Full GT Spec Underbracing Installed & Review

[ElBartoRex]

I recently had the opportunity to work with Ken at GT Spec on ‘officially’ testing some of their existing Mazda3 bracing for fitment on the MS3. Here is some pictures and information on what I found.





Parts tested:
GTS-SUS-1135 4-point ladder brace
GTS-SUS-1190 4-point mid brace
GTS-SUS-1158 Mid-Chassis brace
GTS-SUS-1126 Rear lower tie brace
GTS-SUS-1127 Link reinforcement panel
GTS-SUS-1128 Rear V-brace
GTS-SUS-1125 Front lower tie brace


Fitment and installation:
Fitment was perfect an all of the parts I tested with the exception of the front lower tie brace, which was actually designed to work with an automatic transmission on the fist model year Mazda3. Because of this, it does not clear the trans enough on the MS3; however GT Spec is possibly in the works to build a MS3 specific version.
Other than that, the GT Spec bracing bolted right up to the stock mounting points with no issues. Some of the braces use existing hardware and bolts while other utilize threaded inserts and heavy duty bolts/washers. Installation is pretty straight forward and can be done with standard hand tools. Installing the rear lower tie brace was a bit tricky because the bolt on the passenger side is very close to the gas tank allowing for limited clearance. Also it is important to note that the link reinforcement panel does require you to remove the rear camber bolts. I just made extra sure to mark the stock bolt orientation with some white-out so I could be sure they were reinstalled properly.
Installing the GT Spec underbracing does require you to remove some of the stock chassis bracing. Since I had all of these parts off of the car at once, I decided to do some weight measurements of the stock vs. the GT Spec parts. Here are the results:

GT Spec 4-point mid brace: 1.5 lbs
Stock mid brace: 4.5 lbs
GT Spec ladder brace: 4.1 lbs
GT Spec Mid-Chassis brace: 3.5 lbs
Stock mid-chassis brace: 10 lbs
GT Spec Link reinforcement brace: 4 lbs
Stock link reinforcement brace: 10 lbs.
GT Spec Rear V-brace (combined): 1.7 lbs
GT Spec Rear lower tie brace: 1.2 lbs

Even after adding 3 additional braces to the car, it still works out to 8.5lb weight savings (for all you auto-x gurus).

Driving Impressions:
The GT Spec chassis bracing makes a considerable difference on this car, even when just used as a freeway daily driver. Turn-in feels much crisper and the handling of the car feels tighter overall. I can definitely feel that my stock springs are now the weak link in my handling. I plan on getting the car out on the AutoX course to really experience the competitive advantages of this setup as opposed to when I was running stock. I thought that with the added bracing cabin vibration would be a major issue; however vibration increase is minimal if noticeable at all. This may also due to the fact that I have been driving with a poly rear motor mount for the last 6 months as well.
Overall, I think that the GT Spec chassis bracing is a great handling upgrade for the MS3 on both the street and the track. I drive almost 80 miles a day on this setup and I don’t find it uncomfortable for daily driving, though definitely not as soft as stock. Complimented with a stiffer springs/dampers and some thicker swaybars, this would be a killer upgrade in handling for the MS3.

Let me know if you have any questions or want to see any more photos, I have a whole bunch that I have taken during the testing process.

[Lex]

so which brace is the best to start with?

[kingpin748]

Thanks!

[Fobio]

when can we expect pricing for these things?

[ElBartoRex]

Originally Posted by Lex so which brace is the best to start with?

I never had any of these on by themselves, but I would imagine that the front ladder bar would make the biggest difference by itself.

[ElBartoRex]

Originally Posted by Fobio when can we expect pricing for these things?

these parts are already in production and available from GT Spec or any GT Spec distributor

the part numbers listed are up to date for the correct parts that fit the MS3

[redrocketz]

I have installed these parts on a few MS3's now and more regular 3's and even a Mazda5 yeah I said it a 5 and have only had an issue with the center brace on a couple cars. they make a huge difference on the car for sure.

[Lex]

I wonder if they have any adverse effects on the crumple zones of the car

[Boosted333]

Thanks for the info!

[Lymerock]

very nice of ya to grab the weights
im an autocrosser, but those braces would put me so far out of class

[ElBartoRex]