Popular Post Dommo Posted May 20, 2020 Popular Post Share Posted May 20, 2020 I've just popped this on my blog but thought it might be better served here to generate some well mannered lock down debate. Or name calling, any kind of interaction will do nowadays! It will possibly be a bit patronising in places as we already know what Westfields are like, so apologies for that. My thoughts on owning a ‘big power’ Westfield With a few years of a 340bhp Westfield under my belt, I’ve found myself more and more hinting others against such levels of power. I did have the word “advising” rather than hinting in there, but that’s not fair as I don’t think a big power Westfield is a bad thing. Quite the opposite, in fact. It’s just a very different thing to when it was a middling power Westfield. Given that I’m strongly considering a rather dramatic change of direction for my car, I thought it best to write down my thoughts on what it’s meant, even if just for my own benefit. I’ll approach a few of the more popular themes when someone mentions a rather silly bhp for a Westfield “It’s a handful on the road” Well, I suppose if it’s a track only car, which mine has been for a couple of years, that doesn’t really matter. However, when it had an MOT, it was a fantastic road car. I never had to change gear to find a higher speed, just ride the massively flat torque curve. It’s a ridiculously docile car which, aside from a slightly grabby clutch (more OEM feeling ones that handle the power are available), could probably be driven by just about anyone. It’s about the furthest from a handful that you can get. What you can’t do, however, is work it on the road. It is far too quick for us mere mortals to be aware of hazards, correct the car over any bumps, change gear, process what’s going on around you, have to change gear again and even by the time you’ve read this, you’re significantly above any speed limits or indeed speeds where you’d survive and accident. To that end, it does stop being a Westfield, and become the world’s smallest GT car. Great and smoothing out the corners and cruising up to the next one with the gentlest of squeezes of the throttle. Thoroughly dangerous when deploying all of the horses. This is not a bad thing. In some ways it’s positive because you tend to drive slower and smoother, and you already know that you genuinely are the fastest thing on the road and have nothing to prove. The person with a 150bhp Westfield accelerating hard for 15 seconds between corners might be having more fun though. “You can’t keep it cool” More power, more heat. More revs, more heat. Can’t really escape that one. A Westfield also doesn’t have a lot of ways of getting rid of that heat. The bonnet opening is filled by a radiator originally specced to cool a 1.0 Polo. Now we’re trying to use the same area to cool a power output a comedy factor more than said Polo. This is where you spend your money. The radtec radiator/intercooler combo was the single biggest investment in the turbo projects and it’s fulfilled its role beautifully. These are the coolant and intake temps recorded over a track session that must have had 26 minutes of full speed work. That was on one of those rare summer days with actual sun as well, so mid 20s plus the sunshine baking the tarmac. Those peaks are within 1.5 degrees of each other – to handle that for all that length of time is particularly impressive. Though of course, I deserve more praise for staying out there that long. I’d say one of the benefits of having a large amount of power is also that you can afford to lose some. My engine runs a tiny bit rich precisely to provide a little bit of cooling assistance. “Turbo engines are laggy, peaky and difficult to drive” You tend to see these comments from the older generation, and that’s fair enough… they’ve driven 80’s turbos and, frankly, they’ve earned that opinion! None of it holds true nowadays though. The very modern turbo engines are impressively responsive. I think the only criticism you can throw at them nowadays is they don’t tend to rev that high anymore. My car sits in the middle of those two extremes. It’s not laggy, it’s not peaky and it’s easy to drive. It also revs to 7.4k and makes power all the way there. But it’s not as responsive as something like an EcoBoost when lower in the rev range. Fine on track, but I do think it would be a bit frustrating on the road. Then I suppose, we’ve already decided that the throttle is to be used sparingly on the road. Also, is it any worse than an N/A engine with cams aimed for top end power? Back to throttle response on track, it’s fine. You don’t wait for the power to come in. You don’t wait for the boost to build. It’s all there if you ask for it. Take the following graph of throttle position (blue), boost (red) and RPM (beige?): This shows the entry into a chicane, balancing the throttle through it and powering out of it. The throttle has been off for 4 seconds before this, suggesting I’ve caught a car up and it let me past on the exit. You can see the first input into the throttle produces an instant response from the turbo, and this is from 3.3k rpm so reasonably low for track work. This tracks the throttle position until the second application, where by the turbo responds again but is held back once it reaches the actuator level. Here, because the RPMs are in the mid range, the boost level is reduced to manage that massive lump of torque turbos like to give. Perhaps the reason they’re often described as peaky. The boost is now following a rising limit to keep the torque curve as flat as possible. At the gear change, the throttle is off 100% for 0.5 seconds. The boost follows this, taking 0.6s to achieve 21psi again. Which yes, is higher than it was originally set but crucially, not higher than it has been mapped for. Either way, I think that’s plenty responsive enough. So what do I think? Big power doesn’t ruin a Westfield. I’m 100% confident in that. What it does do though, at least for mere mortals, is change it. I’ve found that corners on track are mere obstacles to be cleared ready for the next application of power. Get the car slowed down (no mean feat!), turn in, get it roughly near the apex, balance the throttle, wait for it to straighten out, then deploy the power down the straight ready for the next corner. It’s made me lazy in many respects. On a sequence of close together corners or chicanes, I won’t be taking stabs of throttle between them. Just a gentle squeeze to smoothly get me to the next one without arriving too quickly and giving myself too much to do. Quite the difference to when I had 150-160bhp on throttle bodies. I suppose in that respect it’s ironically safer on track as you don’t tend to go hunting for those extra tenths. You don’t need to. It’s probably quite telling that since fitting a turbo, I’ve never spun on track. I’ve gone straight on at corners more than once! But never spun it. There is only ever one thing quicker than me on a track, and that’s a lighter, less powerful Westfield/Caterham. They’re usually on slicks, so a more serious effort than mine, but typically 100bhp or more down on me. And if they’re quick enough to catch me up despite the deficit on the straights, it shows how much I waste through the corners by not applying the throttle or pushing the car. Which isn’t speed I’m wasting, it’s fun and personal reward. I’ve had a lot of fun with my Westfield, and I don’t regret any of the options and even at my most modest I think I’ve done a really good job of breaking the 300bhp barrier in the right way. Even if I never actually meant to. But I’ve had my fun now, and it’s time for a change. For a long time now I’ve wanted to build another, knowing what I’ve learned over the last 7 years. So I’m going to rebuild this one, with less power, and more revs, and less weight, and more noise. Goodbye gentle beast. Hello bl**** idiot. That’s an RX-8 231 engine. It’s going to rev to 10k+, it’s going to breathe fire, it’s going to drink fuel like it's a water wheel and confine me to the noisy step on track days… and every now and again… it might even work! 32 Quote Link to comment Share on other sites More sharing options...
Chris Broster - Bristol & Bath AO Posted May 20, 2020 Share Posted May 20, 2020 Fantastic article and thanks for the honesty! Certainly makes you think about the never ending quest for power... or is it speed.... or is it fun? 2 Quote Link to comment Share on other sites More sharing options...
Andrew O Byrne White - Ireland AO Posted May 20, 2020 Share Posted May 20, 2020 37 minutes ago, Dommo said: So I’m going to rebuild this one, with less power, and more revs, and less weight, and more noise Knew the next thing I was going to see was "RX8" as soon as I read this sentence... Interesting read, but something I've suspected for a while. I've been saying to my friends, that I love my 1.6 mazda engine as it is right now. I didn't build it as a car for straight lines, it's for corners. Going through twisty roads around Europe, I was never lacking the power to safely overtake, or seriously craving more power. Maybe a different story when I get to take it on a track. When it feels like that's not enough, it'll get a supercharger, but only seeking 180bhp max. If that ever dies, or feels like it's not enough, RX8 engine would be going in there. I reckon the character of those suits a car like this really well, although it'll take me many more years of Westie ownership to get to the point where I'm at the level on the "mere mortal" scale that can enjoy the amount of power one of those puts out! Quote Link to comment Share on other sites More sharing options...
AdamR Posted May 20, 2020 Share Posted May 20, 2020 Great, balanced, informative write up, thanks! I am perhaps a little "biased" but that 0.6s back to full boost sounds like an age. I've also spent considerable time in a couple of very advanced, modern turbo cars (a fair bit of that on track) and the lag does my head in from a "performance driving" point of view! The noises are cool though 😄 The new lump should suit the car well, and they seem to be reliable as long as they get regularly thrashed. Look forward to build updates! Quote Link to comment Share on other sites More sharing options...
Steve (sdh2903) Posted May 20, 2020 Share Posted May 20, 2020 What's the weight of the w**kel? What ecu will run it or can you get the oem one to work? Sounds an interesting project Quote Link to comment Share on other sites More sharing options...
Steve (sdh2903) Posted May 20, 2020 Share Posted May 20, 2020 see the swear filter doesn't approve of your engine choice 2 Quote Link to comment Share on other sites More sharing options...
Dommo Posted May 20, 2020 Author Share Posted May 20, 2020 1 hour ago, AdamR said: Great, balanced, informative write up, thanks! I am perhaps a little "biased" but that 0.6s back to full boost sounds like an age. I've also spent considerable time in a couple of very advanced, modern turbo cars (a fair bit of that on track) and the lag does my head in from a "performance driving" point of view! The noises are cool though 😄 The new lump should suit the car well, and they seem to be reliable as long as they get regularly thrashed. Look forward to build updates! It does include closing and opening the throttle again rather than foot down and full boost arriving 0.6s later...but you're right, if someone is more used to a "stabby" throttle then that's a sure way to show up more than an enthusiastic but not brutal gear change. 50 minutes ago, Steve (sdh2903) said: What's the weight of the w**kel? What ecu will run it or can you get the oem one to work? Sounds an interesting project I did weigh both engines in the same state of dress (well, very nearly). MX5 engine including alternator, loom, flywheel, clutch, manifolds, turbo, downpipe came in at a surprising 144.2kg. The RX8 engine in similar state but without exhaust manifold was 126.7kg, so all in probably 15kg lighter. They're not spectacularly light, distinctly average on that front. The weight is concentrated lower down and shorter in length than a 4 cylinder engine so I'm sure someone better than me could notice the weight distribution change! I've got the RX-8 engine loom attached and unlike the MX5 loom it's quite a tidy affair. I think I'll probably reuse it which lends nicely to either the RX-8 ECU or a plug-and-play aftermarket effort. 1 Quote Link to comment Share on other sites More sharing options...
NigelO Posted May 21, 2020 Share Posted May 21, 2020 How many times have we read "there's no such thing as too much power"? - well, I agree with @Dommo - huge power can be extremely entertaining, but it can sometimes change a car to the point where it's less enjoyable as a package. I have a similar story.... I have a bit of a "thing" for the Fiat Coupe, especially in 20 valve turbo form. After my first relatively standard example (tweaked very slightly to 240bhp), my second and then third somehow fell onto the very slippery slope of chasing power. Thankfully, I also had the presence of mind (and hefty credit card limit...) to also put in lots of effort into the chassis, so at least it was capable of handling the power. In the end, I temporarily broke the 500bhp barrier, before winding it back slightly to 488bhp (one more than a Ferrari F40!!). It is ballistically fast - 0-100 in 9 seconds, 0-150 in 19 seconds, or more impressively - 60-120 in 7.5 seconds! and on to something in the region of 190mph (it's geared for 205!) However, the performance is difficult, if not impossible to enjoy anywhere on the public road - by the time I'm getting a buzz, I'm at speeds that would result in a custodial sentence if caught. Basically, I've spoilt the car. It was great fun at 350-ish bhp, but I stupidly carried on. Partly because of the inability to enjoy the full potential of the Fiat and partly because I wanted something I could tinker with (there's nothing left to do on the Fiat), I bought my Zetec-powered Westie. 170bhp is fine most of the time - I very rarely find myself wanting more power and I just make sure I drive on roads where 170bhp is more than adequate (ie the many enjoyable Peak District outings...) One of the endearing factors about Westies (and their owners) is that no two are alike - each car is a reflection of its owner and is all the better for it. After only a couple of years of Westie ownership, I have realised that there is almost certainly a "sweet spot" for power, which results in a great blend of accessible performance and fun, without spending a small fortune to only be quicker along the straights (which as we all know, are only there to join the corners up...) It will be interesting to see what rotary power is like in a Westie - I expect it will suit it well - watching with interest! 2 Quote Link to comment Share on other sites More sharing options...
Greenstreak-Andy D Posted May 21, 2020 Share Posted May 21, 2020 37 minutes ago, NigelO said: One of the endearing factors about Westies (and their owners) is that no two are alike - each car is a reflection of its owner and is all the better for it. After only a couple of years of Westie ownership, I have realised that there is almost certainly a "sweet spot" for power, Brilliant! I share both of these sentiments. Just have a new to me mega S2000, my 3rd Westie. Unfortunately only driven 30 miles back in January, but I hope is ideally suited to my intended use. Let’s hope it will have some use this year! Keep safe everyone Andy 1 Quote Link to comment Share on other sites More sharing options...
TableLeg Posted May 21, 2020 Share Posted May 21, 2020 Let's not forget that these are Kitcars, and as such not all of them are bought, many are built. Some people (myself included) enjoy the building as much, if not more than the driving. Being able to modify parts of the build, upgrade parts etc for many is part of the fun of owning such cars. The fact that I opted to build mine with an engine uncatered for by Westfield for me was the challenge and a V8 was always going to produce lots of power and torque but for this build I wanted a V8. I share your view on Turbo cars of this type though, my last build had a highly tuned Cosworth Sierra engine and when it came on boost it got lively. 50-100mph recorded at 3.2seconds! 2 Quote Link to comment Share on other sites More sharing options...
Mole Posted May 21, 2020 Share Posted May 21, 2020 Interesting... What are the two temperatures on the graph..? And where were the sensors? Quote Link to comment Share on other sites More sharing options...
TAFKARM Posted May 21, 2020 Share Posted May 21, 2020 I knew you’d be on this topic @Mole Whats your opinion? 😄 Quote Link to comment Share on other sites More sharing options...
Mole Posted May 21, 2020 Share Posted May 21, 2020 Russ... Well like many have said before I think there is a sweet spot on a Westfield for power.. and maybe a naturally aspirated engine feels natural to me.. I think having 280 - 320 bhp would be a nice sweet spot... Especially for track use.. When you get yours back on track I look forward to seeing if that is correct! What do you think..better with less? Quote Link to comment Share on other sites More sharing options...
TAFKARM Posted May 21, 2020 Share Posted May 21, 2020 12 minutes ago, Mole said: Russ... Well like many have said before I think there is a sweet spot on a Westfield for power.. and maybe a naturally aspirated engine feels natural to me.. I think having 280 - 320 bhp would be a nice sweet spot... Especially for track use.. When you get yours back on track I look forward to seeing if that is correct! What do you think..better with less? 220-250, but I’m a better driver than you. Definitely more than 190. Quote Link to comment Share on other sites More sharing options...
Andrew Posted May 21, 2020 Share Posted May 21, 2020 I reckon for trackdays the sweet spot is around 200bhp. Obviously for any competition, more is better. But, big power on trackdays will just see you blitz the straights, catch up something slow then have to trail round the twisties behind it .. you'll be catching slower cars more frequently and doing a lot of following.. Much better wringing the neck of 170bhp. 😉 Back to the OP. Rotary engines are usually pretty loud.. will need some serious silencing for trackdays? Quote Link to comment Share on other sites More sharing options...
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