Hi Torque gearbox & ECU

[ColonelShagnasty]

I am new to Esprits, but not Lotus and I am thinking of buying an 98/99 GT3. Two questions...

1)I have seen numerous references (not on this site necessarily) to the Hi-Torque gearbox for the '98 onwards V8 & GT3. What is the difference between this and the previous version?

2) What is the Hi-torque ECU? Is this a factory chip or what; and what effect does it have? Many folk appear to criticise the low end performance of the GT3 engine before the turbo kicks in.

Ian

[kmaier]

1- There is a High-Torque ECM for the V8 engines: one which covers 1997-1999 models and another which covers 2000-2001 models. The 1999 Sport 350 had improved torque (standard) which was also used on the 2000-2001 (and later) model years. Currently there is no High-Torque upgrade for the 2002-2003 model years. In short, it improves torque in the lower gears which improves driveability under normal conditions. Needless to say, the 1997-1999 model years benefit the most.

2- Apparently gearbox strength has been improved slightly (but could be considered doubtful). The more significant change was in 1998 as the shifter and associated linkage was improved and no longers requires a translator as previous models. Shifting is better overall and adjustment is greatly simplified. Certainly a nice change overall. Also note that this is not easily implemented in older models as the shifter is quite different and requires some internal changes to the plumbing which runs thru the backbone chassis.

Regards, KM
2000 V8

[rob.e]

Ian - as Kevin says.. the hi-torque upgrade is usually something associated with the v8 engine. The gearbox for a gt3 is essentially the same unit as the v8 which is renault sourced and has been used in esprits since 88 or so. I've never heard of a hi-torque gearbox.

There are several chip upgrade options for the 4 cylinder. Several guys on the uklotusesprit yahoo group have these chips on their cars with good results. The chips are not a factory upgrade. Race-speed and PUK racing sell them.

[adrianmugridge]

I've seen a car advertised ( something like an 87 turbo ) as having the high-torque GT3 gear box fitted as an upgrade. I did not know the GT3 gear box was any different to any other renualt gerbox that has been fitted for years.

Adrian
97GT3

[MikeyRide]

Interesting. I could swear that the service notes identify a "high torque gearbox" arriving with the S4s.

[madmike]

The S4s had an uprated clutch, but the gearbox is the same otherwise.

The uprated clutch can handle additional torque, so I imagine that's what they mean by High Torque transmission.

It will still have the standard Renault failings (ie 2nd gear synchro) regardless...it's probably even more susceptible as the power is being transferred to the tranny with less clutch slippage.

Then again, I may be talking out my ass today...

[colonelshagnasty]

Thanks for your replies. The ECU info at Lotus Espritworld looks very interesting.

Regarding the gearbox, I have searched again for references and found the earliest is on the Esprit Fact File where the 93MY mentions a revised High Torque RH Shift transmission. There are many adverts and web sites referring to cars from S4 onwards as to having the High Torque, but I guess its nothing special or everyone would want one!

BTW, have you heard of Derek Bell (not the driver!) and his gearbox mods? This guy mods the UN1 box for GT40 replicas and similar, but does not appear to be connected to the LOtus world. See www.bell-performance.co.uk/

Thanks, Ian

[kmaier]

I posted info and links for Derek's website a couple weeks back. Also sent him email... he replied and is meeting with some Lotus owners in the UK soon to discuss more of this. Personally, I would like to be able to fit this into the gearbox for my V8 along with a Quaife ATB diff.

Regards, KM
2000 V8

[GRK]

The Renault transmission was upgraded with some supposedly meatier bearings and gear hardening etc - the beefed up transmissions are identifiable by the tag on the rear case - the GT3 and V8 trannies are marked UNI-027 and UNI-028, the earlier SE transmission - ie not uprated is the UNI-016. The clutch was upraed on the S4s cars with an 8400N cover as opposed to the 7000N standard cover. Interestingly the 25% "uprated" clutch offered by Moto concept is marked 6500N.....