SLR R400 K/D advice
Discussion
I am contemplating upgrading to a really quick 7 like a SLR / R400 from my original 1.6 Superlight as I am well and truly into the arena of diminishing returns now; having got it into tip top condition. To tune it would take away from the Superlight specification and not add to the value.
I am pretty au fait with the K series 7’s but haven’t really paid much attention to the newer Ford engined cars, as they were out of my price range.
So what do I get? I am definitely looking for a track orientated spec, so want the bigger brakes, 6 speed gearbox, LSD and wide track suspension short it must be an R spec 7. I know with the higher powered K series the accepted wisdom is it must be dry sumped, but is that the case with Duratec engined 7’s (and SIgma engined 7’s; although I think they only go up to 152 bhp)?
Are dry sump equipped cars any easier to check the oil level on? The wet sumped K Series is a difficult to check when the oil is new because it is so clear i.e. all the time. Also, it is difficult to get a consistent reading even when following the instructions to the letter. I even bought a PGM dip stick which is only marginally better.
Is there anything to be aware of with the higher powered Duratec engined R spec 7’s?
I am pretty au fait with the K series 7’s but haven’t really paid much attention to the newer Ford engined cars, as they were out of my price range.
So what do I get? I am definitely looking for a track orientated spec, so want the bigger brakes, 6 speed gearbox, LSD and wide track suspension short it must be an R spec 7. I know with the higher powered K series the accepted wisdom is it must be dry sumped, but is that the case with Duratec engined 7’s (and SIgma engined 7’s; although I think they only go up to 152 bhp)?
Are dry sump equipped cars any easier to check the oil level on? The wet sumped K Series is a difficult to check when the oil is new because it is so clear i.e. all the time. Also, it is difficult to get a consistent reading even when following the instructions to the letter. I even bought a PGM dip stick which is only marginally better.
Is there anything to be aware of with the higher powered Duratec engined R spec 7’s?
There are always going to be different opinions on K series v Duratec so I'd listen to as much advice as you can and make up you own mind about which one suits you best. I'm a Duratec fan so maybe not totally impartial, but here's my thoughts.
From a day to day practicality the Duratec is still in production (or at least new engine are still available) with spares no problem. The K series is no longer made and getting harder to source . The Duratec can easily be tuned to 220 BHP without any significant impact on reliability and using mostly standard internals, beyond that it can get expensive, but 265 BHP is a good balance of cost v reliability. A 250+ BHP K series is not cheap.
IMHO a dry sump is a must for Duratec track cars. That's not to say people don't track wet sumps successfully, but you are treading a fine line and it does not take much to go wrong to cause problems. The forward dry sump tank has a large capacity and is easy to the check level which is not critical.
On the down side the Duratec is heavier and the handling is different to the K series, not necessarily worse but does lose some of the agility of the K.
Hope that helps
From a day to day practicality the Duratec is still in production (or at least new engine are still available) with spares no problem. The K series is no longer made and getting harder to source . The Duratec can easily be tuned to 220 BHP without any significant impact on reliability and using mostly standard internals, beyond that it can get expensive, but 265 BHP is a good balance of cost v reliability. A 250+ BHP K series is not cheap.
IMHO a dry sump is a must for Duratec track cars. That's not to say people don't track wet sumps successfully, but you are treading a fine line and it does not take much to go wrong to cause problems. The forward dry sump tank has a large capacity and is easy to the check level which is not critical.
On the down side the Duratec is heavier and the handling is different to the K series, not necessarily worse but does lose some of the agility of the K.
Hope that helps
Edited by DCL on Monday 24th July 21:04
Green George said:
DCL that is very helpful, thanks. So the oil level on a Duratec dry ump is easy to reliably check?
Do you know what happened to EVO's 420R?
You just remove the filler cap, look inside and fill it to just above the top baffle - or add 7 litres from empty (oil change, not dry). I've only heard rumours about the EVO car, and I understand it was an oil related problem. But the Standard 420R is a wet sump, with dry sump as option, and I don't know what car they had. Either way, a motor journalist is very different from a private owner.Do you know what happened to EVO's 420R?
Edited by DCL on Monday 24th July 21:26
The Duratec is the same engine as the Mazda MZR in the MX5 Mk3, I think. Designed by Yamaha. Anyway, I understand that in the MX5 SuperCup series (And on road cars that are not checked regularly, too) the Duratec engines are meant to be very sensitive to oil level. Let it run a bit low and it will run a bearing. I think it's something to do with the shallow sump design.
Maybe an Accusump is a decent compromise??
Maybe an Accusump is a decent compromise??
I have a '15 R400D and would endorse everything DCL says.
As far as checking oil level is concerned, I check mine soon after stopping and the level, with about 7L in, will be just over the baffle as DCL says. Leave it all to cool and it'll be about 10mm below the baffle.
I find that I suck and drain out about 6.75L during an oil/filter change. I change the oil every year, 1500 miles or so which will include 2 or 3 TDs. Never needed to add any oil between changes.
The engine might be heavier and a bit less revvy than the K but I find it's great on road and track, solid and easy to service etc.
As far as checking oil level is concerned, I check mine soon after stopping and the level, with about 7L in, will be just over the baffle as DCL says. Leave it all to cool and it'll be about 10mm below the baffle.
I find that I suck and drain out about 6.75L during an oil/filter change. I change the oil every year, 1500 miles or so which will include 2 or 3 TDs. Never needed to add any oil between changes.
The engine might be heavier and a bit less revvy than the K but I find it's great on road and track, solid and easy to service etc.
andy97 said:
The Duratec engines are meant to be very sensitive to oil level. Let it run a bit low and it will run a bearing. I think it's something to do with the shallow sump design.
Maybe an Accusump is a decent compromise??
If I am going to go down the Duratec route it will be with a dry dumped equipped 7.Maybe an Accusump is a decent compromise??
REALIST123 said:
I have a '15 R400D and would endorse everything DCL says.
As far as checking oil level is concerned, I check mine soon after stopping and the level, with about 7L in, will be just over the baffle as DCL says. Leave it all to cool and it'll be about 10mm below the baffle.
I find that I suck and drain out about 6.75L during an oil/filter change. I change the oil every year, 1500 miles or so which will include 2 or 3 TDs. Never needed to add any oil between changes.
The engine might be heavier and a bit less revvy than the K but I find it's great on road and track, solid and easy to service etc.
That is reassuring. Thank you.As far as checking oil level is concerned, I check mine soon after stopping and the level, with about 7L in, will be just over the baffle as DCL says. Leave it all to cool and it'll be about 10mm below the baffle.
I find that I suck and drain out about 6.75L during an oil/filter change. I change the oil every year, 1500 miles or so which will include 2 or 3 TDs. Never needed to add any oil between changes.
The engine might be heavier and a bit less revvy than the K but I find it's great on road and track, solid and easy to service etc.
Out of interest what species your engine? The reason I ask is that the R400 I was looking at is apparently rated at 210bhp not 220 bhp.
Green George said:
That is worth knowing. I was looking at a 2011 model. Did RBTB's become standard or were they a tuning option?
My car, built from a kit in 2015, came with 210. Last year I had RBTBs fitted and now it's 220.
As said the improved torque makes it feel more of an increase but I was surprised by the improvement in drivability too:
Personally I am a k-series fan but its hard to argue with the points made earlier and I would also like to try a duratec car at some point as a comparison. I have been a passenger in a 220bhp R400 and it had a lot more torque than my car (213bhp k-series) and I got to enjoy the induction noise.
I wish there was a modern engine package that was not as heavy as the duratec and had a passenger side exhaust exit. I don't think I would ever tire of the revvy, chase the power to the red-line engine characteristics of the K with the induction bark fed straight to you balanced by the exhaust note pointing away from you. I think the exhaust on the drivers side would be tiresome for any road work.
I'll reserve judgement until I try an R500 though!
I wish there was a modern engine package that was not as heavy as the duratec and had a passenger side exhaust exit. I don't think I would ever tire of the revvy, chase the power to the red-line engine characteristics of the K with the induction bark fed straight to you balanced by the exhaust note pointing away from you. I think the exhaust on the drivers side would be tiresome for any road work.
I'll reserve judgement until I try an R500 though!
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