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Nice going with the engine build… another great success on getting it right first time!
Your car’s suspension definitely seems to behave… oddly.
The car has a huge amount of roll for something with 850/500 rates.
My car is sofffffft like under 400 front springs and it doesn’t look like it rolls that much (bigass front sway bar though)
Got photos of the coilovers installed?
What sway bars do you have?
what tyres and what are the pressures?
Are you sure the shocks aren’t turned all the way down?
In your onboard videos you can see a lot of the movement, the bouncing in the latest track one and the roll in the auto cross one, but it’s confounded a little bit by the stabilisation in your camera.
Next time out can you maybe turn that off and see if it helps highlight the cars movement.
There's another thread here with poster talking about rough track, and video of very loose rear, followed by discussion of solutions, I didn't watch all of your video but while there was vertical movement I didn't see any sliding, but that was an outlap and you may not have been pushing.. The video car was moving too, but hard to compare the two.
How does the car behave otherwise, on other tracks? Is this a high priority track, that you would be willing to optimise the car for at the cost of losing time on other tracks? Have you played with the settings on the shocks to improve the car's behaviour, that would be the first and simplest thing to try, then maybe try different springs. Again, the question is how much to do want to do to optimise for this track?
If adjusting shock settings doesn't do enough for you, I'd approach Emilio directly and ask his advice before taking further steps.
Any idea where that thread is? I skimmed through "Suspension, Brakes, Drivetrain" and didn't see any recent threads that seem relevant. In relation to sliding the car behaved well around the corners. Everything was relatively predictable with little to no pushing. Granted, I wasn't breaking any lap records or anything... I got a couple of videos from outside the vehicle. Not the best video quality but it does show how the car is bouncing.
In regards to overall behavior. I haven't had many events on this setup Only a handful of autox events and a few HPDE days. Still trying to get it tuned in to where it needs to be. But overall I've really been enjoying the Xidas. I was struggling with oversteer at the last couple of events but I'm thinking that was due to tires and possibly because the rear sway bar wasn't connected.
I didn't play with the damper settings at this event. I only focused on getting consistent times. I'll report back with current settings later today.
Originally Posted by slug_dub
Nice going with the engine build… another great success on getting it right first time!
Your car’s suspension definitely seems to behave… oddly.
The car has a huge amount of roll for something with 850/500 rates.
My car is sofffffft like under 400 front springs and it doesn’t look like it rolls that much (bigass front sway bar though)
Got photos of the coilovers installed?
What sway bars do you have?
what tyres and what are the pressures?
Are you sure the shocks aren’t turned all the way down?
In your onboard videos you can see a lot of the movement, the bouncing in the latest track one and the roll in the auto cross one, but it’s confounded a little bit by the stabilisation in your camera.
Next time out can you maybe turn that off and see if it helps highlight the cars movement.
I'm glad the engine build went well. Thanks!
No photos of the coilovers installed. I'll get some later today. Some second opinions to confirm they were installed/set up properly would be great, actually.
Front and rear are original sway bars.
Tires are 225/45/15 Continental ExtremeContact Forces at 27PSI hot.
I don't recall ever turning them down all the way. Last time I remember setting them they were near middle. I'll check and report back. I guess this is a good time to start keeping a detailed log of tire temps/pressures, ambient temps, and suspension settings among other things...
Turning off the stabilization is a good idea. Thank you. I'll try to remember that next time.
Last edited by HalalBuilt; 06-12-2024 at 10:22 AM.
Regarding current setting, they were very soft - and, for some reason not symmetrical...
Front Driver: 19 clicks from full stiff
Front Passenger: 13 clicks from full stiff
Rear Drivers: 14 clicks from full stiff
Rear Passenger: 14 clicks from full stiff
I'm embarrassed that they were so out of wack but I'm surprised the front was softer than the rear based on how the rear was bouncing.
Here are some pictures showing how the coilovers are installed incase you guys see something wrong
I had some time to find the oil leak coming from the front of the engine. The small plug on the oil pump was the source. I just tightened it a bit and it stopped.
This car is rattling itself apart which is kinda scary. I noticed a couple weeks ago that one of the top bolts from the intake manifold bracket was missing. I didn't think much of it, I figured I just forgot to tighten it and it fell out. I checked it yesterday and the bottom bolt also fell out. So it was only being held on by the last bolt at the top. I tried taking the bolt out but ended up shearing it. Fun.
Bottom alternator bolt was also almost completely unthreaded. One of the nuts on the dummy throttle body as well, along with the grounding cable to the right of it.
Needles to say I'm going to though all the accessible bolts to check them. I wonder if they're being vibrated out or if I just never tightened them during the install. I'd be very surprised if I left them loose...
I need to bite the bullet and fix the coolant leak at the reroute housing. I'm not exactly sure what's leaking because I can't see jack back there. I thought I already stopped the leak by tightening the smaller hose barb on the drivers side going to the heater core but something is still leaking. Just thinking about getting the coil pack out hurts... God I hope I don't need to pull the housing to reseal the gasket. That would be devastating.
Last edited by HalalBuilt; 06-13-2024 at 09:44 AM.
Regarding the Xida pictures, it's hard to tell anything about them without more context, and you're only showing the left side.
What jumps out to me is the very different levels of compression on the helper/tender spring front to rear. I'm guessing that's not how it usually sits. Are you jacking up only one side of the car while the other is still loaded on the ground?
Note that your issue is quite different to that other one, he has crappy shocks and a rough track. You have good shocks, and (it seems) smooth track but with longer duration undulations.
When those photos of the springs were taken, was the suspension at full droop? If so, that may be your problem, those tender springs will (should) be extended at droop - visualise the piston in the tube, it should sit more or less around the mid point of its travel, to allow the shock to move up AND down around it when the springs are loaded with the dead weight of the car. Mostly it will be a bit higher than the measured mid point due to the gas compartment at the bottom. Easiest way to tell is to look up the shock travel, halve it, and is that the distance (including bump stop compression) sticking out of the shock when loaded? You don't need to be millimetre-precise here, just reassure yourself that, yes, the shocks are free to travel in both bump and droop. If not, consult your set-up instructions, I'm sure that they came with the shocks, or are probably available on the site.
Couple of suggestions.
corner-weight the car (start by checking your ride height)
nut-and-bolt tightness check, including disconnecting roll bars and checking for free movement
Test.
When I say test, I am talking about the ride, not handling or lap times. Either start both ends at one extreme of the shock settings, or if you run an offset use that but starting one at full hard or full soft, the other accordingly. You don't need to go through each click, break the range up into say three or four steps, make notes at each change (if you can get someone to video each run, concentrating either where the worst bouncing is or else where you can get good quality video of the bouncing, so much the better.) Then home in on the settings that provided the best result, by going up or down the settings - if going up does not improve bouncing, go down.
You can short-circuit this by talking to Emilio, who I am sure has BTDT and may suggest shock settings to start with, or possibly changing springs. The latter raise the issue of how important fixing the bouncing here is, compared to your carspeed at other tracks you run on.
Definitely with race car things and stiff suspension it pays to check various bolts regularly as the NVH will reveal things loosening off unintentionally!
Regarding the shock adjustments being where they were-
Not my proudest interwebs admission. But also not the most embarrassing. So there's that...
Originally Posted by OptionXIII
What jumps out to me is the very different levels of compression on the helper/tender spring front to rear. I'm guessing that's not how it usually sits. Are you jacking up only one side of the car while the other is still loaded on the ground?
That's correct, I only jacked up the drivers side. But even with the car on all four, the helper spring is nearly fully compressed.
Originally Posted by Gee Emm
When those photos of the springs were taken, was the suspension at full droop? If so, that may be your problem, those tender springs will (should) be extended at droop - visualise the piston in the tube, it should sit more or less around the mid point of its travel, to allow the shock to move up AND down around it when the springs are loaded with the dead weight of the car. Mostly it will be a bit higher than the measured mid point due to the gas compartment at the bottom. Easiest way to tell is to look up the shock travel, halve it, and is that the distance (including bump stop compression) sticking out of the shock when loaded? You don't need to be millimetre-precise here, just reassure yourself that, yes, the shocks are free to travel in both bump and droop. If not, consult your set-up instructions, I'm sure that they came with the shocks, or are probably available on the site.
Couple of suggestions.
corner-weight the car (start by checking your ride height)
nut-and-bolt tightness check, including disconnecting roll bars and checking for free movement
Test.
I only lifted the drivers side of the car for that photo. Thank you for the explanation. I think the reason the rears are so compressed is because I was trying to get some rake. There's a note in the instructions that says there's no downside to adding more preload, so I didn't think much of it when I saw the helper springs fully compressed. I'll check the shock travel as it sits and then see if I need to make height adjustments from there.. To be clear, the helper springs should only be fully compressed when the car is on the ground? They just shouldn't be fully compressed when they're at full droop?
Thanks for taking the time to give some valuable advice!
Originally Posted by slug_dub
Definitely with race car things and stiff suspension it pays to check various bolts regularly as the NVH will reveal things loosening off unintentionally!
Yep I'm starting to realize that. I just bought a tube of this stuff to mark nuts and bolts make quick visual checks possible. Thank you.
... To be clear, the helper springs should only be fully compressed when the car is on the ground? They just shouldn't be fully compressed when they're at full droop?
...
...I just bought a tube of this stuff ..
To answer your question, lets go back to tors. The shocks have a travel range, and that is what allows them to function, that should be your focus. The 'helpers' are a tool to handle the distance between the fully extended main spring, and the perch at droop (ie the perch cannot be set so high that at full droop the spring remains seated. You can just allow them to flop around at full droop, without helpers, but that is noisy and the unseated ends may result in eventual damage to the seats as they re-engage. Or you just buy longer springs (of the same rate).
So the length that the helper is compressed at droop is a product of lots of things, but the first question is whether the shocks are working properly (or as you intend) - since you have a ride quality issue, start with the looking at the shock setup, and whether you have enough bounce and droop travel for the shock to control the wheel inputs. Your ride problem, and the fully compressed helper, sets that examination in motion. Those are quality shocks, and assuming nothing is broken inside I'd be surprised if they couldn't handle your track - if so, what has to happen to allow them to function as designed?
Same question for the fronts, though they look to my eyes to be 'more normal' that means bugger all when you have a problem, as you do, so ask the same question of the fronts as you do for the rears. It may be that nothing further is required there, of less of an alteration, but do the work, get the result, enjoy the fruits of your labours.
Note that the helpers are super soft, they add nothing to the rate of the main spring, they function only as a variable length spacer. Their length at droop is a product of ride height, rake, corner weighting, spring choice, etc. If I see a helper fully compressed at droop I ask myself why is that helper there - is it just a spacer, could it be removed and the perch screwed up higher, or ...? When the car has a handling or ride issue, it stops being a curiousity, and becomes a serious question.
Regarding marking nuts and bolts, I use old-fashioned Whiteout, Tippex I think you call it. Doesn't matter, whatever works! I have had mine for eons, probably can't buy it anymore as nobody uses typewriters!
To be clear, there are two kinds of secondary springs used on track coilovers: Helper springs, and tender springs. The difference between them is that one is a high enough rate to actually be considered part of the suspension setup, and one is an extremely low rate that simply keeps everything seated when the suspension is unloaded during service. We're talking the difference of, say, 110 lb/in vs 10 lb/in.
I don't recall which is which. I would think Helper springs should be the stiffer option, as they actually help suspend the car and not just tend to keeping things neat and tidy. But I remember being wrong about it in the past. I find it an esoteric debate and won't care to memorize it again.
Stock car suspensions use soft enough springs that they need preload in order to load the springs enough to support the cars weight at ride height. Even with no weight on the suspension, you've still got preload, which is why a stock strut will explode apart if you loosen the shock nut without spring compressors in place. Aftermarket track focused coilovers usually use springs that are multiple times stiffer than stock, in generic lengths. The dramatically stiffer spring rate means that you don't compress the springs anywhere near as much at ride height. The generic length means a shock made to use all the available suspension travel probably won't have a matching spring to meet your ride height target.
A functional dual spring setup allows you to get some of this droop travel back, by using a softer secondary spring than the main spring to get some preload in the suspension at ride height.
So, say you're going over a crest in the road and unloading your suspension a bit. Oh, and you're mid corner and just hit a bump on the inside. On a car running stiff coilovers with just a single spring rate, you may have completely unloaded the spring on the inside and the only thing pulling the tire down to the road is gravity, and it's fighting against the damper rebound damping meant for 550 lb/in main springs. The inside tire won't droop enough to contribute to traction. On a car with a high rate dual spring system, once the main spring reaches it's max length, there will still be another softer (but still useful!) spring pushing that wheel back down to the ground.
Xidas have a higher rate secondary spring that does change how the car drives in the above situation. Flyin Miata Fox coilovers have the lower rate secondary that doesn't change how the car drives, they just keep the springs from rattling around. When I looked into changing the springs on my FM Fox coilovers to mimic the Xida high rate secondary spring, I found the cost was too high for the reward for my use case. Maybe if I spent more time on UK backroads or rally stages I would feel different.
So the length that the helper is compressed at droop is a product of lots of things, but the first question is whether the shocks are working properly (or as you intend) - since you have a ride quality issue, start with the looking at the shock setup, and whether you have enough bounce and droop travel for the shock to control the wheel inputs. Your ride problem, and the fully compressed helper, sets that examination in motion. Those are quality shocks, and assuming nothing is broken inside I'd be surprised if they couldn't handle your track - if so, what has to happen to allow them to function as designed?
The shocks need to be set in the middle of the travel range. Thank you for taking the time to explain what the end goal needs to be and why.
Originally Posted by Gee Emm
Same question for the fronts, though they look to my eyes to be 'more normal' that means bugger all when you have a problem, as you do, so ask the same question of the fronts as you do for the rears. It may be that nothing further is required there, of less of an alteration, but do the work, get the result, enjoy the fruits of your labours.
Note that the helpers are super soft, they add nothing to the rate of the main spring, they function only as a variable length spacer. Their length at droop is a product of ride height, rake, corner weighting, spring choice, etc. If I see a helper fully compressed at droop I ask myself why is that helper there - is it just a spacer, could it be removed and the perch screwed up higher, or ...? When the car has a handling or ride issue, it stops being a curiousity, and becomes a serious question.
You're right. I need to get this figured out. I plan to corner weight the car sometime this season and get the ride height dialed in legitimately. Before messing with that though, I want to get a DIY alignment setup put together so that I can re-align once completed.
Originally Posted by Gee Emm
Regarding marking nuts and bolts, I use old-fashioned Whiteout, Tippex I think you call it. Doesn't matter, whatever works! I have had mine for eons, probably can't buy it anymore as nobody uses typewriters!
Didn't think to try whiteout. I had bought paint pens which I used during the engine build, but they were oil based, so needless to say they were gone immediately.
Originally Posted by OptionXIII
...
A functional dual spring setup allows you to get some of this droop travel back, by using a softer secondary spring than the main spring to get some preload in the suspension at ride height.
So, say you're going over a crest in the road and unloading your suspension a bit. Oh, and you're mid corner and just hit a bump on the inside. On a car running stiff coilovers with just a single spring rate, you may have completely unloaded the spring on the inside and the only thing pulling the tire down to the road is gravity, and it's fighting against the damper rebound damping meant for 550 lb/in main springs. The inside tire won't droop enough to contribute to traction. On a car with a high rate dual spring system, once the main spring reaches it's max length, there will still be another softer (but still useful!) spring pushing that wheel back down to the ground.
Xidas have a higher rate secondary spring that does change how the car drives in the above situation. Flyin Miata Fox coilovers have the lower rate secondary that doesn't change how the car drives, they just keep the springs from rattling around. When I looked into changing the springs on my FM Fox coilovers to mimic the Xida high rate secondary spring, I found the cost was too high for the reward for my use case. Maybe if I spent more time on UK backroads or rally stages I would feel different.
Thanks for the concise explanation! This makes sense. I'll take it all into consideration while resetting preload/ride height. Hopefully soon...
-----
In other news, big ****, splitter and air dam. My wife is due soon with our second child which means I probably won't make it to many more events this season. So I decided to throw the medium downforce kit that I bought last year onto the car before a time attack event at NJMP this past weekend. It took a few evenings after work and all of Saturday to get everything ready for Sunday. Only thing that went wrong with the install was be breaking a tab off the radiator ducting plate that rests on the splitter the day of the event.
Original NB1 bumper
NB2 bumper I sourced off FB marketplace a while back
Getting ready to form a leading edge on the splitter. I just used a flapper disk like a caveman.
The car performed great. I made slight adjustments like stiffening up the dampeners (7 clicks from fulls stiff all around) and changing the angle of attack of the wing from 0.5% (pretty much just a baseline) to 4.5%. Both of those adjustments made the car feel very well planted and responsive - although, lap times didn't improve by much. I attribute that to increasing ambient temps (it was a scorcher of a day - high of mid 90s) and lack of driver skill/confidence. I didn't realize how scary it is to take these turns at higher speeds... I'll have to ease into the potential of the car at this point. I couldn't believe how some of the faster drivers were entering into turns...
Also, the fear of hub failure mid turn is real. I'll have to seriously consider hub upgrades soon.
In anticipation for the hot day, I made a DIY cool shirt system. Pretty standard stuff, similar to the one @sixshooter made. I planned to put mine under the dash in the passenger foot well. I ended up not using it though. But I did test it between sessions. Some improvements to the shirt are definitely in order. But the cooler portion worked great. I cut up an old plastic jar and hot glued it to the bottom so that it can house a frozen bottle of water. The idea is to keep the bottle from smashing into the pump/wires/tubes while driving.
This was the first time I brought a canopy to an event, and let me tell you. What a game changer. If I just had to sit in my car/truck between sessions I think I would die, but the canopy, some chairs, and a table made a world of a difference in avoiding fatigue throughout the day. All rookie stuff, I know - it's a work in progress.
Last edited by HalalBuilt; 06-27-2024 at 11:50 AM.
06-12-2024, 08:32 AM
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