STEVE GILBERT Posted September 22, 2009 Share Posted September 22, 2009 For road I'd have thought the Quaife would have been better Ammo, a much more elegant design than the Plate Type and more suited to your needs. Steve See My Caterham Fireblade Here. Link to comment Share on other sites More sharing options...
elie boone Posted September 22, 2009 Share Posted September 22, 2009 You can have the best LSD but whats the benefit if you have shod shockabsorbers and no flat flooring done on the suspension, the lsd a part of a package and can not work properly on it's own without other decent components in that package. just my 2p Link to comment Share on other sites More sharing options...
Mickrick Posted September 22, 2009 Share Posted September 22, 2009 Also anti-rollbar setings can affect understeer/oversteer. Link to comment Share on other sites More sharing options...
dannylt Posted September 22, 2009 Share Posted September 22, 2009 The first mod I made to my Jenveys was a home brewed variable rate throttle lever. The standard, bare lever looked like it would give pretty poor fine control at small openings. My map also has more %tps resolution at low openings i.e. the load intervals are not equally spaced from 0-100.I'd like to see pics too! My map also has the smallest resolutions at low openings, but it still jumps to double digit horsepower when you touch the throttle- or at least, it did when Dave was initially mapping it. This is fine in the dry, but is annoying on track in the wet. Link to comment Share on other sites More sharing options...
Mr Locust Posted September 22, 2009 Share Posted September 22, 2009 I did take a few snaps for record when I did the modification. The throttle cable bracket is the standard item supplied with the Bernard Scouse airbox kit. The throttle cable is the standard MG Rover K series item fitted to plenum equipped cars which has the 'barrel' nipple at the engine end. The lever was made from 3mm aluminium (for no other reason than it was to hand and easily worked) and comprises three pieces, the middle plate of the 'sandwich' being smaller than the two outer ones so as to form a cable guide. The basic idea is that the lever has a large effective radius when the throttle is closed and a small radius when wide open. The whole process was a mixture of measure, CAD layout, a couple of hours with tools and a trial fit up (hence there are two cable holes from when I adjusted the throttle pedal return stop as well). Photos it still jumps to double digit horsepower when you touch the throttle A number of maps I have seen for Emerald ECU's have big steps in fuelling and advance between load site 0 and load site 1. On the cars I have seen a combination of that and the poor throttle lever progression combined with a tendency towards drive line shunt in the Caterham installation can give a good recipe for kangarooing when you are trying to drive smoothly and slowly.... Apologies Ammo, your diff thread has been well and truly spun off the road! Ian Green and Silver Roadsport 😬 Edited by - Mr Locust on 22 Sep 2009 19:51:40 Link to comment Share on other sites More sharing options...
AMMO Posted September 23, 2009 Author Share Posted September 23, 2009 Ian I welcome the change of subject if only to stop Danny and Mike taking the mickey about my age and inability to drive. The LSD is staying in for now. Thanks for everybody's comments and suggestions. Regarding the throttle linkage, I was messing around with various quadrants yesterday. One was a spare off the throttle body of my race bike and some other ones that I have accumulated over the years. What you have done is exactly what I was thinking, mainly because we used the same thing on my bike and on the Rizla Suzuki BSB bike. The initial opening of the throttle on a race bike with a very high power to weight ratio through a small contact patch is a real problem. A lot was resolved with mapping with different maps for different gears but the throttle linkage was very important too. I also took the pedal cover off and looked at the throttle pedal. It would be quite easy to change the leverage ratio to increase the travel a bit which might help as well. On Danny's car Stuart Faulds modified the throttle pedal to give more initial travel but we really need to make it even more progressive. I think that Dave Walker said Danny's engine made 30 bhp at tickover or just off tickover. Mine is not a problem in the dry but in the wet the first application has to be quite delicate. So rather than worry too much about the LSD I will make an effort to sort the linkage first. Many thanks Ammo Raceco.com Link to comment Share on other sites More sharing options...
Jason Plato Posted September 23, 2009 Share Posted September 23, 2009 jenvey sell the quadrants to suit a progressive throttle setup here is my Duratec R .... C7 TOP Taffia joint AO with Al Link to comment Share on other sites More sharing options...
AMMO Posted September 24, 2009 Author Share Posted September 24, 2009 Dave I have a couple of different Jenvey quadrants and they are both linear. It would be great if they did a progressive quadrant off the shelf. It would save a lot of messing about. Will give them a call later and post any findings. Ammo Raceco.com Link to comment Share on other sites More sharing options...
Jason Plato Posted September 24, 2009 Share Posted September 24, 2009 ? any use here from 2002 here is my Duratec R .... C7 TOP Taffia joint AO with Al Link to comment Share on other sites More sharing options...
AMMO Posted September 24, 2009 Author Share Posted September 24, 2009 Dave Jenvey reckon they have one. They popped it in the post for me to have a look at. If it's not exactly what I want I can get them to make me a batch to my design. Thanks for the tip. Ammo Raceco.com Link to comment Share on other sites More sharing options...
dannylt Posted September 24, 2009 Share Posted September 24, 2009 Cool, shall I drive over for you to fit it? Link to comment Share on other sites More sharing options...
Mr Locust Posted September 24, 2009 Share Posted September 24, 2009 I never saw any on the website when I did mine. That is why I just got on and made one. Out of interest, could you post a picture when you get it. Ian Green and Silver Roadsport 😬 Link to comment Share on other sites More sharing options...
AMMO Posted September 25, 2009 Author Share Posted September 25, 2009 Ian The quadrant arrived this morning Photo here Unless I've missed or completely misunderstood something, it looks linear to me. To be progressive it should be like the one you've made. The progressive quadrants I have will need adapting to my bodies so I can try them out. Once I have something that I like I can have them made. Already spoken to Jenvey about this. Danny You'll have to wait a while longer I'm afraid. The good news is that I will probably also make cable brackets that will bolt straight to the extra lugs on your throttle bodies. How do you feel about a bit more pedal travel? Maybe another 10-20 mm. You should have approx 60mm at the moment. Can you please check this as maybe yours is different from mine. SF and I messed around with your pedal a bit so it may already be more than that. Ammo Raceco.com Link to comment Share on other sites More sharing options...
Mr Locust Posted September 26, 2009 Share Posted September 26, 2009 Ammo, that was the cable guide type quadrant I saw on the website when I was looking around. Ian Green and Silver Roadsport 😬 Link to comment Share on other sites More sharing options...
millsn Posted September 27, 2009 Share Posted September 27, 2009 Hi Ammo, You haven't mentioned the tyres you're running..? Not wanting to start a tyre thread but some are hateful in the wet Link to comment Share on other sites More sharing options...
Mr Locust Posted September 27, 2009 Share Posted September 27, 2009 Ammo, having thought about this again, you could be at crossed purposes with Jenvey by using the term progressive: Jenvey have taken it to mean gradual operation of the throttle for a given cable movement. Which they give by a relatively large (compared to a cable clamp trunnion straight on to the lever), constant radius cable guide type lever. They could reasonably claim progressive, linear throttle operation by that definition. Alternatively, it could be taken to mean a non-linear linkage with increasing throttle movement for a given cable movement as the throttle is opened. Which was what I set out to achieve and what you have described on your race bike throttles. Maybe on reflection non-linear or rising rate linkage is less confusing. ..........or maybe I'm splitting hairs again. Ian Green and Silver Roadsport 😬 Link to comment Share on other sites More sharing options...
eric Posted November 8, 2009 Share Posted November 8, 2009 caterham Cars does not recommand limited slip diff on a road car !!!! There is a reason why Link to comment Share on other sites More sharing options...
Mickrick Posted November 8, 2009 Share Posted November 8, 2009 Where did you read, or hear that? Link to comment Share on other sites More sharing options...
Myles Posted November 8, 2009 Share Posted November 8, 2009 And - more importantly - what is this apparent reason why? To be honest, I've not noticed anything obviously wayward in the wet with the LSD fitted to my Westie - did a big, wet, fast & long (160 miles) blat yesterday and other than one minor moment (that I'd gathered up before it registered), it felt as predictable as my Caterham (possibly more-so given that I'm running 21s on the Westie compared to R888s on my Caterham). 🙆🏻 🙆🏻 🙆🏻 🙆🏻 🙆🏻 Alcester Racing 7s Ecosse™ 🙆🏻 🙆🏻 🙆🏻 🙆🏻 🙆🏻 Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
AMMO Posted November 9, 2009 Author Share Posted November 9, 2009 I have come to the conclusion that for my style of driving I could have either diff. The LSD is not as scary in the wet as I thought it might be. It was the unknown that worried me never having owned a car with an LSD. Would I bother fitting an LSD to a road car knowing what know now? Probably not. For my style of driving I was perfectly happy with the open diff but wanted to see what driving a car with an LSD was all about. I might even flog the LSD and go back to the open diff and use the money to fund a trip somewhere. For a track car the LSD is essential. For a car that is only used on the road I'm not so sure. It depends entirely on your style of driving. If you are going for it all the time then probably yes. If your driving is more sedate and you are not trying to teach every Porsche driver you encounter a lesson then probably no. If you took my LSD away from me I don't think I'd miss it. Everyone is different and everyone has to decide for themselves what is best for them. Ammo Raceco.com Link to comment Share on other sites More sharing options...
Jason Plato Posted November 10, 2009 Share Posted November 10, 2009 I prefer the predictability of an LSD equipped caterham. The traction level is so much more uniform and consistent. With an open diff you don't quite know if the inside wheel will spin up or if the back end will slew and then will the inner wheel slip again .... with a LSD you know where you are and the car is much more friendly and consistent. [await 3 persone to reply to the contray.... ] dj here is my Duratec R .... C7 TOP Taffia AO Link to comment Share on other sites More sharing options...
Mickrick Posted November 10, 2009 Share Posted November 10, 2009 await 3 persone to reply to the contray Not me Dave. I wouldn't want a Seven without one. Link to comment Share on other sites More sharing options...
Jason Plato Posted November 10, 2009 Share Posted November 10, 2009 but you have a torque bias diff installed - not an lsd..... here is my Duratec R .... C7 TOP Taffia AO Link to comment Share on other sites More sharing options...
Mickrick Posted November 10, 2009 Share Posted November 10, 2009 Well spotted! 😬 I have to admit though, I have no idea what was in my 2005 R300. But it was hilarious hooning fun! 😬 Anyone know what CC where fitting as an option at that time? Link to comment Share on other sites More sharing options...
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