Thread: Need more towing power badly

I tow a 1.3 tonne boat with my 1995 P38 on petrol with a free flow twin system exhaust and the vehicle is brilliant as far as stability and handling, but less than inspiring power wise. The engine starts to bog down at 2000-2200 RPM which unfortunately coincides with my preferred towing speed of 95kph. My solution is to either drop back to 3rd and drive at 90kph (revs up around 3000rpm. plenty of power in this rev range so you use a lot less right foot and it eliminates most of the exhaust drone) or to speed up to 110kph in top (not practical as speed limits and traffic rarely lets you on NQ roads)

My problem is also exacerbated by running 275 x 70 tyres which pushes the gearing up by about 10%. The higher gearing works in my favour when driving in third gear. I've considered a Tornado chip but by all accounts the gains are pretty marginal.
Unfortunately where I live the P38 is a rare breed (deep in Toyota country up here) so I have not had the luxury of driving a the high compression Thor motor for comparison.

Troy N

Problem is, there were very few, if any, high compression Thor engined P38s imported here by LRA. AFAIK they are all LC variants with a CR of around 8.57:1 ... unless some of the late 2001/2002 models were the HC type. NAS models were HC.

Originally Posted by bee utey

If you have an Impco model 200 mixer fitted this is like a cork in the inlet. Remove it and try it on petrol without it fitted. If it is hugely better, then get a proper gas system, either 46mm bore mixer and european (complex) converter or injection.

Tell me more about this 46mm bore mixer. I don't know what I have, but if it could be better (without going injection) then I'm all ears ?

Is it a case of measuring the internal diameter of the mixer ring that is attached to the air intake ?

Dave

The 46mm (bore) size mixer I use is made by AMR manufacturing, part number M352 but needs a light cut from its mounting end. It is 71.2mm dia and needs 72.2 to fit the GEMS intake. I know I posted a pic here once but dont know how to find the attatchment.

Found it!



Mixer on left, lpg computer on right.

And a pic of two different but suitable converters on my desk.

Righto thanks, I suspect mine is already set up this way.

The mixer looks very similar and the air intake hose only just fits onto it ( I think there is a rubber spacer ring in between.

The converter on the right looks a lot like mine.

Originally Posted by adm333

Righto thanks, I suspect mine is already set up this way.

The mixer looks very similar and the air intake hose only just fits onto it ( I think there is a rubber spacer ring in between.

The converter on the right looks a lot like mine.

Do pop off the inlet hose and check as most of these are 40mm bore.

Originally Posted by bee utey

And a pic of two different but suitable converters on my desk.

Thats a lot of space on your desk there, have you had a spring clean


On a serious note, I had the 3.5, 3.9, 4.0 and 4.6 some in low and some in high comp.
On gas get the right plugs, leads and timing plus listen to Bee utey.
My 4.6 on gas would tow a car trailer with car up any hill, in fact when my mate used it he was totally amazed.
The 4.0L would not be as good, and in low comp be a bit less still but in 3rd gear at 2800rpm I can not see a problem going up any hill with a 1.0t load.
thats from my experience.
Listen to him or better still come for a holiday to SA and get it to him.
Good luck