Dazza

Many thanks to Andy for kicking off the replies and all the boys for their sage comments. I will be keen to locate and read up on the previous threads on this subject. My interest in this subject is because I am lucky enough to own a 1994 JPE (the only one that made its way here to Australia), and I have just had it properly tuned on a Dyno Dynamics Dynamometer for the first time. A rolling road type where the back wheels are spinning on drum rollers. All your comments have helped me put this interesting process into some perspective. Now we all know that the JPE has the 250bhp Swindon version of the VX engine, and the original owners paid quite a premium for the privilege. However, the power figure quoted on this rolling road dyno (after tune up) was 120kW (sorry, we are metric down here, but I think that makes it around 160bhp at the back wheels). Obviously this is a long way from the 250bhp. However, the important thing is that this tune up gave me a before and after difference of 30kW! The vehicle was so fast (compared to my entire automotive experience) that I did not realise how out of tune it was. The main point is that this tune up has made a huge improvement over what was already a mind-boggling driving exerience. The best A$300 I have yet spent on the Caterham.

I have recently had my VX engined Caterham (with MoTeC management system ) Dynoed. It has made an enormous difference to the amount of power and the tractability. The graphs I received show the power and torque curves and measure the power delivered at the back wheels. My question is, how does this number relate to the bhp power figure that Caterham quote for the car when you buy it. Also, what is the amount of power loss from the figure quoted for an engine and if that same engine's power was measured at the back wheels. I guess I am wondering if there are different ways to measure the power which will give you greatly differing numbers. If Mr. Webb is reading this, I would be interested to know whether the famous K2RUM power of 281bhp was measured at the back wheel, and what was the figure originally before he did his amazing mods.

Thanks for the advice guys. The only vehicle imported into Australia with the Vauxhall engine, that I am aware of, is the GM Holden Calibra. I don't think Astras were imported until recently, but will check. I shall order the manual and I am sure it will be of great help. Thanks! I was under the impression that the engine and gearbox should be removed together, but separating them will be a lot easier. Caterham also recommended replacing the slave cylinder and your explaination makes sense Captain. Certainly good preventive maintenance. Will probably schedule this task in the new year. Thanks again.

Tony, I also have oil leaking from the speedo drive shaft seal. Is this easy to fix with the engine/gearbox in the car? if so, what parts do you need from caterham apart from a new seal.

Thanks Arnie, Had not thought about the cap being the source of the leak. I have a replacement rear crank seal from Caterham, so between those two it should fix it. Is the Vauxhall OEM sealant that you refer to available from Caterham. As you can appreciate, readily available items in the UK may be completely unavailable here in Oz. I have a new release bearing as my car is from June 1994. You mentioned Haynes.... Is there a manual for the Vauxhall engined Caterhams, or is the manual your referring to for this particular engine as used in some Vauxhall cars. What I am wondering is, can you give me some sort of reference number or title to the Haynes manual that you find the most useful. Thanks! I have a 6-speed, even though the car originally came with the 5 speed. Will order the O-ring. Removing the engine and gearbox will be fun! It is a tight fit to say the least. Any tricks of the trade to removing it successfully without damaging the car, the enging/gearbox or the ancilliaries. cheers

I seem to have a fairly chronic oil leak problem. Engine oil leakes from between the crank and bell housing (only when engine running). I also seem to have gearbox oil leaking from the front of the gearbox and from around the speedo drive seal. Obviously to fix all of this I will need to take the engine/gearbox out. When I do this I want to fix everything that I can. I already have a new clutch release bearing, a new exhaust gasket, a new rear oil seal for the crankshaft. My question is, what else do I need. I assume that you can buy from Caterham a front gearbox oil seal, a speedo drive seal and a rear gearbox oil seal. Caterham suggested fitting a new slave cylinder which has been apparently improved over the years. Any thoughts on the above?

Funnily enough, my alternator died this very day. I have a 1994 JPE and I assume that the alternator is the original one. I noticed the ignition light on the last two times I drove it and took it to my auto engineer. He pronounced it dead. It seems to be a French make of alternator and completely unavailable here in Australia. So we are in the process of trying to find a readily available local unit that will do the job. The main criteria would seem to be that it has the right compatible mountings and small enough to get into position without pulling off the exhaust system. Any ideas or comments most welcome.

I can see you guys have a lot of fun over there in the UK with your se7ens and that some healthy rivalry is alive and well. I like your idea Keith and if I get a silencer from Caterham I am sure I have a suitable collector made here in Oz. Too late on the puke yellow. The previous owner painted the Dymag wheels that lovely colour along with a stripe down the bonnet. It does look rather good, but I can't imagine what a whole car of that colour looks like in the flesh. cheers darren

Thanks for the explanation Arnie. Will pursue getting the R500 silencer sent out from Caterham and getting the rest of the system fabricated here to give the 4-2-1 system. Also, I shall start trying to find out who has the skills and experience locally to build a full optimised system similar to yours. It is amazing the effect of the kink has in the inlet manifold and the exhaust manifold. I guess the theory was that to keep the traditional profile of the car and not have the induction trumpets and the exhaust sticking out of the bonnet vertically, concessions to power were made. You have obviously demonstrated what can be done and I'm looking forward to exploring some of those areas as time and money allow. With regards the fuel pump.... we found that the fuel pressure was fine (around 38psi regulated), but that the fuel flow rate was horrible when the fuel pump got hot (30-60minutes). We was the flow at 1.2 litres/min and dropping fast. Taking the fuel pump out showed that the filter bag was blocked and as it has no "frame" to keep its shape, it had collapsed and the pump was trying to suck fuel thru 1 square cm! We could have ordered an identical part locally (believe it is a Rover unit), but would have cost over A$600. We installed a GMH Commodore pump (locally available and A$150) and it is rock steady at 2.2 l/min even at max revs.

Hey Darryl, Good point about Turn 1 at Eastern Creek. I have heard it referred to as Slazengers (...you need big ones to take it flat out). I really need to get my speedo accurate as the car seems to handle the corner as fast as I am game to take it. I think the diffuser fitted to the rear helps. I am keen to get out there again to check out what improvement my recent wheel alignment has made. cheers

Thanks for the ideas everyone. Arnie, I'm incredibly impressed with your K2RUM. It would seem to be the ultimate manifestation of extracting every last performance improvement out of the Lotus 7 concept! I was very interested in the exhaust layout you have installed. Especially the 4-2-1 format. What is the reason for the high angle of the header pipes? Obviously the JPE has the 4 header pipes collected into 1 directly. I notice in the Parts Catalogue there is a 4-2-1 collector. Do you think there would be a noticeable improvement just fitting this part instead of the current 4-1 collector (in power)? Obviously a fully custom system like yours would be ideal. Arnie, Can you just explain once more for the dummies what to do with the R500 part. Start from the end of the collector (just past where the Lambda probe is)..... how exactly are you suggesting my standard silencer is to be fitted together with the R500 part? Thanks Very interested in your comments on the power output of my engine as fitted standard to the JPE. With my other car being a Volvo (literally!), the power on tap is so phenomenal that I never stopped to think that it wasn't the claimed 250bhp. I haven't had it dynoed yet as I am still in the phase of sorting out some other basic problems (just replaced fuel pump etc), rather than trying to increase performance above standard. Will talk to your further on this in due course. Thanks

Thanks for all the replies guys. Yes, Darryl is right, it was at a commercially organised Car/Bike tack day during the week at Eastern Creek here in Sydney, Australia. The sensors are located at 300m before turn one, about half way down pit straight. I have not had any static other type of noise measurement done on the car, so cannot comment. Certainly a large amount of the noise is induction related. At the time I was at around 7500rpm and the speedo was reading 145mph (which since it is so inaccurate, it was probably more like 120mph.... just one more thing to get looked at!). In any case, they were fine about it and I just promised to not rev it so much at that point on the track. I was just hoping that there was an easy, quick and cheap (is there ever such a thing?) fix to reduce the noise slightly which leaving the power untouched. It would certainly help when driving on the road. Once again, thanks for your comments.

I have owned a '94 JPE for about 4 months now and am still amazed at how LOUD it is. I was recently black-flagged at a track day for being too loud. They clocked me at 96dB (the track limit was 95dB!). Does anyone have any experience with quietening the exhaust note while still keeping the existing original muffler. Can more baffling be fitted without cutting it apart? I would like to try to keep all the JPE parts as original as possible.