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Strut bar Design Comparison
I recently had a chance to do a back to back test on track with no other changes on the car except changing out the front strut bar. I thought I'd share my findings, as it's a "simple" thing, but as everybody knows, the devil is in the details on putting together a fast and easy to drive car.
There are two types of strut tower bars typically found:
1. Bolted type that uses bolts to hold the mounting plates to the bar
2. Welded type that is fully welded as one piece
The main difference between them is that the bolted type allows the mounting plates to rotate about the bolt, and the welded type resists the mounting plates, and thus the top of the strut tower, from rotating. Obviously the welded type is superior in transfering loads between the strut towers and keeping the top of the towers from translating as well as rotating.
The first strut tower bar was the bolted type, a typical GReddy style bar, with a tubular aluminum bar and steel mounting plates. Nevermind the fact that half the engine bay is taken apart, this was taken during turbo install.
Impressions were that the car handled well, and I was curious as to if there was any sort of benefit noticeable to the driver.
The second strut tower bar I ran 2 weeks later on track was a Stealth-Custom Fab bar made by Jonnie Fraz. This uses a tubular steel cross bar welded to laser cut mounting plates. The main thing I noticed with this bar is excellent attention to detail. The plates are all hand deburred and the preweld fitment was obviously very good. Welds were very even with good penetration. I deal with high dollar parts every day in my "day job," so it's very nice to be pleasantly surprised when you open the box to a car part and are impressed with the quality.
One potential problem of a welded bar is that the postwelded fitment needs to be spot on since the bar is one rigid piece. Thankfully the Stealth Custom Fab bar has absolutely spot on fitment without excessively oversized holes. It was literally a 2 minute bolt-on job, which is always nice when working on a car!
Good penetration and fitment on welds:
Initial impressions on the street were that the front end was a bit quicker to turn in and react, but the true test was on the track where you really feel the chassis moving around. I was also excited to feel if the master cylinder brace would improve brake pedal "crispness" during threshold braking (drive a new BMW M3 or something like that with a very stiff firewall for an example of this).
On the track the Stealth Custom Fab FSTB made a large impact on front turn-in feel and it particularly made the car more stable during the long carousel that has tons of bumps and hussling the car through the tight chicane (T8/T9). The MC brace made braking at the limit much better, and as evidence, I had far fewer lockups trying to threshold brake as the firewall wasn't flexing all around with all the pedal pressure. I was really digging the small nuiance of bracing the MC gives - it made the car feel more like an M3 under braking where it's very easy to flirt with threshold braking with the more rigid structure.
Video of the bar in action (no, it's not a video of the bar hanging out in my engine bay, it's in-car video of the old rickety S-chassis being pushed to the limit):
My car has quite a few braces on it, but every time I add more chassis stiffness I really enjoy how the car feels in comparison to the floppy chassis it was at the beginning of its "track life." For a rough qualitative feel on how much "better" the Stealth Custom Fab bar is over the bolted GReddy style bars is about 4-5x the apparent difference. I could honestly leave the GReddy bar off and it'd be difficult to really feel from the driver's seat. The welded Stealth Custom Fab bar makes an immediate and apparent change.
I'm kicking myself for running such a crap FSTB for so long. At least now I've answered my wondering on if a rigid welded FSTB would make a difference - and that is YES.
There are two types of strut tower bars typically found:
1. Bolted type that uses bolts to hold the mounting plates to the bar
2. Welded type that is fully welded as one piece
The main difference between them is that the bolted type allows the mounting plates to rotate about the bolt, and the welded type resists the mounting plates, and thus the top of the strut tower, from rotating. Obviously the welded type is superior in transfering loads between the strut towers and keeping the top of the towers from translating as well as rotating.
The first strut tower bar was the bolted type, a typical GReddy style bar, with a tubular aluminum bar and steel mounting plates. Nevermind the fact that half the engine bay is taken apart, this was taken during turbo install.
Impressions were that the car handled well, and I was curious as to if there was any sort of benefit noticeable to the driver.
The second strut tower bar I ran 2 weeks later on track was a Stealth-Custom Fab bar made by Jonnie Fraz. This uses a tubular steel cross bar welded to laser cut mounting plates. The main thing I noticed with this bar is excellent attention to detail. The plates are all hand deburred and the preweld fitment was obviously very good. Welds were very even with good penetration. I deal with high dollar parts every day in my "day job," so it's very nice to be pleasantly surprised when you open the box to a car part and are impressed with the quality.
One potential problem of a welded bar is that the postwelded fitment needs to be spot on since the bar is one rigid piece. Thankfully the Stealth Custom Fab bar has absolutely spot on fitment without excessively oversized holes. It was literally a 2 minute bolt-on job, which is always nice when working on a car!
Good penetration and fitment on welds:
Initial impressions on the street were that the front end was a bit quicker to turn in and react, but the true test was on the track where you really feel the chassis moving around. I was also excited to feel if the master cylinder brace would improve brake pedal "crispness" during threshold braking (drive a new BMW M3 or something like that with a very stiff firewall for an example of this).
On the track the Stealth Custom Fab FSTB made a large impact on front turn-in feel and it particularly made the car more stable during the long carousel that has tons of bumps and hussling the car through the tight chicane (T8/T9). The MC brace made braking at the limit much better, and as evidence, I had far fewer lockups trying to threshold brake as the firewall wasn't flexing all around with all the pedal pressure. I was really digging the small nuiance of bracing the MC gives - it made the car feel more like an M3 under braking where it's very easy to flirt with threshold braking with the more rigid structure.
Video of the bar in action (no, it's not a video of the bar hanging out in my engine bay, it's in-car video of the old rickety S-chassis being pushed to the limit):
My car has quite a few braces on it, but every time I add more chassis stiffness I really enjoy how the car feels in comparison to the floppy chassis it was at the beginning of its "track life." For a rough qualitative feel on how much "better" the Stealth Custom Fab bar is over the bolted GReddy style bars is about 4-5x the apparent difference. I could honestly leave the GReddy bar off and it'd be difficult to really feel from the driver's seat. The welded Stealth Custom Fab bar makes an immediate and apparent change.
I'm kicking myself for running such a crap FSTB for so long. At least now I've answered my wondering on if a rigid welded FSTB would make a difference - and that is YES.
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