Suspension advice??

[SilentShout]

Greetings all.

I was just asking for feedback from people who have changed their suspension setups to either a lowerd spring (kingspring) or coilovers.

Im on the fence about which route to go, On one hand the coilovers would be able to lower the car how i see fit, however I feel that a spring setup will be all that i need.

My only concern is it is quoted a 30mm drop for the kingsprings in their catalogue, however it doesnt state if this is before or after the factory 15mm drop the car came with (Barina SRI is 15mm lower from the factory)


Also just requesting feedback from thoes who have changed their suspension, what is the improvement in response like for springs vs coilovers?


Many thanks in advance :)

[andrew]

I got kingsprings in mine and it put the front lip 104mm off the ground, I did look at coilovers only thing at the time I did not like was the rough ride, now I have just
got the koni sport adjustable front and rear, also got a brand new set of kingsprings just so it can be all new when I put it in, but now where the care is going
I am looking at coilovers again, lol

[Shadow110]

IMO it depends on budget and what you want to do with the car.
However reading about the coilover route you may want to save your pennies and go for higher end ones, cheapy ones may be crashy.
I have king springs myself with munroe gas shocks and even that is a bit rough but liveable.
Go for a giant rear sway bar and decent shocks and springs and you would be surprised how much better the car is.

[SilentShout]

I was actually very suprised with just the sway bar upgrade, very underestimated mod IMO :)
andrew is the koni sport your talking about shocks? or a coilover setup??

and im thinking ill go with the spring, shock setup and stiffen the rest of the car too. (Strut brace front and rear, Under chassis bracing etc etc.

this will most likely be after new wheels though. after taking my car down the quarter it manages to spin through first gear and into second. Im guessing the 185 profile of the factory sri rims doesnt put the power down well :(

[chris_r]

Considering my SRi has 230,000 on the clock, I'd see more improvement by just replacing the shocks and springs. I don't believe I need my car to be any lower than it already is. I've got the rear sway bar on, set to medium at present. Handles a lot better already. Front strut brace, I'm in two minds about. First one is that I saw the benefit it had when I fitted an OMP brace to the old GSi. But on the SRi and Corsa C in general, the location and mounting of the front strut towers seem to be fairly optimal and I'd wonder if it'd be of any benefit at all.

Tyre width isn't everything in terms of grip. If you're running on el-cheapo hard compound tyres, they'll spin like mad. I had the 16" SRi wheels on my car and the cheap Sailuns would just screech going hard into a corner. I'm now rolling on 17" Corsa D rims with 205/40ZR17 Kumho KU39s which grip like crazy. The Sailuns had a treadwear rating of 340, where the Kumhos are 280. This means the Kumhos are softer and have more grip, but won't last as long. I don't do that much mileage anyway, so I put performance over longevity.

Another trick for more grip, is also lower the pressure in your tyres by a few psi.

[SilentShout]

i usually run at 40psi all round however for the drags I lowered the fronts to 32psi, and im rolling on Kumho's too, I agree they are grippy as heck but still managed to spin them clutch dumping off the line.

I tried launching 2 ways, Clutch dump saw a 16.3 or 16.2 for the best run.

Coming hard off the clutch without dumping saw 16.8 at best as the car just boggs down ( i assume its to do with the electronic Throttle body/Traction control as the power would hesitate and sort of chug before coming on in full with minimum spin)

I still think a wider tyre would help a bit. We will see :)

[andrew]

the koni sport I got are shocks and have king springs to go with them, that's if I don't change to coilovers,

[chris_r]

i usually run at 40psi all round however for the drags I lowered the fronts to 32psi, and im rolling on Kumho's too, I agree they are grippy as heck but still managed to spin them clutch dumping off the line.

I tried launching 2 ways, Clutch dump saw a 16.3 or 16.2 for the best run.

Coming hard off the clutch without dumping saw 16.8 at best as the car just boggs down ( i assume its to do with the electronic Throttle body/Traction control as the power would hesitate and sort of chug before coming on in full with minimum spin)

I still think a wider tyre would help a bit. We will see :)

Another hint, remove the ABS/TC fuse for racing. It'll disable both the ABS and TC (and the dash lights/errors do show up), but your brakes may work as good if not better than when ABS is on. I can't remember which fuse it is off hand, but I remember having to do it for another SRi to get it to run on the dyno. Unlike Astra Gs, removing this fuse doesn't actually disable the power steering either. I advise against doing this on public roads though, mostly for safety and insurance reasons.

[andrew]

i usually run at 40psi all round however for the drags I lowered the fronts to 32psi, and im rolling on Kumho's too, I agree they are grippy as heck but still managed to spin them clutch dumping off the line.

I tried launching 2 ways, Clutch dump saw a 16.3 or 16.2 for the best run.

Coming hard off the clutch without dumping saw 16.8 at best as the car just boggs down ( i assume its to do with the electronic Throttle body/Traction control as the power would hesitate and sort of chug before coming on in full with minimum spin)

I still think a wider tyre would help a bit. We will see :)

and you will see better time's by turning the traction control off if you know how

[chris_r]

It's also a known issue with Z18XEs, that the electronic throttle is on a bit of a delay in standard form. Two ways of fixing/improving this is to get the ECU flashed with a custom tune or fit a 'pedal box'. The latter works as a throttle cable interceptor and forces quicker response from the throttle body.

[SilentShout]

ah so its in the ecu to purposefully have a delay between when the pedal is pressed to when the TB actually opens??

I wouldnt mind just going to a cable TB, none of this electric palava to deal with.

And ill remove the fuse after work and see how it goes :) I have read that its the only way to do it but i wasnt sure if disabling the ABS would lower the braking capabilities :)

[chris_r]

I wouldnt mind just going to a cable TB, none of this electric palava to deal with.

To do that, you will need to go for an aftermarket ECU or fit the entire setup, along with wiring looms, etc. from an Astra G with an X18XE1 engine. The X18XE1 differs from the Z18 with less aggressive cams, cable operated throttle body and EGR valve (Astra Z18s and I believe facelifted Corsa Z18s didn't have them). For that sort of hassle, the aftermarket ECU would be the way to go, although you still need the Simtec in place for things like the dash, etc. It becomes a bit of mash up of wiring.

All ABS does is stop the brakes from locking up in a panic situation. Disabling it would allow to use 100% of the braking power available, but as I said before, be wary on public roads. I believe if you have your ABS light on, it's a defect, not to mention if you have an accident, they'll more than likely invalidate any insurance you have and then throw the book at you when an opposing party sues for damages. Having said that, I wonder what my brakes would be like without the ABS enabled. Bloody things almost put you through the windshield as it is now.

[SilentShout]

cheers for the tip :P

I think i will see about improving the response time via the ecu, seems to be the easiest way.

I heard that its possible to single out the earth wire for the TC and hook it up to a switch so that its possible to toggle it on and off. again seems like a lot more hassle than simply removing and replacing a fuse :P

[andrew]

cheers for the tip :P

I think i will see about improving the response time via the ecu, seems to be the easiest way.

I heard that its possible to single out the earth wire for the TC and hook it up to a switch so that its possible to toggle it on and off. again seems like a lot more hassle than simply removing and replacing a fuse :P

yeah I got mine on a switch and I turned my off with out ever going near the fuse, I think I am the only one doing it the way I do it too, lol before I put the switch in I could turn it off with out going under the bonnet, also I did not have to be even inside the car,