To DCCD or not to DCCD?
Discussion
I started a thread about gearboxes a while ago. I'm now a bit closer to needing a new box (primarily because of a planned turbo change which will hopefully give results in the ballpark of 450bhp and 500lb/ft on the 2.5).
I've spoken to a few people and have the option of a low-mileage DCCD 6-spd box/prop etc. It's going to cost somewhere in the region of £3k plus vat and a lot of labour in fitting and setting it up. I have a Syvecs ECU which can control the DCCD which does help a bit.
I'd pretty much decided to do it but over the last couple of days have been thinking about it and wondering how much would I really use it?. My p1 is first and formeost a road car, for all-year-round use with a few track days per year.
So, if you've got a DCCD equipped Impreza, how often do you really use it? Or do you just leave the centre diff open the whole time?
Ta,
Lefty
I've spoken to a few people and have the option of a low-mileage DCCD 6-spd box/prop etc. It's going to cost somewhere in the region of £3k plus vat and a lot of labour in fitting and setting it up. I have a Syvecs ECU which can control the DCCD which does help a bit.
I'd pretty much decided to do it but over the last couple of days have been thinking about it and wondering how much would I really use it?. My p1 is first and formeost a road car, for all-year-round use with a few track days per year.
So, if you've got a DCCD equipped Impreza, how often do you really use it? Or do you just leave the centre diff open the whole time?
Ta,
Lefty
I have a 500 bhp P1 (2.1) that has a 6 speed dccd from an 04'Spec C fitted. It spends 95% of its time fully open - I just lock it up a little bit if it's really greasy or very wet.
However, I didn't fit it for snow or whatever, I fitted it to get a 67r 33f split and a more rear bias, rather than the 50:50 split of the P1 oem diff.
In fact I originally replaced the oem 5 speed centre diff with a dccd centre diff, and then went 6 speed / big R180 plated rear diff/ shafts/ rear brakes for future proofing (2.35 and Gt 35 R being fitted as we speak)
However, I didn't fit it for snow or whatever, I fitted it to get a 67r 33f split and a more rear bias, rather than the 50:50 split of the P1 oem diff.
In fact I originally replaced the oem 5 speed centre diff with a dccd centre diff, and then went 6 speed / big R180 plated rear diff/ shafts/ rear brakes for future proofing (2.35 and Gt 35 R being fitted as we speak)
FBP1 said:
However, I didn't fit it for snow or whatever, I fitted it to get a 67r 33f split and a more rear bias, rather than the 50:50 split of the P1 oem diff.
The DCCD Imprezas I've driven (older STi-RAs) were far more neutral and balanced with it open than any 50:50 Subaru I've driven. No understeer, just pin-sharp turn-in and a bit of power oversteer if you wanted it.
Being able to increase the lockage to get the balance you want in slippery conditions would be pretty cool too though, I wish my Legacy had DCCD!
Edited by GravelBen on Friday 25th October 05:46
I run a type r with dccd and it is good for stepping the rear out. Seems to have less understeer aswell and feels more lively than a non dccd set up. I run mine pretty much open all the time unless it is really slippy. I like the feel with dccd but..
I felt i could go quicker in my old non dccd car (especially on track) as when the rear stepped out you just keep the accelerator planted and the car would pull itself straight which the type r is less likely to do and more likely to spin. That meant i could get on the power earlier.
Once i finish my type r build, i will be seriously considering a neetronics system to control the dccd.
I'm not quite sure if your ecu will do this but i think it can.
Another bonus is if you take the car on the drag strip you can launch with the diff locked to get more traction off the line. The downside is it makes it easier to snap gearboxes.
Basically what i'm saying is the dccd gives you more options for setting up you car but it will not necessarily make it quicker.
By the way. The standard subaru diff set up is 60/40 not 50/50.
Johnny.
I felt i could go quicker in my old non dccd car (especially on track) as when the rear stepped out you just keep the accelerator planted and the car would pull itself straight which the type r is less likely to do and more likely to spin. That meant i could get on the power earlier.
Once i finish my type r build, i will be seriously considering a neetronics system to control the dccd.
I'm not quite sure if your ecu will do this but i think it can.
Another bonus is if you take the car on the drag strip you can launch with the diff locked to get more traction off the line. The downside is it makes it easier to snap gearboxes.
Basically what i'm saying is the dccd gives you more options for setting up you car but it will not necessarily make it quicker.
By the way. The standard subaru diff set up is 60/40 not 50/50.
Johnny.
I've done a cost benefit analysis and decided that DCCD is a no-go.
6-spd box is going to cost me £2k all-in, ish.
6-spd DCCD is going to be more like £5k, including standalone ecu (to let me use an auto mode) and I really don't think the benefit of DCCD is worth £3k, at the moment...
But never say never! Thanks for the input and opinions chaps.
6-spd box is going to cost me £2k all-in, ish.
6-spd DCCD is going to be more like £5k, including standalone ecu (to let me use an auto mode) and I really don't think the benefit of DCCD is worth £3k, at the moment...
But never say never! Thanks for the input and opinions chaps.
Edited by Lefty on Tuesday 29th October 20:40
Johnny R6 a standard non Dccd Subaru is NOT 60:40. That's incorrect.
It is 50:50.
Eg P1 4.44 front diff/ 4.44 rear diff , 1:1 transfer box = 50:50
Uk model has differing front to rear diffs e.g 3.9/3.54 BUT the transfer box is 1.1:1 not 1:1 so the ratios work out at 50:50 again.
Common error that has been repeated as gospel by lazy cut and pasting journalists for years now
The newer dccd-a boxes are 60r/ 40 front, the older dccd are 67r/33f
It is 50:50.
Eg P1 4.44 front diff/ 4.44 rear diff , 1:1 transfer box = 50:50
Uk model has differing front to rear diffs e.g 3.9/3.54 BUT the transfer box is 1.1:1 not 1:1 so the ratios work out at 50:50 again.
Common error that has been repeated as gospel by lazy cut and pasting journalists for years now
The newer dccd-a boxes are 60r/ 40 front, the older dccd are 67r/33f
FBP1 said:
Johnny R6 a standard non Dccd Subaru is NOT 60:40. That's incorrect.
It is 50:50.
Eg P1 4.44 front diff/ 4.44 rear diff , 1:1 transfer box = 50:50
Uk model has differing front to rear diffs e.g 3.9/3.54 BUT the transfer box is 1.1:1 not 1:1 so the ratios work out at 50:50 again.
Common error that has been repeated as gospel by lazy cut and pasting journalists for years now
The newer dccd-a boxes are 60r/ 40 front, the older dccd are 67r/33f
I stand corrected and i should know better.It is 50:50.
Eg P1 4.44 front diff/ 4.44 rear diff , 1:1 transfer box = 50:50
Uk model has differing front to rear diffs e.g 3.9/3.54 BUT the transfer box is 1.1:1 not 1:1 so the ratios work out at 50:50 again.
Common error that has been repeated as gospel by lazy cut and pasting journalists for years now
The newer dccd-a boxes are 60r/ 40 front, the older dccd are 67r/33f
Sorry, Johnny.
RB Will said:
Are you planning on doing it yourself? if not where are you getting to do the conversion as I'm planning on making my P1 a 6 speeder in the coming months.
As much as I think I would like it the DCCD is a bit expensive for me.
£2k is a lot less than I had been quoted before.
Sorry Will, I just saw your post. No, I'm Not doing it myself. Would love to but I don't have a workshop, the tools, the time or, frankly, the ability to do it myself! As much as I think I would like it the DCCD is a bit expensive for me.
£2k is a lot less than I had been quoted before.
To be honest, the DCCD box wasn't that much more (maybe £1000 of a difference) but the labour in setting it up would be considerable compared to non-DCCD. I already have Syvecs which can control the box so I wouldn't need an aftermarket controller.
I bought the box from RCM. It's from a car they're breaking. They're modifying the prop to suit the p1 diff (I'm not going r180) and my local specialist has got a linkage etc for me.
I did seriously think about DCCD and may still change in the future. The money I've saved goes a long way towards the wrc arches, sills and bumpers which is the next job (along with 18x9.5" wheels and 265x35 ad08's)
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