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65 miles per gallon! 
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Part built GTM

Joined: Thu Jun 19, 2008 2:02 pm
Posts: 78
Post 65 miles per gallon!
dear god in heaven!
right, another one from your man in manchester.
i WAS getting a consistent 60 mpg on runs to and from manchester to surrey.

so at xmas i put in a new carb main jet in my hif44 (the old main jet was worn oval).
and ive now got a really good magnet in my distrubutottler that has the four magents at exactly 90 degress to each other.
so my mixture better and my sparkage is spot on.

65 mpg or more to surrey at easter!! i was shocked
i was using so littel petrols .

here is your recipe for fuel nirvana

1. potter aboot.
2. narrow dunlup eco tyres. im on 165s but will go to 155 s at next change.
3. make sure your carb is not worn
4. short cam - mines a kent 246 - well its a minispares wossname which is a kent 246
5. do the spark mods ive outlined elsewhere - you can ignite a weak mixture better
6. fit a HUGE pulley on your alternator - fart a round for days with alloy ones that are not meant for it
i did . now look a GTM is very sleek. so at 55mph its maybe using 3 horsepower. cut 0.3 of a horsepower by running your alternator with a huge pulley
thats 10 % . i know im right - dont care what you think. :-) ;-) 750 watts is one horsepower
7. 3.2 or 31. final drive or lower
8. big pulley on the water pump - see point 6 above.
9. run your motor LEAN - how did i do that? basically the car must NOT run correctly until its fully warmed up.
so if your engine has not run for 7 miles and you CAN drive without the choke. its not lean enough.
10 . for some reason at pottering speeds (2000 to 2500 rpm) i can sort of tell that its really lean. thats the needle. its always been that way with my 1275. nice
11. if you run a thickish oil in the dashpot the fact that you are sort of lean at cruise DOESNT MATTER - it will sort of be ok on acceleration. im using 20 / 50 in the dashpot
12. do some aero mods - ive blanked off a lot of the front to force the air under and over
13. steal a huge plastic estate agents sign and fit it under the front subframe. smooth the air under the body. you need some flow for the radiator - its a balance
14. get the clear plastic covers for the front headlights
15. my huge ram pipe (6inches - no mini ever had a straight 6inch ram pipe) pokes into the boot and gives me huge torque low down so you can stay in a lower gear - sure i talked about it before

when i hit 65 mpg (got to dorking surrey via sutton from whalley range with more than half a tank left its more like 75 mpg but you wont believe that) i thought - junk the 1275 and get a 998 - and go for 80 mpg.
still debating that one as ive got the wide ratio box in the wings to make her accerate hard .

155 tyres and a 998cc engine - jesus christ! where will that go on one tank of fuel??
7.5 X 80 mpg = 600miles!

best wishes to you gtm daily drivers.

get those mods done - thats why you drive a kit car for gods sakes!


Mon Apr 16, 2018 10:21 pm
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Part built GTM

Joined: Thu Jun 19, 2008 2:02 pm
Posts: 78
Post Re: 65 miles per gallon!
and with huge pulleys you just dont need a tight fan belt
it can be looser.
cos the force times distance is totally transformed.
im not saying you SHOULD run aloose fanbelt with big pulleys - just that you can.
all the stuff ive talked about on this furum ive ran for hundreds if not thousands of miles
with no issues
and im heating my carb with hot water pipes all round it cos my carb has always been far too cold.
ive talked about that before.
so i think warm carbie may help with economy - of course it is.

my nelly looks an absolute shambles - cos i spend my time tinklering with the mechanicals

Mon Apr 16, 2018 10:29 pm
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Part built GTM

Joined: Thu Jun 19, 2008 2:02 pm
Posts: 78
Post Re: 65 miles per gallon!
everybody runs leased cars now (everybody is in debt to run a "nice " car) - nobody runs/tinkers with fun cars anymore
i saw two e-types on my recent run to surrey - that was it. sad.

well screw that - im gonna keep on with the fun daily driver that children wave at
and folks from singapore run up to me asking what it is!

my little nelly. (yes named after 007's autogyro)

Mon Apr 16, 2018 10:34 pm
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Part built GTM
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Joined: Sat Feb 11, 2012 2:51 pm
Posts: 134
Location: NE
GTM: Libra
Post Re: 65 miles per gallon!
Careful what your doing running an engine lean, you can damage an engine quite quickly running that way, you have been warned!

Jamie :)

V6 GTM Libra '10 years in the making!!!'

Libra V6
Hawk AC Ace
TVR 3000M
MG ZTT 180
Skoda Fabia VRS
TVR Griffith 400 (coming soon)

Thu Apr 19, 2018 9:55 am
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Part built GTM

Joined: Thu Jun 19, 2008 2:02 pm
Posts: 78
Post Re: 65 miles per gallon!
its all good after many years of running lean . . . . .

Wed May 23, 2018 10:53 pm
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