TiTAN
Suspension
TiTAN Suspension for Toyota Corolla KE70
Day 14 - Reduce front spring rate
Around April 2004
The front spring rate was reduce from 500 psi / 3 inches to 400 psi / 3 inches while the rear remained 300 psi / 3 inches. This translate to something like 4.4 kg/mm front while 3.3 kg/mm rear.
Due to the fact that changing the front coils were not charged to me, hence I didn't dare to ask for too much. i.e. initially Richard wanted to re-stroke the front absorber, re-oil and re-pressurized to suite the lower spring rate, but I told him not too as I didn't want to bother / trouble him anymore than I need to and that I'm willing to be a guinea pig for testing.
I've been very understanding as a customer and never complain behind their back and Richard respect that and so allowed me to leave without modifying the absorbers.
When I drive out, it feels much softer ........ I didn't like it ...........
After around 2 km I reach the bridge exiting to the highway, where I need to turn 90 degrees left and go down hill at the same time I nearly vomited because the suspension allowed a weird waving effect ........
I was very disappointed and very sad to find that my judgment was wrong to reduce the front spring rate. But what to do, already change, cannot turn back now to change again. I'll get scolding from Richard for sure..... :( no choice, just go home hence keep driving. :(
Strangely, after "that" once only wavy effect ...... the suspension felt normal all the way from TiTAN to home. ??? It turns well too, much less understeer from before, more comfort and more grip as well as more steering control weird ???
Later I have to pick up Bill Sherwood for diner. Right after I pick Bill up, and travel no more than 5 km with around 4 corners. On the 5th corner, which is the one from old Subang air-port to Subang Jaya 130 degrees downwards right-hard-hander under Federal Highway towards Klang toll. Bill asked : What did you do to the car? it turn much better than before!!!
My god ........... I was shocked .............. I haven't even told Bill yet ........ but he already detected the firmer turn-in less understeer behavior and he is only a passenger at the moment. My god, I can't believe it.
I did it. I made another successful adjustment towards better handling :) yippy :) this is great,.... sometimes it is not always higher spring rate better ........
Update February 2005
The front spring rate was measured and found to be 360 psi / 3 inches while rear is 300 psi / 3 inches. It translate to 4 kg/mm front with 3.3 kg/mm rear.
I've been experiencing slight oversteer after some other upgrades, like Roll Center Adjuster with Negative Camber + Track Increase and Front Strut Top Tower Bar.
They affected the overall total handling package. I also noticed the rear bump jump more than the front and seriously suspect that the rear spring rate is slightly too strong. Will need to go back to TiTAN to change the coils again. Hopefully they have to 280 psi / 3 inches or there about.
Report to come later after modification.
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