♦ ♦ ChargeR's DC5R Blog ♦ ♦

[ChargeR]

oo guy ur wheels are weaksauce haha

At least they don't have balloon tyres on them . Thanks for the comment though.

More Wheels: Part 2

I also wasn't happy with my rear wheel girth or fitment so I bought a new pair for that region of the car. SSR Type C in 17x9 +28. Should fit nicely compared to my previous 17x8.5 +30s and the spoke design is nicer on the 9" and wider Type Cs. Weighed them at around 7.2kg on the kitchen scales to they are noticeably lighter than the Volks. Tyres are being fitted on Thursday and I nearly have all the parts together to put my coilovers back in over the Easter weekend so pictures and details will follow then.

[Didz]

wow guy. Was not expected, i expected 8s for the rear!
Now you have double concave!! nice work guy!

[lowie]

very nice work, especially the TE37s they are a personal favourite of mine.

love the aggression in the specs here..always wish I chose mine better

[ChargeR]

very nice work, especially the TE37s they are a personal favourite of mine.

love the aggression in the specs here..always wish I chose mine better

Thanks . Don't worry fellow, this is my second attempt at buying wheels and I am sure I will have more attempts in the future. At least you can do a U turn without your tyres rubbing the chassis.

wow guy. Was not expected, i expected 8s for the rear!
Now you have double concave!! nice work guy!

Thanks guy. TE37 concave makes the Type C concave look weak though.

Tyres were successfully fitted today. The 255 and 225 combo fit like a glove according to the tyre guy and I am moderately sure that the slight stretch won't cause catastrophic failure on track .

[Didz]

woop woop

we want pics of fitment guy :P

[ChargeR]

woop woop

we want pics of fitment guy :P

You can't have fitment pics . The last piece of my suspension puzzle still hasn't turned up in the post so I can't refit my coilovers, hopefully next weekend. Patience is a virtue. Then alignment. Then I need to find an appropriate day for some testing at Symmons Plains.

[lil_foy]

OH MAN
They came out sexy!!

[ChargeR]

OH MAN
They came out sexy!!

Thanks champ I will pass on the compliment to my brother, the ameteur spray painter.

Suspension revamp

Last week the component that I thought would be the last thing I needed to get my suspension setup ready for Superlap arrived. A pair of modified OEM tie rods by Todd from ClubRSX. The difference between these and OEM and my other modified rods is that Todd cuts the end off the tie rod, then press fits a threaded bush into the rod and runs a weld around the outside. A threaded rod is then used in place of the outer end of the tie rod. This allows the length of the tie rod to be adjusted over a massive range, avoiding any issues with running out of toe adjustment with low ride heights or a lot of negative camber . I chose to go for this solution because I am going to experiment with less negative camber in the future and I want the adjustability without having to swap the whole tie rod end from previously modified ones and the OEM ones I have.

This means that my shortened OEM tie rods will be up for sale if anyone wants them .

The tie rods look like this:



In addition to the new tie rods I also acquired a pair of camber and caster adjustable spherical upper mounts for the front from the same gentleman, Todd of ClubRSX. Here is a LINK to a thread on ClubRSX discussing them. When caster is mentioned many speak of the advantage of gaining negative camber at the outside wheel and positive camber at the inside wheel during a turn, but this is negligible in my opinion at the steering angles encountered on a typical race track. Anyone suggesting that a lot of caster will compensate for minimal static camber is kidding themselves.

Caster also has the effect of slightly jacking up the inside wheel and lowering the outside wheel in a turn, which counteracts the gained negative camber at the outside wheel. The most noticable effect I am hoping for is more feel through the steering wheel for the following reason; more caster will significantly increase mechanical trail which is the amount that the centre of force in the tyre print trails the imaginary point where the steering axis intersects the road surface. This is illustrated (poorly) below; LBJ denotes the lower ball joint location, USM denotes the upper strut spherical bearing location. F denotes the lateral force enacted by the road on the tyre. The left hand figure represents zero caster, the right hand represents an exaggerated amount of positive caster. The imaginary point where the steering axis intersects the ground has moved forward by X distance, giving a centreing moment around the steering axis of F*X. Of course there are a lot of other tyre and geometry factors that affect this and the image below is heavily simplified.



The net effect of this is that the lateral force at the tyre in a corner produces a moment about the steering axis, a moment that acts to self centre the steering, and a moment that also increases as lateral forces at the tyre, and hence cornering forces increase. The effect that I anticipate from this is that there will be increased feel of the grip limit of the front tyres through the steering wheel, and hence an easier car to drive. We will see. Either I will be faster or I won't, the stopwatch doesn't lie.

I am anticipating at least 3 degrees of additional caster from these upper mounts.

This is what they look like:



So last week I re-assembled and fitted the old trusty Mugen N1s with the new upper mounts. There were a couple of small issues with the install: Due to the design of the top mounts they space the strut downward significantly so the top of the damper shaft clears the chassis with the significant caster, this caused some issues with achieving my desired ride height. I lowered the lower collar on the coilovers to compensate for the thicker top mount but unfortunately ran out of adjustment before I got to a desirable height. The bottom of the strut is also extremely close to the CV boot. I have a plan to get the 5mm or so more low that I desire.

Another new part I am fitting to the front of the car is flat thrust bearings on top of the springs. This is to avoid any spring binding as the strut turns and compresses. Previously I was using OEM upper mounts that have a plastic bearing that performs the same function, and provided OEM like levels of noise and harshness. Nothing irritates me more than suspension noises so I am hopeful that the addition of these bearings will avoid any spring popping etc.

Here they are:



I also raised the rear of the car a little from my previous ride height to get a little less rear camber, and to get slight rake to the front, mostly for aesthetics. I overshot the mark a little though as you can see in the pictures below. Wheel fitment is a little minty too, it needs more low and a little less camber at both ends but ride height and alignment must remain as a compromise to fit the massive 275/245 Hoosier combo that I will be using the day after Superlap. My intention in the future is to return to a more conservative 255/225 tyre configuration and then add higher roll stiffness and less static negative camber at both ends.

Here are the dampers installed:



And this is the result:





Comments welcome both on my theories and my pictures . I will take better pictures this weekend.

[maracer]

Another great piece of work and write up to your blog.
You are defiantly on a mission on getting the best handling DC5, hands-down.
These are the things so many of us overlook, Me included, It’s just in the too hard basket……..
Unless you get plenty of track time and understand how the car feels and make the adjustments to suit.
WELL DONE TOM

[k20eg]

sek c

Nice write-up also

[Didz]

Wow. Awesome dude! So much thought gone into the control of the car!

i think some of those thrust bearings are in my future.

Also i am VERY interested in the new upper mounts. If it all works out like you hope, i may decide to follow suit (provided i can get my hands on some).

Pro.

[PHATJM]

nice read!

look forward to seeing all your work hard work payoff at superlap, well done

[DrTran]

Your never going to do mods to the motor are you Tom? Sooner or later your going to run out of suspension mods. But from the looks of it your doing stuff where it's going to count. Loving your set up buddy can't wait till I see more stuff. I am about to drop my suspension on my 4 door do poly urethane bushings and do some other suspension mods.

[fatboyz39]

I like those strut tops. I did a similar mod to my evo 7 which uses the same front configuration as your DC5R. It had adjustment for camber, which i thought i had more then enough adjustment from the factory camber bolts so i switched them like what you pictured above. It did in fact gain 3' Castor.

Looking good for superlap Tom. You got the setup going i think you need the extra power now. kpro :P

[lil_foy]

AHHHHHHHHHHHH

I'll be sure to try find you at superlap.
Mass coverage from a mate and myself.