KWE Intercoolers - My Review
Posted: Sat Apr 30, 2016 8:41 pm
***EDIT*** Feb 2020 - Wagners have now created a C6 RS6 replacement Intercoolers for around £2500 inc new radiators and new crash bar which is now at a pricing mid point between the HS Marstons and the KWE IC's but with a proven better performance than either with 1 car hitting almost 1100hp with them fitted.
***EDIT*** Early Oct 2021 - I've now swapped from the KWE I/C's in this review to a set of the Wagners mentioned above, just waiting on a remap now!
***EDIT*** Mid Oct 2021 - I just had my car mapped for the Wagners - made 930hp and 1125nm - way better at the top end, better cooling and flow rate meant the redline could be increased to 7500rpm!
*******************************************************************************************************
I’ve already covered some of this in the HS Marstons thread I posted.
As part of my research into the spec for my car the intercoolers were another thing which seemed to be an expensive and time consuming part to source.
KWE wanted over £1k for their “untested in the UK” IC’s and the only other one we knew of was the HS Marston’s ones that Classba and Brett have which, again, had been posted as costing around £5k-6k originally (price since dropped to £4k).
I decided to try the KWE’s, mainly for their price and also because no-one had fitted them and done any dyno runs to performance check that I knew of (only 1 other with them fitted I believe), so I thought I would be the guinea pig for these.
MRC had the task of fitting them and we knew from a Facebook post by SW Auto’s in Kent (who’d fitted a set to the garage owners own RS6) that fitting was not “Plug and Play” as described on KWE's website. It turns out the UK spec RS6 has some coolant pipework routed differently to the Euro Spec RS6 so while in Germany KWE had no issues fitting them (other than modifying the air shrouds/guides to fit the bigger IC) in the UK we have a pipe that wraps around the right IC. This pipe doesn’t fit the much wider KWE IC’s so the pipe has to be modified (either replaced with a flexible pipe or a new solid pipe made). The shrouds (or air guides) also needed some custom work to fit the bigger IC so mine have been adapted by MRC with a metal shroud “extension”. KWE have since released a new set of shrouds for around 600Euros but that happened after I’d already bought mine so I’ve not had these fitted and don’t really see the need to either to be fair.
So, performance figures! Well it’s a mixed bag of good & bad which doesn’t sound great but let me explain. They do make the power! They made 920hp no problems which is great for their cost, however, there are two “issues” they have which need to be mentioned.
Their flow rate above 6500rpm seems limited and, as they were making no extra power above that, Doug decided to reduce my limiter back to OEM 6500rpm. This isn’t a huge issue as they still make 900hp+ at that rpm but something to be aware of.
Their biggest problem is that they suffer from heat soak when the car is not moving, due to a combination of having no fans fitted (I felt they block the air passing through the core when driving and I’d rather have more cool air when driving) and having a thick metal core which absorbs heat and doesn’t cool back down easily in static air. On the roads I’ve had absolutely no problems or power issues but when in static air (dynos, start line on drag strips, traffic light grand prix etc where the car isn’t moving) after repeated runs they just couldn’t cool down quickly enough between runs which raised the intake temp and robbed power. In fact Doug said my 920hp runs at MRC dropped to 900hp within 3 consecutive runs and to 880hp after a further 5-6 back to back runs and that is with some very good dyno cooling.
Worse still, at the Surrey Rolling Road day the car had not been “prep’d” in the best way prior to the run. I’d been out for a blast, then switched it off for 20 mins, then sat idling for a further 10mins adding even more heat soak before the run which was done without any IC fans (only one engine bay fan so the worst possible setup imaginable) and the power had dropped to only 780hp!!!! Even cooling the IC’s by flicking some water on them brought them back 30hp to 810hp showing how poor they are when in static air (when the car isn’t moving).
So, my review – They work, they’re cheap and they’re adequate for 900hp+ but just stay away from dynos and drag strips as heat soak is an issue.
Will I be changing mine? – It depends on the cost of the Sportmile ones to be fair. Now I know the KWE’s “limitations” I can work with those as I rarely do dynos/drag days/traffic light grand prix but if there’s a better IC for a respectable price then I’d consider it. However I feel the Marston’s are still too expensive for what they are, now I know the cost of the cores.
***EDIT*** Early Oct 2021 - I've now swapped from the KWE I/C's in this review to a set of the Wagners mentioned above, just waiting on a remap now!
***EDIT*** Mid Oct 2021 - I just had my car mapped for the Wagners - made 930hp and 1125nm - way better at the top end, better cooling and flow rate meant the redline could be increased to 7500rpm!
*******************************************************************************************************
I’ve already covered some of this in the HS Marstons thread I posted.
As part of my research into the spec for my car the intercoolers were another thing which seemed to be an expensive and time consuming part to source.
KWE wanted over £1k for their “untested in the UK” IC’s and the only other one we knew of was the HS Marston’s ones that Classba and Brett have which, again, had been posted as costing around £5k-6k originally (price since dropped to £4k).
I decided to try the KWE’s, mainly for their price and also because no-one had fitted them and done any dyno runs to performance check that I knew of (only 1 other with them fitted I believe), so I thought I would be the guinea pig for these.
MRC had the task of fitting them and we knew from a Facebook post by SW Auto’s in Kent (who’d fitted a set to the garage owners own RS6) that fitting was not “Plug and Play” as described on KWE's website. It turns out the UK spec RS6 has some coolant pipework routed differently to the Euro Spec RS6 so while in Germany KWE had no issues fitting them (other than modifying the air shrouds/guides to fit the bigger IC) in the UK we have a pipe that wraps around the right IC. This pipe doesn’t fit the much wider KWE IC’s so the pipe has to be modified (either replaced with a flexible pipe or a new solid pipe made). The shrouds (or air guides) also needed some custom work to fit the bigger IC so mine have been adapted by MRC with a metal shroud “extension”. KWE have since released a new set of shrouds for around 600Euros but that happened after I’d already bought mine so I’ve not had these fitted and don’t really see the need to either to be fair.
So, performance figures! Well it’s a mixed bag of good & bad which doesn’t sound great but let me explain. They do make the power! They made 920hp no problems which is great for their cost, however, there are two “issues” they have which need to be mentioned.
Their flow rate above 6500rpm seems limited and, as they were making no extra power above that, Doug decided to reduce my limiter back to OEM 6500rpm. This isn’t a huge issue as they still make 900hp+ at that rpm but something to be aware of.
Their biggest problem is that they suffer from heat soak when the car is not moving, due to a combination of having no fans fitted (I felt they block the air passing through the core when driving and I’d rather have more cool air when driving) and having a thick metal core which absorbs heat and doesn’t cool back down easily in static air. On the roads I’ve had absolutely no problems or power issues but when in static air (dynos, start line on drag strips, traffic light grand prix etc where the car isn’t moving) after repeated runs they just couldn’t cool down quickly enough between runs which raised the intake temp and robbed power. In fact Doug said my 920hp runs at MRC dropped to 900hp within 3 consecutive runs and to 880hp after a further 5-6 back to back runs and that is with some very good dyno cooling.
Worse still, at the Surrey Rolling Road day the car had not been “prep’d” in the best way prior to the run. I’d been out for a blast, then switched it off for 20 mins, then sat idling for a further 10mins adding even more heat soak before the run which was done without any IC fans (only one engine bay fan so the worst possible setup imaginable) and the power had dropped to only 780hp!!!! Even cooling the IC’s by flicking some water on them brought them back 30hp to 810hp showing how poor they are when in static air (when the car isn’t moving).
So, my review – They work, they’re cheap and they’re adequate for 900hp+ but just stay away from dynos and drag strips as heat soak is an issue.
Will I be changing mine? – It depends on the cost of the Sportmile ones to be fair. Now I know the KWE’s “limitations” I can work with those as I rarely do dynos/drag days/traffic light grand prix but if there’s a better IC for a respectable price then I’d consider it. However I feel the Marston’s are still too expensive for what they are, now I know the cost of the cores.
("change" will be well spent on other mods, most notably Maxton front lip, ARBs and fixing the p/s pump).
.