Red Devil mkII - The Journey Continues

[seangti]

62s here we come

fa shizzle. Hopefully can knock on the door of 61s with some driving tweeks.

Do you get your car back this week?

[grandturismo]

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[Machine]

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Tried any new gins lately?

[nat225]

job done well Sean!

[grandturismo]

Tried any new gins lately?

Haha yes...It's called Makar Glasgow Gin, first one from my home town in 100 years.

[Machine]

Haha yes...It's called Makar Glasgow Gin, first one from my home town in 100 years.

[seangti]

It's been a while since an update, and 3 track days since having the LSD installed.

In short, I've been mostly underwhelmed with the LSD. My lap times have had little to no improvement and still getting quite a bit of wheel spin, even on the semi slicks. I've been working on left foot braking through the corners, that's good fun and is minimizing spin, but negligible effect on lap time. It does feel better mid corner, a bit more adjustable to brush some brake along with accelerator gets the noise tighter. Who'd have thought all that Playstation time would come in handy.

The car has been running really well, I've put in a new fuel pump as the previous one seized on a track day. Gavin rescued me

Further mods to investigate:
I'm wanting to swap out the rear H&R springs to something firmer so I can run less sway bar. Will investigate through King Springs. I'm thinking that running the sway bar on hard is limiting rear travel which is lifting the front on corners - resulting in more likelihood to spin.

I may also swap out the front sway bar from the current Whiteline one, going back to a factory sway bar. Again, to increase the front travel and promote front end grip.

Due for new tyres, I won't go back to the current Kumho V70's. I will likely go an Yoko AO50r or perhaps Hankook Z2221. Planning to run a 235 section tyre. My concern is width and hitting the guards under compression, not sure how to validate clearance concerns without buying a 235 tyre though.


Got a 62.99s at lakeside on the weekend, a new PB for me. Did a QR sprint event a few weeks back too, hadn't been out there since 2013, did a 60.4 best. Quite happy with all that.

[sambb]

I remember reading in an Ortiz article that less compression damping in the rear and more in the front can help power down coming out of corners because it balances the car towards oversteer at that point in the corner. The opposite helps turn in but if you don't have an issue with turn in already then maybe this could be a cheap experiment:

"As to the effect of shocks, yes stiffening the fronts will add understeer during entry and stiffening the rears will add oversteer, provided that the road surface is smooth. This effect requires that the car have a roll velocity outward, and that this be the main source of suspension movement. When the car is cornering steady-state on a smooth surface, the roll velocity should be zero, the suspension should have displacement from static but not velocity, and shocks shouldn't matter. During exit, the car has a roll velocity inward (it's de-rolling). In this situation, the effect of the shocks reverses. Stiffening the fronts adds oversteer; stiffening the rears adds understeer.

So to add understeer or oversteer overall, we use the relative stiffness of the front and rear springs (and/or bars, if present). To change entry and exit properties in opposite directions, we use the relative stiffness of the front and rear shocks (remember, only on smooth surfaces)."


I haven't driven V70A's, only A050's so I can't compare them to anything, but looking around at the hilclimbs most cars seem to be on them and a lot of people who were on V70A's, R888 etc have switched over this year. Since you do time attack maybe A050 mediums would suit the track days and sprints.

just read the last bit - well done on the PB. good on you.

[seangti]

I went to see my mechanic on Friday arvo about my concerns on grip and the diff doing what it should. When I told him what it's doing he suggested disconnecting the front sway bar as a start. I'm running a whiteline bar (installed by previous owner) on soft. I also softened up the rear bar to minimize the chance of spearing backwards of the track.

The car was much more fun and adjustable, more throttle adjustable, the rear would move a whisker but keep the throttle in and it just tuckered down and gripped. Felt really b100dy good. I found I was tipping in to corners a little early initially and gave me more confidence for a later turn in. Yeah it was a good move in the right direction. Lap times were much the same, 2/100ths off my PB of last round, perhaps a little more consistent within 2-3 10th's of a second and most importantly, fun factor improved. Corner exit grip was really good, little to no wheel spin in the locations I was getting lots before. Tyre wear seems lower too...

From here - softer front bar to go in, I still feel the need to run one and firmer rear springs to allow for less rear bar.

[sambb]

Good find. I've seen before and after pictures of cars running no front anti roll bar and it always looked like there was way too much roll introduced so I never did it. I suppose though that if you have pretty meaty spring rates that this wouldn't be the case. A lot of the british hillclimb guys in clios and 106 peogeots disconnect the front bars but are running 400+lb springs. What are your rates?
Made me think of a comment Martin made on my ball joint thread. He was talking about how open diff cars need good droop to be able to keep the inside front attached to the ground when body roll is present. I wonder if no bar allowed a bit more droop for the inside front since its position is then completely independent of the outside front when you don't have a FARB. Maybe that's what was at play more so than the roll stiffness change. Can you adjust droop travel on your coilies? Could be worth playing with droop settings with your existing bar before ripping the whole front end out to do a bar swap.