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BGH Ratios (again)


Myles

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I'm keen to do some work on the current Type-9 while the car is in pieces...

 

Have just spoken to BGH (Chris, I assume) and he suggested the 2.0 (litre) long-first with the following ratios for my 180+ 1.8 k on a 3.92 diff:

 

2.98 vs 3.36 (std)

1.97 vs 1.81

1.37 vs 1.26

1.0 vs 1.0

.82 or .87 vs .82

 

 

Hmm - dunno about that. Other than helping lengthen the first gear (not by much) and offering the chance of a slightly more sprightly 5th, it strikes me that I'll end up with wider ratios in the 2nd/3rd/4th area - and that can't be a good thing...

 

He said that the 2.8 Sporting-Close might be too much of a handful with an overly-long 1st for the engine...

 

'Standard' 2.8SC ratios appear to be:

 

2.8

1.81

1.26

1.0

.85/.87

 

...although I understand from TT-trawling that other options are available...

 

Hmmm - whaddya think??? *confused*

 

 

 

Project Scope-Creep is live...

 

Alcester Racing 7's Equipe - 🙆🏻

 

Alcester-Racing-Sevens.com


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Thanks Norman, I'd already found that thread. *thumbup*

 

I think I need to speak to them again - the 'standard' ratios seem to match 2nd,3rd and 4th of the '2.8 sporting-close' - whereas the 2.0-long ratios that were suggested change everything (apart from 4th...)

 

Several people have warned about going too-long on the first gear as it can be a pain in traffic - but I don't really want to shorten 2nd or 3rd (I think).

 

Hmmm.

 

Project Scope-Creep is live...

 

Alcester Racing 7's Equipe - 🙆🏻

 

Alcester-Racing-Sevens.com


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Hi Myles,

 

I went for these ratios on my BGH 5-speeder, with similar power and same diff:

 

1st 2.66 (2.75 was an option)

2nd 1.75

3rd 1.26

4th 1.0

5th 0.82 (other options were 0.84, 0.86, 0.89)

 

It was called an E7 at the time. I'm completely happy with my choice. I'd ideally like an extra 6th ratio for motorway cruising (80 mph is about 4,500 rpm), but for *driving* it's fantastic.

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Hi Myles I have Fitted the B.G.H long first box in my new biuld Zetec 1800 engined seven and is great the engine is A standard 1800 Zetec with throttle bodys and Emerald management thay claim 160BHP but I don't know but the gearbox is great, *thumbup* can have A go in mine some time before you buy if you like then you will know if its for you mate Regards Paul
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Strangely - hmm, that's odd... The std. 5th ratio is .82 - I don't really have an issue with m-way cruising. Perhaps that's because I always wear ear-protection with the aeroscreen...

 

I *would* actually like a slightly-shorter 5th - it's just a tad too long for my liking - perhaps that's because my engine only really kicks-off at 4500rpm - with peak torque at about 5.9k

 

Project Scope-Creep is live...

 

Alcester Racing 7's Equipe - 🙆🏻

 

Alcester-Racing-Sevens.com


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My 0.82 5th is great for drivability - 80 mph @ 4,500 rpm means that I'm right in the power band for overtaking, but given that I frequently cruise at a somewhat higher speed than that, it can't be good for the engine. Good job I don't do motorways too often.

 

ISTR that the BGH 5th is slightly different to standard, perhaps 0.82 vs 0.825, or the other way around. I didn't mean to imply that cruising had been made worse with that box; it's no different really. If I cared that much about it then I could put on some 16" wheels (CR500s in 185/55 R13 don't help in that regard *tongue*).

 

Edited by - Strangely on 2 Nov 2005 17:48:52

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Myles I've got these ratios in the BGH on my Duratec

 

2.75

1.75

1.26

1.0

0.86

 

The 1st is the shorter of the two options, Chris said the longer one is a bit of a pain on the road. For the 5th I went for something slightly shorter than the standard 0.82 as a 150+ top speed isn't really all that useful. My box is a sporting close although it looks like the 2nd I have is different to the one your quoting.

 

TBH I don't notice the gears which kind of suggests the ratios are a fairly good match to the engine.

 

Rob G

www.SpeedySeven.com

 

Edited by - rgrigsby on 2 Nov 2005 20:45:52

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I've just bought a Tran X gear kit and they buuilt me a shaft up with a short 5th, OK this will hurt a little on the motorways but hey if you want to drive on motorways buy a Mondeo !

 

Using these with a 3.92 gives me the same overal range as a CC 6 speeder with a 3.62

 

The 3.92 might go if I can get my hands on a 4.1 though !!

 

2.48

1.69

1.27

1.00

0.9237

 

There are other ratio sets available and the guys are keen to help if you've specific requirement too.

 

cheers

 

Neil.

 

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Myles, as Rob said about his, I don't notice the gears. The 2.66 1st is fine, and I drive my 7 every day in towns and open roads. I don't notice having to slip the clutch any more than with my pre-BGH box (only when travelling in a very slow queue). This engine, gearbox and AP clutch have done 23k miles so far, and there's no sign of the clutch even needing adjustment.

 

Rob's rev limit must be higher than mine, because I can only dream of doing 150 mph! With my 0.82 5th gear, I can do 129 mph with the shift light flickering on at 7,000 rpm *wink*.

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Just to echo Jason's (strangley) comments. I fitted the same box last winter, and whilst I haven't driven my car much the difference is fantastic. No longer do I change up 2 secs after pulling away, and often pootle along at 25+ (say in traffic, etc) in 1st before realising I'm doing it. I'd say it is better in traffic than the old one as the gap from 1st to 2nd was so large that most traffic jam speeds meant I was running silly rpm in 1st, or bogging down trying to use 2nd. Now you can just hold 1st.

Also really impressed with BGH's service, Brian was happy for me to turn up late the day or so before Xmas last year so I could fit it over the break *thumbup*

 

Phil Waters

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I've been playing with Peter Ogden's gearcalc prog (on Arnies site) this morning and am as unsure as ever...

 

Assuming a 6.5k rpm gear-change (7.5k is the rev-limit I use, but I don't *always* bounce off the limiter...):

 

'2.0 long' vs 'Strangely 2.8 SC'

 

1st->2nd drops 6.5k to 4.3k vs 4.2k (ish)

2nd->3rd drops to 4.5 vs 4.7

3rd-4th drops to 4.8 vs. 5.2

 

I've got a dip in the torque-curve than bottoms out at almost exactly 4.2krpm and it then climbs until softening out at 5.2 with the peak at 5.9

 

ON the face of it, the 2.0-long ratios drop me right to the point where the torque picks up - but maybe too far towards the dip when you've lost a few rpm during the change?

 

Decisions, decisions... ☹️

 

Project Scope-Creep is live...

 

Alcester Racing 7's Equipe - 🙆🏻

 

Alcester-Racing-Sevens.com


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Now in the correct place 😳

 

I would be looking at a 2.3 to 2.6 first

 

Don't forget your pulling a very light car.

 

I have often set of in 2nd with the R5 and on a couple occasions 3rd and the car pulls, of thirst is a tad difficult but the point is it does so because there is no weight. cat 6 spd is 1st - 2.69, 2nd - 2.01. As it pulls 2nd reasonably well I would have thought about 2.35 whick your car should pull as it has more torque lower down

 

I alsways thought the SPC gear ratios looked about right - see here

 

I would tend to leave 5th as .82 as you only need 5th for motorways as when out blatting will be using just 1-4th

 

My ten peneth worth

 

NE7Club Web Site

R5 no 65 😬 *cool*

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I'm not sure that BGH offer anything as long as 2.3 - but that would only give me 15mph between the top-speeds in 1st and 2nd and so 2nd would be redundant...

 

...it would also mean that I'd have to slip the clutch in stop-start traffic.

 

FWIW, BGH seem to feel that the 2.75/2.8 first could be too long to live with on the road, but I think (from the sounds of it) that they're probably about right.

 

Project Scope-Creep is live...

 

Alcester Racing 7's Equipe - 🙆🏻

 

Alcester-Racing-Sevens.com


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