TT260 on and Exige

General General Lotus Talk
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Dear Admin5 I know we have spoken before at Bedford but sorry not sure of you real name, I was in the Blue Exige (X111 FLY), the one with the bean can on the exhaust to get it quiet enough for the noise test.Anyway, nuff waffle tell me about the TT260 conversion, got the glossy stuff through the post today but want to know the real story before I even get slightly excited about it.Has yours settled down? Do you have what is basically the commercial offering of today? Or still a development prototype? I know they have only done a few cars but want know if you think main development is over now and that they have a real product not just Supercharged Glossy. Once armed with your thoughts I will then go and grill them about reliabilty, timescales to build the engine etc.etc…Ric

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What with work, other cars etc. I’ve not had much use from mine in the past month or soBut since they opened up the waterways around the block it’s run alot cooler (it was prone to overheating with extended use)As you say, they’ve done 3-4 260TT conversions now, our resident Brannan being one of them. He may be in a better position to give an opinion since he drives his more regularly and wasn’t a prototype car.I should dust the old girl down and give her a thrashing.

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A followup… You inspired me to dust off the Squeege and take her out for a spin yesterday… she’s still running as good as gold… if a little slow compared to the GT2 [image]http://www.exiges.com/ubb/NonCGI/images/icons/frown.gif[/image]

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Thanks,Want more power expecially having been and played at the Nurburgring but just not sure on how to go about it.The Honda engine that Prototype Racing are working on sounds VERY interesting, Nice pics of it on http://www.prototyperacing.com/k20kit.htm The thought of Honda engine reliabilty in and Exige with 240 Bhp of non tweaked power is what the Exige really needs !!Ric

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I’m not so sure about the Honda conversion…It may return 240bhp (20bhp short of the TT260) but it returns a woeful 160 lbs-ft of torque, a whopping 50 lbs-ft short of the TT260, which means it may take a while to wind all the way around to 7500rpm !While std. VTEC engines are solid, I’d be interested to see how long these tuned versions last, bearing in mind that the std KS20A2 returns just 160bhp…

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You may want to re-consider after you take a look at the Dyno chart on my website. www.prototyperacing.com Keep in mind that these are figures for HP and Torque at the wheels, so add about 30 to get the crankshaft numbers. I’ve got some more Dyno time booked this week, and we’ll be doing more ECU work, as well as a few other things to smooth and increase the torque curve. I’ll publish the new charts ASAP.Another thing worthy of mention is that this engine is coupled to a close ratio 6-speed LSD equipped gearbox, so acceleration never lags. How much pressure did TT have to put into the Rover to get 260 HP out of it?

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Well, my comments about the level of tuning still stands. More accurate at-the-crank figures would be useful. quote:How much pressure did TT have to put into the Rover to get 260 HP out of it? Pressure as in boost, or are you asking about compression ? Either way… TT have the answers for you.Still, I’d be interested to know how much torque the engine achieves, and how it fares over say 15,000 miles.Good luck with it.

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Isn’t it a bit strange that you question the reliability of a mildly tuned Honda engine while you drive a heavily modified Rover? 15000 miles is nothing BTW. No offense, but measuring reliability over 15000 miles tells me quite a lot about what you’re used to in terms of reliability…I do agree about the torque, ofcourse a pressurised engine will produce a lot more torque than a normally aspirated one. However, i really don’t believe torque is the key to accerating a car as light as the Elise/Exige. IMO, the heavier a car, the more torque you need to get the thing moving.Soon my Elise will be fitted with the Prototype Racing K20A kit. I’m real curious to see which is faster - your Exige or my Elise… but i’m pretty sure about which will still be running strong after, say, 100000 kms. [image]http://www.exiges.com/ubb/NonCGI/images/icons/wink.gif[/image]PS: it’s pressure as in boost…

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**** Quote However, i really don’t believe torque is the key to accerating a car as light as the Elise/Exige. IMO, the heavier a car, the more torque you need to get the thing movingErrrm - correct me if im wrong but…torque is possibly the MOST important factor as it is the torque that provides the acceleration!! Power figures are the result of torque at a particular RPM so without torque and revs you don’t develop the power…Regards,Steve M

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quote:Isn’t it a bit strange that you question the reliability of a mildly tuned Honda engine while you drive a heavily modified Rover? Not at all… The only reason, I can see, for going the Honda route over a TT supercharger would be reliability… And while standard Honda units are usually very solid, it would be defeating the object to go down the tuned Honda route if the tuning made it less reliable. Don’t get me wrong, if the Honda conversion turns out to be rock solid, delivering huge amounts of torque (sorry, but torque is important) then I think it’s going to be great for the Exige community. So calm down, and take a pill.(Boost on the TT260 is 0.7bar)

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Please read the info provided at www.g-speed.com/pbh/torque-and-hp.html It should clarify this issue quite well. I think everyone will agree that F-1 cars accelerate quite well. It only takes 210 Lb/Ft of torque to make 720 HP at 18,000 RPM. It may not be the best example, but torque AND HP both play an important role in rapid transit.HP = Torque X RPM divided by 5252

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Joe, it felt great reading that article on torque vs power. I’ve never come across such a good description of the subject. I’ve basically figured it out for myself from bits and pieces over the years, and it’s good to see it written this way just to confirm for myself that I’ve actually got it right.Thanks [image]http://www.exiges.com/ubb/NonCGI/images/icons/smile.gif[/image]

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quote: It may not be the best example, but torque AND HP both play an important role in rapid transit. Kinda sorta. As HP is a function of torque and RPM, a weak torque engine is pretty much reliant on being able to wind all the way round to silly RPM (as per the F1 example) to get the power.The Ferrari F355 is a great example of how on paper 380bhp sounds great… but the car has really poor torque, meaning you have to wait forever for it to wind it the way around to 8500rpm to reach peak BHP.Give me a lower revving (say 7000rpm), punchier torque car than a high revving (say 8500rpm) lower torque car to achieve the same BHP.[This message has been edited by Admin5 (edited 25 October 2002).]

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I guess ultimately what it boils down to is a matter of taste… Personally i don’t like idea of a car as light as an Elise/Exige with gobs of torque… I prefer a flexible, high revving racy engine…Roadkarter: i didn’t say torque doesn’t provide acceleration - ofcourse it does. What i meant is simply that i don’t believe a light car needs that much torque. Admin5: pill taken - calm now… got a bit carried away i guess (i’m a bigtime VTEC fanatic…). I’ve seen 1.6 VTEC engines produce over 200 hp and go for 200000 km without any problems. The idea of a VTEC engine behind me in my Elise has been a dream of mine for years, so i almost took it personal when you questioned the reliability of Hondas [image]http://www.exiges.com/ubb/NonCGI/images/icons/wink.gif[/image] I just have my doubts about a pressurised Rover… apart from the power output i haven’t heard too many positive things about the TT conversion…BTW; if you’re interested i’d be happy to let you drive the conversion once it’s done. I hope to come over to the UK sometime in 2003.