a parallel 25 row system could be some relief to my heat soak issue. (think power of a 50 row!!)

I read 210F is the optimum temp for operation and 104F is optimum for air take air, per Mazda's ECU tuning...(also something I've read). I keep my radiator cycling to maintain a 5% spread around that temp...and my IC really takes the brunt of that operation...being right on top of the radiator.

If I can maintain optimum operating temp with a huge help from oil cooling...I should see less radiator fan cycling, yielding less heat my IC has to soak up; at least in my mind. If someone reads something I've stated incorrect or I'm missing please chime in. This thread is evolving with loads of good info in it.

axr6

Why would you want to run a parallel setup? I personally always run dual oil coolers is series. In that way the first cooler drops the temps down so many degrees then, this cooler oil enters the second oil cooler which, drops it even more. You can touch both coolers and feel the sizable temperatures between the first and the second.

If you run parallel setup the danger may be that you may actually push the oil through too fast and not get the cooling done. I have come across that where I actually had to put in flow restrictors and got better cooling. (that was in a Lamborghini cooler)

The Gotham system looks really good. If I remember from looking at it it came with a thermostat. Beats having to tape up your cooler in colder temperatures. In oil coolers constuction is the key. There are lots of cheap coolers on the market with impressive numbers of rows and size yet, when it some to cooling efficiency you get what you pay for. I had tried to take shortcuts with coolers and did not work. I remember using a cheap, fairly big oil cooler for my transmission and it was just scary to marginal. (my worst day, the transmission oil temperatures went to 325F degrees! Yes, you read that correct) Then, I went to a high quality Setrab cooler, much smaller in physical size (I protested when the experts were suggesting me a smaller cooler) and guess what? My oil temps in the tranny went down and settled around 215-225, compared to the much larger cheap cooler. Guess, you have to do your homework or talk to people who have a very similar setup as yours and actually monitor their oil temps.

I preferred to run my engine oil just a bit below 200F. That gave me a peace of mind. Like I said before, on colder days I was putting tape across the water radiator, as well as the oil coolers, just using guesswork, how much tape for what ambient temperatures. You definitely do not want to stress your engine when its too cold.

dubulup

I see the advantage of series...but what if the first is overwhelmed and starts to not transfer much heat at all, then you are left with basically one again. I know there are thousands of what if's...

My thought on the advantage of parallel is the oil would "see" one large cooler...one that has more transfer capabilities, and won't get "saturated" with heat and pass it to the next. Does that make any sense? If my single doesn't move oil too fast, I don't see how a parallel would pass it too fast either.

Mazda does have tons of $$$$$$$ into R&D, and they are probably correct with the series set-up. Just like most things, when I want to fix something I go thru OVERKILL stage first and visit lots of possibilities, then the homework stage. I've been discussing the parallel set-up with a chem eng. who took way more fluid/thermo courses than myself...I'm a ways off from putting something together, but that's the point of this thread.

Monkman33

iTrader: (28)

Holy heck this turned into a great thread!

So the gotham kit looks good? are the coolers going to be significantly better than stock?

And I agree, Series is better than parallel. You also run the risk of pushing more oil through one than the other, depending on line resistance. And since one cooler is on one side of the car and the other on the opposite side, you would have one cooler that is getting more oil pushed through quicker (thus less cooling) and the other cooler that is getting less oil pushed through slower (more cooling) Not a balanced or coordinated effect. I see more benefit to have the oil cooled somewhat by one cooler, and then sent through another cooler to be cooled even more. This would simulate the effects of a lorger oil cooler, or at least a longer one.

and axr6, glad to see someone that knows ohm's law

Monkman33

iTrader: (28)

the funny thing about liquid to air coolers is that as long as the air on the outside is moving, they will always be drawing heat away from the metal surface of the cooler containing the hot liquid. the hotter they get, the better of a chance of cooling effect occuring. And then putting the liquid through the same process again will undoubtedly help a second time.

It's not a matter of it not working, it's just a matter of it not working enough.

And I see there being more issues with a parallel setup and unbalanced flows and inconsistent results then i do with a series setup and constant flows, and consistent results.

rynberg

No, the driver's side is 10 row, the pass side is 9 row. The cooling fins are much less dense with the stockers too.


A series setup is going to cool better than a parallel setup IMO....and is a hell of a lot easier to plumb!