How much power does it take to make a really quick 7?

How much power does it take to make a really quick 7?

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Discussion

Green George

Original Poster:

316 posts

250 months

Sunday 7th February 2016
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I have an original 1.6 Superlight (2000 EU2 K-series with the Caterham Super Sport kit), which has covered just over 40,000 miles.

On track the car is really quick though the bends and really good on the brakes. However, down the straights and through the faster bends I really lose out to faster cars and can struggle to get confidently past quick cars.

My question is how much power makes for a genuinely fast 7?

I have had the green light to mod the car after I had to cancel a slot with Dave Andrews last year due to family life taking a priority, last year.

I know that the Caterham Super Sport ECU has the rev limit set too high for sustained rpm (@ 7600), so anticipate that I will need a bottom end rebuild to fit forged pistons in order to provide a suitable base for performance modifications.

With regard to performance modifications I anticipate that will involve head work, probably new cams and an ECU; just don't know what figure I am aiming for. The engine must be bomb proof / safe / reliable.

What I do know is that I really don't want to lose the sweet balance I have with the Superlight and the all round drive ability; which is something I have heard levied at some of the more powerful 7's.

Once I have some answers I can work out my budget but I really don't want to spend more than £5,000 all in; preferably less!

radical78

398 posts

143 months

Sunday 7th February 2016
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about 180 will give you the power to overtake but still keep the balance you like if its already got super sport cams etc go to 1800cc that will be cheaper and safer than a lot of expensive tuning

Murph7355

37,649 posts

255 months

Sunday 7th February 2016
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If the only thing frustrating you is faster cars on track, you might be better off just adjusting the track days you attend/how you drive on them (choosing when you go out etc). I say this because the SL is a beautifully balanced car, especially for road use, and many cite it as one of the best models Caterham has made.

If you really want to upgrade, I'd stick to 200bhp. Cheap-ish to tune to this level and they don't take markedly more to keep fresh. You'll need things like a dry sump oil system, but that's a decent thing to have anyway. Balance on the road is still pretty good, though it will frustrate slightly more as you can't deploy everything in the same way you can with an SL.

Trouble is, I suspect you will still find more modern, more powerful cars frustrating you on track. Time has moved on, as has chassis tech, engine tech and electronics tech. I haven't been on a rack day for a few years now (family life took over)....but when I do I'm fully expecting a different experience to when I was last on (my 7's 200bhp).

jelley1970

47 posts

221 months

Sunday 7th February 2016
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I find it's only down force type cars (Radicals etc) only really go past me on track R400k 205 bop, unless it's something like silverstone GP circuit which is a big power circuit or Spa.

To me it's the sweet spot for power in a 7

Tomiam

23 posts

106 months

Monday 8th February 2016
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R400 duratec with roller barrel throttle bodies. 220bhp.
Not much comes past me on a track day. Normally only things like radicals or fully prepped race cars.
Perfectly drivable on the road too.
Some videos of mine on track here.
https://youtu.be/U13FJ_jyAec
I've got quite a few videos uploaded of track days if it helps. smile

Green George

Original Poster:

316 posts

250 months

Monday 8th February 2016
quotequote all
radical78 said:
about 180 will give you the power to overtake but still keep the balance you like if its already got super sport cams etc go to 1800cc that will be cheaper and safer than a lot of expensive tuning
So, to go to 1800cc is that 'just' a matter of new liners and pistons? Because if I am going to use forged pistons then it is just a case of factoring in new liners, which shouldn't cost too much more.

Update: 1600 and 1800 K series engines apparently use the same pistons and liners and 1400 and 1600 K dries use the same crank. Therefore to convert a 1600 K series to 1800 requires a new crank is required. A quick open source search shows that QED sell a std 1800 crank for £540.

Edited by Green George on Monday 8th February 19:25

radical78

398 posts

143 months

Monday 8th February 2016
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also different con rods

Green George

Original Poster:

316 posts

250 months

Monday 8th February 2016
quotequote all
To be quite honest in my case a little knowledge is a dangerous thing and I will get some quotes and specs.
I would ideally like to use Dave Andrews but he is in such demand that a 6month + waiting list feels like a life time! I am based in the South East (just North of London) and my first thoughts are also to approach 7 Workshop, RatRace, James Whiting and or PT Sports cars. Is there anyone else I should be trying?

radical78

398 posts

143 months

Monday 8th February 2016
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McMillan they do the Caterham graduate cars and have been very helpful when I rang them

rubystone

11,252 posts

258 months

Tuesday 9th February 2016
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Ratrace(Protune) build good engines. Had you thought about selling your car and buying an SLR/R400? A cheaper option when all's said and done and assuming yours is a genuine Superlight, you should be able to sell it easily enough. There's a great spec SLR in Blatchat at the moment.

BertBert

18,953 posts

210 months

Tuesday 9th February 2016
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I never really got the frustration of other cars on track with my 1600 exec superlight. In fact I quite enjoyed harrying them in the corners even if they pulled away on the straights. I suspect if the criteria is really to go past others on the straights easily, then you will need to get to 200-230bhp with an 1800k.

I'm not sure if it's feasible to get there from a 1600k with all the bits needed for £5k. I think I'd be looking to find one that's already done and change yours for it. Whole car that is.

If it were me, with that starting point, I'd stick with 1600, have a DVA (or other) job done on it with DTHTBs and aim for around 160bhp.
Bert

DVandrews

1,315 posts

282 months

Tuesday 9th February 2016
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Green George said:
So, to go to 1800cc is that 'just' a matter of new liners and pistons? Because if I am going to use forged pistons then it is just a case of factoring in new liners, which shouldn't cost too much more.

Update: 1600 and 1800 K series engines apparently use the same pistons and liners and 1400 and 1600 K dries use the same crank. Therefore to convert a 1600 K series to 1800 requires a new crank is required. A quick open source search shows that QED sell a std 1800 crank for £540.

Edited by Green George on Monday 8th February 19:25
To convert 1600 to 1800 requires crank, rods and most likely pistons as removing from one rod and fitting to another is near impossible whole keeping the piston whole.

New 1800 cranks can be had for around £250-300.

Dave

Green George

Original Poster:

316 posts

250 months

Tuesday 9th February 2016
quotequote all
rubystone said:
Ratrace(Protune) build good engines. Had you thought about selling your car and buying an SLR/R400? A cheaper option when all's said and done and assuming yours is a genuine Superlight, you should be able to sell it easily enough. There's a great spec SLR in Blatchat at the moment.
Yes, it is a genuine Superlight and yes, I have looked at SLR's and R400's. I have concluded that to buy a new car would be a gamble especially when I know my car is excellent, being very well maintained and in fine fettle (there is a blog at http://www.pistonheads.com/members/showcar.asp?car... if you are interested).

The Superlight is an excellent base as the spec is spot on. What I want to do is improve the performance whilst remaining true to the original design brief...

Green George

Original Poster:

316 posts

250 months

Tuesday 9th February 2016
quotequote all
DVandrews said:
To convert 1600 to 1800 requires crank, rods and most likely pistons as removing from one rod and fitting to another is near impossible whole keeping the piston whole.

New 1800 cranks can be had for around £250-300.

Dave
Thanks Dave for your advice. I am looking at all options and will be in contact in due course to see what you advise and find out what the waiting time is.... I fully anticipate concluding the wait will be worth the end result.

tight fart

2,868 posts

272 months

Tuesday 9th February 2016
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Last year this year or next year?
Mine started with about 120 BHP 27 years ago and was a very quick car, about 20 years ago I upgraded it to about 150 BHP and it was a very quick car, 12 years ago I upgraded it to around 220 BHP and it was a very quick car.
Now I just enjoy it but I still think it's a very quick car.

Edited by tight fart on Tuesday 9th February 22:05

HustleRussell

24,602 posts

159 months

Tuesday 9th February 2016
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Not a popular idea here I imagine but my attitude is to accept the limitations of the car. It's a lightweight sports car, the silhouette largely unchanged since the late 50s. It's not a straight line car. It's a wheelie bin which has blown over. If you want to be the fastest car at any trackday, buy a car which is equally lightweight and powerful but without the 1950s aero.

andylaight

172 posts

125 months

Wednesday 10th February 2016
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Do you use an aero screen on track days ?

rubystone

11,252 posts

258 months

Wednesday 10th February 2016
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Green George said:
Yes, it is a genuine Superlight and yes, I have looked at SLR's and R400's. I have concluded that to buy a new car would be a gamble especially when I know my car is excellent, being very well maintained and in fine fettle (there is a blog at http://www.pistonheads.com/members/showcar.asp?car... if you are interested).

The Superlight is an excellent base as the spec is spot on. What I want to do is improve the performance whilst remaining true to the original design brief...
Thinking about it, your car is a high mileage car, which does limit its value in the marketplace. As soon as you modify it you will limit that value further. That doesn't matter if you will never sell it of course :-)

But you're right, the car has all the right bits already. If you enhance the engine, I'd recommend that, with 40k under its belt you have RRT check the gearbox whilst the engine is out.

If you don't run it on trackdays with an aeroscreen, try one before uprating the engine, it makes a huge difference on track and you might find that it's then quick enough for you.

anotherjohnv

1,285 posts

196 months

Wednesday 10th February 2016
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the actual answer is 200 bhp.

one eyed mick

1,189 posts

160 months

Wednesday 10th February 2016
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Add lightness ! a voice from the grave !