Why stop at 190 bhp?

[AMMO]

My reasoning is this. My road car is in daily use and has to be reliable. It is not just a weekend or track day tool thet gets trailered around. Not that there is anything wrong with this. If I had the money I'd have a road car and a track day car.

 

190 bhp from 1800 is relatively simple to obtain and should give good reliability. One of the plus points is that all stock components can be used such cranks, rods, pistons and clutches. So if anything does go wrong it is cheap and quick to get back on the road again. Your £1,400.00 steel crank is not usually an off the shelf item and if you are lucky you wait 6 weeks. Enough to ruin a short summer.

 

190 bhp in a Seven is over 300 bhp / tonne and good enough to see off most cars. At a recent trackday at Snetterton my car two up with approx 180 bhp saw off Porsches, BMW M3s and Elises(easy). Even had a (badly driven) Ferrari 355.

 

The other thing is that you only need about 60 bhp to go around corners. Since fitting the Zetec I'm not going any faster around bends than I was with my Crossflow. It does of course accelerate a lot quicker now. My feeling is that once I have that bit more power all the gains are going to be in suspension and setup and better brakes.

 

Only posted this as I was bored and have been quiet for a couple of days. It is something I have been thinking about for some time and this is the conclusion I have come to. May not be relevant to everybody (or anybody for that matter).

 

I think I'll make a cup of tea now.

 

 

AMMO

[V7 SLR]

Not sure what the question is... You have just reasoned why you should stop at 190bhp so are you throwing the gauntlet down for reasons why you shouldn't stop there?

 

I don't know much about the Zetec, nor the price per bhp for upgrades. I have a friend who is just about to install a 190bhp Zetec so I assume that this is a milestone for Zetecs. It appears fairly easy to achieve and relatively inexpensive.

 

For the K's, the milestone appears to be around the 230bhp mark. It is relatively inexpensive to buy a VVC engine and then choose your components from a list on the DVAPower web site (amongst others). You don't need to resort to steel bottom ends for this either, yet the engine can still be reliable, although I believe reliability depends upon mode of operation and installation as well as the general care with which it is assembled.

 

I'm bored too. My Totalise mail account appears inaccessible again, and there's not enough new BlatChat threads to get my teeth into properly. Enjoy your tea. I've just sent out for a fried breakfast. 😬

 

Worcs L7 club joint AO.//Membership No. 4379//Azure Blue SLR No. 0077//Se7ens List Tours

 

[AMMO]

I'm not quite sure what the question was either. I suppose I could retort and ask how reliable are K-series at 230 bhp? By the sounds of things neither you or I have conviction to fight their corner. I agree with you no real Blatchat threads to get our teeth into.

 

Sorry for my pathetic attempt.

 

I had a bacon sandwich with my tea.

 

AMMO

[fatcat]

what about a supercharger, e.g. the Turbo Technics...they get 215bhp out of a K-series VVC in an Elise without major mods to the bottom end, etc - supposed to be reliable too as the power comes from bigger bangs rather than higher revs..hang on I'm straying into technical areas here...I'll get my coat

[V7 SLR]

I'm about to up the ante on my engine to (hopefully) 230bhp. I am a member of the Se7ens list touring party so it is important that my engine be reliable at whatever power-output I engineer-in, which is why I have carefully studied other people's attempts at similar designs. It seems that I should be able achieve my desired output without having to exceed a safe rev limit for my crank and rods (the current limiting factors) so I am not even tempted to push the envelope even slightly and will set the rev limit at exactly 8000rpm.

 

I have just missed out on a set of beautiful set of steel rods at an advantageous price. I admit that I would have loved to have bought them, and raised the rev limit a little further, but I can't really complain. If I achieve 230bhp I will have almost R500 power which should be reliable.

 

It's also about mode of use. I tend not to employ the full power of the engine very often. Most of its life it is working in the 6000rpm region, which falls way short of actually stressing it. The power is there when I need (want) it though.

 

In addition to this, I have always had a dry sump. Quite a lot of the failures I have seen (of K's) have been to do with oiling (lack of). And as if any more preventative measures could be taken, my engine gets fresh oil and filter far more frequently than perhaps it needs.

 

I'm keen to watch the way that superchargers go on K's for the next couple of years. I love torque, although if I were to entertain the idea seriously it would have to offer much more power and torque than is currently on offery. I have recently seen a turbo'd Striker with 270ftlb's of torque and an easy 250bhp. That ought to be easy to drive. 😬

 

Currently looking for biscuits or jaffa cakes to go with my next coffee. There's a rumour that the sandwich dispenser-machine has choc muffins in. See you.

 

Worcs L7 club joint AO.//Membership No. 4379//Azure Blue SLR No. 0077//Se7ens List Tours

 

[Mike Bees]

My K-series has been utterly reliable for 5 years in states of tune varying from 125-140bhp per litre. Famous last words, maybe it'll blow up at Curborough on Sunday...

 

Mike

[Bananaman]

I have a 2L Zetec in a Westfield & rather than going for more power I am looking at saving weight, improving breaking & better tyres(this is a bIG plus in the going round corners stakes).

 

However i think that one of the best/cheapest ways of improving your speed may be driver training. I meen to be insulting about your driving Mr Shumacker 😬 but i guess we could all get our laptime down a fair bit with some good drive instruction. & of course a BIG F off turbo

 

Andy

 

West is best!!!!

[tom7]

Already done the breakfast sandwich this morning.

Ammo, It is interesting that you notice no real difference in cornering speeds, yet we all spend money on engine power.

As one who has been well and truly bitten by upgraditis and is contemplating investing in some of Mr. Andrews' kit, I think we all look for the next level of speed and acceleration out of a corner. I'm sure V7 has got used to the level of perfermance 200+hp can give in a seven, even Peter C must be looking for that 'little something else'.

The old adage that "too much power is enough" seems to apply.

Starting with a bog standard 120hp K series, there is a point of diminishing returns, question is...where on the bhp scale does this set in 🤔

 

Tom

[Bananaman]

I meen to be insulting about your driving Mr Shumacker

 

sorry that should read

 

I don't meen to be insulting about your driving Mr Shumacker

😳

 

West is best!!!!

[V7 SLR]

Someone ought to plot a chart of cash required against bhp achieved. I think you'll find the "cash required" goes up significantly once you look into steel cranks for minimal bhp gain. I mean, you can get to 230bhp easily enough, and for about 3 or 4 grand all in (including the engine) but to move to 250bhp (a la PC) requires MUCH more wonga (how much PC 🤔 😳 😬).

 

Worcs L7 club joint AO.//Membership No. 4379//Azure Blue SLR No. 0077//Se7ens List Tours

 

[Paul Ranson]

I'd be using a steel crank/rods at 190BHP if I were building a 1.8K.

 

Paul

[MikeE]

I mean, you can get to 230bhp easily enough, and for about 3 or 4 grand all in (including the engine)

---

 

Is that really true? Even from a 1.6 SS? If so what is the upgrade path and costs for each step?

 

I thought i'd read somewhere recently that an R500 engine would cost you £12K

 

Edited by - MikeE on 11 Oct 2002 12:45:04

[V7 SLR]

It comes down to MO doesn't it? You're more likely to put all of your car's miles on whilst sprinting. Seems sensible to over-engineer your engine for that, but I've done over 16,000 miles with more than 190bhp on tap on a non-steel bottom end. Simon Thornley sprints his vhpd'd pre-lit on a similar spec too.

 

Worcs L7 club joint AO.//Membership No. 4379//Azure Blue SLR No. 0077//Se7ens List Tours

 

[V7 SLR]

Mike, you need to look at the DVAPower web site for prices and specs.

 

Worcs L7 club joint AO.//Membership No. 4379//Azure Blue SLR No. 0077//Se7ens List Tours

 

[AMMO]

My point was to have something that is 100% reliable. Something you can jump in at short notice and do a 3,000 mile trip without thinking about it. At 230 bhp you are looking at 127 bhp per litre. Not what you would call a cooking engine. My personal rule of thumb is that 110 bhp per litre is tops for an every day road engine. Some may not agree.

 

What seems to happen is that people buy a road car and then start upgrading. Before you know it they are trailering the thing everywhere because they are either afraid of crashing at a trackday or worried that something may go pop. I just think it's better to limit your power output and sleep at night.

 

Credit where credit is due, Mike Bees did drive to a recent dyno session. I was half expecting him to turn up with the car on the back of a trailer. The car did make 229 bhp, which is exactly what he expected.

 

Preparation obviously comes into it. Any good engine builder will build reliability into his engine. You come unstuck when you exceed what the components are capable of doing.

 

There is no reason why a 1.8 Zetec cannot make the same power as a K-series. The Zetec is heavier but it's a stronger base engine than the K. The K-series was originally designed as a 1400 cc whilst the Zetec was designed from the outset to be part of a 1.6, 1.8, 2 litre family. The 1.8 Zetec has the same crank as the 2 litre which can make 220 bhp with stock components (110 bhp / litre). So possibly no reason why a 1.8 Zetec couldn't make the same bhp with the stock crank. Nobody opts to do this as it's easier to tune the 2 litre.

 

If I was building a 250+ bhp engine I would pay the weight penalty and start with a Zetec. If money was no object I wouldn't take a second look at a Zetec and go Duratec. I like the Zetec because you can get good performance for little fiancial outlay.

 

Fo lunch I had an avocado pear with a dressing made from extra virgin olive oil and balsamic vinegar from Modena.

 

 

 

 

AMMO

[Paul Ranson]

I think there must be reasons why much over 200BHP is rare with Zetecs and common with Vauxhalls. But I don't know what they are.

 

Duratec may be another deal. But how much do they weigh?

 

Paul

[Paul McKenzie]

Paul,

I believe one of the reasons is that the VX head was originally designed by Cosworth for power and not compromised from emissions considerations. I have heard it said by VX tuners that the standard head with good induction and exhaust gas flow can produce up to 230bhp without head mods., obviously with the right cams and cam timing.

 

Paul

[Peter Carmichael]

The 1.8 Zetec has an 80.6mm bore and 88mm stroke.

 

If the 2.0L has the same crank then it has the same stroke and an 85mm bore.

 

A 1.8K has an 80mm bore and 89.3mm stroke.

 

A honda integra 1.8 Vtec engine has a 81mm bore and 87.3mm stroke.

 

So all the 1.8s are very similar in vital statistics.

 

The honda head is designed from the outset to make good power. You need to take a K-series to the very edge of what's possible to match an Integra head on a flowbench. Don't know much about Zetec heads, but they have the same constraints of valve size that you get on all these undersquare engines. By the looks of it, the 1.8 crank gets an easier life than the 2.0 litre at equivalent revs. To get the same power it will have to rev a bit further and this may outweigh the benefit of the lighter smaller pistons and you might get some vibrations creeping in, but as it is a stronger engine all round this shouldn't be the issue that it is with a K.

 

By my calculations a really well ported Zetec 1.8 should be capable of 220bhp at 7500 rpm, given all the appropriate optimisations of inlet and exhaust tuned lengths, etc.

[Bananaman]

Fo lunch I had an avocado pear with a dressing made from extra virgin olive oil and balsamic vinegar from Modena.

 

You's one posh geezer

[Paul McKenzie]

"Balsamic vinegar from Modena"......fast food!!

[Peter Carmichael]

Should of course have mentioned the Vauxhall with its 86mm bore and 86mm stroke, so not much different to a 2.0 litre Zetec.

 

My conclusion from this is that the 2.0 litre engines have significantly more potential than the 1.8s listed in my last post.

 

The reason there aren't more powerful Zetecs is I am sure down to cost. While the Zetec has lots of potency out of the box, all tuning hits cost breakpoints. The Vauxhall as standard breathes very well. The Zetec also works pretty well out of the box, but many Seven owners have chosen it as a cheap upgrade route from a crossflow and taking the engine further means a sudden step into the expensive world of tuning - porting, big valves, throttle body fuel injection (often turning a carb car into an injection car)... I think this probably means that the Vauxhall XE route of "change the rod bolts, add some cams and she'll be right" is more attractive in the 210-230 horsepower bracket.

[murph7355]

I'm currently having doubts about some big engine plans I had.

 

I'm not convinced I enjoy having any more power than the 190-200bhp in my original car and I'm also not wholly convinced it's so much slower than something with 230bhp in 80% of circumstances.

 

Le Sept made me feel otherwise as there are a couple of circuits we did this year with very long straights, and a 230bhp car (and one or two with more I think) made my mere 190-200bhp feel totally inadequate. I was that wimpy guy on the C4 program about knobs earlier in the week. I would have inherited the earth and I was very despondent about the whole thing.

 

On a wet twisty circuit there was bugger all in it. And the added sphincter factor of ending up in the tyres made one concentrate and work hard.

 

The acceleration is great but as the guy holding the wheel, you very quickly get used to it. The "I want to wet my pants" feeling you get when you first deploy that sort of power diminishes rapidly until it becomes normal. So much so that what you then find is that everything else feels incredibly dull, boring and totally unamusing. You also find that you end up going a tad too quickly on public roads without really realising it. Which for a road car is not good.

 

I've also found a 230bhp car less "fluid" to drive round a track. You end up arriving at corners more quickly, thus you need to brake more quickly which doesn't lend itself to flowing round a track (note to self - this could be because I've had the bigger car a 30th of the time of the other one). This rationale is what makes many say a std. SL is the best bet, but I wouldn't want to give up the extra shove of 190-200, and there-in lies a big problem with searching for power. Once you have even 5bhp more you will never admit to yourself that it's silly and unnecessary.

 

Suspension and gearbox considerations are probably better focused on once you're in the 180-210 zone.

 

The real question is, should I still try for a 280-300bhp Duratec. Or stop being silly and throw some cash at some other sort of metal, keeping a tatty but well loved 190-200 7 for track use.

 

 

 

[AMMO]

I agree with the cost thing. My Zetec was to upgrade an 11 year old Crossflow De Dion. I simply couldn't afford the performance I have now if I had to buy a new car.

 

I'll tell you a little story. I'll try to keep it brief.

 

I recently built a prototype single cylinder motorcycle for an Italian client. The project took a couple of years. It has 60 bhp at the rear wheel and weighs 125 kilos with lights etc. It has state of the art suspension and brakes. No expense spared.

 

In many ways it is similar to a Seven. We even discussed selling it in kit form when it goes into production. It is minimalist in every respect.

 

The client invited some of his friends, all riders of similar abilities, to go up in the mountains with their own bikes to try the single out. Everyone rode it. Nobody could catch it no matter who was riding it. It was gaining approximately 100 metres for every kilometer. Nobody could understand why this should be so, they were all scratching their heads.

 

On paper a GSXR or a 996 has better power to weight. But this thing arrived at corners in such a composed manner, had better corner speed, and was more fluid. Everyone said that it was very easy to ride. It has a top speed of only 125 mph but in these circumstances it reigned supreme. From experience if it had another 30 bhp it would be slower in the hands of mere mortals. It could be faster in the hands of a talented rider but would probably need a lot more work to set up and make it handle.

 

I am sure that I'm pretty slow on four wheels compared to some of you guys out there. Give me another 40 bhp and I'l probably be slower still except for in a straight line. Power, although nice, is not everything. I don't ride motorcycles anymore. Some are so powerful that they just scare me. If you have a lot of power you feel a wimp if you don't use it. If you use it it gets you in trouble.

 

With my car I use all the power available all the time. I know I need just a little bit more to make it perfect for me.

 

AMMO

[caterhamnut]

Andy - I think you have a very good point here

(accepting all the usual quotes about 'the driver' in the following...)

 

As I am sure most of you know, Peter C had 254bhp, in a proven and reliable car - the 'blow-up' was caused by ancillary failure, not engine failure. Since then Peter has put his 'old' engine back into his car whilst the bigger engine is repaired. Peter can tell you the exact spec, but IIRC it is a 1.8 (maybe even a 1.6 actually) with throttle bodies, emerauld, bit of head work etc etc. In other words - very similar to the spec which we want on our 1.6k ss as we start to gradually upgrade. With this is mind, Peter took me out for only 5-10mins (checking some mapping he had just done for idle) to show me what the car was like.

 

I was blown away! I had driven the 254bhp car at Brooklands on that fateful day, been it it once or twice, and followed it (!) many times on the road. Had I not known the engine was different, I would not have recognized that it had about 100bhp less. We were only on an urban dual carriage way, but flooring it out of a roundabout, the car took off. It was sharp, responsive, idled perfectly and was, quite frankly, bloody quick!! Did I - as a passenger admittedly - miss that 100bhp - no. Now I am a known 'bad' passenger, and yes I am used to a windscreen, and yes, the exhaust is louder than ours, so the perception of speed would of been greater to me. So far more telling was Peter's admission that HE had difficulty missing the bhp. Ok - this is on a public road, but his lap times at Cadwell also demonstrate that there must be a plateaux of power, above which the extra is less important.

 

It also shows that it is the other details that are important - not just power.

 

If our car starts to feel like that (accepting it will always be heavier and have clamshells - unless we nudge a tyre wall at Spa ) as we add things like throttle bodies, then I shall be a happy bunny!

 

We want a reliable car for our touring trips, along with track days. I have had useful conversations with Dave A about options, and have come to the conclusion that I am happy to spend a little more - in stages - to get a bullet proof engine with circa. 170-190bhp, than worry about getting 220bhp by spending alot more money. Law of diminishing returns etc.

 

😬27,000 miles in 14 months!

angus@tinyworld.co.uk

[Peter Carmichael]

It is a 1.6.

 

The good times at Cadwell are probably in large part due to running Nitron dampers instead of Bilsteins.

 

I do miss the power on the road, but not really on the track. Weird, huh 🤔

 

Having a powerful engine with an extended rev range let me keep the power in reserve for special occasions without having the intimidation of a bucketload of torque a toe twitch away. To go *really* fast with the big engine you had to hold onto the gears and use the revs. That made it absolutely 100% road usable. As long as I was only using 6500rpm I *only* had a 200bhp engine. Its excellent manners meant it wasn't a problem trolling around in a high gear.

 

The ickle engine works better than I expected. I wrote an article for Low Flying (Banshee Wail) when I first test fitted the throttle bodies to that engine. I said it was good then, even though it was definitely a lash up. If anything, it feels like the other engine on an off day with a killjoy rev limit in place at 7800rpm.