Advice on Improvement of Performance for HWY Speeds

[bsjbrown]

We all know the D90 and D110 are bricks on wheels and that is why we love them. However is there some merit to changing the gear ratio on the defender.

Another option would be to have some performance tweaks made to the turbo charger. Thoughts, comments, suggestions, critical concerns - please share.

[RoverDover]

Swap in a V8 and a 1.000 high range LT230 and run 215-75-r16s like Discos and rangies came stock with

[bsjbrown]

OK good call but I am a diesel snob. Not to mention not that easy to convert.

[RoverDover]

The most important thing to do with a non-TDI rover diesel is accept its limitations and appreciate it for what it is. Economical and reliable. I have been a 2.5NA owner for 5 years and have learned to enjoy life in the slow lane. No powersteering, choosing proper lines offroad and finessing my way through tricky trails is much more rewarding than bouncing through with the throttle down and tires spinning madly.

Problem is that you cant get that much out of a 2.5td as far as performance goes. they barely tolerate the turbo in stock form, more boost will just be harder on the head gasket. if you have a die grinder and dont mind taking the head and intake off, a good port and polish goes far in improving airflow. I did it to my 2.5NA while doing the head gasket and noticed an improvement. the problem is at 100km/h with 235-75-r16s and 1.4 gears the engine is screaming. there simply isnt any more RPM left and there isnt enough torque to run taller gears without losing what little acceleration the truck has.

I have been a 2.5NA owner for 5 years and have learned to enjoy life in the slow lane. Picking proper lines offroad and finessing my way through tricky trails is much more rewarding than bouncing through with the throttle down and tires spinning madly.

I once saw a 90 that had a 2.5 petrol running propane and a Volvo turbocharger it seemed to be a perky little engine. though I never rode in it so I dont know if it was worth the effort of the modifications.

[ArlowCT]

Does Rocky Mountain Rovers supply a roverdrive For those trucks? If they do that might be a good way to gain a little bit. Otherwise enjoy driving the truck for what it is and if you ever think about selling that engine give me a ring.

[bsjbrown]

The most important thing to do with a non-TDI rover diesel is accept its limitations and appreciate it for what it is. Economical and reliable. I have been a 2.5NA owner for 5 years and have learned to enjoy life in the slow lane. No powersteering, choosing proper lines offroad and finessing my way through tricky trails is much more rewarding than bouncing through with the throttle down and tires spinning madly.

Problem is that you cant get that much out of a 2.5td as far as performance goes. they barely tolerate the turbo in stock form, more boost will just be harder on the head gasket. if you have a die grinder and dont mind taking the head and intake off, a good port and polish goes far in improving airflow. I did it to my 2.5NA while doing the head gasket and noticed an improvement. the problem is at 100km/h with 235-75-r16s and 1.4 gears the engine is screaming. there simply isnt any more RPM left and there isnt enough torque to run taller gears without losing what little acceleration the truck has.

I have been a 2.5NA owner for 5 years and have learned to enjoy life in the slow lane. Picking proper lines offroad and finessing my way through tricky trails is much more rewarding than bouncing through with the throttle down and tires spinning madly.

I once saw a 90 that had a 2.5 petrol running propane and a Volvo turbocharger it seemed to be a perky little engine. though I never rode in it so I dont know if it was worth the effort of the modifications.

I already drive like a blue hair anyway. I will be ok with it just want to be able to maintain a nominal Hwy speed of 70-75 MPH without overworking the engine. Not wanting to tear up the asphalt. For city driving on the freeways not worried considering the traffic and the speed limit is 60 anyway.

[bsjbrown]

Does Rocky Mountain Rovers supply a roverdrive For those trucks? If they do that might be a good way to gain a little bit. Otherwise enjoy driving the truck for what it is and if you ever think about selling that engine give me a ring.

Actually they Do not but Global Roamer Corporation does. I have looked at them and you know what - I like them. I think that may be the better solution than anything. It would keep the RPM lower - obviously would not increase the top speed but would allow hwy speeds without causing my engine to overwork. Not sure if that or High Ratio Transfer Case is better but what I like about the Roverdrive is that it is portable and frankly if it does not fill the need you can still change the HRTC. Not a bad suggestion at all, in fact a great suggestion. I think I am going to contact them.

If I do get rid of the engine and swap something else in - which I may also do at some point - consider this my handshake that you have the first right to it if you want it. I am not into making money off stuff like this so I am all about what is a square deal on the level for both of us.

[RoverDover]

Does Rocky Mountain Rovers supply a roverdrive For those trucks? If they do that might be a good way to gain a little bit. Otherwise enjoy driving the truck for what it is and if you ever think about selling that engine give me a ring.

Here is the problem, the engine is screaming at 60mph, but has barely enough torque to run in 5th gear below 50mph. so you choose between gutless at 50 (incapable of climbing the slightest hill) and deafening at 60 (which it can only maintain on the flat). The problem of lack of power cannot be remedied with overdrives unfortunately.

[RoverDover]

I already drive like a blue hair anyway. I will be ok with it just want to be able to maintain a nominal Hwy speed of 70-75 MPH without overworking the engine. Not wanting to tear up the asphalt. For city driving on the freeways not worried considering the traffic and the speed limit is 60 anyway.

It wont go 75 unless its a steep grade youre descending!

[ArlowCT]

What I have found with the overdrives in the older trucks is its a great way to "split" gears. Sometimes 3ed is too low and 4th too high, welcome to 3ed overdrive! It just keeps the motor in its sweet spot. I'm sure someone knows the gear ratios in your transmission and what the roamerdrive(?) is too. May just find its a nice step between 4th and 5th that keeps the motor happy!

Plus a truck with 36 different gear combos is just cool.

[bsjbrown]

Yeah like the combo and just having the option. Based on what I am hearing its a reality - I will be in the slow lane regardless of the overdrive, engine, gear ratio. So love every minute of it and remember I may not go fast but I can go anywhere.

[bsjbrown]

I have been calculating it up. Here in Texas we drive like bats out of Hell. 75MPH on most HWY is the legal limit. That means 85 is the norm. So I am going to be that "guy" that everyone passes. So after one hour on the hwy at 60 I am 15 to 25 miles behind. I can live with that. It will just take some time to get used to it. I am more thrilled by the fact that I am going to be the only one on the road in a real Landy.

Honestly - there are not many of us here in the states. Sure you will see a NAS 90 from time to time - rare at best. I have only seen an NAS 110 once - he is a friend of the family who has his 110 up at his home in Crested Butte, CO. So I am figuring people will just slow down to get a look and then pass. This is going to be fun.

[RoverDover]

anybody know anyone willing to trade a V8/wiring harness/auto tranny for a 2.5NA/lt77 setup?

[EdH]

I have a 3.9 zf harness ecu etc out of a rr if interested.

[Revtor]

If you want to go fast, put a v8 in. You can have as much HP as you want, and 80mph all day becomes possible.