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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Green George

Original Poster:

316 posts

251 months

Wednesday 10th February 2016
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I do use an aero screen on track days (depending on the weather) as it does make a noticeable difference to the performance.

In my opinion with Caterhams, mileage is not as significant as condition allied to a full and detailed history. It took me a long time to find the right car with the right spec; which is why I am loathed to buy a SLR or R400 instead.

The important thing to me is to sympathetically modify the engine. Dave Andrews is very clear about the limitations of the standard K Series bottom end and the potential issues of using the Super Sports higher rev limit for sustained periods. So a set of forged pistons and associated work makes sense; and to my way of thinking if you are going to do that it is worth looking at the top end at the same time as the engine will be stripped down to do the bottom end.


Green George

Original Poster:

316 posts

251 months

Wednesday 10th February 2016
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BertBert said:
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
Good points well made; although I am almost certain my starting point will be the fitting of forged pistons for peace of mind and longevity.

BertBert

19,035 posts

211 months

Wednesday 10th February 2016
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Agreed. Forged pistons, mild port, sensible cams, Jenveys, exhaust, 160+bhp. #Superscreamingfun

harry b

329 posts

174 months

Wednesday 10th February 2016
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I would suggest to also give Simon Rogers a call for suspension mods. That really makes a car quick in my opinion, apart from mention above about the added lightness

rubystone

11,252 posts

259 months

Wednesday 10th February 2016
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Green George said:
I do use an aero screen on track days (depending on the weather) as it does make a noticeable difference to the performance.

In my opinion with Caterhams, mileage is not as significant as condition allied to a full and detailed history. It took me a long time to find the right car with the right spec; which is why I am loathed to buy a SLR or R400 instead.

The important thing to me is to sympathetically modify the engine. Dave Andrews is very clear about the limitations of the standard K Series bottom end and the potential issues of using the Super Sports higher rev limit for sustained periods. So a set of forged pistons and associated work makes sense; and to my way of thinking if you are going to do that it is worth looking at the top end at the same time as the engine will be stripped down to do the bottom end.
I've had a lot of experience of Caterhams, both in owning them and in a business venture involving them. Their value is incredibly mileage-sensitive, rightly or wrongly. An SL has a fixed spec btw so I don't see why you had a problem finding one with the exact spec (or are you talking about paint, dials and Tillets or leather?).

But that's neither here nor there with your car as it is already a high mileage car. From memory, the SLR is simply a Superlight with a VHPD engine - no other changes to spec on chassis or brakes. Didn't even come with DS as standard, so what have you to lose by uprating the engine? If you go that route, I'd strongly recommend you DS it though!

Ziplobb

1,358 posts

284 months

Wednesday 10th February 2016
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Just going to chuck a few thoughts in:
My 1.8 Roadsport is my 2nd 7 and when I first did a trackday I was fustrated about my lack of progress compared to other cars. First thing I did was fit some Mintex brake pads and some R888s.I could not believe the difference those simple mods made to my track performance and how quick I could go. I then got Gary May to flat floor the car and put one of his suspension kits on - again massive gain on track. During this period I also paid for some professional instruction and after a couple of solid 1/2 day TD sessions got much more confident with the car. I then swapped the engine out for another 1.8 with jenveys, cams, emerald (the DVA bolt on kit) which gives 167 bhp according to the mapping session - its now quite rare for a car to fly past on a TD and it has to be another 7 or something quite exotic/dedicated TD car. Visited Snetterton last year for the first time though and that made me realise that my current spec was no good for that long back straight there .... 200bhp here we come.

cwin

953 posts

219 months

Wednesday 10th February 2016
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I'd also depends on how good you are at driving, we have 4 Caterhams all different powers, a Busa powered car at 170bhp ish, a R300 current race car @ 175 bhp,a Duratec car at 238bhp and another at 308 bhp.
I am about a good average driver and the later two cars are too fast for me on a circuit as I don't seem to be able to have the confidence of carrying the same speed through the corners and feel they make me point and squirt,
I think 180/200 bhp is a good sweet spot and if you can ring the neck out of this power you will be going very quick on a tracday,
Just look at the lap times from 175 bhp R300 racers, I know they run a sequential gearbox but another 30 bhp would make up the difference.

As for top speed if you end up towards 300 bhp you will see 150 mph at Spa and Snetterton among others even with the crap aro dynamics.

And I'd second the opinion of Metior Motorsports suspension (Simon Rogers) it will make a big difference to your cars handling.

Edited by cwin on Wednesday 10th February 14:32

DCL

1,216 posts

179 months

Wednesday 10th February 2016
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cwin said:
I'd also depends on how good you are at driving, we have 4 Caterhams all different powers, a Busa powered car at 170bhp ish, a R300 current race car @ 175 bhp,a Duratec car at 238bhp and another at 308 bhp.
I am about a good average driver and the later two cars are too fast for me on a circuit as I don't seem to be able to have the confidence of carrying the same speed through the corners and feel they make me point and squirt, I think 180/200 bhp is a good sweet spot
I couldn't agree more. Once you go over that 200 BHP then every thing just starts to get harder and more extreme. Small mistakes that would normally go unnoticed are amplified and if you don't have the skill to deal with it, your driving just deteriorates - I found braking, in particular, becomes so much harder to get right. In a 210 BHP car I can lap consistently within a 1/10 second, at 270 BHP I'd be lucky to get two laps within 1/2 second of each other.

AtWork

142 posts

189 months

Wednesday 10th February 2016
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Can't help with naming the 'magic number', but I would certainly advocate speaking to Chris at the 7 Workshop. He did my Crossflow->Zetec (160bhp Raceline job) conversion and I couldn't be happier with the job he did.

Green George

Original Poster:

316 posts

251 months

Wednesday 10th February 2016
quotequote all
rubystone said:
An SL has a fixed spec btw so I don't see why you had a problem finding one with the exact spec (or are you talking about paint, dials and Tillets or leather?).
Thanks for your advice. I am aware of the SL spec and the various options that were offered by Caterham. As you have asked, the problem I refer to having was finding a 7 with the spec I wanted. I looked at a lot of 7's before the I found the right car which in my case I discovered was an SL; as it was pretty much the right spec out of the box; however finding one with the right history and provenance took a while as they are quite a rare 7.

Anyway, returning to the original topic, I thank you all for your advice. I think I am aiming for between 160bhp and 180bhp and the advice from BERT BERT makes a lot of sense to me, with regard to "Forged pistons, mild port, sensible cams (*not sure if the standard Super Sport cams count), Jenveys, exhaust, 160+bhp. #Superscreamingfun".


Re. the suspension my car is on the original Bilstein springs and shocks which seems to be performing fine but I have read about Meteor Motorsports Nitron valving and I am already looking at investing in a set of Simon's Nitron NTR1's and I see that Simon can supply front and rear Powerflex polyurethane suspension bushes, which might make sense to do at the same time....



Edited by Green George on Wednesday 10th February 18:15


Edited by Green George on Wednesday 10th February 19:16

tankplanker

2,479 posts

279 months

Friday 12th February 2016
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Are you able to reduce the weight of your 7, particularly unsprung weight? Nearly everything, not just straight line performance, will improve if you can reduce the weight. Adding more BHP will just improve acceleration.

Other thing to think about is switching to paddles, my Indy has full bore throttle up and downshifts via the paddles, it is way faster than using a normal gear stick and makes a big difference for longer stretches of acceleration.

BertBert

19,035 posts

211 months

Friday 12th February 2016
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Paddles with a 6spd box? How?

Green George

Original Poster:

316 posts

251 months

Friday 12th February 2016
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tankplanker said:
Are you able to reduce the weight of your 7, particularly unsprung weight? Nearly everything, not just straight line performance, will improve if you can reduce the weight. Adding more BHP will just improve acceleration.

Other thing to think about is switching to paddles, my Indy has full bore throttle up and downshifts via the paddles, it is way faster than using a normal gear stick and makes a big difference for longer stretches of acceleration.
Tank platter I like your thinking but I am a big lad at about 110 kgs! I must endeavour to do something about that before focusing on the 7!

I believe Meteor Motorsport does a paddle shift conversion https://www.meteormotorsport.com/caterham/caterham... not cheap but looks Gucci!

tankplanker

2,479 posts

279 months

Friday 12th February 2016
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How about putting in x £s in the 7 upgrade kitty for every lb lost? Imagine how much faster your car would be if you lost over 50kg between you and the car! smile

Green George

Original Poster:

316 posts

251 months

Friday 12th February 2016
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Hmmm food for thought!

Mario149

7,754 posts

178 months

Friday 12th February 2016
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Green George said:
Hmmm food for thought!
Mmmmm....fooood. (I'm also 110kg biggrin)

Green George

Original Poster:

316 posts

251 months

Friday 12th February 2016
quotequote all
Mario149 said:
Green George said:
Hmmm food for thought!
Mmmmm....fooood. (I'm also 110kg biggrin)
We must never ever under any circumstances share a car, we wouldn't be able to keep up with a smart car!

BertBert

19,035 posts

211 months

Friday 12th February 2016
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Green George said:
Tank platter I like your thinking but I am a big lad at about 110 kgs! I must endeavour to do something about that before focusing on the 7!

I believe Meteor Motorsport does a paddle shift conversion https://www.meteormotorsport.com/caterham/caterham... not cheap but looks Gucci!
It's for a sequential box, so an entirely different upgrade path. Not necessarily unappealing upgrade path if you like sequential boxes, but not a low budget item biggrin

anotherjohnv

1,285 posts

197 months

Friday 12th February 2016
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so then:

anotherjohnv said:
the actual answer is 200 bhp.

tight fart

2,906 posts

273 months

Saturday 13th February 2016
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Got to agree 200 bhp is about right.




As long as I can have 220 BHP.