Cooling: how to improve on oem?

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Dowx

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Hi,

New owner of a rotary, I had big plans before I got my rx7 to go ported and single turbo straight away but the car i bought is so unmolested (exhaust and apexi ecu) that I'm thinking of sticking with the twins. I've sorted out a couple of niggles so now I'm on to cooling.

I've noticed the water and oil temps look good but the air temp and the heat from the engine bay is high! Would a hks downpipe and koyo n flo rad keep me safe? And thing else that could be improved on?

Thanks
 
If you are looking for inspiration I would start with Roy's (Cib24) car as his is probably one of the best examples of a near stock but lightly modded car still running twins: cib24's 1999 Mazda RX-7 Type RS

Koyo N Flo is definately a decent upgrade for the rad.

While the HKS downpipe is a bit less restrctive I wouldn't say it was the best of the downpipes. I would look at some of the other brands if money will stretch such as the Feed etc.

If you are keeping the stock cat mid pipe then it's worth getting the front flange ground out as it has a lip internally and can be ground and therefore increase the diameter of the pipe which aids in reducing heat a little.
 
Myocardial Infarction said:
If you are looking for inspiration I would start with Roy's (Cib24) car as his is probably one of the best examples of a near stock but lightly modded car still running twins: cib24's 1999 Mazda RX-7 Type RS

Koyo N Flo is definately a decent upgrade for the rad.

While the HKS downpipe is a bit less restrctive I wouldn't say it was the best of the downpipes. I would look at some of the other brands if money will stretch such as the Feed etc.

If you are keeping the stock cat mid pipe then it's worth getting the front flange ground out as it has a lip internally and can be ground and therefore increase the diameter of the pipe which aids in reducing heat a little.
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Thanks, great read
 
Haven't updated that thread in absolute ages but basically things are hot with twins under the stock bonnet, but to be honest it's not the end of the world. Start with an upgraded Koyo N Flow 48mm radiator in the stock location, and as Neil said water injection is your saviour if you are not keen on completely reconfiguring your engine bay to fit a V Mount or Front Mount. Plus, the AEM water injection kit can be had for less than £400.

When you decide to go for more power follow my mods as it's all light touch focused on better intake, intercooler and exhaust flow to make it a little easier for the twins to work at higher boost pressures.

I'd love a single like everyone else and will probably get there one day if I don't sell my car first, but I'm also not keen on spending £5-10k to do a 450+ hp single properly.
 
I know nothing

Screenshot_20200715-092808.png
 
Its what i thought. Especially how abrupt the back plate is. Could at least be a bit more coned or something

I've seen a few in the past like this too
 
That it does.

I'm kinda interested in it as a package the more I look.

However I was talking to a a couple of tuners who say the stock set up does a bloody good job
 
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MILLION said:
How do people feel about this?

Just popped up and haven't seen this particular one before

https://www.facebook.com/100006500384156/posts/3048157298744253
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Sacha's stuff is like 5x more money than is realistic. Same with the 500hp twins him and his friend market which are full of shit.

Not saying it's not nice but who the hell knows because hardly anyone is crazy enough to pay £5k for twins and £2k for a Knight Sports intercooler copy with a stupid fan on the back that will cause performance loss when moving.
 
Mate, bigger fmic or vmic whichever! Either is as good as the next tbh. Water injection is by far and away the single best way to cool the intake air. I opted for a eBay rad but a nflow is probably the better option but my eBay is bigger.

Getting heat out is a big issue so the biggest and best dp/ exhaust combo you can afford is best.


Tbh for street use most of the above is overkill but still worth doing.
 
The new Nflow is good because it's 48mm and more densely packed and efficient than the older 53mm Nflow, so no cooling loss. This helps because at 48mm you don't need to modify anything to make it fit. It just drops in.

FYI the stock radiator on pre-99 cars is 25mm thick and on 99 and later cars is 27mm thick with a slightly denser fin density. Still only barely enough for a Street car.
 
cib24 said:
The new Nflow is good because it's 48mm and more densely packed and efficient than the older 53mm Nflow, so no cooling loss. This helps because at 48mm you don't need to modify anything to make it fit. It just drops in.

FYI the stock radiator on pre-99 cars is 25mm thick and on 99 and later cars is 27mm thick with a slightly denser fin density. Still only barely enough for a Street car.
Click to expand...

Cib would you know where I could get a 48mm? All I can find is 53mm
 
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