Hey all!

Recently, I have been planning out my handling upgrade path, and I think I have it settled for now.

1. TB Performance mid chassis brace
2. Coilovers OR KYB struts
3. Wider wheels (maybe)

Currently my RS7 is on TRD springs, and it handles pretty well in the twisties, but after reading some of the rave reviews of going from springs+struts to coilovers
here I have started saving up. Of course I have also seen the very good results that come from the mid chassis brace, which is why that is at the top of my list.

My plan is to see how the car handles with the brace, and if it really fixes the bump instability as much as people say, I will probably hold off. If I end up still wanting more, or wanna lower the car anymore,
then it's on to step 2. Fastscions.com has KYB Excel G struts, which claim to pair nicely with lowering springs. It also advertises "10-15% more response", whatever that means. Can anyone chime in on their quality?

I've got good tires, almost no wheel hop/one wheel peels even if you stomp on it mid hairpin! (TC/ESC off of course)

After seeing Drizzoh's review of the Tein Flex Z coilovers (especially the difference by swapping the basis Z's for them), I am a little swayed in that direction,
but of course I want to see the other options as well. There are quite a few in the $800-1200 range just like the Flex, but I am not sure what I should look for.
Derrick Aquino on YouTube recently reviewed a set by Maxpeedingrods. At a price of $329 for a whole set, I am very suspicious about the overall quality though.

So, if anyone has reviews of other options, please let me know!

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Flexxxxxxxxxxxx <3

Have installed KYB's before. Decent upgrade to stock if you're looking for handling benefits but a little on the stiff side. They don't last very long (60k-ish in lowered applications). If swapping struts only, would opt for the Tein Endura Pro Plus's. A big part of the ride quality increase will come from changing out those TRD springs to something better though - as they're designed to be used with the stock struts. Still would vote for coilovers on this car as its one of the best bangs for your buck upgrade on nearly any platform. Most coilovers in this mid-range price bracket are pretty similar feature-wise - I chose Tein because they're tuned for street driving vs some others that emphasize track performance only. Wanted my car to still be comfortable as it's going to be the daily until it explodes. Have setup suspensions for full autocross and track day applications and while there is no denying the performance increase in handling, the ride ends up absolutely jarring. The tC is anything but a racecar, so the daily drive comfort was my main priority. With the dampening adjustments you can also tailor it to handle exactly how you want. Out of the box Tein anything is a huge handling increase to anything the tC comes with stock.

I don't have any experience with the Maxspeed's, but I really can't image they're that great in the long term. I mean they're cheaper than Raceland and Raceland is absolute garbage.

Am on board with your upgrade plan. This car costs too much to make fast but if you can make it handle it gets immensely more fun to drive. Also consider installing a front strut tower bar as it helps with
feedback from the front tires- very beneficial if you do spirited driving. Tire upgrades also go a long ways on this car, I am really into my Hankook S1 Noble2's (I don't ever need to disable traction control)

FWIW have now installed Tein's on a 1G, tC, 2G tC and an A90 supra and all owners including myself are in love with the ride and handling upgrade. Will be doing them on a Mazda3 as well whenever my buddy finally lets me drop his car lol.

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Yeah, after checking some reviews on Maxpeedingrods' (rolls right off the tongue ) options, they seem to be pretty poor in quality.
Might even be a rebrand/repaint of some Chinese wholesale manufacturer, as some have pointed out striking similarities to some eBay-spec kits.

I have a DC Sports strut tower bar already, it was the 2nd mod I did after the MWR short throw kit. I haven't autocrossed with it yet but I can tell that the wheel feedback is a bit better now.

Just went out and checked again, I have BFGoodrich g-Force COMP-2's right now, in 215/45 r18. I am not exactly sure why the previous owner got a narrower tire than the stock width of 225.
The slightly shorter sidewall seems to have a good effect on overall responsiveness though.

Not really sure what you mean by "costs too much to make fast". I've already got 4 stickers on the hatch and it didn't cost me a dime!

 

Heh,heh...they used to be called MaxSpeedingRods... but I think they caught heat for encouraging street-racing and anti-social behaviors... ;)

I'd skip struts and wheels for now, until they're worn-out.
When they do need replacement, don't get common off-the-shelf stuff.
Most of them is crap without any engineering behind them, just commodity parts slapped together.

Get coilovers that have separate height (length) and preload-adjustment. They actually behave differently and using pre-load to adjust height will work, but has compromises. Also make sure struts are double-adjustable, that is... rebound-damping and compression-damping is adjustable independently. A lot of time when tuning suspension, you need to make rebound & compression changes in opposite directions. Even better is 4 or 6-way adjustments (separate high/low-speed compression/rebound and knee-point), but now you're looking at Ohlins or Penske at $6k+

On wheels & tyres, for any given tyre-width, wider-rims will give you better grip and response. A 225mm tyre performs best on 9" rim for minimal sidewall flopping. Best to stick as close to factory offset as possible for minimal changes to scrub-radius.

Best upgrade by far for handling is swaybars, especially adjustable ones. Much, much better cornering without sacrificing ride-comfort like equivalent-performing effect from just coilovers alone. Most have springs that are way, way too stiff, because uninformed market thinks that's what they want. I have dedicated +400bhp race-car and it doesn't even have springs that's as stiff as some of these coilover kits.

 

Danny have you ever run a street car with sways? It absolutely effects the ride quality in a negative way. The sway and suspension options you mentioned also do not exist for the tC platform. Also FWIW my coilovers ride significantly smoother than the factory suspension did.

Nice post, in theory, but doesn't pertain to the tC directly. Pretty generic info.

 

Yeah, so far I have only found that CT200H rear swaybar (forgot if a front one exists), and from what I've read they really hamper the ride quality, especially fronts.

AFAIK the Flex Z's have a single damping adjustment that affects compression and rebound at the same time. I really am not that concerned about dialing my tC in to shave off split seconds, I am driving more twisties than tracks after all.
Therefore I still believe they are the best option for me.

 

Of course, I've upgraded swaybars on all my cars since my 1st MKII Supra back in 1984.

Due to multiple overlapping and often contradicting goals in design, no manufacturer ever specifies suspension settings for pure cornering and handling fun. Due to their compromises, there's always areas for improvement to customise to your specific goals.

Questions:

1. How many miles did your tC have on it when you installed coilovers? As in, how many miles did your factory struts have and how many miles did your coilovers have at same time?

2. What is spring-rate of your coilovers vs. factory struts?

3. What is damping-rates of coilovers vs. factory struts? Do you have shock-dyno of each?

4. Did you do before & after skidpad and track laptimes of factory suspension vs. coilovers?


These are factors I consider in my upgrades. As result, I've compiled LONG list of upgrades and their effects. Bottom line, you need to measure lap times and see how much improvement you get for each upgrade. Sway bar upgrades always gave significantly higher lap time improvements than coilovers. Also, for same amount of roll-stiffness and improvement in lap-times, sway bars affect ride-quality less than equivalent stiffness from springs alone.


Check out these references:

Physics of Racing - Beckman
How to Make Your Car Handle - Puhn
An Introduction to Race Car Engineering - Rowley
Tune to Win - Carroll Smith
Tyre and Vehicle Dynamics - Pacejka
Fundamentals of Vehicle Dynamics - Gillespie
Race Car Vehicle Dynamics - Milliken
Chassis Design: Principles and Analysis - Milliken
Vehicle Handling Dynamics - Masato Abe (should have MatLab to make most of this)

And of course these suspensions options exist for tC. When you get to top-levels of performance, you cut and weld as necessary to install best suspension options on market. Nothing exists off-the-shelf for FSAE cars and we build them from scratch with tubing and angle-iron from Home Depot.

 

Here's how to convert sealed struts to rebuildable units so you can use large variety of inserts from Koni, QA1, Bilstein, Penske, Ohlins, etc.









Or build from scratch:





Now you have access to real performance stuff, such as:

Koni 8611 double-adjustable inserts
Bilstein Motorsport struts

 

Some quicker to access articles:

How Sway Bars Work and Why You Should Care | Speed Academy
https://www.racingbeat.com/mazda/per...uspension.html
https://forum.miata.net/vb/showthread.php?t=493061
https://www.iwsti.com/threads/sway-b...st-mod.245315/
https://www.audiworld.com/forums/a6-...grade-2868281/


Back when I used dual-purpose car for track and street, used some adjustable sway-bars. I'd have them set to full-soft for street-use, way, way better cornering than factory with equivalent ride-quality. Then stiffen them up for track or twisties. Typically about 1/2-way in front and make incremental changes in back.



Then I didn't want to crawl under to make adjustments, so I made customized cockpit-adjustable (blade-type) swaybars from off-the-shelf parts.

 

Excellent Information!

Thank You, Danno!



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Thanks MR_LUV!!!

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