mdw1000

My initial secondary radiator wasn't enough either. We used the same Summit trans cooler as a secondary radiator that olddragger does. We went with a bigger one and a more water heavy mix (see previous post), and it helped quite a bit.

Funny that this topic came up. I was planning on creating one telling people what I had found that worked on the 4AT for track cooling. Now I don't have to

mdw1000

I would say run a 80/20 or 90/10 water to coolant mix.

And run a bottle of Royal Purple Ice. I figured it would do nothing, but it dropped temps on track by about 5 degrees with no other changes.

As far as the mods I would recommend if you decide to go further: good size secondary radiator, a second oil cooler (I use one that I bought from someone who was parting out an MT), and a Mazmart water pump.

Bigbacon

iTrader: (4)

I sit here and read all the stuff you guys post.....Why do my hobbies always becomes uber expensive hobbies? It all your faults!! I know after tomorrow I will want to do this SO much more and I'll have to have the fun learning experiences of changing all this stuff out...

I guess so much for computers, not that i'm playing many games anymore.

mdw1000

It all starts with the first mod. Once you do that, it is all downhill from there... downhill meaning your bank account goes downhill...

mperformance

it doesnt start with the first mod... it starts with the first real track day
I actually own several cars and for some reason I want to track the eight now... the slowest car I have owned. Guess is just a challenge...more so when keeping it stock.

mdw1000 thanks for real practical input... u know after I read the responses here I kept feeling stupid for not turning on the heater at the event. I would have been able to finish without major worries I was doing a superb job at the track but I was worried about burning up my engine when the temps fluctuated a bit.

can you please talk to me more about the small secondary radiator deal?

mperformance

lapped who?

Brettus

iTrader: (2)

lapped the guy in the AT8

Red Devil

It's actually not a small radiator...it's 26x7x2, dual pass. It is mounted flat on the undertray with ducting and the undertray underneath it partially cut out. Here's a link to what was used:

http://www.frozenboost.com/product_i...676a3756b81468


On a related note, Pettit racing offers a similar product ($500, I think) that is in effect a dual pass arrangement mounted near the same way. Theirs is mounted directly to the undertray, and MDW's is mounted by a welded AL bracket to the frame. Both rest in the same location.

Red Devil

Don't know your track credentials, but I'd guess there are lots of drivers that could take a completely OEM AT RX-8 and embarrass you in your RX-8 at the race track.

Brettus

iTrader: (2)

finally someone bites LOL .
You are probably right on a tight circuit . But 10s or so per lap with similarly experienced driver is a LOT to make up - especially when the lap is mostly straights .

mperformance

very interesting, did anybody post pictures? sorry that I have`'t searched that much about it but sounds like a good alternative and something that can be used daily.

mperformance

I would not compare a stock AT to a modded manual RX8 anytime nor a Supercharged or turboed AT to a stock one... the cool thing in my case is that I went out to compete with cars that are supposed to be quick and the AT did not do that bad... so Imhappy... Im going to start an rx8 project soon though a real race car for track. This is just for kicks now. THe FC Im selling it, just too old as far as suspension goes, I do love the FC though but I have to make room for newer things.

Thanks for the input

mdw1000

I will let mac and red devil chime in on the radiator stuff. They did most of the work on it.

oops - I see he did already.

mdw1000

The part about the first track day is true. Almost all of my mods have been as a result of wanting better performance and reliability at the track.

mperformance

I cannot say the same about drag racing, I used to race on the streets many years ago (I know bad, but I admit it was fun yet stupid) and by the time I went to a real drag event I beat everybody with a first gen rx-7 in my class... it just got too easy rx-7s can't lose.

Now with track racing it's a whole different story, mods are very technical, not just power which RX-8 lack so it's a big handycap, but makes for a very good driver at the track you have to really push the car on the curves and learn how to brake consistenly and smoothly to make up for the lack of power the renesis puts out. another thing I learned was that its interesting to feel the same way when racing a kart, not worried about shift points and rpms with an auto. This gave me an edge concentrating purely on driving perfectly on turns and braking and accelarating exactly on each lap. Its like a driving a practice course without too much effort on shifting. I know that the first thing to do in order to run is to walk and before that crawl so my experience was right on... I'm hooked

BTW reddevil thanks for the radiator link.

mdw1000

With the RX-8 you learn the art of maintaining momentum, which IMHO makes you a better driver than if you just start out with a high hp, high torque car. Too easy to make up for mistakes in the corners by just putting your foot down more.

Charles R. Hill

iTrader: (7)

Are any of you aware that radiators are not intended to lower, nor control, engine temperatures? Thermostats do that. Radiators allow for the opportunity to shed the heat to the air and fans pull the air across the core. All three of these elements must be balanced in order to be most effective.

What I find peculiar in the "observations" about the BHR A/T rad is that the tranny cooler is immersed in engine coolant and yet I read claims that the trans is running cooler while the engine is not. That, I find curious.

What I find even "curiouser" is that the one who actually purchased, and uses, the BHR radiator has yet to contact me in any way regarding the matter. Meanwhile, his associate with a 2 year+ personal grudge against me has all sorts of "objective" observation to offer.

Mark, if you are dissatisfied with your BHR radiator there have always been options available to you that you have never inquired about.

mdw1000

I thought I covered that in a thread way back when that we were both in, so I didn't see a need to send a follow up message.

I said that I felt I waited too long to install it for it to be fair to return it. I also said I felt that the radiator did have a freer air flow design than the stock unit (based on looking through the front of both the stock and the BHR unit, you could see more light through the BHR unit). However, because of the configuration of the area in front of and behind the RX-8 radiator, I don't think the potential extra airflow is helping the coolant temps because the main restriction seems to be the flow of air around the radiator, not the radiator itself. I did say that if that area where somehow redesigned, the BHR radiator might be more helpful with coolant temps.

But with all that said, on track it did improve trans temps but not coolant temps. Track trans temps dropped from the 230s to the 210s with the BHR radiator. Coolant temps did not change - they were still in the 230s and 240s. This is with standard 20 to 30 minute track day sessions. Maybe with longer track sessions the trans temps would have went up higher.

I can't speak for mac and haven't followed all your discussions with him (I don't spend as much time on the forum as I used to), but I think his feeling was that it was a bad idea to devote more cooling area to the trans fluid when the engine coolant temps seem to be the real issue. From reading charts, etc from a couple different sources, it seems like ATF temps in the 230s, especially if you are using synthetic trans fluid, are fine. But I thought the extra trans cooling wouldn't hurt, which is another reason I kept the radiator.

Basically my point here was to say what worked for me tracking an 4-port AT as far as coolant temps go. For me the mods that helped were the larger second radiator with a water heavy mix, Royal Purple Ice, removing the airbox tray (I can do this because I have a non-stock intake configuration with a supercharger), and the Mazmart water pump. Plus running the heat on high from the time the car is started to go to the grid. If you wait till you are on track and you've got more heat into the motor to turn on the heat, it doesn't get the water temps as low.

mdw1000

As far as the trans cooler being immersed in engine coolant and them not being the same temp, I would think that it would take ATF longer to heat up than engine coolant with it being a much thicker fluid.

Also, I should say the coolant temps didn't get any worse with the BHR rad. They just stayed the same.

Red Devil

Ok, it has been stated the results from your radiator were less than desirable - as in no temperature decrease under road race conditions.

Given that, perhaps rather than wax poetic about what is and isn't - why not say what should be actually done? Let's be blunt, this is a product that as advertised is supposed to lower and/or keep temperatures in check. The factory radiator kept temps in check the same. This rad was advertised alongside claims of being from a line of cores able to handle high hp V8s and that it would be more than up to the task.

If you've seen, or logged, different results at the track (I'm assuming the product was road race tested before release) than what were they and under what parameters?


In a nutshell - water temps are ~230 F. The thermostat is fully open allowing for the radiator the "opportunity" to perform its job. The car is traveling >60 mph...if there's a way to further lower water temps by better utilizing the radiator, I'm all ears...take it from here...

Charles R. Hill

iTrader: (7)

Every unit we have sold, both M/T and A/T it has done exactly what radiators are supposed to do including the several used here in AZ, CA,and NV, where we deal with the harshest conditions one will find.

As for the "secondary" radiator idea; you are welcome for that too as my associate MM came up with that a few years ago.

Red Devil

So it kept temperatures the same as the factory radiator and they were unacceptably high with both. And it didn't lower coolant temps either when given the "opportunity". So it's supposed to do nothing?

That's just diverting the subject at hand. And there is no thanks required when there is zero original thought involved. In series, dual pass type arrangements have existed for decades. What's next, further changing the subject by trying to take credit for using a corvette ignition?




I asked specific questions - all of them were ignored. Care to actually answer them?

mdw1000

Ray,

Do you mean that you have seen lower coolant temps with the AT rad on some cars? Have you found specific things that help work with the AT rad to lower coolant temps? If there is some other mod that showed improvement when paired with the rad, I'd love to hear about it and try implementing it. You mentioned fans - has someone tried a different fan setup with the BHR rad?

Charles R. Hill

iTrader: (7)

Thanks for allowing the discussion, Mark. I appreciate it.

Radiators do not lower temperatures. They reduce the time it takes for the cooling fans to draw the coolant temperature down from the peak temp to the target temp. As it relates to A/T rads, the trans fluid temps on the outlet side of the transcooler are supposed to parallel those of the engine coolant, since the transcooler is submerged in engine coolant and trans fluid is designed to operate in the same general temperature as engines do. (Actually, trans fluid will do it's job over a wider range of temps but you get the idea.)

Here is how I would perform any analysis of your entire system (you probably already did all this);

1) Verify your water pump is operating properly (which it seems to be), and that there are no restrictions in your coolant flow (you may want to check the condition of your thermostat as we have had at least one aftermarket unit blow apart and cause dangerous a flow restriction).

2) Also verify that your thermostat opens and closes properly and at the target open/close temps.

3) Verify unobstructed airflow across the radiator core, both front and back. In the case of the BHR and Mazmart/Davis rads, keeping the intake box undertray in-place is not as much a restriction as one might think and the engine undertray is important fopr proper flow across the rad core. If this is a seriously tracked car, you may need to install air divertor panels on all four edges of the radiator inlet area in the same fashion as Roar and MazdaTrix have done.

4) Set your cooling fan "on" temps to the proper temps (IIRC, Mazda targets 208 as a top temp and you really want to have it be 195, maybe less). Although one would think that 60 MPH is enough roads speed to naturally draw air through the radiator core, we have discovered that to not necessarily be the case.

I also agree on the 80/20 water/coolant mix and using a surfactant is not a problem, either. Sometimes it help, sometimes it doesn't.

If you have a rather unique, and challenging, situation that would be compelling and potentially helpful to us in making any product improvements/updates. Cooling systems and clutches are special kinds of parts because they are a lot less predictable and controllable as one might think, and for many reasons.

The one car I regret never having had the opportunity to install the BHR A/T radiator on was Easy_E1's car as he had NOTORIOUS cooling issues, to the point that Mazda examined his car quite a few times. Once they were shown the Mazmart impeller design they "coincidentally" updated the impellers on subsequent water pumps. I am not sure if that was a coincidence or conspiracy, though.

If all of this does not yield the results you were seeking, I have always had a 100% guarantee on BHR's products, on a case-by-case basis (otherwise douchebags would use our products as diagnostic tools rather than sincere purchases), and I would have had no problem considering that course of action in your case since you are not among the aforementioned.

This is the best I can do for you, or anyone else, and if that falls short of everyone's expectations I don't know what else to do. I have a well-reputed company manufacturing our rads, I try to keep in personal contact with all of our customers (especially those with issues/problems/concerns), and I am always open to a full refund if our customers are genuinely dissatisfied.

Charles R. Hill

iTrader: (7)

1) No, it does what radiators are designed to do. The factory temp problems are partially the 208 target temp and the obstructed airflow across the factory core. The Davis/Mazmart radiator is damned near identical to the BHR version, btw, and we both improve upon the factory unit by reducing the fin count.

2) So, what defines "original" to you? Reinventing the wheel? The BHR radiators are not series/dual-pass so you have many issues of your own to confront, observation skills being one of them. Reading comprehension may be another. BHR has never taken credit for using a "corvette ignition". We have taken credit for designing a plug-and-play coil conversion harness, for discovering the efficacy of using GM D585 ignition coils on the RX-8 (which are typically used on the GM Yukon truck, btw, and NOT the corvette), and for devising a mounting scheme that makes it a truly bolt-on/plug-and-play swap. Apparently, it is impressive enough to people because they have copied our design in their DIY attempts, people have reverse-engineered our harness design, and places such as MazdaTrix support our efforts. I suppose you wanna challenge their standing in this community and their judgements, as well?

3) I don't care to answer your questions because you are not a BHR customer and you are not the one using the product in question. You are just another one with hostilities disguising themselves as concerns for the situation at hand.

How's that for waxing poetic?