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Does anyone here have any experience of fitting the Direnza extra thick radiators?

Good or bad?

42mm core thickness vs normal?

Thank you
 

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Does anyone here have any experience of fitting the Direnza extra thick radiators?

Good or bad?

42mm core thickness vs normal?

Thank you
If this is the same as the one Autodelta advertise yes I have one fitted to my 147 GTA. So far could not be happier with it.

Allan
 

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Anything to help with engine temps can only be a good thing. Still surprised that no one come up with a solution to reduce the heat generated by the cats in the CF3 V6 engine, apart from going to the great expense of removing them altogether..
 

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Anything to help with engine temps can only be a good thing. Still surprised that no one come up with a solution to reduce the heat generated by the cats in the CF3 V6 engine, apart from going to the great expense of removing them altogether..
Which would be to fit CF2, wizzard or supersprint manifolds.

What else do you expect? :confused:
 

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Does anyone here have any experience of fitting the Direnza extra thick radiators?

Good or bad?

42mm core thickness vs normal?

Thank you
Unless you're planning signicant engine modifications or live in a sillyhot environment (i.e. not the UK) I can't see the point.

Even with heavy track use and an air con rad fitted and working, I've found the standard radiator to be up to the job.

The Oil cooler less so. Oil temp got up to the full 5 bars at one point on one of my old cars when I wasn't watching properly.

However, I accept that a thicker coolant radiator may help with this issue, but it's an indirect approach to solving a problem that only seems to occur under extreme circumstances.
 

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I can't see the point in an oversized radiator unless you have modified the engine or are tracking the car heavily.

The standard radiator is designed to shed sufficient heat to maintain engine temperatures at full power output, which you'd rarely use on the road for more than a few seconds. It is designed to do this under harsh operating conditions, such as summer heat, where the difference in temperature between the coolant and the air is only about 50K. Almost by definition, high power means forward motion which means good airflow. At full power, the engine needs to dump something like 200 kW in heat.

At idle, the engine needs to shed very little heat, probably less than 10 kW. It gets hot because there is no airflow, hence the fans.

By adding a "bigger/deeper" radiator, you're addressing the high speed problem, not the idle one. If anything, the ambient temperature in the engine bay will be higher with the bigger rad as it will dump heat more violently when the fans start up. It will do nothing for the catalyst temperatures, they aren't water cooled. Given that at high speed there is no problem, then you're just wasting money, certainly if you've paid Autodelta £500 for one.

That said, they look nice and probably will last longer than the standard ones.

As an aside, having just changed the rad in my GTA Shed-Wagon, I can confirm that the standard rad, even when very tired (30% of the fins missing) can keep the car at temperature on a warm day doing a load of ragging round country lanes.
 

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I can't see the point in an oversized radiator unless you have modified the engine or are tracking the car heavily.

The standard radiator is designed to shed sufficient heat to maintain engine temperatures at full power output, which you'd rarely use on the road for more than a few seconds. It is designed to do this under harsh operating conditions, such as summer heat, where the difference in temperature between the coolant and the air is only about 50K. Almost by definition, high power means forward motion which means good airflow. At full power, the engine needs to dump something like 200 kW in heat.

At idle, the engine needs to shed very little heat, probably less than 10 kW. It gets hot because there is no airflow, hence the fans.

By adding a "bigger/deeper" radiator, you're addressing the high speed problem, not the idle one. If anything, the ambient temperature in the engine bay will be higher with the bigger rad as it will dump heat more violently when the fans start up. It will do nothing for the catalyst temperatures, they aren't water cooled. Given that at high speed there is no problem, then you're just wasting money, certainly if you've paid Autodelta £500 for one.

That said, they look nice and probably will last longer than the standard ones.

As an aside, having just changed the rad in my GTA Shed-Wagon, I can confirm that the standard rad, even when very tired (30% of the fins missing) can keep the car at temperature on a warm day doing a load of ragging round country lanes.
yes that might be the case.. except the alloy item i have is much better made and does allow me expansion once/ if i ever get the 3.8 finished. that and the fact i think i paid less than 75.00 on an ebay auction makes it great value..
 

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yes that might be the case.. except the alloy item i have is much better made and does allow me expansion once/ if i ever get the 3.8 finished. that and the fact i think i paid less than 75.00 on an ebay auction makes it great value..
Is it a direct fit?

I've set up my car to run higher rpms, for track, at about 33-36 degrees Celsius, 80-90% humidity.
Water Temps don't go more than 110C on the stock radiator. but that saying, I'm keen to explore a good radiator set up to bring it lower.

Could you send me a link on the seller to see if he's got more of the same, if its a direct fit. I suppose there's a caveat of the extra weight once it is larger, and with possibly more water capacity.
 

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looks like one of those bar and plate cheap rads, which ok they are fully aluminium and they could last longer than standard. But the flow rates on some of these ebay specials are pretty poor compared to what they replace. You can make things worse by fitting one of these.
We actually had a Mishimoto one fully lifetime fitted in a Cooper S and it failed after a year, it was easy to replace, but if it doesn't have lifetime guarantee i would not touch it. The Mishimoto one was a good radiator for the Mini, but even it failed. yet to see how the new one will get on.

I would go for the more OEM type replacement alloy rads or if you want a proper alloy rad, get a well renowned company to make it for you and then get them to make it for retail. But price will be £400+ i reckon.

I also as others above don't see the point of replace unless the car is used hard on the track in warm climate. The std rad is more than capable.
 
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looks like one of those bar and plate cheap rads, which ok they are fully aluminium and they could last longer than standard. But the flow rates on some of these ebay specials are pretty poor compared to what they replace. You can make things worse by fitting one of these.
We actually had a Mishimoto one fully lifetime fitted in a Cooper S and it failed after a year, it was easy to replace, but if it doesn't have lifetime guarantee i would not touch it. The Mishimoto one was a good radiator for the Mini, but even it failed. yet to see how the new one will get on.

I would go for the more OEM type replacement alloy rads or if you want a proper alloy rad, get a well renowned company to make it for you and then get them to make it for retail. But price will be £400+ i reckon.

I also as others above don't see the point of replace unless the car is used hard on the track in warm climate. The std rad is more than capable.
I only changed mine because of the very hot summer temps (40c+}at times so the road temps are anybody's guess. I did a track day with the 3.2 GT on a 32c day and it got a little worm so that's why I bought it but I didn't get around to fitting it. After I sold the GT I fitted it to the GTA. I think if you do track day in this sort of climate its a must.

Allan
 

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I only changed mine because of the very hot summer temps (40c+}at times so the road temps are anybody's guess. I did a track day with the 3.2 GT on a 32c day and it got a little worm so that's why I bought it but I didn't get around to fitting it. After I sold the GT I fitted it to the GTA. I think if you do track day in this sort of climate its a must.

Allan
I'm running under similar conditions. Any obvious improvements on the water temps?

Sent from my E6883 using Tapatalk
 

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I'm running under similar conditions. Any obvious improvements on the water temps?

Sent from my E6883 using Tapatalk
The engine runs cooler when on the open road and only when in heavy traffic does the cooling fans operate, the oil temp seems a bit cooler also. As its winter at the moment I've only driven it in temps up around 24c so until summer returns I wont know for sure. It does seem to shed temp more quickly when on the freeway after heavy traffic.

Allan
 

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interesting thread.
I am also tempted to replace (when needed) the standard radiator with a bigger one. Just did a 20min trackday session, outside temp around 20 degrees, so not hot, but after a few laps the oil temp is at 4 bars which I found the trigger to slow down as I feel 5 bars is too much.
So in hotter climates (like Saabretooth in Singapore) I recon this to be a real issue, right?

My line of thinking would be that a bigger rad would help in lowering temps. (note I have already have a new, bigger oilcooler installed).
Is this a correct consideration?

Second question: why would temperature be higher?? Does it block air flow into the engine bay?
By adding a "bigger/deeper" radiator, you're addressing the high speed problem, not the idle one. If anything, the ambient temperature in the engine bay will be higher with the bigger rad as it will dump heat more violently when the fans start up.
 

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interesting thread.
I am also tempted to replace (when needed) the standard radiator with a bigger one. Just did a 20min trackday session, outside temp around 20 degrees, so not hot, but after a few laps the oil temp is at 4 bars which I found the trigger to slow down as I feel 5 bars is too much.
So in hotter climates (like Saabretooth in Singapore) I recon this to be a real issue, right?

My line of thinking would be that a bigger rad would help in lowering temps. (note I have already have a new, bigger oilcooler installed).
Is this a correct consideration?

Second question: why would temperature be higher?? Does it block air flow into the engine bay?
I just think the cooling surface cannot keep up with the thermal load off the outside temp under a heavy load. Here in summer at times you could fry an egg on the road, any larger capacity radiator has to help. We tried this with a Land rover discovery V8 series 1 that used to cook on the beach in summer until we put a HD radiator in it. after the conversion no more over heating. horses for courses, depends on climate I suppose. If I lived in Iceland I would not bother, here it can be a thousand k's to an Alfa specialist and the cost of the tow if you cook it

Allan
 

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Yes ArielB, the choice of EO makes a difference as well.

Recent track day, I switched from AGIP to Motul 300V, the Motul oil climbed higher, faster than the AGIP. I too have a larger EO cooler, the Mocal set up from Autolusso. even this didn't help. I hit 5 bars and straight away cut down to cooling laps straight away. Ambient temps were 33-35C and track temps were in the mid to high 40s.

Although I'd have to say, my water temp remained constant at 90, its not accurate as say, a proper Defi Meter set up.

Thus my curiousity as to how well this oversized radiator would function, even if it is the cheap bar and plate radiator.

Sent from my E6883 using Tapatalk
 
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