TurboWood
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posted on 23/8/13 at 11:48 PM |
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type 9, bgh or spc?
Hi Gents,
I'm working on putting together a 7 and have settled on the type 9, but I'm not sure which vendor has the strongest/best build. BGH and
SPC are the two I've found (are there others?) and they offer similarly priced and named (HD) transmissions. Does anyone have any experience of
one being better than the other? I'm a little partial to the SPC since I should be able to hit 60mph in first gear at 7500rpm, but I'm
also unsure if first will be too long with my 3.38:1 final drive. Any advice would be great.
Thanks,
Daniel
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snapper
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posted on 24/8/13 at 06:40 AM |
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3.38 is long unless you have a bike engine
Most use 3.6 and 3.9
If using on the road a very close box can be a compromise
BGH will fit any gear ratios a d attend a lot of kit car show
Other suppliers are Quaife and Elite
I eat to survive
I drink to forget
I breath to pi55 my ex wife off (and now my ex partner)
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zetec
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posted on 24/8/13 at 06:42 AM |
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Not too sure 60 in first gear is making the best use of your power, it will have to be very high, I would have thought aiming for 70 in second would
be closure to an ideal.
" I only registered to look at the pictures, now I'm stuck with this username for the rest of my life!"
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Paul Turner
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posted on 24/8/13 at 07:31 AM |
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I have a BGH box in the car and a SPC box as a spare. Both are nice companies to deal with. Had problems with 2 BGH boxes that were replaced FOC, not
used the SPC one yet but I bought a diff from SPC in 1998,still in the car, quiet and leak free. What I have said to most people in the past is go to
the closest one, handy if you have issues. BGH is 200 miles for me, SPC less than 100 miles.
Now for my technical feelings.
If you are considering one of the "expensive" boxes SPC is IMHO without doubt the best.
SPC use ALL new gears in their boxes including a new lay shaft assembly. BGH use a new lay assembly but use reclaimed gears on the
mainshaft.
SPC use needle rollers on 1st and 2nd gears, makes a big difference to gearchange quality at full chat and the gears also have a far easier life at
high revs, in a BGH box they run directly on the mainshaft like a standard production box.
SPC use all new syncros, BGH clean up used syncros if they look OK.
On the budget boxes (the ones where they change 1st and sometimes 5th) SPC still use new syncros and the prices are lower.
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TurboWood
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posted on 24/8/13 at 12:23 PM |
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snapper,
I would think bike engines would actually be worse since they have lower reciprocating inertia at idle. In other discussions I've had some cat
owners tell me the 3.62 with cat 6spd transmission was shorter than needed (off the track). I also know of at least one guy with a BGH 5spd and 3.14
final drive that uses the car on the street (Duratec 2.3L). Of course each person may have a different tolerance or idea of ideal.
zetec,
I'm shooting for 300-350hp (turbo 4). From my calculations I'll be able to accelerate well over 1g in first gear which is almost surely
more than the tires can handle. My biggest concern is just the driveability from a stop. I don't want to start a clutch burning business.
Paul,
Thanks for the feedback! That's the first b2b information I've found. I am more interested in the HD boxes in order to handle the power.
As i'm in the US neither supplier is super convenient. There just aren't many options in the US for the type 9.
Daniel
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beaver34
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posted on 24/8/13 at 12:30 PM |
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i run s spc gearset on my zetec turbo engine, long first gear revving to 8k
i run between 250 and 350bhp with no issues
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TurboWood
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posted on 25/8/13 at 02:31 AM |
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beaver,
Do you have any pictures of you engine bay? I haven't come across too many turbo 7's. Do you have a dyno chart? Do you use the car on the
track?
Thanks,
Daniel
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laptoprob
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posted on 25/8/13 at 07:40 AM |
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quote: Originally posted by snapper
3.38 is long unless you have a bike engine
Most use 3.6 and 3.9
If using on the road a very close box can be a compromise
BGH will fit any gear ratios a d attend a lot of kit car show
Other suppliers are Quaife and Elite
Completely agree with snapper here.
I have a Quiaffe ATB 3.92 with a TranX straight cut installed. It will happily do late 70's in second and top out at 140mph(not that its there
much) with 262hp on tap. Id say its about bang on for all conditions. I can happily get a 3.5 sec 0-60 etc.
With a 3.38 installed you will hit 100mph in second and nearly 70 in first which is what i think you are heading for. in my opinion you car will be a
pain to drive from the lights unless you have a belly full of torque or are considering setting off with high revs. Considering you are going for a
low compression turbo setup you will starting out of boost anyway(most times) so no torque at all.
Agreed that if you are planting your foot well into the boost before setting off(track conditions) it will be one quick car but your top gear will
give you 166mph which i'm not sure id like in a car that weighs very little.
Why not compromise and try the 3.62?
THIS SHOULD HELP
Just my opinion matey.
http://www.youtube.com/watch?v=ajlF4nWJtGA
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Paul Turner
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posted on 25/8/13 at 08:04 AM |
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Having had a Seven now for 25 years my personal opinion is the cars are all about rapid in gear acceleration for overtaking. A decent top for
reasonable cruising is also required but in mine with a 3.9 diff it is doing 3500 rpm at 70 which is fine (although higher than many tintops).
If you fit a 3.14 diff with either a SPC or BGH box you will end up with a car that will theoretically do about 58 mph in first at 7000 rpm (depending
on tyre size) and have a theoretical top speed of approx 175 mph. Such a high first gear will put quite a strain on the clutch. In a light car like a
Seven its normally the tyres that break traction in the lower gears before the clutch slips unless the clutch is knackered.
Based on my personal experience I would not want a turbo in a Seven ever. Driven a supercharged car once, did not suit the character of the car. With
175 bhp and a weight of about 600kg my car will beat almost anything on the road and does not frighten me. It had 208 bhp at one time but on a normal
road trip the car was no faster, it just used more fuel. I do not have to worry about the turbo coming on boost and throwing me off the road.
There are many Seven owners out there with 1.3 pushrods who have more fun than those with stupid power levels.
Just my opinion.
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beaver34
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posted on 25/8/13 at 08:04 AM |
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quote: Originally posted by TurboWood
beaver,
Do you have any pictures of you engine bay? I haven't come across too many turbo 7's. Do you have a dyno chart? Do you use the car on the
track?
Thanks,
Daniel
here you go. not used it on track yet just ironing out some issues on the road first.
let me know if you want to know anything else
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TurboWood
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posted on 25/8/13 at 09:15 AM |
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Thanks again guys, this is the exact conversation I was looking for since I have very little practical experience with a 7. My car will be used
primarily as a road going car, but I do look forward some track time. Hopefully I can find someone that has beat the SPC transmission hard enough to
know how its limits compare to the BGH.
laptoprob,
Your advice is sound. Attached is an estimated accel curve for the SPC transmission and 3.38 rear end. This includes an assumption for drag and shows
speeds close to what you had mentioned. For me 5th gear is really just for cruising so the top speed is irrelevant. 4th tops out around 140-150 which
as you pointed out is already crazy fast for these cars. For me it really does come down to if it will be manageable on the street or not. I may just
have to avoid the light weight flywheel/clutch. I think it's time to do some math on inertia to find out how this compares to other cars
I've driven.
Paul,
I agree the 3.14 is very aggressive. I'm only aware of one gentleman that has it (with BGH). I'm starting with the 3.38 and trying to
figure out if it will be reasonable with either the BGH or SPC transmission. I can always change later. Your comments about the turbo are interesting.
You aren't the first person to heed this warning. I can certainly understand the appeal of a predictable response. Turbos are just my thing and
I am putting an emphasis on transient response over ultimate power. Keep in mind modern 2L turbo engines are making 300hp from the factory (355 in the
case of AMG). Obviously I won't be buying a not-yet-released Merc, but it tells me the technology exists for a driveable turbo engine.
bearver,
Thanks and nice looking car! It's definitely a tight fit. It will be interesting to hear how the SPC transmission holds up and to see how much
power you can sustain on track before temperatures start to rise. The oil cooler is going to be working hard. I was thinking of running a more
conservative boost level on track for this very reason.
Regards,
Daniel
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beaver34
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posted on 25/8/13 at 10:54 AM |
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it is tight, i see oil temp of 105 after hard use on the road, thats laps on full boost on the dual carriageway
no doubt it would be higher on track but by how much i cannot tell you yet
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Paul Turner
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posted on 25/8/13 at 05:40 PM |
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quote: Originally posted by TurboWood
I'm shooting for 300-350hp (turbo 4). From my calculations I'll be able to accelerate well over 1g in first gear which is almost surely
more than the tires can handle. My biggest concern is just the driveability from a stop. I don't want to start a clutch burning business.
Paul,
Thanks for the feedback! That's the first b2b information I've found. I am more interested in the HD boxes in order to handle the power.
As i'm in the US neither supplier is super convenient. There just aren't many options in the US for the type 9.
Daniel
Only just spotted that you are taking about 300 -350 bhp. Forget the type 9, it simply will not cope with the power or torque. 260 bhp is normally
quoted as the limit for a HD box and even then regular rebuilds are essential. A mate of mine with 250 bhp regularly breaks syncros, he uses steel
ones on 1st and 2nd now but the box requires a strip to lap them in every 2000 miles or so.
You need a Borg Warner T5 box as used by Ford in the early 2WD Sierra Cosworth. Its bigger and heavier but since it originated in the Mustang it can
cope with outrageous power and torque. The Sierra ratios are pretty OK but Quaiffe do closer ones in needed. TVR also used the box but the ratios are
naff. Not sure what ratios the Mustang used.
But does anyone make a T5 bellhousing to suit your engine.
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beaver34
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posted on 25/8/13 at 05:51 PM |
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quote: Originally posted by Paul Turner
quote: Originally posted by TurboWood
I'm shooting for 300-350hp (turbo 4). From my calculations I'll be able to accelerate well over 1g in first gear which is almost surely
more than the tires can handle. My biggest concern is just the driveability from a stop. I don't want to start a clutch burning business.
Paul,
Thanks for the feedback! That's the first b2b information I've found. I am more interested in the HD boxes in order to handle the power.
As i'm in the US neither supplier is super convenient. There just aren't many options in the US for the type 9.
Daniel
Only just spotted that you are taking about 300 -350 bhp. Forget the type 9, it simply will not cope with the power or torque. 260 bhp is normally
quoted as the limit for a HD box and even then regular rebuilds are essential. A mate of mine with 250 bhp regularly breaks syncros, he uses steel
ones on 1st and 2nd now but the box requires a strip to lap them in every 2000 miles or so.
You need a Borg Warner T5 box as used by Ford in the early 2WD Sierra Cosworth. Its bigger and heavier but since it originated in the Mustang it can
cope with outrageous power and torque. The Sierra ratios are pretty OK but Quaiffe do closer ones in needed. TVR also used the box but the ratios are
naff. Not sure what ratios the Mustang used.
But does anyone make a T5 bellhousing to suit your engine.
there are afew people on here running zetec turbo with stock type 9 and they have been fine as i was worried with my box and the power i have
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TurboWood
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posted on 26/8/13 at 04:04 AM |
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Paul,
You are right that the T5 would cover my power, but it won't fit in the chassis I have. It's unfortunate too because quad4rods actually
does have a bell housing.
I'm hoping the SPC or BGH will be ok since most of my driving will be on the street. So, it won't have to live with sustained 300+hp
abuse. On the track I'll probably need to dial it back a bit for cooling reasons anyway.
The quaife 56G is my backup plan, but I would hate to take out a mortgage for a transmission...
Daniel
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jeffw
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posted on 26/8/13 at 05:23 AM |
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All this talk about power is not really relevant, it is torque that kills gearboxes. I run a BGH E8 box in my Phoenix which has a Rotrex'ed
Zetec making 340BHP/260 ft lb on a 3.54 ATB English axle.
In this situation the box is marginal and I have linear power delivery unlike a turbo which while have a big lump of torque suddenly coming in. If
you go for the SPC or BGH you will likely be rebuilding it frequently. I am looking (at some stage) to change my Type 9 for either a 57G or 60G
Quaife which 'should' cope with the power.
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puma931
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posted on 26/8/13 at 07:35 AM |
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+ 1
quote: Originally posted by Paul Turner
Having had a Seven now for 25 years my personal opinion is the cars are all about rapid in gear acceleration for overtaking. A decent top for
reasonable cruising is also required but in mine with a 3.9 diff it is doing 3500 rpm at 70 which is fine (although higher than many tintops).
If you fit a 3.14 diff with either a SPC or BGH box you will end up with a car that will theoretically do about 58 mph in first at 7000 rpm (depending
on tyre size) and have a theoretical top speed of approx 175 mph. Such a high first gear will put quite a strain on the clutch. In a light car like a
Seven its normally the tyres that break traction in the lower gears before the clutch slips unless the clutch is knackered.
Based on my personal experience I would not want a turbo in a Seven ever. Driven a supercharged car once, did not suit the character of the car. With
175 bhp and a weight of about 600kg my car will beat almost anything on the road and does not frighten me. It had 208 bhp at one time but on a normal
road trip the car was no faster, it just used more fuel. I do not have to worry about the turbo coming on boost and throwing me off the road.
There are many Seven owners out there with 1.3 pushrods who have more fun than those with stupid power levels.
Just my opinion.
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mcerd1
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posted on 26/8/13 at 09:04 AM |
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the T5 size compares quite well to a type 9 (smaller than a lot of other boxes folk have fitted in 7's) are you really so tight for space that
you couldn't make it fit
[Edited on 26/8/2013 by mcerd1]
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Paul Turner
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posted on 26/8/13 at 04:12 PM |
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quote: Originally posted by jeffw
All this talk about power is not really relevant, it is torque that kills gearboxes.
I know that but it is very difficult to quote the torque capacity of a gearbox when Quaiffe etc quote only the max BHP and max revs.
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jeffw
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posted on 26/8/13 at 04:43 PM |
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BGH will tell you the torque rating of their various boxes, as will Elite. I've spoken to Quaife in the past and they have torque figures in
their site as well.
A 300HP Turbo car is much more likely to kill a box than a 300HP NA car or a Rotrex car. And this is simply because the torque comes in all at once
on most turbo cars.
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beaver34
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posted on 26/8/13 at 08:22 PM |
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So what are the realistic option for 350bhp and 270lbft of torque if wanting to something that will not break
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jeffw
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posted on 26/8/13 at 09:04 PM |
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Not a Type 9...56/57G Quaife or a T5.
this is what I did to a Type 9 with 260 ft lb
I'm running a BGH E8 alloy Type 9 with all the extra strengthening they can do and it is holding together at the moment. Brian and Chris are
talking about a stronger Type 9 but there is no timescale. If this one goes bang I'm off to get a 57G.
[Edited on 26/8/13 by jeffw]
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beaver34
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posted on 26/8/13 at 09:06 PM |
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How long did that take jeff?
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jeffw
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posted on 26/8/13 at 09:08 PM |
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About 5 Sprints. 3rd gear is very brittle if you use the standard Ford third (which the BGH E6 does). As I said the BGH E8 is in the car now and has
been for about 12 months but that is a Rotrex not a turbo...
[Edited on 27/8/13 by jeffw]
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TurboWood
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posted on 27/8/13 at 06:58 AM |
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Jeff,
That is a good looking gear set . A little JB weld and it should be good to go.
Does anyone know of someone that has used the Quaife 56G transmission?
Daniel
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