A tiny (398kg) car that'll leave a 600 super bike behind...

PeterPan

Torque Junkie
Points
172
Location
Northwich Uk
Car
SECMA QT-R1000
That's the goal...

Hello to all, I was searching around for ideas on the net and stumbled on this site and decided to register and share what I've just started creating and ask for ideas/input etc

The donor car is a SECMA 'QT500' aka 'FUN500'

diapo3.jpg


Quite a rare little car in the UK, great fun to drive but somewhat underpowered to be used on the roads, where we have things like tractors, caravanists and of course nervous "Captain carefull" who always seems to be in my way on a lovely country road on a sunny afternoon...

Much as I enjoyed driving my quirky little toy car for most of last summer, I decided that it really needed more power to be able to overtake safely.

After some research it became apparent that the factory engine (only 21bhp) was not going to be able to produce the 50 or so horsepower I felt in needed to transform the car's lacklustre performance.

So, ok new engine. Many hours thinking, researching later I found a company to whom I would entrust the heart transplant. Zcars.

I was thinking of something fairly mundane like perhaps an engine from a HONDA CB500 but two things happened after Zcars' suggestion of an engine and sequential box from a GSXR1000.

Firstly I realised that the largest portion of expense would be the bespoke fabrication work and therefore the engine choice was largely irrelevant and secondly I spoke my insurance company to discover that this little modification would put my insurance up by a mere...

Let's just say I was happy with their quote. So anyway enough waffle.

Final specs are yet to be decided and I guess that's why I thought I'd share, ask some questions and get some feedback. At the moment it's looking like a 1000cc GSXR1000 engine, sequential gearbox and custom gearbox/LSD arrangement (final drive undecided).

ENGINE
  • Type 4 stroke, liquid cooled, 16 valve, DOHC, TSCC
  • Cylinders 4
  • Bore 73 mm
  • Stroke 59 mm
  • Displacement 988 cm³
  • Compression ratio 12.0:1
  • Fuel System Electronic fuel-injection
  • Ignition Computer-controlled digital electronic
  • Air Cleaner Non woven fabric element
  • Starter system Electric
  • Lubrication system Wet sump

GEARBOX
  • Clutch Cable operated wet multi-plate type
  • Transmission 6-speed constant mesh
  • Primary reduction ratio 1.553 : 1 (73/47)
  • Gear ratios 1st 2.687 : 1 (43/16)
  • 2nd 2.052 : 1 (39/19)
  • 3rd 1.681 : 1 (37/22)
  • 4th 1.450 : 1 (29/20)
  • 5th 1.304 : 1 (30/23)
  • 6th 1.208 : 1 (29/24)
  • Final reduction ratio 2.470 : 1 (42/17)
  • Drive chain DID530, 110 links

Other upgrades planed (to help tame the power hike)
  • Wider wheels (6.5J)
    Wider tires (175/60/13 to 195/45/15 AVON CR500s)
    Bigger cycle guards to cover the wider tires

Brakes (discs all round) are from a Peugeot 106 I believe and in theory should still be well up to the job of scrubbing off speed from the little featherweight toy car.

The guys at Zcars have mentioned a distinct probability that the finished car will out accelerate a 600 super bike! Perhaps not all the way to 170+ but at that speed I'd rather be on the bike think!

Anyway, love to read some comments.
PeterPan.
 
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old-git

Moderator
Points
657
Location
Essex
Car
Elan & Robin Hood
Hi and welcome

Neat little car. However 50bhp in a 394kg car won't get anywhere near any 600cc bike. You are looking at around 0-60mph of 13 seconds or so. 150bhp will get you to 60 in around 5 seconds.

You need to either lower your goals or increase your power :)

Are you sure the guys at Zcars were talking about a car with 50bhp?
 

obi_waynne

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Interesting, not seen one of these before thanks for sharing it with us, they look like fun cars to drive. It's a sort of go cart with a roof and other proper car bits! I bet they are fun in the wet.
 

PeterPan

Torque Junkie
Points
172
Location
Northwich Uk
Car
SECMA QT-R1000
Hi and welcome

Neat little car. However 50bhp in a 394kg car won't get anywhere near any 600cc bike. You are looking at around 0-60mph of 13 seconds or so. 150bhp will get you to 60 in around 5 seconds.

You need to either lower your goals or increase your power :)

Are you sure the guys at Zcars were talking about a car with 50bhp?

Hi Steve, the heart transplant that's planned is a GSXR1000 (191bhp), the point about 50hp was that it was my feelings that it really needs around 50hp to be that bit more useable, but after a conversation with my insurance company I decided... "Screw it, put something silly in there!"

The GSXR engine was suggested by Zcars, my thoughts were that 50hp would do to give it reasonable performance, GSXR1000 will be bloody loopy! But when I got the price from the insurance co. for the GSXR I thought, screw it why not have something silly! It was Zcars who suggested the high probability that the GSXR lump would result in performance that would likely leave a 600 behind!

I guess we'll have to wait and see!

Primarily I want it to be fun to drive!
Not intimidating or too much of a handful to enjoy, just fun.
With that engine it'll be very fast be default regardless.

Because the original engine and gearbox are going to be junked it'll probably end up with a weight of 370kg and power to the rear wheels of around 175(ish) I would think.

It handles like its on rails and when you do throw it into a corner too hard deliberately and it does let go its got so little weight and such low centre of gravity it's beautifully balanced. In the wet it can be very VERY scary!

Last year I was running it as my only car, and whilst I only tended to use it in the dry (walk to work most days) there was an occasion I was running late for a date and decided to take the motorway in HEAVY rain as the A-roads were so sodden and that was frightening! Anything above 50mph meant aqua-planing!

A very scary drive! I'm hoping that CR500s will help with that.
Anybody have experience with those tires?
 
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old-git

Moderator
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657
Location
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Car
Elan & Robin Hood
Ah, that's more like it :)

With 191bhp, you should be looking at sub 4 seconds to 60mph, as long as you can get the grip.

With a car this light, suspension set up will be critical if you want to get anywhere near this sort of performance. Damper and spring choice/set up will be the deciding factor.

Look forward to seeing progress updates.
 

PeterPan

Torque Junkie
Points
172
Location
Northwich Uk
Car
SECMA QT-R1000
Suspension set up currently is double wishbone suspension with coil overs all round, I'm the first one to admit that when it come to suspension set up my knowledge is quite limited so any advice would be gratefully received.

But yes I concur, getting the power down will be the biggest challenge.

I can get wider wheels and cycle wings but the biggest I could go (and still keep it looking close(ish) to the original design) would be to go to a 225 section tire. However after doing some research I chose the Avon CR500 as there seems to be a consensus that it is the best wet tire available.

Am I likely to get that much more grip from a 225 over a 195?
225 is the biggest that I can get under the wings but then what tire choice?
 

old-git

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Elan & Robin Hood
You might want to check with the car manufacturer as to how wide a wheel/tyre combinaton the existing suspension parts can handle. With the orignal car being built with low weight in mind, I doubt that there is much in the way of excess strength in the suspension components. Wider tyres exert more stresses on bearings, struts and mounts.

Wider tyres don't increase the contact patch area, just alter its shape, making it wider but narrower back to front. For example, if a 195 tyre's patch is roughly 195x100 this gives an area of 19500mm2 (this is just an exercise, I have no idea of the actual contact patch size and they aren't retangular, more oval).

If you increase the tyre's width you don't increase the contact patch area. So increasing width to, say, 225mm will give you a patch size of 225x87.

Wider tyres do, however, increase the actual available grip, which seems to fly in the face of conventional school physics. This extra grip is achieved, in part, due to the tyre's surface not being rigid so it is able to take up the shape of the road surface. This results in more tread in contact with the road surface at any one time giving better real world grip.

With wider tyres the cooling cycle is improved so, in theory, softer compounds can be used resulting in even more available grip, but this is unlikely in conventional road tyres.
 
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T9 man

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??? My OP has been deleted ???

Note to PeterPan.

Our rules clearly state buddy that new members need to have made 10 posts FIRST before they can upload any photos or URL's. Your posts got stuck in the moderator queue for this very reason. I have made an exception in this case and allowed these through, but I would appreciate it if you would wait until you have reached the required 10 posts before posting any more. ;)

T9 man
Super Moderator.
 

Yugguy

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Rugby (expat Preston lad)
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Hey OG. How does a wider tyre not have more contact area? Why does its other dimension get smaller? Not doubting you, I just can't picture why an increase in width would mean a decrease in length?
 

TCJBOLDIE

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Hey OG. How does a wider tyre not have more contact area? Why does its other dimension get smaller? Not doubting you, I just can't picture why an increase in width would mean a decrease in length?

Same weight over a larger area = less weight per square inch of the contact patch.
 

old-git

Moderator
Points
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Location
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Elan & Robin Hood
The size of the contact patch is determined by weight of car and the air pressure in the tyre.

If the car weighs 1000lbs and the tyre pressure is 25psi you will need 1000/25 square inches of contact patch to support the car = 40 square inches spread over 4 tyres = 10 square inches per tyre which is independent of the tyre width.

This works pretty well for tyres of the same make and specification. However, due to many other variables (side wall stiffness, tread compound, tyre construction,etc) the contact patch doesn't stay exactly the same area when comparing different tyrers, it can vary by around 10-15% in both directions.

This is my take on it anyway.
 

Hansi

Track Warrior
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Bifröst, Iceland
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Getz GLS 1.6
That is an interesting project. I've been working on schematics myself for a lightweight high output car for the dragstrip and this is giving me some good ideas.

Looking forward to seeing this project evolve
 

PeterPan

Torque Junkie
Points
172
Location
Northwich Uk
Car
SECMA QT-R1000
Love the idea of the car for tracks and the like but you're a braver man than I am driving that on a motorway! (;->

I get your point but its no more dangerous than riding a motorbike, apart from perhaps the lack of bike leathers and a helmet maybe...

Driving on the motorway in the dry it was OK, apart from the 65mph top speed!

No that is not a typo, as standard the the QT500 has a top speed of 65mph flat out! And any kind of hill means that's lower still.

Hence my decision tha it really 'needs' a bit more power to be more useable, 50hp would mean you could get up to 60 reasonably quickly and cruise a 70 without too much issue.

But no matter, that path is set and insane loopy loo performance will be the end result IF I can get the power down effectively.
 
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PeterPan

Torque Junkie
Points
172
Location
Northwich Uk
Car
SECMA QT-R1000
That is an interesting project. I've been working on schematics myself for a lightweight high output car for the dragstrip and this is giving me some good ideas.

Looking forward to seeing this project evolve

If the car is finished in time I'd like to be at USC held at Santa pod held first weekend in August, that could be fun.

Lots more little tweaks planned for the car before it's 'finished' but it all starts with the heart transplant!

Here are a couple more pictures now that I can post them :lol:

Here are a couple for size comparison...

This is how I collected the ca from previous owner and transported it back home...
image1.jpg


This one, just for size reference...
image2.jpg


And here's one the proves that even a tiny little car can also be practical!
image3.jpg


And here is one of the best modifications made so far!
image4.jpg

Seats re-upholstered in leather with contrast stitching, courtesy of KJR TRIMMERS in Middlewich, there handiwork is very very good, so much so that full interior retrim will be on the cards for next winter when my little car goes back into hibernation and I have buy something boring to drive until the spring :lol:
 
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PeterPan

Torque Junkie
Points
172
Location
Northwich Uk
Car
SECMA QT-R1000
Not much of an update yet, but progress nonetheless...

Original engine and gearbox are now out of the car and final specs have been decided upon!

Engine and sequential box will be GSX-R1000, mated to Zcars own LSD/chain drive conversion (fwd/rev) gearbox, New swing arm/suspension set up with new shocks and springs set up, track will be widened to accommodate stronger half shafts and improve handling. Original Mudgaurds will be junked and replaced with these
51_1.jpg

To accommodate wider wheel/tire set up.

Next step; source the engine/gearbox and decide on brand new vs. reconditioned.
Awaiting an email back from Suzuki with a price for a brand new one. Although Zcars did say that used motors from the GXS-R1000 tend to be very good, strong reliable units and that also if I decided to replace the unit for a brand new one at a later date it is probable that the modifications required would likely be very small indeed as most bike manufacturers tend to vary their frame mounting mounts very little from year to year.

Will post pics as soon as further progress has been made. :smile:
 

PeterPan

Torque Junkie
Points
172
Location
Northwich Uk
Car
SECMA QT-R1000
Hey guys,

Remember me and my ridiculous little toy car..?

20130604-115941.jpg


Well the project had to be put on hold for a couple of months, but is now progressing again. Zcars came up with the goods!

They found the right engine (2003 K2 generation I think) GSX-R1000 engine, loom and full dry sump set up at a great price. Although an older engine this generation are apparently one of the strongest units built for the GSXR and are well suited to such conversions. Anyway, so that's now been purchased and things are moving forward again at last...

Time frame has had to be adjusted because my lottery numbers still haven't come in! :(
But it's moving forward now nonetheless and that's the important thing...
Realistic time frame to completion is now looking like spring of next year.

Look forward to posting some further updates soon :)
 
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PeterPan

Torque Junkie
Points
172
Location
Northwich Uk
Car
SECMA QT-R1000
Perhaps the only other thing I've decided upon is to keep the car looking standard for now, going to stay with original wheels and cycle guards but upgrade the tyres.

Going to go with a set of Michelin TB5 tyres...
Michelin-TB5R-Tyres.jpg


I was going to go ultra wide, but when I did some research I looked at cars like the caterhams and even ariel atom use tyres that are 195 section!

So decided that with semi slick TB5's in softer compound 185/55/13 should provide sufficient grip and keep the car looking standard to the untrained eye :)

Anybody use these?
I've found nothing but rave reviews so far!
 

old-git

Moderator
Points
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Location
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Elan & Robin Hood
These are the tyres that I plan to use. My MOT station said, despite the tyre being DOT marked, they would fail the tyres as they don't conform to section 4.1 that states that the tread must extend across 3/4 of the tread width, which is defined as that part of the tyre that is in normal contact with the road.

I have discussed this with the DVSA and now have a letter confirming that the tyre is considered to be legal. They recommend that I keep a copy of the letter, along with photo of a new tyre, to show to any interested parties :)
 

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