- Thread starter PhillipM
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slim_boy_fat
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Looks like loadsa fun! 
PhillipM
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Okay, so no great pictures this time, just a few quick snaps from setting the car up last night - as I've been away resting after my eye op and basically just chilling with some good food and company in Germany. Eddy however cracked on and built up the new front arms as the old ones had a bit of an issue last time it went testing:
Can't think why:
Whoops.
Fortunately it's somewhere we already had an upgrade planned - they were just made out of some machined tube initially but we've got some nice chrome plated hydraulic ram tube to make better ones:
We've gone with another mod at the same time as well - as you probably noticed in the vids it's been suffering severe understeer when it was in low grip terrain - some of that was the front beam bushes were too tight - they'd swollen slightly from the grease and were stopping the front end moving properly for low speed chassis movements, so there's new bushes to match the new chrome plated pivots, machined a little looser this time to account for that.
It's something we've had before but normally you just let them settle and then ream them out.
That's improved things a lot and you can now throw the car in when it would just skate onwards before, even with a flick or cranking the brakes to the back it was too stiff to respond - the next thing was a bit too much midcorner understeer. I knew what this was before we even really took it anywhere - the front arb I went for was intended to set the car up for not having a rear LSD and therefore compromising a bit of the front end to keep the rear inside wheel loaded.
With an LSD in there, that's not as much of a concern, so we've turned the front bar down in the lathe so it's only about half the stiffness it was previously - that's still enough to give a little mid corner understeer, but it pays it back slightly with a little more traction and if you land on one front wheel after a big jump it helps transfer some of the impact across both springs and dampers.
Okay, the next one. Absolutely terrible turning circle - even using the fiddle brakes, again, you probably saw that on the hairpins on the videos.
The ackerman angle on the steering on this car has always been a bit off - it had about 130% ackerman, far too much, especially with toe out on the static settings, unfortunately with the changes to the front arms, rotating them around some when we took the big change in castor out of the front end, and various other things including taking some of the slack out of uprights, etc - it made it even worse than that at around 160-170%, and also meant the effects were felt more without so much slack in the system.
Anything that was very low speed, tight turns was either hold the brake and force it around spinning the rears hard, or just sit waiting for it to turn.
So that's been corrected a little with quick and dirty tweaking on the upright mounts - it's not quite as low as where I'd like it yet but it's around 100% now:
The front end is still not as good as it used to be, but it's a huge chunk better - however there's a flutter stack in the rear shocks that's having an effect too which I want to remove for a more conventional stack when I get the tools to open these ones more easily than messing around with clips and hammers, then after that we'll mess with the geo for more tuning.
I did run a flutter stack in the old setup but it was one that was mainly to affect low speed bleed, this is a weird one built around landings in the desert, etc, for the little Polaris UTV they originally came off and are just stealing our midspeed damping and softening the knee from low to high speed far too much.
Speaking of the rear dampers, they now sport the piggyback canisters they should have originally had, and package much better for it:
So basically we've solved about 2/3rds of the issues we're having with the front, there's some more work to go on yet but hopefully it's picked up a chunk of time already.
We're off to Tiverton this weekend to do another race/test session, see how it goes!
Can't think why:
Whoops.
Fortunately it's somewhere we already had an upgrade planned - they were just made out of some machined tube initially but we've got some nice chrome plated hydraulic ram tube to make better ones:
We've gone with another mod at the same time as well - as you probably noticed in the vids it's been suffering severe understeer when it was in low grip terrain - some of that was the front beam bushes were too tight - they'd swollen slightly from the grease and were stopping the front end moving properly for low speed chassis movements, so there's new bushes to match the new chrome plated pivots, machined a little looser this time to account for that.
It's something we've had before but normally you just let them settle and then ream them out.
That's improved things a lot and you can now throw the car in when it would just skate onwards before, even with a flick or cranking the brakes to the back it was too stiff to respond - the next thing was a bit too much midcorner understeer. I knew what this was before we even really took it anywhere - the front arb I went for was intended to set the car up for not having a rear LSD and therefore compromising a bit of the front end to keep the rear inside wheel loaded.
With an LSD in there, that's not as much of a concern, so we've turned the front bar down in the lathe so it's only about half the stiffness it was previously - that's still enough to give a little mid corner understeer, but it pays it back slightly with a little more traction and if you land on one front wheel after a big jump it helps transfer some of the impact across both springs and dampers.
Okay, the next one. Absolutely terrible turning circle - even using the fiddle brakes, again, you probably saw that on the hairpins on the videos.
The ackerman angle on the steering on this car has always been a bit off - it had about 130% ackerman, far too much, especially with toe out on the static settings, unfortunately with the changes to the front arms, rotating them around some when we took the big change in castor out of the front end, and various other things including taking some of the slack out of uprights, etc - it made it even worse than that at around 160-170%, and also meant the effects were felt more without so much slack in the system.
Anything that was very low speed, tight turns was either hold the brake and force it around spinning the rears hard, or just sit waiting for it to turn.
So that's been corrected a little with quick and dirty tweaking on the upright mounts - it's not quite as low as where I'd like it yet but it's around 100% now:
The front end is still not as good as it used to be, but it's a huge chunk better - however there's a flutter stack in the rear shocks that's having an effect too which I want to remove for a more conventional stack when I get the tools to open these ones more easily than messing around with clips and hammers, then after that we'll mess with the geo for more tuning.
I did run a flutter stack in the old setup but it was one that was mainly to affect low speed bleed, this is a weird one built around landings in the desert, etc, for the little Polaris UTV they originally came off and are just stealing our midspeed damping and softening the knee from low to high speed far too much.
Speaking of the rear dampers, they now sport the piggyback canisters they should have originally had, and package much better for it:
So basically we've solved about 2/3rds of the issues we're having with the front, there's some more work to go on yet but hopefully it's picked up a chunk of time already.
We're off to Tiverton this weekend to do another race/test session, see how it goes!
PhillipM
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Well bar a bit of a mishap on frosty/icy grass in the morning (basically tried to cross a field and was a passenger to the bottom) - pity we didn't have the plate diff in any more as it would have been worth it there, and probably a good 10s a lap after that tbfh too - it went pretty well today, front end is much better, probably gone from about 1/3rd of the confidence and grip it had before to 75%. It's not quite there and there's some other jobs but it finally feels like you can learn to drive it and it's responding to different driving styles now.
We were putting in a lot of top 10 times after the mishap which was good too.
We were putting in a lot of top 10 times after the mishap which was good too.
PhillipM
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Times are out, ended up 15th overall, probably would have been 9th I think without the problem with the frosty sideslope - had enough pace for 8th I think if we'd pushed more out of the gate, still, encouraging already, especially on that course, we've picked up about 20-25 seconds I think with the front end work.
Wasn't a bad venue though, although I don't think it'd be any good for a 2wd if it was wet, it was bad enough with frost - the tracks were only 6ft wide at some spots which is a bit of an issue for trying to find a line when your car is 6ft6...
And a nervous new co-driver:
Wasn't a bad venue though, although I don't think it'd be any good for a 2wd if it was wet, it was bad enough with frost - the tracks were only 6ft wide at some spots which is a bit of an issue for trying to find a line when your car is 6ft6...
And a nervous new co-driver:
Frost? Are you sure? Not been that cold yet?Well bar a bit of a mishap on frosty/icy grass in the morning (basically tried to cross a field and was a passenger to the bottom) - pity we didn't have the plate diff in any more as it would have been worth it there, and probably a good 10s a lap after that tbfh too - it went pretty well today, front end is much better, probably gone from about 1/3rd of the confidence and grip it had before to 75%. It's not quite there and there's some other jobs but it finally feels like you can learn to drive it and it's responding to different driving styles now.
We were putting in a lot of top 10 times after the mishap which was good too.
stuvy
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Screen was frozen last week in northants
PhillipM
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Little bit more work tonight, gearbox oil change and a few plans to maybe change the breather system or put a pump and spray bar in there - the transaxle got a bit warm last event and slowly breathed out half a litre of oil - the breather is quite short and low so we'll shift it up to the top of the car and see if that helps, gearchange goes notchy when it gets too warm, doesn't want to go into second, which makes things tricky...
Also made some changes to get the rear suspension softer on the spring rate but still with a couple inches of stiffer bumpstop formed by the rear torsion bars, and lowered the car a bit front and rear along with some slightly stiffer compression settings on the dampers - it was a bit too high at the last event, made it skittish and tentative over some stuff that you'd expect to just hammer over usually, hopefully going back to the old lower spring rate and our little trick for more preload is a good balance.
Apart from that it was mainly servicing work and retensioning belts, etc, haven't had time to test it so it's gonna be on the trailer tommorow and just fingers crossed at the event!
Little clip from last time out:
The new pulley setup is ready, which should give the car another 50bhp and bring it back around the original target boost level - almost just slapped it on and ran it because Walters has a lot of Cat A rally tracks and 50 horsepower is probably worth 10-15 seconds here, but without change to test it and check the temps and fuelling we decided not to risk it quite yet.
We're being sensible for a change, I know, weird right?
Also made some changes to get the rear suspension softer on the spring rate but still with a couple inches of stiffer bumpstop formed by the rear torsion bars, and lowered the car a bit front and rear along with some slightly stiffer compression settings on the dampers - it was a bit too high at the last event, made it skittish and tentative over some stuff that you'd expect to just hammer over usually, hopefully going back to the old lower spring rate and our little trick for more preload is a good balance.
Apart from that it was mainly servicing work and retensioning belts, etc, haven't had time to test it so it's gonna be on the trailer tommorow and just fingers crossed at the event!
Little clip from last time out:
The new pulley setup is ready, which should give the car another 50bhp and bring it back around the original target boost level - almost just slapped it on and ran it because Walters has a lot of Cat A rally tracks and 50 horsepower is probably worth 10-15 seconds here, but without change to test it and check the temps and fuelling we decided not to risk it quite yet.
We're being sensible for a change, I know, weird right?
PhillipM
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Okay so - it was a mixed weekend, incredibly slippery the first day - felt like the car was on ice, no grip anywhere - I bet anyone watching thought we were out for a Sunday drive from the outside, it was like driving on marbles, some of the downhill corners you just couldn't touch the brakes and it was a case of just letting the car slowly slide itself into a turn without doing a 180* and heading down the the hill backwards after the corner.
However I made some big changes overnight to the damping as the new spring rate on the rear seemed to be okay, so I kept that and then went far softer on the low speed and rebound to suit - no big hits to kick the rear end up here so felt fairly safe to do so in the name of finding some grip and feel, and cranked the cracking pressure up instead to still take out the bigger hits - car came alive on the second day on the other course, we put a few times in that were top ten which was pretty good on such a fast, slippery course.
Doesn't sound too much but there were a lot of quick cars here this weekend, to put it in perspective some of the 4wd Canam cars that are fairly consistent across courses were about 60-90 seconds faster than us at the start of the year on a similar course length, we'd dropped that to 30 seconds by the second event, were faster at the last event at Tiverton by a few seconds and now we're pulling 30-60 seconds on them at this one - and matching some of the guys who are usually contenders for the championship on odd runs, which was a surprise even to us
We're certainly not front running pace, not even close yet, but this kind of championship is as much about endurance as pace, if we can get there and keep it consistently at that pace, it's boding well for some fun at least.
It's still very situational so I've a lot of work to do on the damping once I get tools to strip these new Foxes, to make them more consistant across more terrain, and we could do with finding some of the soft compound race tyres in the right size for the rear - currently we're on standard road tyres whereas most teams are on either soft grass race compounds or Michelin forest rally compounds, I bet there's a chunk of time there to find. Also need a bit more front camber we're on the edges of the tyre all the time even with 3* static on there:
We had another issue which was we got 300m from the finish line on one run and lost all power - the car just cut out completely - turns out the connector for the electronic cutoff switch had somehow managed to work it's way out and cut the power to the car as a safety measure - doh!
Anyway, one session with tie wraps and the dashboard out overnight fixed that problem from coming back but that was a bit of a pain for a simple plastic plug. It's getting a session with some epoxy resin and hot glue before the next event, rather annoying that one.
Issue #2 was the last two runs of the event on day 2 - the torsion bar in the power steering snapped - so there was no feeling in the steering unless you were full lock left or full lock right - not the best thing on a race off road!
It's a standard part out of a Peugeot 405 but finding them these days is tricky, so it might be a redesign on that front, on the upside after we worked out what it was and that it wasn't going to cause any complete failures, Ed took the car back out anyway and somehow put the two fastest runs in we'd had. Apparently steering slows you down. Somehow.
On the upside, we've 100% sorted our breather issue with the engine we had before, the cars responding to suspension changes much better now which it wasn't doing too well before the work on the front arms and rear springs, the engine doesn't use a drop of oil or water, temperatures have been great at all events - if anything I'm going to play with blocking some cooling off over winter, maybe even drop the oil cooler and just add some fins to the dry sump tank - the oil barely gets warm, and the cooling fans only run at half speed most of the time.
Along with that the oil, belts and filters always look perfect, so it looks like we're doing well on the engine front.
Might also shrink the side intakes slightly, make them a little less draggy.
Along with that I think it's time to crank the engine up with that new pulley to give it some torque and horsepower - not for the next event, it'll be winter - but we've been also short shifting most of the time for grip, so I'll push the warning lights up and the limiter up in the ECU and wring it out a bit more next time around, there's another 1500rpm to play with yet which is a fair bit more power already and still be conservative, it only really gets run out to there when holding second gear for a corner so it's time to use it more in anger through the other gears.
We ended up well down the results due to the run we had the car cut out on us on, but still 24th out of 42 entries, so nothing exciting but we're not too bothered about that, we got to have fun and it was looking promising. Upset a few people anyway on odd runs which is the main thing
I also have a higher quality video of those jumps from earlier at Tong:
However I made some big changes overnight to the damping as the new spring rate on the rear seemed to be okay, so I kept that and then went far softer on the low speed and rebound to suit - no big hits to kick the rear end up here so felt fairly safe to do so in the name of finding some grip and feel, and cranked the cracking pressure up instead to still take out the bigger hits - car came alive on the second day on the other course, we put a few times in that were top ten which was pretty good on such a fast, slippery course.
Doesn't sound too much but there were a lot of quick cars here this weekend, to put it in perspective some of the 4wd Canam cars that are fairly consistent across courses were about 60-90 seconds faster than us at the start of the year on a similar course length, we'd dropped that to 30 seconds by the second event, were faster at the last event at Tiverton by a few seconds and now we're pulling 30-60 seconds on them at this one - and matching some of the guys who are usually contenders for the championship on odd runs, which was a surprise even to us
We're certainly not front running pace, not even close yet, but this kind of championship is as much about endurance as pace, if we can get there and keep it consistently at that pace, it's boding well for some fun at least.
It's still very situational so I've a lot of work to do on the damping once I get tools to strip these new Foxes, to make them more consistant across more terrain, and we could do with finding some of the soft compound race tyres in the right size for the rear - currently we're on standard road tyres whereas most teams are on either soft grass race compounds or Michelin forest rally compounds, I bet there's a chunk of time there to find. Also need a bit more front camber we're on the edges of the tyre all the time even with 3* static on there:
We had another issue which was we got 300m from the finish line on one run and lost all power - the car just cut out completely - turns out the connector for the electronic cutoff switch had somehow managed to work it's way out and cut the power to the car as a safety measure - doh!
Anyway, one session with tie wraps and the dashboard out overnight fixed that problem from coming back but that was a bit of a pain for a simple plastic plug. It's getting a session with some epoxy resin and hot glue before the next event, rather annoying that one.
Issue #2 was the last two runs of the event on day 2 - the torsion bar in the power steering snapped - so there was no feeling in the steering unless you were full lock left or full lock right - not the best thing on a race off road!
It's a standard part out of a Peugeot 405 but finding them these days is tricky, so it might be a redesign on that front, on the upside after we worked out what it was and that it wasn't going to cause any complete failures, Ed took the car back out anyway and somehow put the two fastest runs in we'd had. Apparently steering slows you down. Somehow.
On the upside, we've 100% sorted our breather issue with the engine we had before, the cars responding to suspension changes much better now which it wasn't doing too well before the work on the front arms and rear springs, the engine doesn't use a drop of oil or water, temperatures have been great at all events - if anything I'm going to play with blocking some cooling off over winter, maybe even drop the oil cooler and just add some fins to the dry sump tank - the oil barely gets warm, and the cooling fans only run at half speed most of the time.
Along with that the oil, belts and filters always look perfect, so it looks like we're doing well on the engine front.
Might also shrink the side intakes slightly, make them a little less draggy.
Along with that I think it's time to crank the engine up with that new pulley to give it some torque and horsepower - not for the next event, it'll be winter - but we've been also short shifting most of the time for grip, so I'll push the warning lights up and the limiter up in the ECU and wring it out a bit more next time around, there's another 1500rpm to play with yet which is a fair bit more power already and still be conservative, it only really gets run out to there when holding second gear for a corner so it's time to use it more in anger through the other gears.
We ended up well down the results due to the run we had the car cut out on us on, but still 24th out of 42 entries, so nothing exciting but we're not too bothered about that, we got to have fun and it was looking promising. Upset a few people anyway on odd runs which is the main thing
I also have a higher quality video of those jumps from earlier at Tong:
