♦ ♦ ChargeR's DC5R Blog ♦ ♦

[eskimo_firefighter]

just finished reading the whole blog, thanks for the vast detail you put into this blog. its very helpful for a track noob like me. good luck on your next build!

[ChargeR]

just finished reading the whole blog, thanks for the vast detail you put into this blog. its very helpful for a track noob like me. good luck on your next build!

Thanks for taking the time to read it, feel free to post up any abuse or questions though. I feel like I wasn't called out enough on the foolish things that I did during my car ownership.

[eskimo_firefighter]

No worries and what? I haven't seen anything foolish in your build. haha.

Just a question though i'm interested in increasing the caster angle on my car. However i do not want to invest in the caster plates. I'm more keen on investing on the LCA bushes to add caster but how much more caster angle will this add? I think stock is at 1.5, but please correct me if i'm wrong i am still learning. . When you added in the additional caster what benefits did u notice from doing so and how much caster do you have? Also did it make daily driving seem like a chore because i have read it increases steering effort when caster is added in.

I have also read that lowering a car is very bad for out cars ep3/dc5, did u take into account of the angle of the LCA? My car is currently lowered quite alot and i would like to get rid of this disgusting under steer. It's really bad at Winton hairpins and even the s bend exit. i am planning to raise it and add more front camber around -3.5. but what is your take on this because from what i can see your car is lowered i think but its quick as hell.. (i can't tell how much lower it is from the photos to be honest, especially with your wheel setup, haha)

http://forums.clubep3.com/showthread.php?t=569763

And sorry if any of this has been covered on the thread. But i'd rather ask for help than not ask at all.

Thanks a lot for helping.

[ChargeR]

No worries and what? I haven't seen anything foolish in your build. haha.

Just a question though i'm interested in increasing the caster angle on my car. However i do not want to invest in the caster plates. I'm more keen on investing on the LCA bushes to add caster but how much more caster angle will this add? I think stock is at 1.5, but please correct me if i'm wrong i am still learning. . When you added in the additional caster what benefits did u notice from doing so and how much caster do you have? Also did it make daily driving seem like a chore because i have read it increases steering effort when caster is added in.

I have also read that lowering a car is very bad for out cars ep3/dc5, did u take into account of the angle of the LCA? My car is currently lowered quite alot and i would like to get rid of this disgusting under steer. It's really bad at Winton hairpins and even the s bend exit. i am planning to raise it and add more front camber around -3.5. but what is your take on this because from what i can see your car is lowered i think but its quick as hell.. (i can't tell how much lower it is from the photos to be honest, especially with your wheel setup, haha)

http://forums.clubep3.com/showthread.php?t=569763

And sorry if any of this has been covered on the thread. But i'd rather ask for help than not ask at all.

Thanks a lot for helping.

There is definitely some madness in my car modifying process if you look closely .

Regarding the caster plates, I agree that the they probably aren't necessary just to get a little extra caster. Stock is +1.5° as you say, and I got to around 6-6.5° with just the Todd's top plates. I noticed no difference in steering effort at low speeds but I rarely venture into carparks or do U turns because I can't turn the wheel all the way to full lock due to my tyre/wheel setup. Straight line stability was much improved with all the added caster, my car previously tram lined a lot because of the offset of the wheels and signficant camber. It made the difference between having to have a death grip on the wheel to prevent accidental lane changes to the car being fairly relaxing to drive at speed on varying surfaces. I didn't notice a change in balance (under/oversteer) of the car on track but did feel that there was a little more feedback through the wheel.

If I were you I would just get offset LCA bushes in the front (PCi etc. not polurethane) and see how you like it and how much caster it nets you. This is killing two birds with one stone in some respects because apparently the front compliance bushing sucks and fails (according to that mustclime kid and a lot of US guys) so it should improve dynamic toe behaviour and steering response as well. My front compliance bushes looked mint when I pulled them out at 135,000kms and after a fair few track days.

Regarding mustclime's ideas, on some points I think he is on the right track, even if his logic and reasoning are a bit tenuous, whereas on other things he is just plain wrong. Firstly on his comments regarding ride height, the lower control arm going past horizontal isn't where things start to go pear shaped and push the suspension through it's travel, it is more so that the front roll centre migrates downward quickly as the car is lowered making the roll couple of the car greater as the car is lowered and hence using more suspension travel, it isn't so much a matter of the cornering force pushing the unsprung mass upward more that the spring/sway has a larger roll moment to resist. It is also worth mentioning that despite what some say the front suspension doesn't start gaining positive camber once the LCA (or an imaginary line drawn through the lower ball joint pivot and the inner LCA bushes) goes past horizontal, positive camber gain begins when the angle between this imaginary line and another line drawn from the ball joint to the top mount pivot exceeds 90°. Referring to the diagram below the virtual reaction point (or instant centre) in this situation will approach infinite distance from the unsprung mass on the inboard side and then move to the outboard side of the car, thus gaining positive camber. Not something worth worrying about, since steering axis inclination on our cars is about 17° or so the LCA would have to be angled upward by that same 17° before the front suspension would start going into positive camber. I think the difference between my understanding and mustclime's are just semantics though, but conversely to mustclime's argument a car with a LCA angled down heavily has a high roll centre which results in forces at the unsprung mass called jacking where the tyre is pressed into the tarmac and jacking can be bad. Interestingly cars exist that have the roll centre above the centre of gravity and when entering a turn the car rolls inward not outward, maybe mustclime would like to drive one of those on tarmac but I don't.

His ideas on swaybars are wrong. Whilst it is appropriate to think of a swaybar as a grip reducing device when the relative roll stiffnesses of the front and rear of the car are considered, since the end with the big bar on it will saturate the outside tyre with vertical load and make it lose grip before the other end does, the same is true of a car with more spring at one end than the other. In a more general sense though the car and tyre doesn't care whether the roll stiffness comes from bars or springs or some combination of both. Given two cars, one with springs only, the other with springs and bars, assume they have perfectly rigid chassis and the same wheel rate in roll at both the front and rear. Put both cars in the same steady turn with the same lateral load. Both will roll exactly the same amount, have exactly the same vertical load on the tyres (since the CG height is the same) and the tyres won't know the difference. Things get a lot more complex once you consider transient behaviour and a car with two ends that is not perfectly rigid though but the fact remains that a car that gets part of its roll stiffness from sway bars doesn't have inherently less grip than one that doesn't.

If you wan't some good reading on sway bars, read this thread on Honda-Tech started by RR98ITR: LINK. And good further reading is any thread started by RR98ITR: LINK. Any thread/post by a guy named beanbag on Honda-Tech is good too.



No need to apologise mate, I think that the thread lacks a little in technical discussion anyway. Sorry for the wall of text though, if I don't make sense let me know and I will try to make more sense. Maybe with pictures.

To answer your question that I seem to have missed in my essay writing haha, raising your car is probably a good idea. You will have more suspension bump stroke room, less messed up bump steer, and if your understeer is partially the result of touching the bump stop every now and then you won't have that problem any more. Definitely more camber, and if you raise the front it is probably a good idea to raise the back too. I don't run my car that low because I know it will handle better, I do it because I can, it looks better and I don't know it will make it handle worse . My car is about 330mm from wheel centre to mangled guard so maybe a pretty tight finger gap if I had stock guards.

[edfung81]

Why not polurethane LCA bushing such as the superpro,it will give you more castor and at the same time not as harsh as PCI interms of ride quality ( not as much as PCI busihing IMO). For my car o got 3.5 total castor using it with standard coilover camber top.

[ChargeR]

Why not polurethane LCA bushing such as the superpro,it will give you more castor and at the same time not as harsh as PCI interms of ride quality ( not as much as PCI busihing IMO). For my car o got 3.5 total castor using it with standard coilover camber top.

I guess I am biased against polyurethane bushes because to me it seems foolish to add another relatively undamped spring to the front suspension. Polyurethane by definition is stiffer than the OEM rubber used in the front compliance bushing and when used in off axis bending (ie. not a single axis rotating bush like the rear bush in the LCA) it will add stiffness like a spring when the LCA moves up and down. The PCi (and other decent sphericals) don't do this so the LCA is free to move as it pleases, with the knuckle disconnected I can move my LCAs from full droop to full compression with minimal effort just by hand. I bet that is a lot harder with a polyurethane compliance bushing.

So which would have more of an effect on ride comfort? Adding an extra spring in parallel as in the poly bushes or removing vertical and horizontal compliance in the transfer of load from the LCA to the subframe with sphericals? I am not sure which will have the more negative effect but I can't tell the difference in ride comfort with PCi sphericals fitted. I know which is better for handling, less hysteresis/binding and less compliance of the PCi's wins hands down.

You got good caster numbers though, the 3-5 range is probably a good compromise for the DC5 chassis I think. When I get a chance to get my alignment checked I will post up how much caster I gained with the PCi's.

[Importtuner]

Curious to what you think about the SAI change due to camber plates. How dramatic of an affect would the change in SAI that occurs when adding negative camber through a camber plate affect dynamic camber as the suspension compresses (since the angle obviously won't be 17 degrees anymore)?

Maybe this is part of the reason people seem to love about roll center adjusting ball joints because most of them have camber plates and SAI angles that are greatly different from stock.

[Importtuner]

Actually looked back at some data I collected, the camber plates increase the negative camber gained through suspension compression but at the cost of increasing bump steer due to SAI change.

[ChargeR]

Curious to what you think about the SAI change due to camber plates. How dramatic of an affect would the change in SAI that occurs when adding negative camber through a camber plate affect dynamic camber as the suspension compresses (since the angle obviously won't be 17 degrees anymore)?

Maybe this is part of the reason people seem to love about roll center adjusting ball joints because most of them have camber plates and SAI angles that are greatly different from stock.

Actually looked back at some data I collected, the camber plates increase the negative camber gained through suspension compression but at the cost of increasing bump steer due to SAI change.

That makes sense since increasing the SAI without changing anything else would shift the instant centre of the knuckle more toward the outboard side of the car, giving greater camber gain. I wonder if that increase in negative camber gain would offset the camber lost as the wheel is turned due to SAI? I very much doubt it. Keeping the SAI somewhere around stock and keeping camber gain and roll centre height under control by manipulating the angle of the LCA is probably better in my opinion. Adding camber with plates does have the advantage of minimising scrub radius change though I guess.

I think people love RCAs because they are probably a great idea . If someone wants to donate a set to me to test I will throw them on the car and see if it goes faster?

[stevan]

That makes sense since increasing the SAI without changing anything else would shift the instant centre of the knuckle more toward the outboard side of the car, giving greater camber gain. I wonder if that increase in negative camber gain would offset the camber lost as the wheel is turned due to SAI? I very much doubt it. Keeping the SAI somewhere around stock and keeping camber gain and roll centre height under control by manipulating the angle of the LCA is probably better in my opinion. Adding camber with plates does have the advantage of minimising scrub radius change though I guess.

I think people love RCAs because they are probably a great idea . If someone wants to donate a set to me to test I will throw them on the car and see if it goes faster?

speaking of scrub radius how much is the minimal inner front wheel to strut clearance you would suggest is safe to run? Running 3 degrees my +35 wheels are very close that now i can see why you were using such low offset wheels

I actually took a few photos of my front LCA before and after the Hardrace RCA using as close as possible to my original car height, there is a noticeable difference in angle after the install and i do feel like the car's roll behaviour has changed but its hard to describe the feeling.

[ChargeR]

speaking of scrub radius how much is the minimal inner front wheel to strut clearance you would suggest is safe to run? Running 3 degrees my +35 wheels are very close that now i can see why you were using such low offset wheels

I actually took a few photos of my front LCA before and after the Hardrace RCA using as close as possible to my original car height, there is a noticeable difference in angle after the install and i do feel like the car's roll behaviour has changed but its hard to describe the feeling.

I am probably not the guy to talk to regarding the inner clearance of wheels. I once test fitted Mugsee's 9.5 +24 Advan RGs and found the inner clearance to be only a handful of mm, maybe 2-3. They have more inner clearance than my 17x10 TE37s on the car at the moment, so it is safe to assume that 2-3mm is okay. Anything more than that isn't worth worrying about. I haven't looked at the clearance with the TE37s on, I just put them on and was happy when they span freely .

[Importtuner]

The SAI being affected by the camber plates has a negative affect on the dynamic toe under suspension bump. Gaining camber from offset lower mounting holes on the strut (I.E: Mugen lower brackets) would be ideal vs a camber plate, and, like you said, changing the angle of the LCA.

[l__i__l]

update???

whats happening with this car

is it an antique yet.....can i salvage some parts??

[ChargeR]

update???

whats happening with this car

is it an antique yet.....can i salvage some parts??

Ha! I was home a couple of weeks ago and it wouldn't start because I forgot to disconnect the battery. Washed it though. No part out ever, it will just sit there until I decide to do something with it .

The car is fairly antique though, in less than two months I will have owned it for 10 years.

[plAythiNG]

In under two months- honda nationals. Its ur calling to bring the dc5!