416 replies to this topic

[wingnut]

Great job, glad to see its finally on the road.Thats gonna be a lot of fun to drive

[KTS]

I'm going to get my new project to a rolling road at some point, so for my understanding, do these numbers mean that 98/97 engine bhp only gives 55 wheel bhp - is that normal to lose 40+hp? (assume that is what the "drag power" figure is) 

 

How does that work across other minis; for example my 998 I assume only has about 40-ish engine BHP - If that lost 40bhp it would mean I haven't got anything at the wheels, surely that's impossible - Have I misunderstood something?

 

Is it a percentage? so (rounding a bit for simplicity) for 100bhp with 40 bhp loss its 40% therefore 40% loss from 40bhp is 16 so I've got 24 wheel bhp in my 998? 

 

Is there anything that can be done to reduce the loss?

 

after a bit of research; what the the numbers mean is that on that run, at 5800rpm in 4th gear, the dyno measured 55.4bhp at the wheels.

 

from the powerdown calibration run that was carried out before (i.e. run the car up to peak power, put the clutch in and let the rollers coast to a standstill) the amount of drag on the rollers at the same speed was 41.4bhp.

 

the power at the wheels plus the amount of drag the engine was having to overcome to get to that speed equals the power the engine is producing.

 

it's worth noting that the drag power figure increases exponentially as speed increases, so that whilst it's 41.4bhp at 5800rpm, at 2900rpm it's only about 14bhp

 

in other words, the faster you drive the wheels on a rolling road, the greater the resistance there is to the wheels being driven, and a less powerful engine will reach the point where drag is increasing faster than power is at an earlier point

[KTS]

taken it out a few times over the last week to get a feel for the car try and find flush out any issues that need attention, which apart from the obligatory rattling heater fascia mainly involved fluid leaks..

 

alarmingly (..and annoyingly..) hydraulic fluid around the brake and clutch master cylinders

 

 

initial concern was that one or other of the master cylinders was leaking, but the base plate itself was dry and the fluid was mainly on the bulkhead itself.  Checked all the unions and the pedal side of the system which was all dry so looked at the reservoirs themselves.  brake reservoir and cap was dry, but the clutch reservoir and cap were wet

 

what i think has happened is that with the clutch reservoir filled to the max line, the fluid is splashing up onto the inside of the cap and then wicking out through the breather port and running down the back of the reservoir onto the bulkhead.  Temporary solution is to remove some fluid, but i think an extension sleeve may be a sensible option

 

also had a leak from one of the heater unions as i'd used the sized wrong clamp on the hose - an annoying but easy fix.  just need to dry the carpets out now

 

Remembered to drill a pilot hole through the rear adjuster plates so i can accurately refit them it when i need to 

 

 

and splashed out on a set of Newton Commercial overmats;  they're a great fit in the car and i'd certainly recommend them

 

[IronmanG]

Ah yes the pilot hole is a good idea. Must do that

[KTS]

Hmm; that's not right.....

 

[KTS]

picked up a new set of front trunnion bushes from minispares on friday and fitted them yesterday; both radius arms had to come out but after removing the exhaust centre hanger there was enough play in the fuel and brakes lines to drop the front of the subframe low enough to clear the bodywork and get the pins out.

 

the old bushes were a lot softer than the new ones, but i think the most significant factor was that i'd fitted them backwards 

 

Took it out for a drive and the handling is vastly improved;  now doesn't feel like the back end has a mind of it's own when changing direction

 

Having sorted that out, i thought i'd take it out on its first proper trip which was 120mile round trip to the Brill classic car show - a real mixture of cars there from pre-war to moderns and a few bikes.  I'll be back there again next year i think.

 

[IronmanG]

Took it out for a drive and the handling is vastly improved; now doesn't feel like the back end has a mind of it's own when changing direction

Interesting

[KTS]

 

Took it out for a drive and the handling is vastly improved; now doesn't feel like the back end has a mind of it's own when changing direction

Interesting

 

 

yep - a floating rear subframe was quite 'interesting'.  not that i'd recommend it...

[KTS]

the recent warm weather has forced me to deal with another issue i've been having in that the diverter valve wasn't doing it's job meaning I couldn't turn the bloody heater off; not so bad when moving with the windows open, but the radiant heat from the heater was cooking my feet !!

 

the solution was a VAG coolant valve

 

..which meant making up a new bracket

 

..to fit it

 

Still needs wiring up and a suitable location for the switch to be found, but as that's only needed for the heater I can live without that at the moment

 

Conveniently, switching to an electric valve frees up the existing heater cable which i'll attempt to repurpose to control a butterfly in the fresh air intake duct which works a little too well at speed

[Retro_10s]

 

 

Took it out for a drive and the handling is vastly improved; now doesn't feel like the back end has a mind of it's own when changing direction

Interesting

 

 

yep - a floating rear subframe was quite 'interesting'.  not that i'd recommend it...

 

 

Oh this is one of those Self levelling rear subby's that all the cool kids are talking about these days! 

 

I absolutely love that VAG coolant valve, looking forward to seeing that become functional, nifty little bracket you made there for it too! 

[KTS]

wiring up the coolant valve was a bit of a pain as it involved stripping out the dash and dropping the heater to route the wiring to a push button switch to the side of the old heater control

 

 

As part of the plumbing work i was going to add a restrictor into the line between the cylinder head take-off water pump inlet to limit the flow of water that was bypassing the radiator but had a better thought....

 

take an AN-10 to 5/8" barb fitting and create a new inlet port on the radiator so the water from the heater take-off no longer bypasses the radiator.  It's possible this end up over-cooling the engine so may need to add a restrictor to the line at some point

 

 

By way of a change to the plumbing and following the resurrection of an old thread i'd forgotten about, I splashed out on a dynamic brake light module which will cause the brake lights to flash at 4Hz according the deceleration setting that's been enabled

 

Designed for installation on a motorbike i figured there wasn't any reason why it wouldn't work on the pickup, and after bench testing it to figure out how best to integrate it in to the loom, and with the dash already stripped out for the coolant valve switch it was a straightforward job to locate the module at the point where the front and rear looms join and use the existing connectors to insert the module into the brake circuit.

 

 

Took it out for a quick drive out today dodging the rain, and it's all working;  my feet no longer get cooked, the radiator take-off doesn't leak, and heavy braking makes my brake lights flash,

[timmy850]

Is that a bolt on/thread on style barb fitting or did you get it brazed/soldered on? I’ve been considering an extra port like that for the heater circuit

[KTS]

it's a bolt on type, and at that size (AN-10) i had to cut the nut in half to get it through the radiator neck

 

if you're using standard hoses, a smaller fitting like AN-8 to 1/2" barb should be easier to work with

 

ignore the o-ring;  i didn't use it in the end

 

Edited by KTS, 17 September 2023 - 09:43 PM.

[KTS]

relocated the brake light module as I wasn't keen on having to pull the dash apart if i needed to change the setting..

 

[KTS]

i've been getting out and about in the pickup when i can but keep getting caught in roadworks which seem to be everywhere at the moment.  Last weekend got caught in a horrendous jam and had to resort to running the heater on full pelt to keep the temperature under control so decided i needed to fit a cowling around the radiator to improve the efficiency of the auxiliary fan.

 

I wasn't keen on fitting the factory cowling to the inner wing as it makes getting the radiator out much more challenging, so spent the weekend making up some panels to fit around the top and sides of the radiator

 

 

 

just need to order some seals to fill the gaps to the inner wing, but even without them and a panel across the bottom it's a big improvement