Doctor

I've used Allen head bolts in 12.9 tensile strength, the original TORX head ones are 10.9. Ro issues with clearance, easy to undo. Recommended.

I've joined last year, done a few track days - they are well run.

It looks awesome. When are we going??

MSV-T has just kindly cancelled this for me.

Not a L7C track day, collides with our Cadwell Park Track Day, detail in the for Sale section.

Dear all, I know it's the club trackday at Cadwell Park on the same day. I've bought this as a shakedown for the car after a major rebuild, but we are running late. The price is £249 - that is exactly what I get if I cancel via email by Monday 10th May 2021. Anyone up for this?

Dear all, I know it's the club trackday at Cadwell Park on the same day. I've bought this as a shakedown for the car after a major rebuild, but we are running late. The price is £249 - that is exactly what I get if I cancel via email by Monday 10th May 2021. Anyone up for this?

Absolutely fantastic video, well done!!! Can't wait to join the season this year.

ZFs are very solid, you are lucky.

Which oil are you going for?

That look tight. At least it is a proper bolt head.

what was the reason for it to come out and which LSD (if any) do you have?

When putting the diff back in use proper washers: top through bolt (usually half inch) https://caterhamparts.co.uk/washers/282-washer-1-2-x-11-8-chamfered-plain.html?search_query=washer+1%2F2&results=476 bottom side bolts next to the prop connection (usually M12) https://caterhamparts.co.uk/washers/942-washer-m12-plain.html?search_query=M12+bolt&results=246 Don't use small thin washers - they are s**t and cause trouble.

The tyre's clock starts to run once driven and the factory protective coat has been broken. Only then you expose the rubber to the atmosphere/UV/oxygen/humidity.

Is it the Hybrid Sport with the plastic shoulder piece?

The Titan ramp angle was 30 degrees under power and I didn't really want anything less progressive.

The Titan ramp angle was 30 degrees under power and I didn't really want anything less progressive.

Imperial CSR chassis? I thought they were all metric.

Dear all, prompted by a few friends I was asked to share my experience with the different LSD functions and durability. I don't work in the automotive, I'm self taught - apology for the inaccuracies in advance. All of my Caterham experience has been Duratec based and 250BHP plus. They have had some reasonable torque. Here it goes. I've bought my first Caterham in 2014 - it was a new CSR chassis with 2.0 Duratec engine from Duratec R500 Superlight. The reason for the change was the revvs of the highly tuned 2.0 and probably me being unlucky with the CSR 2.3 test car - lackluster, not revving, swoopy dash - all the wrong signals. The car came with 7" Sierra diff (as did all CSRs) with Titan LSD based on my previous experience. That had a shape of my friend's 2011 CSR EU4 car with 2.0 175 BHP car delivered with Quaife ATB LSD. Very quickly it became obvious that this is not the way - even when not pushing 100% on the race track the car's behavior was very erratic in the corners - every time the car hit the curb with the inner wheel it virtually stopped - for obvious reasons stemming from the function of the ATB - never locking up fully and transferring only the part og the torque to the outer wheel, never all of it. Once the driveshaft snapped, ATB was done for as not suitable for a track use. The next in line was Tran-X plated LSD marketed by Quaife - a product with a friendly price tag. Working much better than ATB when in one piece we recognized that the while principle was correct, the product was not. After talking to Steve from SPC I now understand why - it was developed to deal with much less power and torque in mind then what we exposed it to in Duratec engined Caterham. So this brings me back to Titan. Again, reasonable product when in one piece, my car was able to disintegrate it within about two years and the rebuild was due. All while using the car enthusiastically on the road and doing anything between 3 and 7 track days per year - mainly organized by the club. Same symptoms as described here many times - sinister sounds, erratic locking and unlocking. Spinning at Brands Hatch left hander (Surtees?) on the dry when putting the power down was the final straw - taking it apart (courtesy of Gave Gemzoe Motorsport in Wakefield) revealed the usual - worn clutch plates, broken both Belleville springs, milled away thrust washers. And I consider myself lucky. Why? If the Belleville spring decides to fracture into small enough pieces (this issue is more of a problem with BMW 168 where the Titan LSD has bigger holes in the LSD casing foe the oil. If a piece of a broken Belleville spring finds its way out of the LSD casing (possible) it can also find its way into the pinion and the crown wheel, the consequences of which could be disastrous.... Now let us have some theory, even though it's all merely a repetition with many people here making a very good valid points (Simon Rogers, Neil (7wonders) and a few other spring to my mind immediately). So what is the meaning of all of these things that determines the behavior of our LSD? 1. Static pre-load: this basically describes the amount of torque that will always be locking the wheels together. Increasing it will improve the responsiveness of the locking effect, but it will also increase the noise and the under steer (by not allowing the clutches to slip when the car is cornering. Pre-load represents the base amount of locking torque built into the LSD system. 2. Ramp angles: depending on the manufacturer, the lower the angle the less torque from the engine needs to be applied to initiate the locking action above the static pre-load. The current LSD designs usually allow for different setups and the description of the ramp angles usually contains two numbers - the first represents the ramp angle used for locking action under power (the torque applied via the prop shaft) while the second one represents the ramp angle applied when we lift off (coasting, the torque is applied via the driveshafts). Titan has exchangeable pinion rings - the first (usually installed as a default) offers 30/90 (usually active as this is the setting allowed for Caterham Racing) with 45/60 as the second option. The second has 30/60 and 45/45 alternatives. The SPC Tracsport comes with 30/30 or 45/45 options for both Sierra 7" and BMW 168 casings. 3. Locking capacity of the LSD - usually by varying the clutch arrangement that will determine the friction surface - it will have the similar effect on the response of LSD as ramp angle change but it will also limit the maximum torque transferred to the other wheel. Used if despite the low static pre-load and less progressive ramp angles the diff is still too aggressive - not really applicable to us as our problem is usually the slip. So why has Titan so many problems and what are the differences if we compare it with SPC Tracsport? I'll try to keep some clear continuity here but the problem is that everything is connected together so one thing changes - everything else changes. The easiest to dissect is probably the pre-load Belleville spring failure. Titan has two of them (40ft.lb), they are much stiffer and bulkier than the one found in Tracsport (20ft.lb), yet they fail way more often than the single spring in Tracport that is much finer - I hold both in my hand side by side. Neil has described it quite well already - the Belleville spring has a shape of a cone - hence the name coned disc spring. The problem of the Titan LSD is that once under load (locking) it repeatedly squashes the spring completely flat (using 100% of the spring lift) which (together with the increased heat induced by the clutch slip) introduces accelerated metal fatigue and fracture with the loss of pre-load. Now, why does Titan need the double of the Tracsport pre-load? It is because it is trying to compensate (unsuccessfully) for the insufficient area of the friction plates to prevent the slip (wheel spin) under load. What is the evidence for that? That would be our thrust washers nearly completely milled away we see on rebuild and also the worn clutch plates. How do we increase the friction area of the LSD? We increase the number of friction plates and increase the size of them. In order to do that we need to increase the size of the housing. Essentially we need more plate friction area that will prevent wheel slip/spin when torque applied to LSD and that will also allow us to use less pre-load and that in turn will reduce the noise and also makes the diff more friendly when there is a difference in the wheel revolution (turning). One crucial difference - without going into too much of a detail the Tracsport design is clever enough to prevent the Belleville spring to be completely flattened by the action of the LSD - that is an in-built feature. Now this is where I speculate a bit so I could do with a bit of a facts check. Looking at the TitanExpress website it would appear that the LSD service kit for the Titan LSD is the same for Ford Sierra 7" and BMW 168 diffs - implying that the size of the clutch plates is the same which I would consider this a mistake since the Sierra 7" is a much larger housing allowing for a bigger LSD - that is exactly what the Tracsport is. I've seen Tracsport versions for Ford 7" and BMW 168 side by side and the Ford version is bigger - possibly using bigger plates that would give more friction area (I'll check this with Steve). Conclusion: I now run 620R SV with Sadev sequential, masses of torque compared to my normally aspirated Duratec and it came with Titan LSD. Incidentally I was forced to drop the diff due to the pinion oil seal failure, so I've decided to go for Tracsport there and then. Steve has been a delight to deal with, showing me all of his secrets (not that would possibly dream to understand them all), patiently answering all of my silly questions. He did the final assembly right in front of my while debating comprehensively about all sorts of topics in life!! An utter professional. My impressions? Awesome. I went for 30/30 ramps, chickened out a bit with the oil and went for 75W-110 LSD spec of Millers Oils Nano thing, and the car is a joy to drive under power out of the corner (due to no "I can't cope" LSD slip and the utterly predictive behavior under power). The result is that the rear of the car now feels much more planted and it simply grips and pulls. the biggest transformation for me, however, came under braking - the car is much less nervous under braking on bumpy surface, and also much less thrown out of composure by a cheeky downshift. This one part simply made me feel way more in control of the car then I've ever felt to be before. I'm not forcing any of this on anyone, I was simply asked to put something together. Well, here it is.

Hi all, I have been through the pain of Quaife ATB, Tran-X and Titan LSD until I discovered (via Simon Rogers and Dave Gemzoe) Steve at SP Components with his Tracsport diff. It has been a long journey with a lot of pain and I (not working in automotive) have been forced to learn a lot of things. Steve has kindly asked me to sum up my experience and post it here. Not keen to start with, I've agreed, so hopefully over the weekend. Loads of misconception in this thread.

Another brilliant day. Forgotten the known characteristics of Donington - as in the path of the planes taking off from East Midlands it gets quite slippery when wet. Got reminded this feature when flew into the Redgate way too fast on cold tyres - wafted graciously into the gravel trap at the end of main straight by choice as I was worried I could roll otherwise. My truck guy was sensible pulling me out and I might have been the only person on a day who drove the main straight in the opposite direction. Anyway, after some brain recalibration carried on and thoroughly enjoyed the rest of the day in the car - the new LSD is awesome - especially the overrun locking under braking makes a massive difference for the stability - should have done this a long time ago. I think she is coming into the shape now.

Apologies for my absence in this very relevant thread. Way too many hours under the rear of the car due to the diff oil leak. All well and good now, I've even managed to sneak in some of the promised upgrades. The car now reads oil pressure/water temp on one gauge and engine oil/gearbox oil temps on the other. all wired up and ready for the track day test. Have been investigating the oil stats and gearbox oil cooling system in the meantime. Well done to Neil for his guidance and Mark W for pushing me the right direction to accomplish this and also for forwarding our project to the relevant people at Caterham Cars. Let us hope that something good comes out of this.

Silly question to start with, but you've arrived to the correct conclusion. More powerful cars have the brass vent tapped in on top of the rear cover where you do connect the breather hose that lives under the boot floor. Sierra casing for a 7 inch diff with a big ass LSD takes about 1.2-1.3 litres of oil. Make sure the car is levelled.

I see. N13B16 - Prince engine.

three pot 1.5 Turbo?