Bendoon

New Member
Hey guys,
I’ve got a 105 cruiser with a 6.5 Chev Brunswick conversion with std 5spd Man, it’s NA at the moment as I bought it already in the car like that but plan is to eventually throw a turbo on. Was going to have a chat with Brunswick but wanted your ideas. It currently sits at 2400rpm at 100km and I’m trying at 90km to see if lower revs improves fuel economy but what transmissions are you guys running? And is it worth converting to an auto? Or what are my options with if I keep the manual?
Will update on current fuel usage once I know.

Keen to know who’s had had issue

Cheers
 

shanegtr

Well-Known Member
The landcruiser manual trans R151 has an overdrive ratio of .838:1, vs a 4 speed A442F overdrive .765:1. If you have a lockup torque converter then its a marginal decrease in rpm, but with an unlocked converter would be very similar due to the slip.
Diff ratios in the 100s where 4.3:1 from memory so if you could find a diff gear set under 4:1 that would make the biggest difference. You may have to look at a set of low range reduction gears however as the diff gears would increase the speed in every gear - without it you may find first gear low is not low enough.
 

mauriceb

Well-Known Member
The landcruiser manual trans R151 has an overdrive ratio of .838:1, vs a 4 speed A442F overdrive .765:1. If you have a lockup torque converter then its a marginal decrease in rpm, but with an unlocked converter would be very similar due to the slip.
Diff ratios in the 100s where 4.3:1 from memory so if you could find a diff gear set under 4:1 that would make the biggest difference. You may have to look at a set of low range reduction gears however as the diff gears would increase the speed in every gear - without it you may find first gear low is not low enough.
Unfortunately going from 4.3 to 4.1 with the stock R box will only decrease rev's by @80 rpm at 100 kph . The R151F box is not strong enough and will fail. If you fitted the H150F turbo box you could run 3.9 diffs as this box has the lower 1st and 2nd gear ratio's or fitting 35's with current 4.3(illegal in my state) will give you almost the same final drive ratio as 3.9. Its also possible to fit the H152F box out of the later Vdj 79's with a few mods ,these have the taller 5 gear
Here's some comparision i worked out a while back . I will do one of them to my 105 with 4.1's Holding back for now as my H box has only done 140,000km and cluch is new... H152F versus Terrain Tamer Ratio's to Rev's. H152F with 4.1 diffs 33 tyres at 100kph = 1941 rpm in 5TH
H152F with 4.3 diff 33 tyres at 100kph = 2036rpm in 5TH
Terrain Tamer mod 5th .736
with H150/151F box 4.1 diffs 33 tyres =1905rpm at 100kph in 5th
H150/151F box 4.3 diffs 33 = 1998rpm at 100kph
5th gear ratio's H150F/151 = .881 / H152F =.75O .https://www.allfourx4.com.au/5th-Ge...iser-HDJ-VDJ-76-78-79-33421-60121-33036-60010
 

shanegtr

Well-Known Member
Unfortunately going from 4.3 to 4.1 with the stock R box will only decrease rev's by @80 rpm at 100 kph .
I know, thats why I said go under 4:1 if any gear sets are available, something like a 3.56:1 ratio would be my pick. As you mentioned the cruiser boxes all have the same 5th gear ratio apart from the later 79 series and terrain tamer has a 5th gear set for the earlier ones
 

Bendoon

New Member
Unfortunately going from 4.3 to 4.1 with the stock R box will only decrease rev's by @80 rpm at 100 kph . The R151F box is not strong enough and will fail. If you fitted the H150F turbo box you could run 3.9 diffs as this box has the lower 1st and 2nd gear ratio's or fitting 35's with current 4.3(illegal in my state) will give you almost the same final drive ratio as 3.9. Its also possible to fit the H152F box out of the later Vdj 79's with a few mods ,these have the taller 5 gear
Here's some comparision i worked out a while back . I will do one of them to my 105 with 4.1's Holding back for now as my H box has only done 140,000km and cluch is new... H152F versus Terrain Tamer Ratio's to Rev's. H152F with 4.1 diffs 33 tyres at 100kph = 1941 rpm in 5TH
H152F with 4.3 diff 33 tyres at 100kph = 2036rpm in 5TH
Terrain Tamer mod 5th .736
with H150/151F box 4.1 diffs 33 tyres =1905rpm at 100kph in 5th
H150/151F box 4.3 diffs 33 = 1998rpm at 100kph
5th gear ratio's H150F/151 = .881 / H152F =.75O .https://www.allfourx4.com.au/5th-Ge...iser-HDJ-VDJ-76-78-79-33421-60121-33036-60010
Cheers mate, gives me a better idea on my options. I like the idea of that terrain tamer mod but starts getting up in price if I have to get someone to do it. Would the revs be too much of a jump when towing from 4th to 5th with the 5th gear mod?
 

Bendoon

New Member
The landcruiser manual trans R151 has an overdrive ratio of .838:1, vs a 4 speed A442F overdrive .765:1. If you have a lockup torque converter then its a marginal decrease in rpm, but with an unlocked converter would be very similar due to the slip.
Diff ratios in the 100s where 4.3:1 from memory so if you could find a diff gear set under 4:1 that would make the biggest difference. You may have to look at a set of low range reduction gears however as the diff gears would increase the speed in every gear - without it you may find first gear low is not low enough.
Cheers mate, diffs might be the first option then work it out from there
 

wedgetail

Member
Maurice and Shane are spot on, but gearbox also depends on whether yours is a GXL or standard - if it’s a GXL the only upgrade that’ll bolt right in is the H151F from an HDJ100, FZJ105 or UZJ100 (this one might or might have a different input shaft). These have a higher first than H150Fs, but the same 5th (lower than R151F). Your 6.5 will never You can swap internals (whole assembly) between all H15** boxes. If you have a standard any box from a Ute or 80 series will work. The difference is in the shifter location.
 

G_ute

Well-Known Member
Fitt 33" or 285/85 tyres.
Slow down, relax, enjoy the scenary and bumble along at 90kph. At 110kph, even with the lower revs wth all the mods, wind resistance will still chew the fuel.
6.5L n/a will last forever and you dont have the worry about a turbo on a non-factory turbo motor, the exrta plumbing and the more heat to deal with. And a super simple manual.
Great tourer (not so great daily driver but...)
 

Bendoon

New Member
Fitt 33" or 285/85 tyres.
Slow down, relax, enjoy the scenary and bumble along at 90kph. At 110kph, even with the lower revs wth all the mods, wind resistance will still chew the fuel.
6.5L n/a will last forever and you dont have the worry about a turbo on a non-factory turbo motor, the exrta plumbing and the more heat to deal with. And a super simple manual.
Great tourer (not so great daily driver but...)
Thanks mate, I’ve since ordered a set of 3.5 diff ratios instead so just waiting for them to arrive. It’s tall but this engine seems to like low revs anything under 2000rpm so I’ve realised that under 90km is better, 95% of my driving is highway so gets frustrating after a while. Yeah, I’ve got 32s at the moment and planning to go 33s but knew it wouldn’t give me the change I needed and didn’t want 35s. I would like to keep NA but this engine I’ve got was built for a turbo and I really want more torque since I’ll be towing but not chasing big power just want more and with these tall gears I think I’ll need it too. It’s good fun figuring it all out though to suit what I want... love the engine the more I drive it!!
 

mauriceb

Well-Known Member
The 3.5 Crown and pinion set will drop your revs lower than the later factory Vdj79 H152F box and the Terrain Tamer kit posted above in my last post. If you retain your R box it will cruise at @1836rpm on 33 . Stock gearing on 33's is @ 2280 rpm .This is great for cruising with a drop of 444 rpm ,However it will also effect your 1st gear ratio and worst ,very steep downhills sections where you need to crawl down using engine breaking .
 

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G_ute

Well-Known Member
I would have thought that before the orginal conversion was done, they would have considered the turbo verses NA.
Perhaps speak to Brunswick for the reasons why they chose to go NA. Cant have been a huge difference in cost (already costly)
 

Bendoon

New Member
The 3.5 Crown and pinion set will drop your revs lower than the later factory Vdj79 H152F box and the Terrain Tamer kit posted above in my last post. If you retain your R box it will cruise at @1836rpm on 33 . Stock gearing on 33's is @ 2280 rpm .This is great for cruising with a drop of 444 rpm ,However it will also effect your 1st gear ratio and worst ,very steep downhills sections where you need to crawl down using engine breaking .
Yeah mate that’s the plan. I mostly do highway driving and just wasn’t happy with the figures calculated on 3.9 that most people recommend... 3.5 ratios were also the recommendation by Brunswick and everything I looked at lead me that way. I’ve heard a lot of mixed things about 5th gear upgrade with the main issue being it’s a massive jump from 5th to 4th (plus it’s expensive) this worried me when towing too.
With the 3.5s I can use forth without it screaming or forced the slow down too much but the next thing will have to be crawler gears or similar change to help with low range like you said. Low range was my big issue with the 3.5s but couldn’t ignore overall suitability for me. Haven’t looked at my options for low range yet.
 

Bendoon

New Member
I would have thought that before the orginal conversion was done, they would have considered the turbo verses NA.
Perhaps speak to Brunswick for the reasons why they chose to go NA. Cant have been a huge difference in cost (already costly)
Yeah mate it was all about cost and he must of stretched out to do what he already did. He was planning on going turbo down the track which is why he got the turbo engine in NA but my plan is to do my own turbo setup... it’s about $4500 for a Brunswick kit plus fitting
 

shanegtr

Well-Known Member
The 3.5 Crown and pinion set will drop your revs lower than the later factory Vdj79 H152F box and the Terrain Tamer kit posted above in my last post. If you retain your R box it will cruise at @1836rpm on 33 . Stock gearing on 33's is @ 2280 rpm .This is great for cruising with a drop of 444 rpm ,However it will also effect your 1st gear ratio and worst ,very steep downhills sections where you need to crawl down using engine breaking .
Nothing a new set of low ratio transfer case gears cant sort out. Plenty of $$$ to spend once you start modifying a few things:rolleyes:
 
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