Renault 369 5 speed
- Thread starter Neal
- Start date
Robert Logan
Defunct Manufactuer - Old RF Company
The quick answer is a big NO !!!!!
The R30 gearbox is good for 250 to 300 HP at the flywheel and is flawed because of its design, bolts along its length. The gearbox is used in other forms in the Lotus Esprit and the Renault 25 Turbo. These only have different ratios and are still flawed because of design.
The Audi box is without the best gearbox for performance / price.
Good luck, Robert
The R30 gearbox is good for 250 to 300 HP at the flywheel and is flawed because of its design, bolts along its length. The gearbox is used in other forms in the Lotus Esprit and the Renault 25 Turbo. These only have different ratios and are still flawed because of design.
The Audi box is without the best gearbox for performance / price.
Good luck, Robert
G
Guest
Guest
Can't necessarily agree with Robert on power that a Renault box can handle. From practical experience I have run 24000 miles at 350 (flywheel) dyno proven horsepower through a renualt transaxle. I have broken more AP racing clutches than had problems with the gearbox itself. Not to say there haven't been some problems but remember I have been in competition now for 9 years basically concentrating hill climbs and sprints which involve many standing starts. The only main problem I have had is that my synchros suffered after this amount of competition and track use. I have just bought a second hand box for £350 and bunged it in.
Problems other people have suffered is that if you do too much wheelspin the diff's can suffer. A pin in the diff is located by a knurled friction fit. If this comes out it serously damages your diff. If you know this then a simple home made mod can be done to prevent it coming out. There has been a spurt of these recently.
If you start to go into the 400 bhp plus territory then you are going to be on borrowed time. However to overcome this there is now an off the shelf replacement diff from Quaife which also gives LSD capability. Something worth having. In addition a club member designed his own input and primary shaft as a single one peice item removing the spline and also increased the diameter of the shaft at its considered weak point. Whilst doing this he also raised the 1st and 2nd gear ratios by about 10-15%. A number of our members run this in their gearboxes now but in general that is because they are at the 500 bhp level of power and climbing.
Over 400 GTDs are out there, most on the raod. 90% will be running Renault transaxles and have over 300 bhp.
The reason why CAV and otehrs are shying away from Renaults is getting them new costs a fortune now. £2500 and second hand units are also climbing in price. Supply is drying up. Ever since Lotus put them on their V8 Esprits the prices went silly.
Internally the Renault gear box family that 40 users use are all pretty much the same. The casing is considered to be good. So there is now a chap out there who is working up to commission Quaife to use the casing and supply all Quaife gears and shafts inside. This however won't be cheap.
The Renault box is still one of the most popular boxes out there. It has been in use for many years now and has survived years of competition. Other makes are now being used such as the Audi. Have they been in hard enough use (compared to Renault boxes) over a long enough period of time to say that they are the only way to go now? That is your question to answer. People thouht this about the Porsche G50 box but it is coming out now that it is not all that it was cranked up to be.
How many ordinary road car gearboxes are designed to take 400 bhp? Not very many if you think about it. And also how many are designed to be revved highly with this high horsepower? Like Renault Audi do not make cars with 350 plus bhp as a general rule and have boxes that we can afford to bung in our 40's.
Finally in my opinion it is not bhp that kills your gearbox but torque.
Malcolm
Problems other people have suffered is that if you do too much wheelspin the diff's can suffer. A pin in the diff is located by a knurled friction fit. If this comes out it serously damages your diff. If you know this then a simple home made mod can be done to prevent it coming out. There has been a spurt of these recently.
If you start to go into the 400 bhp plus territory then you are going to be on borrowed time. However to overcome this there is now an off the shelf replacement diff from Quaife which also gives LSD capability. Something worth having. In addition a club member designed his own input and primary shaft as a single one peice item removing the spline and also increased the diameter of the shaft at its considered weak point. Whilst doing this he also raised the 1st and 2nd gear ratios by about 10-15%. A number of our members run this in their gearboxes now but in general that is because they are at the 500 bhp level of power and climbing.
Over 400 GTDs are out there, most on the raod. 90% will be running Renault transaxles and have over 300 bhp.
The reason why CAV and otehrs are shying away from Renaults is getting them new costs a fortune now. £2500 and second hand units are also climbing in price. Supply is drying up. Ever since Lotus put them on their V8 Esprits the prices went silly.
Internally the Renault gear box family that 40 users use are all pretty much the same. The casing is considered to be good. So there is now a chap out there who is working up to commission Quaife to use the casing and supply all Quaife gears and shafts inside. This however won't be cheap.
The Renault box is still one of the most popular boxes out there. It has been in use for many years now and has survived years of competition. Other makes are now being used such as the Audi. Have they been in hard enough use (compared to Renault boxes) over a long enough period of time to say that they are the only way to go now? That is your question to answer. People thouht this about the Porsche G50 box but it is coming out now that it is not all that it was cranked up to be.
How many ordinary road car gearboxes are designed to take 400 bhp? Not very many if you think about it. And also how many are designed to be revved highly with this high horsepower? Like Renault Audi do not make cars with 350 plus bhp as a general rule and have boxes that we can afford to bung in our 40's.
Finally in my opinion it is not bhp that kills your gearbox but torque.
Malcolm
John Owen the former Lotus engineer who designed the Lotus twin-turbo 3.5 V8 says that the engine was "de-tuned" from its' original form to allow the Renault gearbox to survive in the Esprit. That would indicate to me that Lotus had concerns about life span of the unit with more power.
That said, the basic rule of powertrain capacity is that if the tires can be broken loose, the parts will be OK, if they hook up the shock load will transfer directly to the parts and pieces that are asked to transmit it.
"If you drop the hammer, you are hammering the bits"
Rick
That said, the basic rule of powertrain capacity is that if the tires can be broken loose, the parts will be OK, if they hook up the shock load will transfer directly to the parts and pieces that are asked to transmit it.
"If you drop the hammer, you are hammering the bits"
Rick
Robert Logan
Defunct Manufactuer - Old RF Company
Malcome,
Concur to 300 / 350 BHP and with the Torque problem and definately with the idea of letting the rear break away.
To evertbody looking a 'what box ':
The strength of all gearboxes is a function of the Forth power of the seperation of the shafts. This is what counts together with design.At Roaring Forties we have measured many gearboxes from Renault to Porsche to ZF to Audi (read Gatrag at CAV ). We have even measured a number of Hewland boxes and other full race boxes. Please do this exercise and you will see the numbers for yourselves.
The second and equally important requirement is Design ! By this I mean the method of holding the shafts together. The examination of gearbox failure is the only method of improving design. Many failures occur when the gears are forced out of mesh. The methods used to keep them together is bearing cradles and the overall shape of the outside casing. The ZF and other race boxes tend to have an almost rectangular design and not the oliptical shape associated with the normal roar boxes. One of the reasons is that power being transfered through the box tries to seperate the shafts the poor designed boxes tend to change in shape and the major axis increases in size and the minor reduces in size, the gear teeth mesh reduces. A failure could occur.
It is a fine art of looking and understanding and looking at the other boxes, the modifications available and asking yourself 'why have they done that and what is the reason'.
In Australia we race 'Group A Touring Cars' a V8 engined car producing almost 650 HP and weighing 1350 kg. (almost 3000lbs.) with insane grip levels. These cars have or have had such things as traction and launch control. It is from this category that my key staff cut their teeth. The gearboxes used here are full race boxes made just for the category. One of the companies making these boxes ( just about 50% of the total field) has modified many race boxes to deal with very high horsepower cars. One of his Porsche 915 boxes is racing with over 800 HP being blasted through it.
We are currently working with this company to do internal mods to our Audi boxes so that we can race with over 500 HP, well over.
The Renault gearbox is a good box and works well with normal levels of power, but a box that has a bolted seam running north / south is fundimentally flawed and the examination of other boxes would show that the 'can ' method (east / west bolting ) must be stronger. I think that the Renault boxes were designed this way for ease of manufacture and assembly and not strength, a requirement of cost.
As a final point regarding the Roaring Forties choise of box, the Audi, the best way is to explain the rejection process.
ZF - excellent box, original, TOO expensive.
G50 - must be inverted, drive shafts angle wrong and CV's under to much load in race conditions.
Renault - refer to above.
Audi - excellent road box with typical over engineering associated with Porsche. Posible to improve with re- engineering. Only problem first gear part of input shaft.
I hope this helps and also indicates the level of engineering that was undertaken in the selection of our gearbox.
To those of you pondering over 'which box' look at the application and choose for yourselves. Good luck !!!
Robert
Concur to 300 / 350 BHP and with the Torque problem and definately with the idea of letting the rear break away.
To evertbody looking a 'what box ':
The strength of all gearboxes is a function of the Forth power of the seperation of the shafts. This is what counts together with design.At Roaring Forties we have measured many gearboxes from Renault to Porsche to ZF to Audi (read Gatrag at CAV ). We have even measured a number of Hewland boxes and other full race boxes. Please do this exercise and you will see the numbers for yourselves.
The second and equally important requirement is Design ! By this I mean the method of holding the shafts together. The examination of gearbox failure is the only method of improving design. Many failures occur when the gears are forced out of mesh. The methods used to keep them together is bearing cradles and the overall shape of the outside casing. The ZF and other race boxes tend to have an almost rectangular design and not the oliptical shape associated with the normal roar boxes. One of the reasons is that power being transfered through the box tries to seperate the shafts the poor designed boxes tend to change in shape and the major axis increases in size and the minor reduces in size, the gear teeth mesh reduces. A failure could occur.
It is a fine art of looking and understanding and looking at the other boxes, the modifications available and asking yourself 'why have they done that and what is the reason'.
In Australia we race 'Group A Touring Cars' a V8 engined car producing almost 650 HP and weighing 1350 kg. (almost 3000lbs.) with insane grip levels. These cars have or have had such things as traction and launch control. It is from this category that my key staff cut their teeth. The gearboxes used here are full race boxes made just for the category. One of the companies making these boxes ( just about 50% of the total field) has modified many race boxes to deal with very high horsepower cars. One of his Porsche 915 boxes is racing with over 800 HP being blasted through it.
We are currently working with this company to do internal mods to our Audi boxes so that we can race with over 500 HP, well over.
The Renault gearbox is a good box and works well with normal levels of power, but a box that has a bolted seam running north / south is fundimentally flawed and the examination of other boxes would show that the 'can ' method (east / west bolting ) must be stronger. I think that the Renault boxes were designed this way for ease of manufacture and assembly and not strength, a requirement of cost.
As a final point regarding the Roaring Forties choise of box, the Audi, the best way is to explain the rejection process.
ZF - excellent box, original, TOO expensive.
G50 - must be inverted, drive shafts angle wrong and CV's under to much load in race conditions.
Renault - refer to above.
Audi - excellent road box with typical over engineering associated with Porsche. Posible to improve with re- engineering. Only problem first gear part of input shaft.
I hope this helps and also indicates the level of engineering that was undertaken in the selection of our gearbox.
To those of you pondering over 'which box' look at the application and choose for yourselves. Good luck !!!
Robert
G
Guest
Guest
Robert
Don't forget availabilty of adapters.
There are several for the Renault.
Until Audi adapters are readily available,
it's difficult for those (like me) with
existing cars to change design.
MikeD
Those
Don't forget availabilty of adapters.
There are several for the Renault.
Until Audi adapters are readily available,
it's difficult for those (like me) with
existing cars to change design.
MikeD
Those
G
Guest
Guest
Paul Thompson 'Hooligan'
Admin
Hi all,
Roy Smart and I use a R21 turbo box as Malcolm describes (Un1), it has been modified in two ways. Firstly, the main shaft has been built by Quaife with a straight cut first and higher ratios on first and second. The larger diameter input shaft is also one piece to the spigot bearing, thus removing the problem of the quill shaft breaking where it had been necked down on the standard item. The spline is also now 'Ford' instead of Renault giving a wider choice of clutch options.
This Shaft / Gear modification was designed by a GTD club member and is available from Quaife, with his permission, as a retrofit kit of parts.
The strength of these parts was proven at the Wiscombe Hill Climb this year, when Dave Parker (GTD-R42 / Chevy 350) had the pin supporting a planetary gear break in the std diff. This pin exited the differental and attempted to pass between the crown wheel and the bevelled pinion gear to which it normally meshes. The resulting 'Bang' burst the Renault casings apart (depositing a 100yd oil slick) but all the Quaife parts survived unscathed. Once fitted to another casing - Dave was back up and running again.
Secondly, we and others now use the Quaife ATB differential which thus far has performed well. Our 0 to 60 mph has been recorded at 3.7 seconds with 100mph in 8.6.
The failing of the std diff seems to stem from 'excessive wheelspin' which in turn causes the two planet gears to rotate at very high speeds. These then overheat, sieze, break their supporting pin etc etc.
Ray Christopher uses an Audi 6-speed in his GTD-40 spyder which is beginning to show form. Watch this space..
regards
Paul Thompson
ps - the 'bang' mentioned is shown 'in-car' on this years GTD Club Video - 150 mins of '40' fun.
For details of video (currently PAL only) - Contact club & forum member [email protected]
[ December 15, 2001: Message edited by: P Thompson ]
Roy Smart and I use a R21 turbo box as Malcolm describes (Un1), it has been modified in two ways. Firstly, the main shaft has been built by Quaife with a straight cut first and higher ratios on first and second. The larger diameter input shaft is also one piece to the spigot bearing, thus removing the problem of the quill shaft breaking where it had been necked down on the standard item. The spline is also now 'Ford' instead of Renault giving a wider choice of clutch options.
This Shaft / Gear modification was designed by a GTD club member and is available from Quaife, with his permission, as a retrofit kit of parts.
The strength of these parts was proven at the Wiscombe Hill Climb this year, when Dave Parker (GTD-R42 / Chevy 350) had the pin supporting a planetary gear break in the std diff. This pin exited the differental and attempted to pass between the crown wheel and the bevelled pinion gear to which it normally meshes. The resulting 'Bang' burst the Renault casings apart (depositing a 100yd oil slick) but all the Quaife parts survived unscathed. Once fitted to another casing - Dave was back up and running again.
Secondly, we and others now use the Quaife ATB differential which thus far has performed well. Our 0 to 60 mph has been recorded at 3.7 seconds with 100mph in 8.6.
The failing of the std diff seems to stem from 'excessive wheelspin' which in turn causes the two planet gears to rotate at very high speeds. These then overheat, sieze, break their supporting pin etc etc.
Ray Christopher uses an Audi 6-speed in his GTD-40 spyder which is beginning to show form. Watch this space..
regards
Paul Thompson
ps - the 'bang' mentioned is shown 'in-car' on this years GTD Club Video - 150 mins of '40' fun.
For details of video (currently PAL only) - Contact club & forum member [email protected]
[ December 15, 2001: Message edited by: P Thompson ]
Jim Rosenthal
Supporter
I spoke with Hobart Kennedy last week regarding GT40 trnsaxles. They do make adapters, and he can direct you to a company in California which rebuilds and modifies Porsche transaxles of various types. I think it is called Transaxle engineering. Also, possibly of interest: he has a ZF 5DS25-2 transaxle which has been sitting in his shop for several years. It was rebuilt and never put into a car, according to him. He also has a bellhousing (ZF) for it. That would need a clutch arm, I think, and throwout bearing, probably a few other odd pieces. The price was $5500US for the two. The other pieces could probably be obtained from Lloyd at RBT Transmissions, who have the rights to these ZF boxes.
I ran across these items looking for a ZF box for a GT40; I've made other plans but someone else out there may want it. The reputation of Kennedy Engineered Products is such that I would have no qualms about buying anything from them. Email me if you have any questions and I'll pass on whatever else I know.
Jim Rosenthal
I ran across these items looking for a ZF box for a GT40; I've made other plans but someone else out there may want it. The reputation of Kennedy Engineered Products is such that I would have no qualms about buying anything from them. Email me if you have any questions and I'll pass on whatever else I know.
Jim Rosenthal
G
Guest
Guest
the best tranny, in my opinion, would be the the G50/50. there are porsches out there with 800 hp using this transmission so this should be a very good option for the SB ford motor. all you have to do is stay away from the torque and that is easy to do with a cam and a port job. you should stay away from low end torque on any transaxle.
the G50/50 is a bit expensive but the parts are out there(availability) and the adaptor you can find at kennedy eng. or at patric eng.
in my car i have a G50. it doesn't have the same top end as the G50/50 but its too late now for me. i think this tranny will suffice for the time being. if i decide to change it later on i'll already know what to do.
just my .02
luis
the G50/50 is a bit expensive but the parts are out there(availability) and the adaptor you can find at kennedy eng. or at patric eng.
in my car i have a G50. it doesn't have the same top end as the G50/50 but its too late now for me. i think this tranny will suffice for the time being. if i decide to change it later on i'll already know what to do.
just my .02
luis
G
Guest
Guest
FYI
I received an E-mail from Kennedy and they
do NOT make an Audi/Ford adapter nor do they have plans to. Of course if someone threw
buckets of money at them things might change.
Looks like the boys in the UK have done a lot
of work to upgrade the Renault box. Does anyone have a price tag for what one of these
"custom built" would cost and how much HP
it will hold? The G50 trans is not cheap
and requires rework to use in a 40 so
the economics may still work in favor
of the Renault, depending upon the HP level.
Also, I understand that a 6-speed will soon
be available. That would be way cool!
MikeD
I received an E-mail from Kennedy and they
do NOT make an Audi/Ford adapter nor do they have plans to. Of course if someone threw
buckets of money at them things might change.
Looks like the boys in the UK have done a lot
of work to upgrade the Renault box. Does anyone have a price tag for what one of these
"custom built" would cost and how much HP
it will hold? The G50 trans is not cheap
and requires rework to use in a 40 so
the economics may still work in favor
of the Renault, depending upon the HP level.
Also, I understand that a 6-speed will soon
be available. That would be way cool!
MikeD
Mike, I self imported an R21 from Chris at Mach I Transmissions (UK)this past spring. Granted it is a rebuilt unit, but it has been converted to accept either a left or right hand gear change, and incoprorates all of the proven quick shift mods that the UK boys have sorted out. It DOES NOT have the locking differential, or heavier input shaft that have been recently discussed. However, I plan on keeping the H.P. to manageable levels, say 375 to 400, so this should perform adequately for me. The reality for me is how fast does "REAL FAST" have to be? I never plan on fender to fender encounters on a track. Price, I don't think it appropriate for me to advertise this for Chris, but it was very reasonable. If you wish, email me for additional specifics about adapters, clutch, CV joints, etc. Brian
G
Guest
Guest
The G50 and G50/50 as compared to the ZF (who also makes the G50s) is cheap. As far as rework goes this is a simple matter of making the breather the plug and the plug the breather. Some drill a oil level hole in the side of the case, but a simple dipstick does nicely for me thank you. Only real knock on the G50 is that, since it is inverted, the proper oil level is at the same level as the input shaft; this leaves it prone to leaks if the input shaft seal should become worn. Since I have used U-joints with adapters the CV joints aren't an issue (Corvette short shafts,bearings, etc.) As mentioned they can handle the V8 fine thank you and are much newer design than the 5DS25 (if you use this,saftey wire the diff bolts!) As far as angles of the half shafts, in my car they are not nearly what the Pantera has and they are not straight either (a little angle is a good thing.) I believe I will have many years of happy motoring with this transaxle and if I want more speed, the gear sets are available @ around $120per. I only wish I had the range of final drive ratios that US diffs have.
G
Guest
Guest
Lynn
The G50 may be 1/2 the cost of of a ZF...
but from what I've seen, the Renault and Audi
are 1/2 the cost of the G50 (or less)!
It all depends on what HP/torque
you expect the trans to handle. Like Neal, I'm looking for 400-450 BHP capability, using street clutch and street tires.
If the Renault can handle that level(with a few mods)it sounds like that would be more
cost effective than the G50 (that means I'm on a TIGHT Budget)!
Do you have a source for cheap G50s?
MikeD
The G50 may be 1/2 the cost of of a ZF...
but from what I've seen, the Renault and Audi
are 1/2 the cost of the G50 (or less)!
It all depends on what HP/torque
you expect the trans to handle. Like Neal, I'm looking for 400-450 BHP capability, using street clutch and street tires.
If the Renault can handle that level(with a few mods)it sounds like that would be more
cost effective than the G50 (that means I'm on a TIGHT Budget)!
Do you have a source for cheap G50s?
MikeD
Mike D,
I was able to find a G50 easily over the internet. 5th person I contacted had a 0 Mile
rebuild. It was $3500, but no core, add $1500 for that and $1500 for a new Quaiff LSD.
$6000 for basically a new gearbox w/LSD. I
hope that $# doesn't scare you too much.
Regards,
Bill Bayard
DRB GT40/005
351W/400HP
750 Edelbrock
I was able to find a G50 easily over the internet. 5th person I contacted had a 0 Mile
rebuild. It was $3500, but no core, add $1500 for that and $1500 for a new Quaiff LSD.
$6000 for basically a new gearbox w/LSD. I
hope that $# doesn't scare you too much.
Regards,
Bill Bayard
DRB GT40/005
351W/400HP
750 Edelbrock
G
Guest
Guest
i found my G50 in california at parts heaven. it had 25k miles and it cost me $1900 with shipping. when i took it apart to flip it, it looked perfect inside exept for the 2nd gear synchro. the cost for flipping and new parts was $675. for the limited slip diff i went to phantom grip(www.phantomgrip.com). they will make a limited slip for your open diff and it costs $300 plus shipping of parts. they don't show that they had a kit for the G50 but when i showed it to the owner he said that there was no problem. luckily the guy is a local so i can drive there and back. so for less than $3000 i got a great tranny for my 40. all i need now is the cable shifting linkage and shifter which is another $800 from patric engeneering.
cheers
luis
cheers
luis
I believe the G50/50 already has LSD as
well, so that would be an extra expense
you need not worry about. And, plenty
of (really weird) people do the Chevy 350/911
conversion and still use the G50/50 or
G50.
But, the Audi trans can be had for real
cheap -- maybe $300, and an LSD from RF
runs around $1600, so for around $2K, you're
set. And it should be good up until
insane amounts of HP and torque (which a 40
would not need -- I'm talking 600+ HP and
500+ lbs/ft of torque).
Ian
well, so that would be an extra expense
you need not worry about. And, plenty
of (really weird) people do the Chevy 350/911
conversion and still use the G50/50 or
G50.
But, the Audi trans can be had for real
cheap -- maybe $300, and an LSD from RF
runs around $1600, so for around $2K, you're
set. And it should be good up until
insane amounts of HP and torque (which a 40
would not need -- I'm talking 600+ HP and
500+ lbs/ft of torque).
Ian
G
Guest
Guest
Like others, I found mine off the internet and actually called a few places from adds in the back of C&D and R&T. The price of around $2K seemed pretty consistent for an "as-is" used G50s. With all the talk of LSDs, I had a chance at one, but I am building a road car that may get a little track time on occasion. Therefore, I purposely chose not to use an LSD - I don't plan to drag race either. I would rather have nice smooth corners and even tire wear. Having limited slip to say you have limited slip doesn't do anything for me.
