p.mole1

Hi Chris, Its a Dedion car with radius arms only fitted in the upper position. I am going to try and reduce the bump steer with shims and see if that improves things. I did not know about the Watts link. Hi Jonathan I still have problems with photo's due to file sizes. I do not have a bump steer gauge but will have to make one. I used a tracking gauge to check the toe in/out. I set the toe in to 0 degrees at its normal running height then lifted the front to full droop this altered the the total toe to 1 degree toe in and then altering to 0.5 degrees toe out at full compression. I assume that is 75 mins per side. Rather than use shims to lift the rack I am going to lower the tie rods using the spherical rod bearings but it should achieve the same outcome My car is a 1995 and I have heard the rack placement was not very accurate on some cars of this age.

I finally got myself a Caterham last year after years of wanting one. My newfound enthusiasm quickly wore off as I found it to be one of the worst handling cars I have ever owned! loads of grip but unstable, any bumpy road was had me darting all over looking for the nearest ditch with white knuckles. So far I have made some large improvements,new dampers and have set the car up with 10 mm rake. The steering rack was also not installed correctly! but I am still having to run with 30 mins of toe in just to retain some form of stability. Its ok on a smooth road and if I stiffen up the front dampers its ok on a bumpy road albeit you loose your fillings I have quickly checked and it seems to have a large amount of bump steer about 1.5 degrees though its full travel! seems like Caterham don't know how to position a steering rack. Rather than shim the rack I have found a company that makes 3/8th taper pins that replace the track rod end so I can use a spherical rod bearing and shim this up or down as required. Has anyone gone down this route or have shimmed your rack or had your suspension checked for bump steer.

Doesn't look like the wheels have ever suffered from any impact damage, its not so much of a vibration more of a "shimmy" I can feel the run out though the steering wheel. I have fitted the best wheels to the front and it is now fine, it just means I won't be able to rotate them. I would have thought that alloy wheels would have had almost zero run out since they are machined.

I have 14 inch twogates wheels fitted and have been suffering from steering wheel vibration. I have just fitted new tyres and it is still present. I checked all of my wheels and 3 have about 0.8mm lateral run out and 2 have about 0.3mm I fitted these to the front and the vibration is gone. I am quite surprised at the level of runout. I have checked the backface of the wheels and it is fine,I even cleaned it down to bare metal and they were all still the same. Are modern wheels this poorly made?

Hi Alexander I'm in the very north. Not much up here! I will at some stage remove my injectors and get them flow tested and I should really measure my fuel pressure, that should give me a reasonable idea.

Hi Revilla thanks for the input,that's an interesting article. I have just completed a compression check and all is fine,in fact couldn't be better 1 220 psi 2 220 psi 3 215 psi 4 220 psi I have never had an engine with such a consistent reading. If my injectors are able to flow 10% more than standard this give me around 140 hp which is what I was expecting. I will get my injectors flow tested,that's the only way I will know with any certainty

Hi Rob I know I am running quite mild cams, I intend to build a 1.6 in the future ( all the stuff is transferable) so I wasn't really expecting any real gains from the throttle bodies, but I was expecting something from the cylinder head and the K6. I am limited by the pistons I can't fit any wilder cams,as it is the power looks like its still useable to 8000rpm and I suspect maximum power on a 1.4 will be above this figure also I can only use solid tappets which mean using the 285 solid version which is more aggressive One thing I have gained is a massive boost in the midrange or at least that's what it feels like driving it. I'm off into the garage to do a compression test.

Thanks Revilla it is quite confusing I can only assume the injector flow charts are a guide and they are capable of flowing more that stated. I certainly hope that is the case. I am assuming the rolling road is reading low. It seems strange that the 1.4 Super sport has an a 149cc/ min injector that is rated to give 103.5 hp at 95% duty cycle on an engine that is supposed to develop 128 hp

I have found and injector table ( Stan Weiss efi flow data table ) The black injectors 176cc/min give 122 hp est at 95% duty cycle at 3 bar The cream injectors 218cc/min give 152 hp est at 95% duty cycle no fuel pressure shown All these figures seem very low since its not recommended to run injectors at these duty cycles,am I missing something or is everybody running higher fuel pressures to compensate for the low flow rates on these injectors. Are the quoted Rover power outputs accurate ?

I'm getting a bit worried about taking my car on a trackday with my injectors working flat out,it won't take much to go lean at full throttle ie a slight dop in fuel pressure and pistons will let go. How difficult is it to re-scale larger injectors and how accurate is it, as regards getting the fueling correct. Dave Andrews kindly sent me a 1.6 re-scaled map just so I could get the car running but is was very rich at part throttle because it was a best guess. Now I have a the fueling set up is there a method of calculating the % figures or will I have to back to a rolling road?.

Have been doing some homework Looks like 127.5 bhp is about spot on if the formula is correct Known Hp x Brake specific fuel consumption equals fuel used in lbs/hr Number of injectors x duty cycle 127.5 x .42 ( I think this is the correct figure) 14.09 x 10.5 to convert to cc/min 4 x 95% I get an injector flow of 148 cc/min Math's is not my strong point, but if the formula are correct, (probably an over-simplification) it looks like achieving 100 Bhp per litre is going to be a lot harder than I thought. I think my exhaust primaries are probably to large, and the throttle bodies are a tad to big for a 1.4? also maybe the intake trumpets could be to long? Since the valves are the maximum size the only way to achieve the goal would be more lift and a lot more revs. So after all that I'm .5 bhp down! Have double checked everything and I'm getting full throttle, I will do a compression test however the valves and seats looked brand new

I'm assuming my injectors are at the absolute maximum if my calculations are correct that's not a very good idea they should be around 80 to 90%. I came away from the rolling road with 127.5 bhp after fitting a Janspeed ported head with 11-1 compression ratio, 4-2-1 exhaust,verniers,42 mm Jenvey DTH 90mm bell mouths and an Autotechnics air box and a heat shield to keep the hot air from the radiator away to an otherwise std 1.4ss. In standard form a SS should make 128 bhp, but it's injectors don't appear to be large enough unless it has higher fuel pressure. Assuming Caterhams power ouput claims are 10% optimistic that would give a realistic output of 115 bhp. I seem to have gone to all this effort just to get to the manufactures claimed output,not really very impressive,it works out at about 90 bhp per liter, I was expecting a bit better than that,embarrassingly my friends 1430cc A series Mini nearly matches that on a single SU carburetor and a distributor! measured at Aldons Looking at the dyno graph the power seems quite linear and is peaking at about 7500 and not really falling of at the limiter so I don't think there is anything wrong with my cam timing Fitting larger injectors wouldn't of made any difference to the power output it would stop them running close to maximum.

I have been looking at injectors and it seems I should have used a higher rated one. Looking at the rough calculation of injector sizing 149cc/minute x 4 divide by 5 gives the rough maximum hp output at 100% duty cycle at 3 bar fuel pressure. So with that calculation it gives me a maximum rating of of 119 bhp or 95 bhp at an 80% duty cycle I'm assuming these calculations are erring on the side of caution. If this is the case the Supersports rated power output seems wildly optimistic unless it is using a higher rated fuel pressure regulator. I don't know if this calculation is the same or even correct for both batch fired and sequential injectors, I should have done my homework before I started, never had any of these problems with carbs

Thanks oilyhands that's about what I was expecting,John Sleath does not have a reputation for over inflating dyno readings and outputs,he had some impressive V8 stuff in his workshop and has a 1000 bhp Ultima! which he inherited and detuned to 500 bhp to make it more usable. I suppose when you can dyno cars with over 1500 bhp at the wheels! a lower reading makes no difference whatsoever. The car feels much quicker but now I've convinced myself its not (probably a placebo effect) however if my injectors are close to limit I must be producing more power unless the standard injectors were already at the state in standard form. Just to convince myself everything is ok I will do a compression test and may order a cheap cylinder leak down tester from China

It seems like the transmission loss is about right, RWD cars - add 10 to the wheel bhp and then divide the result by 0.88 i know its a rough estimate that gives about 125 flywheel bhp.

If I am using solid tappets do I have to take into account the valve clearances when setting the cam timing? I used SuperSport cams and the recommended timing figures are 80 thou inlet and 60/65 thou exhaust.( with throttle bodies). Should I have deducted the valve clearance 80 - 8 and set the timing to 72 thou. Have I over advanced my timing and killed all the top end power? seems I am .5 bhp down on standard. Are the standard 1.4 Supersport injectors running close their maximum output in standard form. I must say I was a tad disappointed I was expecting around 140 bhp. I also noticed my transmission losses were quite bad I ended up with 100 bhp at the wheels. I was almost managing that output with A series Minis! 25 years ago

I was quite surprised at the end result I'm .5 hp down on standard, after fitting a ported Janspeed head with higher compression ratio, 4-2-1 exhaust, Piper verniers, Jenvey DTH throttle bodies, Autotechnics air box with 90mm trumpets and a M3D K6 ECU and I even made a cold air box to shield the air intake from the radiator. Takes a special skill to bolt that lot on and lose power! The car runs like a treat after being set up no flat spots pulls from tick over up to the limiter it could do with the limit being raised. I should have done a compression test first however the head was almost new and the rest of the engine is fine,doesn't use a drop of oil although I might give it a leak down test just to check everything is ok.

John Sleath he seems to specialize in powerful V8 stuff, not weedy 1.4 K series

Oh dear all that effort -127.5 hp at 7400 rpm and about 100 ftlb of torque at about 5800 rpm mind the torque curve is just about flat from 3400 to 7500 it doesn't drop below 90 ftlb These match exactly the the the Standard SS outputs,either Caterham are vastly exaggerating the output or I'm a useless engine builder or the rolling road is reading low,optimistic! I wonder if I have to much advance on my cams I am using 80 thou inlet and 60 thou exhaust although I have just realised I did not take the valve clearances into account I was told my injectors are now running right at their maximum limit, what ever the figures say its a lot quicker and one hell of a lot more economical pity it now sounds like an old duffers 214 Rover

It's all back together with an Autotechnics air box and and DTH throttle bodies and a map supplied by oilyhands, it really goes well and is still pulling strongly to the rev limiter 7600!. It pulls from 1500 rpm, ticks over perfectly. It sounds a bit rattly with the solid tappets and has no induction roar or exhaust noise in fact it sounds a bit tame. I have it booked in on a rolling road on 27th to get the fuelling and ignition sorted, best take a bin bag just in case!

Thanks will check Emeralds site,I will have a look at Motorscope

Has anyone had experience of John Sleath in Yorkshire or Falkland Performance in Fife. I am looking for someone who knows about the Emerald K6. Some tuners don't seem to like the operating system.

I've got one it's in my garage somewhere

Can anyone recommend a rolling road in the NE who is au-fait with Emerald ECU's and throttle bodies?

Thanks I now have a thermostat