Cornish Rattler Posted July 5, 2021 Share Posted July 5, 2021 Hi guys Today I fitted a boost pin / ring kit to my S2a 200tdi ( 300tdi FIP ) that I bought from the recent Billing show Quote Link to comment Share on other sites More sharing options...
Jackjack Posted July 5, 2021 Share Posted July 5, 2021 Im interested in that, although i think i need to calm down the power going into the old series gearbox not increase it. But im curious to see if you getter MPG apparently i hear that the right hand peddle isnt just on and off but it is analogue.. Quote Link to comment Share on other sites More sharing options...
Cornish Rattler Posted July 5, 2021 Author Share Posted July 5, 2021 3 hours ago, Jackjack said: Im interested in that, although i think i need to calm down the power going into the old series gearbox not increase it. But im curious to see if you getter MPG apparently i hear that the right hand peddle isnt just on and off but it is analogue.. Recon'd gearbox with 3.54 diffs, before i did the back to std transferbox swap i was getting 33 mpg and after the transferbox swap i'm getting 35 mpg so when i get chance i will do another mpg test 🙂 Quote Link to comment Share on other sites More sharing options...
jason110 Posted July 6, 2021 Share Posted July 6, 2021 The brother fitted a fourby boost pin to his 200tdi hybrid. Far more drive-able and mid range flexibility. not a clue on mpg 😂 Quote Link to comment Share on other sites More sharing options...
Cornish Rattler Posted July 6, 2021 Author Share Posted July 6, 2021 4 hours ago, jason110 said: The brother fitted a fourby boost pin to his 200tdi hybrid. Far more drive-able and mid range flexibility. not a clue on mpg 😂 Yeah that's the one i've got 🙂 Quote Link to comment Share on other sites More sharing options...
Jackjack Posted July 6, 2021 Share Posted July 6, 2021 Hi Cornish Rattler. what rpm are you getting on a dual carrageway. mine is comfortable at 50 tops out at 60 and (feels like the box will explode if i find a down hill). what does yours comfortably sit at on the A30? as i was looking to do the diff swap. thank you Quote Link to comment Share on other sites More sharing options...
Chicken Drumstick Posted July 6, 2021 Share Posted July 6, 2021 I put 3.54 diffs in my Tdi Series III. Swings & roundabouts on the pros and cons. Cruising rpm is lower and you'll be able to cruise at higher speeds. I even clocked mine at 92mph (GPS) on the level (non public highway). And sitting at 60-70mph is certainly doable, if a bit lot noisy. Downsides, 1st gear is quite a bit taller to pull away in. You will notice it when trying to whip out at junctions or cross a lane of a busy bypass, forcing you to slip the clutch a little more than ideal. If towing this is exaggerated. 30mph is a PITA as 4th gear is just slightly too tall unless on level or downhill grades. But 3rd will feel like you are revving the engine high. Basically there is a bit of a gap between 3rd and 4th ratios and the 3.54 diffs exaggerate this. But most of all I found the vehicle less fun and less peppy on the 3.:54 diffs. When touring & laning in Wales with the standard 4.75 diffs, 3rd gear was lovely on twisty Welsh lanes. With the Tdi you could steer it on the throttle and drift round some of the corners. Had huge fun chasing down a herd of Lotus Elises in the wet around the Elan Valley. I'm sure they could have gone quicker than me if they really tried. But I think they were surprised to see an old Series Land Rover catch them up! With the 3.54 diffs the gear is just a bit too tall to be able to do this. And 2nd would be way too low. I also found the low 1st crawl speed was far to quick for my licking on technical off road obstacles with the 3.54 diffs. Had I kept the vehicle I planned on going back to 4.75 diffs and an Overdrive. 2 Quote Link to comment Share on other sites More sharing options...
missingsid Posted July 7, 2021 Share Posted July 7, 2021 Slightly different experience as I have V8 power. I have driven over a log pile in 1st low with 3.54s, at one point I came off the throttle completely and came a stop feet off all pedals. After a sec or two slight throttle and it climbed out. One difference is that I have a very light S1 with an S1 transfer box so lower ratio. One warning with high ratio diffs, it will negatively affect you handbrake wich is poor to start with. Quote Link to comment Share on other sites More sharing options...
Cornish Rattler Posted July 7, 2021 Author Share Posted July 7, 2021 10 hours ago, Jackjack said: Hi Cornish Rattler. what rpm are you getting on a dual carrageway. mine is comfortable at 50 tops out at 60 and (feels like the box will explode if i find a down hill). what does yours comfortably sit at on the A30? as i was looking to do the diff swap. thank you As Chicken Drumstick said but mine will top 80 but as been said 1st is more like 2nd but plan to fit a 3.9 :1 diff and fit a Roamerdrive later so I should have best of both worlds Quote Link to comment Share on other sites More sharing options...
Anderzander Posted July 7, 2021 Share Posted July 7, 2021 I can echo a lot of this. I had 4.2’s in and it was fantastic on country roads, loads of pep and third gear was lovely. However, it just ran out of speed and was really uncomfortable even at 50 mile an hour. Then one of the diffs let go. So I tried 3.54’s in and it was awful. Better on a the motorway or a fast A road - but in traffic or on the windy B roads it spend most of its time on, it was awful. I hated it. So I sourced another 4.2 and couldn’t put the P4 diffs back in quickly enough, and I am now fitting an overdrive. That’s the answer for me. Having settled on the rations I’d next like to buy someone’s 10 spline arbs and get them rebuilt with Ashcroft 4.2 Ring and pinion, so it’s all new and solid. 1 Quote Link to comment Share on other sites More sharing options...
Stellaghost Posted July 7, 2021 Share Posted July 7, 2021 8 minutes ago, Anderzander said: I'd next like to buy someone’s 10 spline arbs Ahhh so that's why you were getting carried away for mog axle installation lol regards Stephen Quote Link to comment Share on other sites More sharing options...
Anderzander Posted July 7, 2021 Share Posted July 7, 2021 😯 Quote Link to comment Share on other sites More sharing options...
Anderzander Posted July 7, 2021 Share Posted July 7, 2021 Honestly - the ARB’s are long term, my enthusiasm for what you are doing is just being in awe of the work. 1 Quote Link to comment Share on other sites More sharing options...
Stellaghost Posted July 7, 2021 Share Posted July 7, 2021 1 hour ago, Anderzander said: Honestly - the ARB’s are long term, my enthusiasm for what you are doing is just being in awe of the work. Thanks Your waaaaay too kind regards Stephen 1 Quote Link to comment Share on other sites More sharing options...
Cornish Rattler Posted July 8, 2021 Author Share Posted July 8, 2021 On 7/7/2021 at 12:09 PM, Anderzander said: I can echo a lot of this. I had 4.2’s in and it was fantastic on country roads, loads of pep and third gear was lovely. However, it just ran out of speed and was really uncomfortable even at 50 mile an hour. Then one of the diffs let go. So I tried 3.54’s in and it was awful. Better on a the motorway or a fast A road - but in traffic or on the windy B roads it spend most of its time on, it was awful. I hated it. So I sourced another 4.2 and couldn’t put the P4 diffs back in quickly enough, and I am now fitting an overdrive. That’s the answer for me. Having settled on the rations I’d next like to buy someone’s 10 spline arbs and get them rebuilt with Ashcroft 4.2 Ring and pinion, so it’s all new and solid. Yeah i was toying with the idea of going to 4.3 diffs but with a roamadrive the overall gearing would be close to what i have now so have decided on 3.9's, 4.1's would be even better but think they are custom made though l. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted July 8, 2021 Share Posted July 8, 2021 I think Ashcroft do 4.1s, no? Lots of options here: https://www.ashcroft-transmissions.co.uk/differentials/stock-rover-type-diffs.html Quote Link to comment Share on other sites More sharing options...
Cornish Rattler Posted July 8, 2021 Author Share Posted July 8, 2021 3 hours ago, Bowie69 said: I think Ashcroft do 4.1s, no? Lots of options here: https://www.ashcroft-transmissions.co.uk/differentials/stock-rover-type-diffs.html Arw yeah i forgot about them but i would need 2 so a lot of saving to do or get 2 good Rover p5 3ltr diffs cheaper 🙂 Quote Link to comment Share on other sites More sharing options...
Snagger Posted July 10, 2021 Share Posted July 10, 2021 I have a Tdi with overdrive. I tried 3.54s and thought them absolutely awful for town driving and too tall with overdrive on the motorway as the engine worked too hard - revs were reduced, but not fuel consumption. It would have managed better without the roof rack, though. The 4.71s went back in after breaking the gear box by combining 3.54s with overdrive in third gear - only use the overdrive in 4th or in low range if you change diff ratios. I have 4.1 sets for the Salisbury and Rover diffs to fit when the car comes out of storage, along with ATBs. The final drive ratio will be very comparable to a Defender, so should pull well but not be too revvy like it is now, and should get the mpg sweet spot. Quote Link to comment Share on other sites More sharing options...
Gazzar Posted July 10, 2021 Share Posted July 10, 2021 Interesting debate, this. I've an Ashcroft high ratio transfer box for my 109 with a tweaked TDI 200. I've not fitted it yet because I quite like the way it drives on standard everything. Except when on fast roads. Where it feels under geared. However, I've just picked up a couple of Iveco massif front axle casings, and the ratio of the diff looks to be 3.9 to 1. So. What to do? The Salisbury doesn't help, but it's the right axle for the vehicle. I'd hate to lose the way it drives around the country roads, but I do need it to cope with motorways. And I don't like the risk that overdrives bring, especially when towing. Not that I have time to do any work on the 109. It's a shame there isn't a 5 or a 6 speed box that would fit between the flywheel and the transfer box, that's got an over driven top gear or two. There's so much space there! And modern boxes in front wheel drive boxes are so short. Ah well. Something to develop when I win the lotto. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted July 10, 2021 Share Posted July 10, 2021 In a 109 you have acres of space for a later R380/LT77 and LT230 with a 2WD conversion, would drive like a coiler, and be vastly improved on motorway with the fifth gear. Quote Link to comment Share on other sites More sharing options...
Gazzar Posted July 10, 2021 Share Posted July 10, 2021 Sure, but it would be nice if there was a neater, simpler, stronger, serieser alternative. I plan on doing exactly what you suggest on one of my dreaming builds, so I agree with you. But.... Quote Link to comment Share on other sites More sharing options...
Anderzander Posted July 10, 2021 Share Posted July 10, 2021 Chap I know has this in his 109 Quote Link to comment Share on other sites More sharing options...
Anderzander Posted July 10, 2021 Share Posted July 10, 2021 I think the LT77 and R380 are 1:1 in 4th and overdriven in 5th (0.75:1 ?) Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted July 10, 2021 Share Posted July 10, 2021 0.77 TDI R380 0.73 V8 R380 0.83 - LT77 all engines except late V8 90/110 V8 0.83 0.77 - LT77 V8 92 and 93 defender and V8 discovery Slightly more complicated, but very close 1 Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted July 10, 2021 Share Posted July 10, 2021 Then there is this: https://www.ashcroft-transmissions.co.uk/the-series-vehicle/series-5-speed-kits.html Quote Link to comment Share on other sites More sharing options...
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