Strip Of Shift Lights

[smckeown 1]

I'm interested in replacing my 1 x ECU controlled shift light with a row of say 8-10 LEDs. I have read the benefits of this is that you can program the lights to be in line with your torque curve. Over and above knowing when the end of the peak torque is coming, it would also be very useful to know when you are outsude the rev range, i.e. no lights on for a significant period of time out of a corner, would be easy to spot with a system like this.

 

Furthermore, I have read conflicting advice. Some people say change just after peak torque, others say change just after peak power. What have you guys got to say about that ?

 

cheers

sean

[pdd144c 0]

Power! My peak torques at 3.5k!

 

Surely the one shift light is fine? You'll know when you are outside the range because you'll be going slow Think your looking a bit to deeply into it, once you get to know your car you change gear naturally at the right point anyway. Or is that just me?

[S33GAV 0]

Sounds like a cool idea to me

[smckeown 1]

Surely the one shift light is fine? You'll know when you are outside the range because you'll be going slow Think your looking a bit to deeply into it, once you get to know your car you change gear naturally at the right point anyway. Or is that just me?

 

My anglsey vids proved I was consistently usinf 3rd rather than 2nd out of the hairpin, this system would have told me that very easily. I suppose everyone's different, I think this system would be of benefit to me.

 

Still interested in people's opinion in whether it should be programmed to torque of bhp. I suppose the answer is dependent on the characteristics of your engine.

[pdd144c 0]

Thats cool. Like you say it should be dependent on the characteristics of your engine. My turbo lump will be completely different from your NA one.

 

Do you not think it would cause you too much of a distraction though Sean? A shift light is either on or off, where as a line of LEDs will be changing all the time.

[James_m 0]

Depends on the scenario too, i.e you might want to hold onto a gear way past peak power if there was a corner coming up etc

Seems like a major overkill to me, especially just for track day use where gaining the odd tenth is irrelavent.

[VisaGTi16v 1]

I had a single led shift light in mine so I made my own small box up with 4 in. They all come on at the same time which is all I need. I dont use them all the time anyway as you can tell by engine noise most of the time in sprints if youre paying attention, far less of an issue on a track day or the road as well. As for using too high a gear, again noise related, especially in my 16v, just keep the revs up! Ive had mine rolling roaded and the power curve starts to slow down at 6500 (this is a mi16) but is still rising so my shift light comes on at 7000 and I shift just after to avoid the standard 7200 limit

 

A lower gears not always better though as out of a hairpin for example you may struggle for traction in 2nd and feather the throttle far more than if you were in 3rd which although may be producing less actual bhp due to lower revs, more of it is going to the ground and not to the air as tyre smoke

Edited October 18, 2006 by VisaGTi16v

[smckeown 1]

Do you not think it would cause you too much of a distraction though Sean?

 

I had 3 LEDs on my old spa-design tacho and didnt fint it a distraction, you notice the lights (rather than actually looking at them) while still concentrating on the road ahead.

[VisaGTi16v 1]

Yes on that last point. My friend in his sprint mini used to put his on the steering column so you had to look down through the wheel to even see them which seemed pointless as the rev counter was there! I mount mine up on the top of the dash in the middle so I see them light up in the bottom of my vision without having to take my eye off the road or focus on them.

 

I do think for road/posing purposes sequential ones are much better but when competing you just need one or a few that come on at the same time, I dont care if the things at 6800 or whatever, I just need to know when its at 7000 and to shift

[crogthomas 0]

A good idea, but I think you're looking at it the wrong way round.

 

Commercial vehicles (HGV's etc) will often have a green area marked on the rev counter which indicates the most efficient range over which to use the engine. The 'Powerband' if you like.

 

If you go past the top of the range, change up, if you drop out of the bottom of the range, change down a gear to get the engine back in the desired range.

 

You already have a shift light to tell you when to change up. What you need now is a light to tell you when you have dropped out of the bottom of the useful powerband, and that you should change down a gear where more thrust will be available.

 

To calculate the correct point requires all sorts of information about your engine characteristics and gear ratios, drawing lots of graphs, swearing and beer. You will also most likely end up with different rev points for each gear. I suggest you get a good book on the subject. I think A Graham Bell's book on four stroke tuning covers it.

 

Alternatively you can make a close enough guess from your gear ratios and upper rev limit.

[smckeown 1]

I've done some research and found this excellent site

 

On that page it basically tells you to work out the torque at the wheels per RPM, and simply see for yourself at what RPM will give you the most torque compared with shifting at that point. If your said gear shows more torque than the torque you will get if you shifted at that point, then keep climbing until you either reach a point that the next gear shows more torque at the revs you'll go down to if you shiftet, or you run out of revs in the current gear. (that's my synopsis anyway)

 

On a 1.6 box, if you shift at 7k revs, you'll roughly go down to 5.5k revs

 

So here are my car's figures

 

.................1st...........2nd...........3rd...........4th...........5th

RPM..........3.251.......1.850.......1.360.......1.069......0.865

1500..........130...........74............54............43............35

2000..........260..........148...........109...........86...........69

2500..........341..........194.......... 143..........112...........91

3000..........384..........218.......... 160..........126..........102

3500..........374..........213.......... 156..........123..........099

4000..........403..........229.......... 169..........133..........107

4500..........416..........237.......... 174..........137..........111

5000..........458..........261.......... 192..........151..........122

5500..........462..........263.......... 193..........152..........123

6000..........442..........252.......... 185..........145..........118

6500..........429..........244.......... 180..........141..........114

7000..........400..........228.......... 167..........131..........106

 

1st - I climb the revs and even though max torque of 462 is reached at 5500 rpm, if I shifted not my torque would be 229 @ 4000 RPM (5500-1500) so it's best to keep going, so at 7000 I have 400 lb/ft (which was more than I would have had in 2nd if I had shifted at 5500 rpm)

2nd - Start at 5500 rpm (shifted at 7000 in 1st) and climb the revs. Same situation as 1st gear, max torque reached at 5500 rpm but torque in next gear will be significantly lower, so need to keep going

3/4/5th all the same.

 

I'm now educated

Edited October 18, 2006 by smckeown

[veloce200 3]

I've done some research and found this excellent site

 

On that page it basically tells you to work out the torque at the wheels per RPM, and simply see for yourself at what RPM will give you the most torque compared with shifting at that point. If your said gear shows more torque than the torque you will get if you shifted at that point, then keep climbing until you either reach a point that the next gear shows more torque at the revs you'll go down to if you shiftet, or you run out of revs in the current gear. (that's my synopsis anyway)

 

On a 1.6 box, if you shift at 7k revs, you'll roughly go down to 5.5k revs

 

So here are my car's figures

 

.................1st...........2nd...........3rd...........4th...........5th

RPM..........3.251.......1.850.......1.360.......1.069......0.865

1500..........130...........74............54............43............35

2000..........260..........148...........109...........86...........69

2500..........341..........194.......... 143..........112...........91

3000..........384..........218.......... 160..........126..........102

3500..........374..........213.......... 156..........123..........099

4000..........403..........229.......... 169..........133..........107

4500..........416..........237.......... 174..........137..........111

5000..........458..........261.......... 192..........151..........122

5500..........462..........263.......... 193..........152..........123

6000..........442..........252.......... 185..........145..........118

6500..........429..........244.......... 180..........141..........114

7000..........400..........228.......... 167..........131..........106

 

1st - I climb the revs and even though max torque of 462 is reached at 5500 rpm, if I shifted not my torque would be 229 @ 4000 RPM (5500-1500) so it's best to keep going, so at 7000 I have 400 lb/ft (which was more than I would have had in 2nd if I had shifted at 5500 rpm)

2nd - Start at 5500 rpm (shifted at 7000 in 1st) and climb the revs. Same situation as 1st gear, max torque reached at 5500 rpm but torque in next gear will be significantly lower, so need to keep going

3/4/5th all the same.

 

I'm now educated

 

but won't yours hang on to 7500-8000rpm? just rag the nuts of the thing Sean. In my experience the more your thrash it the faster you go. I've done many acceleration and 1/4 mile tests in many cars that prove this to be the case. I take my bog std 8v to 7000rpm at lydden up the hill. can you see why now long induction length might be a waste of time?

[smckeown 1]

but won't yours hang on to 7500-8000rpm? just rag the nuts of the thing Sean. In my experience the more your thrash it the faster you go. I've done many acceleration and 1/4 mile tests in many cars that prove this to be the case. I take my bog std 8v to 7000rpm at lydden up the hill. can you see why now long induction length might be a waste of time?

 

Well yes I have figures up to 7200, but after 6800 ish it tails off fast. And yes, I now understand that a bigger mid range at the detriment of top end 'may' make me slower. I'm learning...

Edited October 18, 2006 by smckeown

[smckeown 1]

I have done some more research and calculations. In the previous stats the final drive is not used, as you are only comparing gear with gear. But to compare different gearboxes you have to include the final drive ratio.

 

So rather than listing all the figures, as they all look more or less the same, I have produced a graph to show the wheel torque between my current 1.6 box and the popular 1.9/mi16 box.

 

You can clearly see that the wheel torque is greater. I know a lower ratio box = faster acceleration is common sense, but i still found this path of education fascinating for me, this proves the actual difference to acceleration. I know there are other factors like corners, top speed etc, but it's still very interesting to see that the reason it's faster acceleration in a straight line in the same gear, is because of the wheel torque being higher.

 

 

Sean

[veloce200 3]

Well yes I have figures up to 7200, but after 6800 ish it tails off fast. And yes, I now understand that a bigger mid range at the detriment of top end 'may' make me slower. I'm learning...

 

I know I should be a convert to low ratios as PeterT is. There are many situations in sprints though where they hinder rather than help. eg at lydden IMO a std 1.9 box is an advantage off the line, round the elbow and up the hill. With low ratios 1st simply spins away, and 2nd is too short. Ideally you want a custom box - you could than have a really long first and then stack the other close together at the top like a superbike. IMO this would make any pug no matter how much power a real weapon. Case in point - Richard Brents 1.6 GTI in Track and Race Car...

[VisaGTi16v 1]

This Richard Brent from Lydden a few weeks back? http://homepages.nildram.co.uk/~visa/pics/temp/P1010422.JPG

 

It has this under the bonnet! Not a 1.6 surely http://homepages.nildram.co.uk/~visa/pics/temp/P1010428b.jpg

 

I ideally need a custom box for my Visa. I used to run the standard mi16 one which was ok as I only have 13" wheels. 4th gear went so ive swapped to a 1.6 which has kept 3rd and 4th the same, lowered 5th and increased 2nd which are all good when up and running but 1st is too low. Hard to get traction off the line and the gap to 2nd is a bit too big. On the hill at Longleat the change point to 2nd was at the steepest bit and the engine just went *$!"$(*& heh

[VisaGTi16v 1]

I will plot my torque curve out tonight as you have done as quite interested. It was a bit flatter than yours from memory. I must find one for a standard xuj4rs as well as I drive a xsara vts as my every day car and it flies at low revs compared to the mi16 equiped visa which really has to be wound up but the power curve suggests it should have good power low down. I had a zx 16v before (306 s16) and that also had bags of torque low down

[veloce200 3]

This Richard Brent from Lydden a few weeks back? http://homepages.nildram.co.uk/~visa/pics/temp/P1010422.JPG

 

It has this under the bonnet! Not a 1.6 surely http://homepages.nildram.co.uk/~visa/pics/temp/P1010428b.jpg

 

that's not his engine bay...! he has a 1.6 8v and that Escort is a 2.2 IIRC (definitely over 2 litres) and is 218hp....he is in class e but beats class E,D,C and often B...watching him quickly makes you realise that power is not that important...

Edited October 19, 2006 by veloce200

[smckeown 1]

I will plot my torque curve out tonight as you have done as quite interested. It was a bit flatter than yours from memory. I must find one for a standard xuj4rs as well as I drive a xsara vts as my every day car and it flies at low revs compared to the mi16 equiped visa which really has to be wound up but the power curve suggests it should have good power low down. I had a zx 16v before (306 s16) and that also had bags of torque low down

 

i'm interested in analysing more, especially overlaying gear ratios over the torque curve etc. I've posted seperately to get hold of that performance simulator which i believe does all that for you.

 

i've seen those quaift gear kits which apparently are a really good close ratio set, but cant get the details off the quaift site. It anyone has the rations i'd be most interested to see on paper the difference it makes

[VisaGTi16v 1]

Hmm guess I was confused then. Im sure I only saw one red 205 there on that day which was him going by sticker in the rear window. Other one was his brother or friend in a black one and he rolled at Devils Elbow.

 

Yes I used to sprint against the Craigs a few years back till they started racing. 99% of Escorts in sprints are over 2 litre and use illegal blocks in modprod ie the 205 block. A particular highlight was a certain west country one on ebay very recently advertised as 2.4 but hes entered 2 litre class against me a few times!

[GLPoomobile 958]

Sean, have you thought about the extra weight those 10 LEDs are going to add to your car?

 

 

 

 

 

Sorry