Outer Limits 4x4 Board

On pretty standard tyres (265/75/16) in 5th at 100km/h the rev counter reads approx 2100-2200.

Feels about perfect for cruising.


Thanks for the reply mate.
Wow...ok...that's pretty low. Well....lower than I thought it would be tho I never knew what standard is. That's what I needed to know ...

Hi guys.
Just trying to find out what speed people with Diesel turbo 4.2's are reving at 100 to 110km/hour. And with what tyres?

Where is the sweet spot for a nice cruise at 100km/hr???

I have had the GQ TD42 running 37's with a 4.6:1 dif. She was cruising at 2750rpm at 100km/hr.

Now I am ...

Hi all.
I am in the process of fully re-hauling a GU3 Diesel engine TD42Ti . Pistons liners etc.
I have been getting prices from various companies but they are extremely different in price.

Just wondering whether there are people hear with experience to know what the differences in the quality and ...

Mine goes to a one way valve & then into brake booster. It controls the power of my brakes. Without it I have very bad brakes. I had a split pipe & knew it with 37's. Almost smashed into the rear of someone. My GQ is a 95 model.
Hope that helps.

Gday Zol
Just tuned into your thread.
I have done exactly what you have with the 2.8-4.2 conversion. Running 35" STTs and the speedo is back about normal. Mine is also nonturbo so far. The revs sit at 2700 @ 100kmh but the grunt is amazing.
I guess the only sacrifice in going bigger rubber is the ...

OK here's the latest figures that members might find interresting.

Just put on 37's MTR's.
Still no turbo.
Still plenty of power & acceleration (for a non-Turbo) in all gears.
4.6 difs
60km/hr in 4th at 1400rpm & 5th at 1200rpm. Both feel comfy
100km/hr in 5th at 2100 revs...very comfy
Speed reads ...

Truck looks great mate. Don't know if anyone has mention but you can run a 10 mm spacer on the front control arms...at the chassis end. Don't know the technical name for it. About $50 pre-made. Pushes the dif just far enough to avoid any rubbing on the rear of the front guards.

I was running 35's ...

GUJohnno wrote:I would suggest talking to Andy at Diesel-Tech regarding turboing the truck

Where abouts is he & do you have his number?

Hey guys.
Towing went well. First gear was absolutely brilliant. Didn't even need to drop into low gear on the ramp at Tunks park...and that' a pretty steep ramp. Freeway was good. I could cruise nicely on about 80 to 90km/hr in 4th on some hills & even fifth & could manage 100 in 5th no dramas ...

I think that with Turbo & lower rev on freeway with 37's it will be more economical. That's my thinkin.....Seems sorta logical....don't know.

Not really.
You could be doing 2000 rpm but the throttle could be open more to keep the engine at those revs.
Think of a generator. The throttle opens to ...

I think that with Turbo & lower rev on freeway with 37's it will be more economical. That's my thinkin.....Seems sorta logical....don't know.

MyGQ wrote:Mine is a slug that's for sure

it won't hold 110K's with 35's on and 4.11:1 ratios, maybe my engine is dying or something.

Wow. That's interresting. I've been driving a 2.8dt with 35's with 4.6's & it held up. I'm sure that a 4.2d should manage with 4.1's. Has it always been like that?

first throught to third seems fairly good but it loses a fair bit of power in fourth and fifth. Fuel economy with extractors and pump tweak is about 15l/100k's. I'm thinking of going to 4.3's when i turbo it so i would say 4.6's would be ideal for 37's.
Let me know how it goes with the 37's as i ...

my N/A td42 with 35's and 4.11 gears sits on about 2000 revs at 100k's and reads 90k's on the speedo

Aha.... Tomo...That's prolly the balance I'm looking at ending up with once the 37's are on.

I'm really interrested to know how your truck feels with your setup?! Eg First gear, through gears ...

coxy321 wrote:Why dont you see if you can borrow someones 35's for a test??

I already run 35's

If your putting a turbo on, i'd just leave it.

I have 4.1:1/TD42 and currently sits on 2700RPM at 110km/h on my 31" HT's. Speedo is 15km out (it actually reads 125km/h).

With 35" ET's speedo is spot on and engine does 2150RPM at 100km/h.

I'm happy with my current gearing, as a turbo should bring ...

Hi all.
I have just converted my GQ to a 4.2 Diesel from th 2.8.
I have 35's & will possibly go 37 or 8
I also have 4.6 difs

My question is...What is the ideal revs a 4.2 should be doing at 100kms?


ATM it revs at 2200 RPM at 100km/hr. Feels a little high. First gear is short tho I have plenty of ...

Ok. I am one step closer to getting it done. :cool: :D

I just picked up 4.2 Deisel Maverick. Will be doing some research before I pull the engine out & have parts everywhere.

Next step is maybe looking for an after market turbo....be it second hand or new.

Can anyone tell me how big I can go ...

Does anyone make the engine mount pre-fabbed?


This is great information guys. Thanks very much. It will help ease the pain once the time comes.

Trump. that's great information.

I might have an option to buy a 4.2d Maverick cheap. Was thinking of installing the 2.8 into the Mav & take out the 4.2 then sell off.

Can the turbo be used from the 2.8 ?

Does anyone have experience in Knowing what the needs done on a conversion from 2.8 to 4.2 besides the obvious engine,gearbox & radiator?
Are there mounting conversions? Driveshaft diferences etc?

NutterGQ. What dif ratio are you running?

Had a few offers on GQ engines & are all out of my price range. Might have to drop down to a 4.2 Deisel from a GQ.

I'm aware of the tyre issue but it's not as bad a difference & plus I'm not prepared to go into the pits every day to change tyres as my crew is me.
I have 4.8 dif ratio. 3 tonne of towing will make any 4wd sweat a bit anyway. But with 4.8's & 4.2 DT & new G'box it will alleviate all of that I ...

Been trying to find posts in regards to GQ conversions but couldn't find any so I might have to bore you all with a typical question.

I have a 2.8 turbo deisel GQ. Engine is fine but the gearbox is too high in first gear for heavy towing (3 Tonne).

Need to find out if the 4.2 Deisel gearbox can be ...

I own a 2.8 TD GQ & I have had no probs with it & have reached 300,000km. I run 35's on it as well. I don't expect it to fly....It's a deisel. Deisels don't fly. She has never let me down.

The only bad thing is the first gear ratio (especially with 35's). It's too high when it comes to towing a 3 ...

Thanks MyGQ.

I found the problem. The short out blew the cold start plug relay. Though the relay still sounded like it was working, it burnt out the bridging wire inside & plug was not getting power. You would think that the fuse would go first but the factory fuse wire is twice as thick as the one ...

Hi all. I have a 2.8 deisel Turbo GQ & I have just changed the timing belt & valve stem seals. My ol man took the glow plug railings off & didn't realise there were plastic spacers between the long & short glow plug rail as the rear 3 glow plugs are duel resistance. Spacers fell out as he pulled it ...

I have a 2.8 Deisel Turbo. I run 35's on 4.8 & tow a 2.5 tonne boat. 2.8's were never good with first gear under heavy load. Even with standard wheels.

I had the same problem. Ended up getting a SH box but by the time I got it the problem went away. Lasted for a month.

That is fantastic Spimon_NH

You read my mind. I was going to write something similar but soon realised that I couldn't be bothered typing it out.

Hehehe. What a crack-up?!

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