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Discussion Starter #1
Hi,
We have 2 Insights a 50k CVT and a 17k manual.
Prior to buying the CVT we began preparing the manual car for tarmac stage rallies. The car was fitted with an FIA spec rollcage, seats and harnesses and a free flowing exhaust system, and runs the control tyre for our championship, Falken 175/60/14. The only other mods so far carried out are weight related, removal of air bags interior trim rear wiper etc. The car is built to compete in the UK F1000 series for lightly modified 1 litre cars, in which the 16 valve Nissan Micra is totally dominant.

Whilst this car was being built we purchased a Jap import CVT to use as a road car, and after some hard use on demanding roads in the Scottish Highlands began to wonder whether the CVT car would make the better option for competition.

We have competed in 2 rounds of the 2005 championship as a learning exercise and soon realised that the tall overall gearing and wide space between first and second gears were spoiling the potential performance advantage of the hybrid system.

So before embarking on some expensive modifications during the close season, which will include bespoke suspension units, removal of aircon and ABS and uprating of the hybrid system, we decided to do a back to back test of the manual and CVT cars.

Typical format for these rallies are 12 tight twisty stages, each of around 3-5 miles length. On the 2 events we completed we never used higher than second gear.

The test constituted 5 timed laps of a Kart circuit, which included a variety of corners including a slippery chicane into tight hairpin and a fast downhill straight. Both cars used the control tyre , had the same driver, but the manual car retained its exhaust system. The stage length was 3.5 miles. The manual car ran first after a 15 minute warmup and completed the stage in 5 minutes 16 seconds. After a short warmup the standard CVT car completed the same course in 4 min 56 sec an enormous advantage in stage rally terms.

My assumption is that there are two key factors that produce this advantage. The first is that the CVT, in sport mode, finds the ideal gear for any particular road situation where the manual car requires constant up and down changing between first and second gear. The CVT also seems to damp out excessive torque, not allowing the car to wheelspin out of the tight slippery corners. There are obvious durability advantages here in terms of tyres, transmission, and engine abuse.
The other factor that contributes to the advantage is that the CVT allows the driver to quickly find a groove as a lot of effort is not being wasted working out the best use of two unsuitable gears, and as such effort can be devoted to smooth, ideal corner lines, application of the handbrake and anticipating the slight lag inherant in the CVT system.
It will also allow the driver to develop a left foot braking technique to balance the attitude of the car through corners.

This leaves us with the regretable task of having to restore the 'rally'car to road spec and conduct a reverse operation on the CVT 'road' car, and then with all the further mods hopefully kick some Micra bottom in 2006.
After our 2005 forays the Insight is regarded as a bit of an eco-oddity so it would be nice to educate the great rallying unwashed.

Fuel consumption was miles better on the CVT as well, as it was not spending time hard on the rev limiter.......
 

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Hi Paul and thanks for you interesting posts in regard to Insight racing modifications :!: :)

However, multi posting is strongly discouraged on most Internet message boards.

Simply stated it fractures the topic making it harder for members to follow as replies grow.

Therefore your duplicate post in the General Discussion forum has been deleted.

AFAIK your a pioneer in this area of Insight racing. There is an Insight drag car here in the states, but it's the shell only. All the drive line mechanicals have been replaced. There are several SCCA "racers" that visit this board, but it's more of a weekend warrior type of racing. With strict rules and classes in regard to modifications such as you are attempting.

Thanks again for your contributions and I look forward to reading about your successes (and failures) as your one of a kind Insight develops :!:

Sincerely,
 

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I knew the manual Insight was suffering because the gears are so tall and far apart. The fact that the CVT is so much faster is amazing.
There are a number of Insight drivers that compete in autoslalom/auto-x events but as far as I know they all have manual transmissions.
I hope this encourages some CVT drivers to try it.
 

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While it may be an expensive undertaking, modifying the man-trans ratios for racing would be even better :!:
 

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Discussion Starter #5
We are only allowed to do that by swapping the ratios from another standard Honda box.
Any suggestions?
 

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Doubt you'll find one since the Insight's box was designed to be extra light weight. Read: Whatever off-the-factory-shelf the engineers used I believe they further tweaked them to meet the Insight's weight goals.

Still there is a chance, but its going to take a lot of hunting to find a match. :( Obviously you'll need an Insight MT disassembled for gear set dimensional measurements. Then begin the tedious process of the same for different Honda models until you find what your looking for.

Some of these dimensions are listed in every factory service manual, Section 2. With some "book" time you may also be able to identify whether the hands on step even has a chance.

Should you choose this approach the only help I can be (and you may already be aware) is since the Insights predicessor the CRX HF had some similar design concepts. That's where I'd begin followed with the 92-95 Civic VX. Yes, they too were geared "tall" but the differences in the specific ratios _may_ be what your looking for.

But I think its a looong shot. :(

HTH! :)
 

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Do you have to use the 175/60R14 tires?
The Insight has much more grip with 195/55R14 tires.
 

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I am surprised that the CVT is that much quicker. Previously I would have thought the extra weight of the CVT tranny would penalise times and transmission losses on a CVT compared to manual would affect performance too. Plus the feeling in a CVT sometimes that the engine can rev up without the power being immediately put through the wheels. As you say, the shiftless gearing and finding the correct ratio must make all the difference!
 

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Something else to consider, is that from the factory, the CVT Insight makes a few HP less than the Manual.

Something about a focus on emission... If yu are going to race the CVT version, I'd swap the engines around.

Would you be allowed to swap in a different IMA motor? I've not seen them in person but in the drawings it looks like it *MIGHT* be possible with an adaptor to put a 06 Civic's larger IMA motor in (~20hp instead of ~14hp) Of course you'd have to know someone with a CNC shop :)

My $0.02
--Ash
 

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Discussion Starter #10
This test was done on a course that emulates a typical F1000 rally stage ie very tight and technical, where the manual car used only first and second gear.
Had we run the test at a proper race circuit like say Silverstone or Oulton Park I would guess the result would be very different and a lot closer, and the manual could well be faster. May well take the cars to a track day to find out.
 

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Paul
Interesting post.
I have found that the MIMA system with the ability to supply and maintain full electric torque has made a huge improvement in performance through out the full rpm range. With PIMA, the full electric drive can be activated with the throttle just like the standard IMA, but the activation point and ramp up in electric can be adjusted with MIMA to be much more aggressive.
That may push the 5 speed performance past the CVT?
No one racing with MIMA yet, so the jury is still out.
Of course then there is the possibility of pushing the electric motors performance a bit with a higher voltage battery and new controllers. :twisted: :wink:
 
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