Sam@TDi

My thoughts exactly

Hi Talat, to be honest at this point I think it's best to just take a look and see exactly what the problem is and whether there's a straight forward solution. If there is then no prob's, we'll make it happen.

Actually I think extending the wheelbase is a nice direct solution for a poor DI but it's rarely a viable solution on a production road car because of problems like we're seeing here which the kinematic geometry being wrecked. As I said it's going to need investigating extensively before any possible solutions can be tabled

Corner weighting wouldn't be a good tool on this one as the problems sounds totally goemetry based, the important thing will be to make sure that the rear wheels arn't being pulled into a toe out geometry as the suspension articulates. Actually tracking the geometry as the wheel moves will be very difficult. This will need a very good looking at, and some serious thinking

Blimey this could a be a complete can of worms, to analyse the effects of these changes accurately we would need to replicate the entire rear suspension set-up inside a computer model and manipulate it there. At first glance it seems as though the overall aim has been to lengthen the cars wheel base. That in essence is actually quite a sound idea because these cars suffer from a dynamic index somewhere around 1.50, possibly worse depending on spec. The only question is how has this has impacted the kinematic geometry

The car is actually very good, quite a violent power delivery for a fwd so it'll be spectacular for people to watch for sure I think it will be just fine on the track in a "maximum effort" situation when accelerating hard through the gearbox using the top third of the rev counter. Unfortunatley there is one small problem, the turbo compressor side appears to be poorly matched to the engines air flow and pressure requirments, the result is that at mid to high engine revs with less than full throttle the compressor gets repeatedly forced into a surge condition causing the engine output to pause and "shuffle", the car does eventually drive out of the problem but it's there none the less. Below is a typical compressor map, pressure ratio is on the X axis and air flow by weight is on the Y, note the surge limit to the left Map1.bmp The solution would be to tone down the turbine side by having the turbine wheel modified (cliped) at the expense of more lag, or to replace the compressor side with one which is more suited to the relitively high pressure low flow style of this engine The chassis dynamics are really quite good with a very balanced feel

Yep noise and cost of manufacture.... That said both the S2000 and the Civic type-r both have silent timing chain systems ... Honda rock

I agree that does sound like over kill, the only possible reason I can think of right now is that by adjusting both trailing arm and toe adjuster together you could totally mis-align the wheel hub, perhaps some drifting guru did it once and everyone else just copied, but sounds like a can of worms to me unless it's backed up by hours of track time. The most effective way to adjust the anti-squat property's on these is to shim either the front or the rear of the main rear sub-frame (depending on what your trying to stop or promote)

Very slow at the moment I'm sorry to say. We got a late start on it today due to some issues with Daves car, so we're in the process of installing the boost controller etc. We definately won't be doing any tuning today unfortunately, but it should be OK for Tuesday (no dyno time available tomorrow) I had hoped that we would be finished by now so I'm sorry for any inconvenience

Thank you very much. Makes a change from making tea for you Have you got any biscuits? Funny you should ask.............Usually we have a supply of Choccy Digestives - but Barrie ate them all (although that was because I didn't make him any lunch the other day - no wonder he has sacked me ) Harsh but fair - not making lunch is a sackable offence

Thank you very much. Makes a change from making tea for you Have you got any biscuits?

It's Sam and Anna's big day today. I received a text from him yesterday - apparantly the resort in St Lucia is phenominal, so I think it'll be a great day today for them

I think you'll see them use emp as the technology's tried and tested... it'll be bloody distructive though and could have unknown effects on some modern cars like the new Merc S'class with it's brake by wire system

noooo ...................he is far too good looking for that, ..............................deserves far worse he didnt mention what happens when you are limited by wheel size went for grooved and dimpled , little bit of function and they look pretty Thanks! I think... if the disc diameter is limited then you've got 2 options ..... 1. make the pad and the disc out of materials which will continue to operate properly even when extremely hot (think Porsche style silicone carbide disc's and ceramic pads) 2. make the disc wider. The more disc material there is in total then the larger it's thermal capacity. A bit like a large body of water, steel has a latent heat capacity so for a certain time governed by it's mass it'll absorb energy and not actually increase in temperature. This is of course making the huge assumption that the problem you have is that your brakes are over heating. If the problem is simply insufficient friction that can easily be sorted by selecting an appropriate pad compound, for example the ultra aggressive carbon metallic that Jon runs. Remember F1 cars run on 13" rims and can pull 4.5g in a braking moment, aanndd keep that up for 1.5hrs, so wheel size is no real excuse I'm afraid...... money however is a good excuse

Personally I'm a fan of giving the brake pads as much disc surface to contact as possible. Friction is a straight function of pad compound vs disc compound x pad to disc surface area (it goes without saying contact pressure is all important as well) If the thermal capacity of the disc isn't large enough then by far and away the most effective way of increasing it is to make the disc bigger. In my opinion messing about with slots and drilling holes is just an emergency measure, and reletively speaking makes little difference to disc's real ability to absorb kinetic energy and then radiate it as heat energy, in this scenario size really matters :rolleyes_anim:

To see if the wheel is buckled

Yep i'm with you regarding the heat curing on the r888's And personally I rate the Michelin Pilots sports as an almost perfect road tyre, my fave for sure, just wish they made a wider range of sizes

Perfecting the tyre contact patch is our goal through developments of the suspension and geometric compensation. It is easy to forget this patch has limitations.. This car was traveling with the commands below the saturation limits... As it approached the bend lateral commands, weight transfer and braking forces were all retained within the patch. As the Yaw continued the commands at the patch saturated the ability of the entire calibration, this exceeded then... Under-steered (by design) and the car crashed. This is also a superb example of exactly why normal passenger cars are built to perform a "front first departure" in limit control situation..... look at how the car hit the solid obstacle, smack bang in the middle of the crumple zone, and straight enough for the occupants to get the most benefit from their seat belts and front air bags In a sentence, modern cars are designed to hit things head on.... so the chassis dynamics is tweeked to make this the most likely scenario. This accident happened exactly how the Ford design team would of hoped, and i'd guess that any occupants walked away.

No not at all.... conventional auto's use an oil filled (viscous) coupling device known as a "torque convertor" instead of the clutch that you find on a manual

Beleive it or not that will present exactly the same set of problems and considerations. It's the process of moving the tyre contact patch away from the suspension that gives rise to the issue's, not how you do it

Very interesting. Other than doing some analysis on the Arigo Geo machine i cannot comment. Out of curiosity though do you have any TOOT or Ackerman data your are willing to display? I'd certainly tell you if did but unfortunately I don't. Beleive it or not I don't have regular access to a global alignment machine and my car is pulled apart on a fairly regular basis, so the only new and relevent data I have is from bbt's 8-angle machine

Yeah I can see what you meen but remember that the rack position and steering arm geometry was disgned for the EP2 1.6 shopping trolley edition, if i remember correctly the type-r model is around 40mm lower from the show room and then in turn i'm running approx 70mm lower that the standard type-r. I never quanitfied the toe change on bump with my car, but when I was building the Nemesis brit car civic I spent alot of time looking at this and it since turns out it's something that Honda racing legends Barwell motorsport, Mardigras and Syncro motorsport have all had to deal with to improve front end response

If you mean the static toe in the rested position it's 0'01... straight ahead at the front

Glad you like it i've dropped the rod end around 50mm

To be honest i'd love to use some pull downs and quantify the exact amount of toe on bump i've got but I've never had the time. It's been set up purely by "development driving" My ground breaking design is shown below, sorry about the quality was a 5min MSPaint effort