Engine/Gearbox combos

[shaginwagin]

Hi Tweaker, what 4 speed auto would it have to be to put behind  a red 308.
Julian

[Tweaker]

I'd go a T700 out of say a VN or the like. They can be toughened up to handle in excess of 600 horses. I'd be supprised if Dellow in Sydney didn't have a kit to bolt the box straight up to the 308.

I haven't installed mine yet, but am told it should drop my revs to around the 2000 mark at 100k. With my 3.08 diff and 15" rims. Which for me is a drop of around 1000 RPM and I'm running a 4 speed manual.

The other groovy thing is the number of cable operated shifters available for it I'll be mounting ours next to the steering wheel coming off the steering column.

I've got the number and details of a guy in Sydney that builds autos for dragsters, if you need it.

[hammers_spanners]

The t700 runs the "turbo" bolt pattern so if your block is a turbo no problems then you just need to change the flex plate as the convertor mounting points are different to the t 350 or t400. If your block is a "trimatic" type then Dellows will have a kit to suit. Watch ebay as the block adaptors come up all the time and range from $35 - $100.

[westy12]

gday guys hows it? warren im running straight gas and your fuel economy is way better than mine. but im not sure if its the extra weight or the highway diff ive got. i can hold around 140 litres and get only 650kms out of it!im running a 202 with gas heads with a trimatic and a 3.08 diff. ive got it tuned as lean as i can so its really gutless and goes backwards up a hill! why do you say its more economical on straight gas? im thinking of going back to dual fuel. ive got a 50l tank where the spare wheel went, a 90l tank behind the drivers seat lengthways and the spare sitting in the petrol tank brackets.  i cruise at about 2700 at 100. before i left on our trip around oz i didnt get a chance to play around with diff ratios but i think id be better with a 3.36 or something. i think with the 3.08 diff its working harder to stay at the same speed so when i get back to mebs im going to play around with a few options. might even go back to 3.5
take it easy... luke

[Tweaker]

Hey Westy, if you were to go up to a 3.36 or 3.5 wont that increase your RPM at 100k? Although it will give you better pull up hills. Sounds to me like you really need that 4th gear. What's your van weigh in at?

[westy12]

gday tweaker not sure what the van weighs i would be keen to find out but id guess ive got at least 500kgs extra? yeah a 3.5 diff would increase my revs but the vacuum would drop and wouldnt have to accelerate as much to stay at the same speed. with the highway diff, i have to accelerate harder to keep at 100 so using more fuel.. we talked about this on the old site and i dont have a definite answer so thats why i want to play around with my diff ratios when i get home so i can find out for sure. thats another reason i went for the holden banjo diff so i could change ratios easy myself... i would love to put a celica 5 speed in it but its too much work converting to manual, and i cant be bothered changing gears too!!

[Tweaker]

Yeah, no point excellerating all the time! You need to be rolling along really.

I sick of changing gears all the time myself, which is partly why I'm changing from 4 speed manual to 4 speed auto.

There's a faint possibility we might be going straight gas next year if we end up on our trip round Oz.

[Warren]

Hi Westy

Im running a 202 with a 4 spped manual and a 3.08 diff.

With dual fuel, timing is done by feel/ear.

The reason a straight gas setup should run better is because the timing curve and advance can be set for the gas only, from memory there is about 15 degrees difference in timing between gas and petrol.

And I think gas is a higher octane rating than unleaded, so if everything was optimesed to gas, your economy should be good as well as the power being adequate.

I would talk to the likes of "Gas Research" for more info on the timing curve etc.

I would have thought that running "Lean" would be a false ecconomy, setting it up to deliever max power would be better.

The extra weight may be a factor, but I tow a A liner camper van, and while I dont pay to much attention to economy, it still preformes, reasonably well in all but the hilliest conditions.

Warren

[ben]

i did a bit of an experement..

i drove for 60kms with my fuel mixture really really lean that i only had just enough power to stick to 90kms..

then did the same trip with it at about normal and the difference cost me $1.

so i said stuff it an extra $1 - $1.5 an hour is worth it for the extra power.. and its bad for your valves to run lean also so that was my conclusion.

ben

[Tweaker]

Lean is not good. Running an engine at anything than optimum performance will only achieve a greater expense in my opinion. Gas does have a higher octane rating than unleaded, so if your engine is set up for stright gas it should perform alright I'd have thought. I agree with Warren, I'd talk to Gas Research. I've seen photos of 6 cylinder Cortinas doing wheel stands on straight gas.

A very common false economy I often see, especially with cars and vans the age of ours, is people filling up with 95 octane or even worse standard unleaded thinking they are saving money on fuel by buying cheap.

Have a go at setting your van to run at the correct temperature and timing while you're still traveling and see if it makes a difference for you.

Peace!