What about that 'box!
Discussion
I'm considering the purchase of a Lotus Esprit V8. Looking at the specs and development of the car I'd guess a '98 onwards model would be preferrable if only for an interior that doesn't look like it's been made as part of a child's woodwork project!
What worries me the most is the gearbox. Not so much the quality of the shift but the fact that the gearboxes don't really seem to be able to take the power of the V8. Call me cynical but I also suspect the peak torque of 295lb/ft for a 3.5 litre twin-turbo V8 is artificially restricted - is that the case?
Are there upgrades or alternatives available for this 'box apart from the 12k Quaife item?
What worries me the most is the gearbox. Not so much the quality of the shift but the fact that the gearboxes don't really seem to be able to take the power of the V8. Call me cynical but I also suspect the peak torque of 295lb/ft for a 3.5 litre twin-turbo V8 is artificially restricted - is that the case?
Are there upgrades or alternatives available for this 'box apart from the 12k Quaife item?
Jamie. The power and torque outputs of the V8 esprit are set to not exceed the limitations of the gearbox. Lotus could have easily had more power and torque from the v8. There are simple upgrades that will give you big power increases, but then you risk your transmission..
The stock ecu will further limit the torque available in the first three gears in all v8 esprits to prolong the life of the gearbox. The Sport 350 (and 2000-on cars) had a revised ecu that allowed greater torque in the lower gears (but still not the full 295lbf). You can upgrade any car to the hi-torque/sport350 spec ecu.
That said, the car is still WAY fast - even with these restrictions. Autocar quote 4.1 seconds to 60mph and 9.5 seconds 0-100 mph. So... its debatable whether the car actually needs any more power.
If you want to do burnouts, donuts or drag race the car, then you'll probably break something. Drive sympathetically however -ie take your time over shifts and don't rush the box - just like you would on an open gate ferrari change - then the box is fine.
I've done some research into possibilities of alternative transmissions - I've come to the conclusion there is nothing that is cost effective. My v8 now has 60 miles on it, i use it every day and i've (touch wood) not had any transmission problems.
The renault box is stronger than people think. Johan Hybinette drag raced his car (10.9 sec) with the standard transmission and it held up ok. His car has probably double the standard v8 cars output btw!
Johan tells me he now has a porsche g50 that he intends to fit. Hopefully he share his knowledge on this
cheers
Rob
The stock ecu will further limit the torque available in the first three gears in all v8 esprits to prolong the life of the gearbox. The Sport 350 (and 2000-on cars) had a revised ecu that allowed greater torque in the lower gears (but still not the full 295lbf). You can upgrade any car to the hi-torque/sport350 spec ecu.
That said, the car is still WAY fast - even with these restrictions. Autocar quote 4.1 seconds to 60mph and 9.5 seconds 0-100 mph. So... its debatable whether the car actually needs any more power.
If you want to do burnouts, donuts or drag race the car, then you'll probably break something. Drive sympathetically however -ie take your time over shifts and don't rush the box - just like you would on an open gate ferrari change - then the box is fine.
I've done some research into possibilities of alternative transmissions - I've come to the conclusion there is nothing that is cost effective. My v8 now has 60 miles on it, i use it every day and i've (touch wood) not had any transmission problems.
The renault box is stronger than people think. Johan Hybinette drag raced his car (10.9 sec) with the standard transmission and it held up ok. His car has probably double the standard v8 cars output btw!
Johan tells me he now has a porsche g50 that he intends to fit. Hopefully he share his knowledge on this
cheers
Rob
Thanks for that Rob. I was really only concerned with some of the tales I've heard of people having to restrict full-on accelleration in the first two gears to preserve the gearbox. Whilst I'm not planning on wheel-spinning my way to work the prospect of not being able to put my foot down when I like isn't exactly a selling point. I suspected the truth was somewhere in between.
I've heard the Porker gearbox is a very involved conversion, but I was wondering whether a Toyota Supra gearbox could be made to work as they are plentiful here in NZ, cheap and very, very strong. Of course this would only be if I had problems with it or I wanted to upgrade the engine to produce more power which I think would be on the cards! I still think 295lb/ft of torque sounds very low for a turboed 3.5 V8. I would expect the figure to be on the right side of 350 lb/ft so I suspect the torque is curtailed even on the Sport 350.
As you say they are plenty fast enough, and the main attraction of an Esprit to me is the handling. I haven't driven an eight cylinder car yet and there's only three in NZ so I'll be lucky! The four cylinder cars I've driven in the past handled beautifully but were distracting in the lack of brakes, heavy steering and poor build quality (although I'm used to some of that in earlier TVRs!).
Thanks
I've heard the Porker gearbox is a very involved conversion, but I was wondering whether a Toyota Supra gearbox could be made to work as they are plentiful here in NZ, cheap and very, very strong. Of course this would only be if I had problems with it or I wanted to upgrade the engine to produce more power which I think would be on the cards! I still think 295lb/ft of torque sounds very low for a turboed 3.5 V8. I would expect the figure to be on the right side of 350 lb/ft so I suspect the torque is curtailed even on the Sport 350.
As you say they are plenty fast enough, and the main attraction of an Esprit to me is the handling. I haven't driven an eight cylinder car yet and there's only three in NZ so I'll be lucky! The four cylinder cars I've driven in the past handled beautifully but were distracting in the lack of brakes, heavy steering and poor build quality (although I'm used to some of that in earlier TVRs!).
Thanks
You can run with more power and keep the standard box, you just have to be a bit careful that's all. I know of several people who have the 'race' ecu in their v8s and still run the stock transmission. It gives about 450bhp (not sure about the torque figure).
The sport350 had more torque in allowed in the lower gears, but the max power and torque figures were no greater than the regular car. I have this ecu in mine.
I drive mine very hard in all the gears - no problem. The biggest risk is rushing the change, say 1-2 and giving it full whack before the gear is complete engaged - you'll trash the synchro. Take your time and allow the synchro to do its job and you'll be fine.
The sport350 had more torque in allowed in the lower gears, but the max power and torque figures were no greater than the regular car. I have this ecu in mine.
I drive mine very hard in all the gears - no problem. The biggest risk is rushing the change, say 1-2 and giving it full whack before the gear is complete engaged - you'll trash the synchro. Take your time and allow the synchro to do its job and you'll be fine.
Jamie. The Toyota Supra gearbox is just that, a gearbox. It does not incorporate the differential unit in the same casing. Its also longer than the Renault box overall. The idea is unworkable.
The Renault boxes are very strong. I have a 350 Chevrolet V8 on a UN1-13 box. I have 430 Hp and 440ft/lb. If you abuse the box, you will break it, any gearbox, rev the engine to 6000 and slip your foot off the clutch sideways and anything will break. Be smooth with your gear changes not notchy and wait till the driveline is taken up before you boot it. But if you do break the box, I have a few here in NZ you could have.
The Renault boxes are very strong. I have a 350 Chevrolet V8 on a UN1-13 box. I have 430 Hp and 440ft/lb. If you abuse the box, you will break it, any gearbox, rev the engine to 6000 and slip your foot off the clutch sideways and anything will break. Be smooth with your gear changes not notchy and wait till the driveline is taken up before you boot it. But if you do break the box, I have a few here in NZ you could have.
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