My New Engine Pictures

[Butler 0]

Don't you want the gears closer together to the further up the box you go? I guess it depends how flat the peak torque and power curves are.

[petert 550]

Anyway, this talk about gear ratios is interesting. I've never quite been able to get my head around the idea that changing to a lower CWP ratio gives faster acceleration. If the gear ratios are the same then the section of the engine's rev range in use is the same, which means the average power/torque used in each gear is the same - regardless of CWP. So it follows that acceleration shouldn't be any different, apart from having to spend more time changing gear. Do you follow that? I'm not sure I do!

<{POST_SNAPBACK}>

 

F=ma

 

where F, the force, is the Newtons in the axle torque I spoke about earlier in the thread.

 

Yes, the % change between each change should get closer with each shift.

Edited June 14, 2005 by petert

[Rob Thomson 6]

Yeah, but imagine for a minute you have a box in which 2nd is 20% longer than 1st, 3rd is 20% longer than 2nd, and so on. Each gear is 20% higher than it's neighbour. Then lower the FD by 20%. All you've done is make 2nd-5th the same as the old 1st-4th, made 1st uselessly low, and knocked 20% off your possible top speed. Not really a useful improvement, is it?

Edited June 14, 2005 by Rob Thomson

[Rob Thomson 6]

Don't you want the gears closer together to the further up the box you go? I guess it depends how flat the peak torque and power curves are.

<{POST_SNAPBACK}>

Yep - I reckon that sounds sensible.

[cybernck 400 1 Cars]

rob, i know what you mean. also with longer gears in powerband the car

might actually gain speed faster that with shorter gears and faster revving

and more gearchanges. but that's theory while practice is a different matter.

you won't be in the powerband 100% of the time, not even on a track(day).

 

i also think that with enough power, you need longer first gear to maximize

traction and use all the power up. i think for straight line acceleration such

as qtr mile, where you do spend all the 15 or so secs in the powerband,

long gearbox is not necessarily a bad thing.

 

however, it's all about compromises and you simply can't build a (cheap)

gearbox with long first and then closely stacked other gears, out of the

gearboxes / gear ratios most commonly used. i suggest 1.9 gear ratios

and then selecting the CWP to suit individual needs.

[petert 550]

take the 1.9L/4.43 combination:

.................overall....... %

1..2.923.....12.949

2..1.850.....8.196.......36.7

3..1.360.....6.025.......26.5

4..1.069.....4.736.......21.4

5..0.865.....3.831.......19.1

 

then the std. 1.9L/3.62 combination:

 

1..2.923.....10.581

2..1.850.....6.697......36.7

3..1.360.....4.923......26.5

4..1.069.....3.870......21.4

5..0.865.....3.131......19.1

 

 

The % change is the same in each case, but look what's happened to the overall ratios. 5th gear in the top set is approx. the same as 4th in the bottom set.

 

edit: it's impossible to tab those numbers neatly!

Edited June 14, 2005 by petert

[tom_m 0]

what does the 4.43 FD come out of, is that the TD FD?

[Anthony 1,000]

what does the 4.43 FD come out of, is that the TD FD?

Mi16 gearbox. Higher the FD number, the lower the overall gearing

[jackherer 543]

edit: it's impossible to tab those numbers neatly!

<{POST_SNAPBACK}>

use

[ code ] [ /code ] tags

[Jonmurgie 2]

Thought I'd bring this back up and ask if there is any news on this engine being on the road yet?

[Robsbc 0 1 Cars]

Thought I'd bring this back up and ask if there is any news on this engine being on the road yet?

 

Thought I would also bring this back up and ask if there is any news on this engine being on the road yet?

[maxi 36 1 Cars]

I was only thinking about this project earlier today, whats the progress Martin?

 

Maxi

[crf450 0 1 Cars]

I'd booked my engine in to be set-up on the engine dyno that stew had his set-up on which was about three or four months ago now, later on that same day my life fell apart and I'm no closer to putting back together yet and my car/engine hasn't been thought about since. If there's any news I'll post it hear.

Cheers Martin

Edited December 12, 2005 by crf450

[PumaRacing 1]

Sorry to hear that something adverse has happened in your life. Hopefully one day we'll still get to find out how the engine runs.

[smckeown 1]

yeah sorry to hear that Martin. that's the problem with long running projects, in that circumstances can change. Been there got the t-shirt.

 

I couldnt afford anything fancy these days, just as well I have the pennies put away to finish the current project

[PumaRacing 1]

PS - whatever has befallen you, if you ever feel the need to share, privately or on here, I'm sure there is no shortage of people willing to help or at least lend an ear if that's all that anyone can do. Once you reach a certain age it's the law of averages that something horrible will have occured. At the moment a good friend of mine (my age - mid 40s) is watching his best friend (and ex-wife as it happens) die of breast cancer 30 years before her time. This is going to be her last Xmas and it's been a struggle getting even this far with the constant pain and drugs. Whatever it is you are going through there will be others who have been through similar and can help.

[phatgti 0]

noble words.

[Shevy 4]

PS - whatever has befallen you, if you ever feel the need to share, privately or on here, I'm sure there is no shortage of people willing to help or at least lend an ear if that's all that anyone can do. Once you reach a certain age it's the law of averages that something horrible will have occured. At the moment a good friend of mine (my age - mid 40s) is watching his best friend (and ex-wife as it happens) die of breast cancer 30 years before her time. This is going to be her last Xmas and it's been a struggle getting even this far with the constant pain and drugs. Whatever it is you are going through there will be others who have been through similar and can help.

 

 

I totally agree with Dave.

Things happen in life when your least expecting it and some of these things do test us to our limits sometimes, but we get through things with good friends and family around us.

Take me for example, my 205 has had no work done on it for a year now it's just been sat on the driveway missing front suspension and my new head and cams and it's a bit of a running joke with some of my friends.But this has mainly been due to other circumstances in my life. The last couple years of my life have been awful,particulary the last year watching my mum slowly die of cancer and becoming this totally different person, mainly due to all the drugs she was taking.My mum who was in her fifties (non drinker or smoker and a bloody hard worker) came out of hospital back at the beginning of August with the Doctors saying they couldn't treat her anymore. Me and My fiance were due to get married in September 2006 but we bought the wedding forward as soon as we found out about my mum.

It took us 3 weeks to arrange absolutely everything for the wedding and we got married on August 28th Bank holiday. The whole wedding was amazing ,but very emotional mainly due to the fact that my mum passed away a week before the wedding, on top of that the day she passed away I had gone to Anglesey on a track day as part of my friend Steve's (BiFf off this Forum) Stag doo, mainly just watching for the day as I didn't have my pug ready to use.

I got a phone call during the day from my Dad asking how quick I could get back as my mum wasn't gonna last much longer.I did my best to get back home to Wallingford in time speeding all the way, but I failed to make it and to this day I still feel guilty for not being there that day for my mum.

Over time things will slowly get better with support from friends and family, I may even finally finish my pug in the New year.

I didn't mean to go on there. I'm sure what ever trouble Martin is having at the minute he will get through it and he certainly has plenty of friends on this Forum.

Edited December 14, 2005 by Shevy

[Jonmurgie 2]

MAJOR resurrection of a thread... but I just wondered if CRF450 is still about and has any news on this engine?

[C_W 3 1 Cars]

I've bought it now, and with 100% more power will be halfing lap times

[Jonmurgie 2]

Nice one... looking forward to catching up with you at a track somewhere for a buchers

Edited June 17, 2006 by Jonmurgie

[nick 3]

Thats strange, he sold it to me last week!!

 

Nick

Edited June 17, 2006 by nick

[Jonmurgie 2]

Oh right, your both joking...

[nick 3]

Well I am!! not sure about Chris though.....

 

Nick

[C_W 3 1 Cars]

Yea I was too but I'll offer to run it in for him though