Snagger

Hi folks. Late into the discussion, so apologies - I have been busy with interviews for a new job, which did involve a long drive which may be relevant! As mentioned, I have been running this and other gearing combinations behind a Tdi, so have some relevant experiences. The V8 torque curves differ and are a little taller at peak, but the smoother application of the V8 should mitigate its higher output. As should its noise level in respect to driver comfort. So, what have I found? With 4.71 (standard) diffs and overdrive behind the Tdi, the car was under geared. Maximum comfortable driving speed was around 60 mph due to noise levels, though the car would top out at about 82mph. With all the accessories on the outside, and the increased weight due to the mods, I got a comparatively meagre 27mpg - not bad for the vehicle, but less than many owners with clean, light 88"s report. The good news is that 27mpg was utterly consistent whether I used super-duper diesel or supermarket diesel, and whether it was long motorway use or combined cycle use too and from work with all those hills, junctions and town driving. With 3.54 diffs, I get 30 mpg with or without overdrive. Again, this is extremely consistent, regardless of type of journey or grade of diesel. Total gearing is overgeared in first, but the engine still runs out of revs in 4th and is undergeared on fast roads. The overdrive and 3.54 diffs together are overgeared for a Tdi, and I suspect even a V8, hence the lack of economy improvement with the overdrive (the same 30mpg). Top end speed is similar, too, as the engine runs out of torque at about the same road speed that it previously ran out of revs. With the overdrive, engine noise in the cruise is greatly reduced, but at the expense of considerably more gear noise at all speeds. Transmission noise is up, but the main noise problem at the practical limit of 70mph is from the tyres and airflow (again, my accessories will be a significant factor). In general terms, 3.54s are not a nice drive. They are too tall for hill starts, on road as well as off, and they will have adverse effects off road as they seriously reduce the engine braking in first low. They're fine once up to speed, except that on standard transmissions, 30mph is a nice low rpm rumble in 4th gear, which as a straight-through coupling, makes minimum noise, heat and wear losses in the gear box. However, with 3.54 diffs, 30mph is a mid-revs 3rd gear drive, with increased heat generation and wear, as well as reduced engine efficiency. Furthermore, and most critically, combined use of 3.54 diffs and overdrive puts far more strain on the gear box than it can safely handle. Behind a V8 or Tdi, it will eventually shear the teeth off the gears or cause other internal failures if used in any gear other than fourth. The 3.54 diffs essentially limit the overdrive to acting as a fifth gear unless you don't mind frequently rebuilding the gear box. The ideal combination would be to have 4.11 diffs and overdrive, but that gets really expensive. So, assuming you are retaining the standard transmission, you have to decide whether to go 3.54 diffs, od or both. The diffs are inflexible but quieter and more efficient. You will lose the ease of driving at low speeds and on hills. The OD is much more flexible, but noisier and a little less efficient, but at least lo speed driving, off roading, towing and hills are no problem. And the combination where you have the increased gear noise and the possibility of gear box failure unless you make sure you always disengage the od before selecting lower gears, but more comfortable noise levels overall for long range driving at a practical limit of 70mph. There is a trick for mitigating the offroad issues of the tall diffs. Using SII Suffix B low range gears will offset roughly half of that diff gearing increase. Of course, these can be used in conjunction with the standard diffs for those wanting lower than standard gearing offroad. I am continuing to use the 3.54 diffs and OD together until my RRC is restored (a long time), bt once I can use that for commuting, the 109 will definitely be going back to 4.71 diffs.

From your description, it sounds like you have a sender fault, so just fit a genuine replacement (pattern parts are notoriously unreliable).

Brake cleaner leaves a residue, panel wipe is what you should use. I don't rate the Acid-8 etch primer highly. It is a combined etch and high build primer, and consequently doesn't etch well, even if the surface is keyed and meticulously cleaned. Use separate etch and high build primers.

Door and window seals are no problem - I have Defender types (I know, I know! ). I think the noise is coming through the bell housing area, but not from the housing itself - it's where I have the least insulation, the engine side of the bulkhead being quilted but not the underside of the bell housing and tunnel covers, and the WOR matting is at its thinnest there. I have a galvanised bulkhead, so the fibre matting shouldn't harm anything. I also don't get leaks, so it shouldn't get wet. But with the bituminous matting applied first, that should protect any metals. Thanks guys - it has given me good information on what to mix and match.

Thanks.

I had the WOR kit before I did the rebuild. Then I installed the Noise Killer matting on the front of the bulkhead, including the upper surfaces of the foot well uppers, the heater box, the whole underside of the bonnet and the entirety of the inner wings. That made no difference over the sound dampened by the WOR kit alone. The noise seems mostly to come from around the bell housing area, so that flashband sheeting and some medium density foam should do the trick. Where did you get the flashband? Builders merchants?

Hi all, I want to add to the sound proofing under my Wright Off Road kit (bulkhead, tunnel and footwells), as well as the interior of the foot well upper surfaces. I have not been that impressed by Noise Killer matting, which lines my entre engine bay and seems to have done little. I'm thinking of lead flashing, Dynamat or the old fashioned hessian fibre kits. Any suggestions?

Hi all, I want to add to the sound proofing under my Wright Off Road kit (bulkhead, tunnel and footwells), as well as the interior of the foot well upper surfaces. I have not been that impressed by Noise Killer matting, which lines my entre engine bay and seems to have done little. I'm thinking of lead flashing, Dynamat or the old fashioned hessian fibre kits. Any suggestions?

It's the contraryness that amuses me - in the UK, most LRs and Discoverys are Tdi and we drool over V8s, but over in the US, they have almost entirely v8s and want Tdis...

No - seris has parallel splines and a pinch bolt, while the coilers have taper splines and a compression nut.

Be fair, Fridge, most of us don't have the equipment to do that sort of testing. Stating that the engine won't be harmed by running without an intercooler but will lose performance is hardly a controversial opinion, ether. Just because I can't post up some numbers, that doesn't void what I said.

Don't get them from Paddocks - almost all their stock is Britpart, and of all their poor components, their seals are the worst. Use Dunsfold Land Rover - they do decent parts and are sensibly priced.

235, even with offset rims or spacers, are fine running around the country, but become a little irksome when manouevering in town, especially parking. It's fine having a heavy steering vehicle as a toy, Fridge, but as an everyday vehicle it become less fun. I still manage with mine, but my wife finds it too heavy to use unless compelled, and I'm not getting any younger myself.

The older type seems likely, but can you not ask your local specialist to supply both types with a refund on the type you don't need? They'll be able to sell them again soon enough, as long as you don't open the sealed bag.

... and while the offset rims regain the lost steering lock, they make turning the steering wheel heavier still, so you you get a double whammy from the wider tyres. The thicker tyres will also reduce forward visibility more in the case of a bonnet mounted spare. 7.50s are better if you can find a decent quality radial in the right tread.

That is the hub seal, and it will vary in dimensions depending on whether you have a pre or post rationalised axle. Get original seals, not pattern, and especially not Britpart.

I agree with all of the above - 7.50 will suit you best. 235/85 are a little wider, which is not ideal for Series rims (other than 1-ton or FC) and will not help steering loads or fuel economy. 225/75 would be an alternative for 6.50s on 88"s.

I have used two Zeus sets and found them to be excellent. When fitting seat retaining rings, I find it helps to run a file around the outside edge to make a small bevel, helping them into their holes.

Todd, I did a Tdi retrofit into a 109. If you use a Defender engine, you can use the engine driven fan from a 2.5 petrol, but I think the viscous fan will be too close to the rad unless you move it forwards. I used a Discovery engine, and that has the fan too low to be retained - it'd overlap the front cross member and probably make contact with it. I used a 14" electric fan with XEng XFan switch and manual activation switch (to pre-empt the temperature rise for long climbs or if the XFan fails. The intercooler is not covered by the fan, so has limited benefit at low speed, but everything runs just fine.

That's a good guide, but it doesn't mention the baseline fuelling adjustment screw on the rear face. I would try retarding the injection a tiny amount first and seeing if that reduces the black smoke without power reduction. If you get grey smoke instead, then it's still delivering too much fuel but is too retarded. In that case, I'd try that fuelling screw at the back, no more than 45 degrees at a time.

The main part of the injection pump is not sensitive to altitude or air pressure, just to engine rpm and throttle demand. SInce it would have originally been calibrated for sea level use, it will be throwing in fuel to suit sea level air intake. That would create a noticeable though not enormous amount of smoke. If you have any kind of restriction in the intake, then the air consumption would be even further reduced until the turbo spins up enough to compensate, causing thick black smoke until on boost. Check the induction system for blockages and drain and flush the intercooler, replace the air filter. You may also need to recalibrate the injection pump by turning the baseline fuel down a tad - it's the screw on the rear face of the pump below the fuel solenoid and the leak-off hose connection. Turn it anti clockwise to reduce fuel, but note the original position and try no more than a 45 degree turn at a time. Make a written tally of the number of adjustments and use Tipex or nail polish to mark the original orientation of the screw before you start so that you can reset it to factory settings if it doesn't help.

The intercooler does get more oxygen into the cylinders. It still amounts to the same 20ish% of the air, but by cooling the charge, you increase the density. The pressure will be the same in the manifold and the cylinder on induction with or without the intercooler, so if you can maintain that same pressure but increase density by lowering temperature, then you will have more air and oxygen by mass (even though the volume is the same), and thus more oxygen to burn. Remove the intercooler and you lose density, and thus air mass. You can restore that density by increase turbo pressure, but that costs energy from the engine and thus fuel economy. So, while forced induction increases the performance of the engine without mass and size penalty (and the incurred performance and economy penalties of having a bigger chassis, body and suspension to support the bigger engine), and turbo charging used waste thermal energy from the exhaust to run the compressor at little fuel cost (unlike supercharging which does cost a lot of fuel and some of the gained performance), an intercooler increases the effect of the forced induction for free.

The resistance against the boost pressure is by a spring, but that spring and the plunger the diaphragm operates sits in a void vented to atmosphere. If it can't vent, then any displacement in the diaphragm will pressurise the void, helping the spring and reducing boost response. Equally, a change in altitude will affect boost response if the void breather is blocked because an increase in altitude will reduce the pressure from the turbo, but the trapped pressure below the diaphragm will assist the spring. You may think that won't happen because the turbo will spin faster to provide the boost setting on the waste gate actuator rod, but remember that the actuator senses boost pressure on one side and atmospheric on the other, so the boost from the turbo may be the same, but overall output pressure is lower. Conversely, an engine tuned for high altitude will gain pressure for a given boost from the turbo at lower altitude and a bocked lower void breather will increase fuelling because of the increased atmospheric pressure plus any boost acting on the diaphragm against the spring.

Sorry, Boydie, but it's not the turbo/super charging that creates huge adiabatic thermal rises to detonate the fuel as it's injected but the adiabatic rise from the pistons' compression strokes. The forced induction is not primarily to overcome the drag of the induction tract and filter but to compress a large volume of air into a smaller volume, increasing its density very significantly to increase the amount of oxygen, allowing more fuel to be injected and thus simulating a big capacity engine without the mass and external size of such. The thermal rise of the charger is not a big problem, it merely reduces the amount of density gain and can be easily countered by use of an intercooler. You could just run the charger at higher boost to get that desired density, but the higher pressure could cause problems for the structure of the tract and engine. Mainly, though, compressing the air to a higher amount will require more energy, working the charger harder, putting ut under more strain and requiring more energy from the engine to drive it, while the intercooler will give you that density increase with less charger effort, less strain and no extra engine effort (ie, no extra fuel consumption). The intercooler is essentially a free charge, giving performance increase at no cost to the engine longevity or fuel consumption. So, removing the intercooler will have a slight reduction in performance and will require a turning down of the injection pump's boost system (remember, it sensed the air density by taking its pressure from the turbo's compressor, not the manifold, and is originally calibrated with the intercooler in the system). You could leave the pump alone and put up with a little black smoke under load, or you could turn up the turbo waste gate actuator and turn down the fuel response to get a clean exhaust with the same performance as with the intercooler.

The boost diaphragm has atmospheric pressure on its underside. St high altitude, this pressure would drop and it would be easier to turbo boost pressure to overcome and add more fuel, giving black smoke, but that should only happen once the turbo is spinning up, not at low rpm. It sounds like you need to retard the injection timing a little.