SK400

KnifeySpoony Did you install a proportioning valve after all? If so, does it change the pedal feel and travel? I was told by someone to avoid the proportioning valves. I’m asking because I’m considering installing the rear AP racing brake kit from Caterham I had ordered 2 yrs ago and never installed. It comes with Pagid pads and of course the two piston calipers and concerned that I will increase the rear bias more than I’m looking for. Thoughts?

Based on your experience, are you then suggesting the Caterham “race” setup? You seem pretty happy with it, are you ?

I asked that very question to Simon. He assured me no understeer. I too currently have my rear ARB set at the second hole from its stiffest. Now perfectly balanced. I agree that I may have to get the next level of rear ARB diameter to balance things out.

Thanks all for the replies and apologies for the delayed answer back on the forum. KnifeySpoony - correct. After some research I do have the 170 lbs spring in front and progressive in the rear (probably 110 lbs). I think this is the standard Road setup that came with the R400 car when I bought in 2012. I’m quite amazed with the handling and until I started to drive with full slicks and with an R500 spec engine, I could argue that the setup was well sufficient for both road and track. I connected with Simon Rogers from meteor Motorsport in the UK. He recommends a set of Core dampers and track spring setup with 250 lbs in front and 150 lbs in the rear. He suggests that the ARB that I have from stock are sufficient (arguably the front one being a bit too stiff). i think I will pull the trigger and order a set. They come with bright red springs that will match my car quite well. (As the NJMP gang knows, these little things and color coordination matter a lot to me… ). What’s more, I think I’ll save a few more pounds of weight compared to the stock shocks. Curious to know if anyone in the US has already bought and driven with the above mentioned Core spring damper setup. Let me know. thanks all.

Winter is here! Which means I’m now shifting gears to maintenance and slight upgrades on the car. I finally plan to install the AP racing brakes (rear) I had ordered several yrs ago and considering changing my shocks / springs to nitron or core systems as I feel the car rolls a bit too much when leaning heavily into curves when using full slicks. With that said, I’m reaching out because I’m trying to find out what spring rates I have on my car right now (and wonder if changing the damper system will indeed improve or not the handling or should I only upgrade the sway bars). Suspension is stock 2012 R400 superlight (wide track) for s3 chassis. Any input or advice would be welcome. Thanks all.

Bruce. Good to see your car in pictures. I was your neighbor at eyes on design with the red r400/r500 caterham. Is your car sold? If not, might be someone in Michigan / Ann Arbor who might be interested. (Might). Let us know. Txs.

Went to Gingerman, MI, last Saturday to shake the winter cobwebs and get mentally ready for the 2022 season and eventually NJMP in September. Starting to enjoy the new 500 spec engine after SBD fuel mapping session earlier this winter and almost a year of trouble shooting. Don’t want to jinx it but I think slowing getting there. The car is a real pleasure to drive.. sooo strong! A noticeable difference from our 400 spec .. might now have to upgrade the brakes!!! Gingerman was a real challenge to drive. Took me two days to recuperate physically trying to hold on to the beast. Can’t wait to seeing the gang soon.

Really - really - looking forward to it. Will be there guys! Thanks for organizing as usual. Can't wait to see the gang.

Standard duratec uses grade 6 NGK plugs I believe . Caterham recommends grade 7 for the r500 spec. I now use grade 8 and did the tuning using 8, cooler plugs. as for advance, unsure if Steve played with it honestly but could be wrong. We discussed it. I do know he focused on fuel across the range. proof in the pudding will be this summer. Will be inspecting the plugs on a regular basis.

Friends, Its has been a while since I've reported on progress on this topic. I took a day off on Friday, and my son and I spent a long morning at RM Motorsports (www.rmmotorsport.com) in Wixom, Michigan, for a Hub Dyno and fuel mapping session with Steve Boughton from SBD connected remotely. The goal was to identify potential lean conditions and adjust the fuel map to eliminate risk of auto ignition, burning the plugs and putting at risk the engine. It was a successful day. We had 3 computers going, one for the dyno, one for the fuel mapping connected to the ECU and Steve Boughton connected remotely controlling the Esimap 6 software, and one to connect with him via google meet in England. Overall Steve found the map to be a bit lean at mid range under load which might explain some of the challenges Simon and I had with some of the plugs. Steve did a great job smoothing the map and setting parameters to be slightly on the safe side. I've also installed a wide band O2 sensor that will adjust fuel plus or minus 4 percent in a closed loop system with the new MBE ECU. In terms of horsepower, the new R500 spec / blueprinted engine managed 235 hp at the wheels so 260 hp at the engine at 7950 rpm - 8000 rpm almost on the nose assuming a 10% transmission loss, 160 ish ft-lb torque at 6000 rpm, which is exactly what I thought we would get with the build specs (Kent Tec35 cams, Supertech pistons 12.5:1 compression ratio, fully ported head with 35% more flow than original head, custom oversized exhaust, 4-2-1 configuration, design from Dave Hershey engine). I've attached one of the HP graphs. Weighted the car at 1214 lbs, wet, with the Apollo wheels and Avon DOT tires ZZR A24 compound tires, or 1174 lbs with my Image Wheels and Avon full slick Kevlar tires. Happy to say that the car car bare the R500 name officially. I hope all of the above helped the car so that I can drive with confidence this summer, on roads and on the track, terrorizing pretty much anything road legal. Btw - the guys at RM were loading up their 53 foot long trailer with 8 cars to go to Sebring this week. Insane cars such as March 73S, Lola T70, Chevron B23S, formula 3 etc. Really impressive racing stuff. Clients are from all over the country. They have one of Ken Block's car at the shop too and a few Ligier Carbon Fiber F3 for sale. Awesome place. Highly recommended. Run1 Graph HP over RPM.pdf

Something seems off. What gearbox do you have if I may ask? Typically, peak horsepower for the r420 cams is at 7,100 rpm, so surprised the peak on the graph seems to be before 7,000. i did not dyno my car before adding roller barrels unfortunately but with the roller barrels, 6 speed gearbox, and the Caterham ECU, my car dynoed at 198 hp or roughly 200 hp at the wheels. The roller barrels made a difference but not more than 10 or 15 hp (felt it at top end). i ll try to find an old post on this forum where I had included a few dyno charts.

This is Star Trek stuff. How are you able to see all of this from the pictures Dave? From now on, you shall be known as Dr Plug. Yikes on the engine blow up Bball. Really nasty and very unfortunate mistake from the attendant. Sorry to see this. Makes our stomach turn. Carl - yes agree on the latest plug I’ve been using. They are the competition ones and these extend further into the chamber and have a longer ceramic nose. I plan to change back to B type NGK plugs that are shorter, with a protected ceramic nose, and perhaps go for an even colder plug, B9EFS. I’m also scheduling a road dyno tuning session and will have SBD connect remotely to fine tune the map, advance etc. Let’s see. I will keep the group posted. thanks all.

Thanks Dave Steve B from SBD is surprised and does not think this is the result of auto ignition. He states that he runs 13:1 on 98 RON / 93 octane with no real issues. On the other end, NGK had a closer look at Simons plugs and suggests that it is auto ignition or hot spots in the chamber. We will probably try a combination of mods e.g. grade 9 NGK plugs B9EFS that have a more protected ceramic than the grade 8 competition ones we are running and perhaps a bit of octane boost and yes, fuel mapping tuning. Perhaps one change at the time and see. I do agree Dave that WOT condition seems a bit lean but again Steve suggests that the spark plug “lean looking” color is quite normal when ones drives these race engines flat out.

Thanks Tom. I think I ll give the Sunoco GT 100 a try. Here are some of the pictures. Grade 8 spark plug cathode melted after track day (Simon’s). I had the same happened to me with grade 7 and street driving. And grade 8 spark plug after 15 minutes of use. The ceramic is sparkling white.