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928 Innovations Aero Strut Bar for 87-91 S4/GT (PRICE DROP~!)

Posted: Wed Dec 24, 2025 10:47 pm
by maddog2020
(PRICE DROP)
928 Innovations Aero strut bars for the 87 to 91 S4 & GT's are ready to order. This is going to be a pre order buy only. Bars will be solid bare 7075 T6 Aluminum. Unfinished.

Original price was $700 ONLY IF WE COULD GET AN ORDER OF 10.

(PRICE DROP INFO)
We're able to get in on a bulk purchase of 7075 T6 so I'm dropping the price on the pre ordered S4/GT strut bars to 549 with a deposit of $275. 6 out of 10 are pre sold. I decided to buy 2 for stock, so that leaves 2 open for purchase.

Original Deposit was $350 and was due by Jan 2nd. I've extended the pre buy until January 15th. Bars will be available to ship 1st week in March.

These are specifically for 87 -91 S4 & GT models only, with notches for the oil filler cap as well as a longer notch in the rear side for the intake.

We do have a design for ITB engines that should fit the earlier 78-84 models but I need a car to test fit in the DFW area, however this version is curved. We are working on a version specifically for the 78-84 versions that will have a notch on the rear side specifically to clear the oil filler housing.

Factory strut bars are hollow thin wall 5052 H32 Aluminum. This strut bar is solid 7075 T6 aluminum which is much stronger than the 5052 factory bar. They also look much better and fit the styling of the 928 body lines.

5052-H32:
Ultimate Tensile Strength: ~33,000 psi (228 MPa)
Yield Strength: ~28,000 psi (193 MPa)

7075-T6:
Ultimate Tensile Strength: ~83,000 psi (572 MPa)
Yield Strength: ~73,000 psi (503 MPa)

Keep in mind the factory bar is hollow thin wall, and these are solid.

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Re: 928 Innovations Aero Strut Bar for 87-95 S4/GT/GTS

Posted: Fri Dec 26, 2025 1:48 pm
by Skyhawk172
dang that sure is pretty

Re: 928 Innovations Aero Strut Bar for 87-95 S4/GT/GTS

Posted: Fri Dec 26, 2025 3:57 pm
by maddog2020
and pictures do not do it justice either. With the bar shaped like an airplane wing, it just seems to fit the 928's personality. 6 out of 10 are spoken for and I'll probably buy one and keep as a display model for my table when I go to events.

Re: 928 Innovations Aero Strut Bar for 87-95 S4/GT/GTS

Posted: Sun Dec 28, 2025 11:28 pm
by linderpat
man that's a nice looking bar. Best design I've seen.

Re: 928 Innovations Aero Strut Bar for 87-95 S4/GT/GTS

Posted: Mon Dec 29, 2025 2:43 pm
by maddog2020
Thanks~! I've got 6 buyers out of 10 needed. I'll probably buy 1 or 2 just to make it happen. At 8, I barely break even. 7075 T6 is expensive and the machine time with all of the compound curves is time consuming. If I have to buy 2, after they are made the price will be higher than the group buy. I'm sure once they show up at a few events I'll need to buy more. I'm also working on a version for the 85-86 as well as the 78-84 models as well.

Re: 928 Innovations Aero Strut Bar for 87-95 S4/GT/GTS

Posted: Mon Dec 29, 2025 2:47 pm
by maddog2020
These are just the major revisions. The curved ITB model had over 15 revision & the straight S4/gt/gts version had close to 10 revisions.

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Re: 928 Innovations Aero Strut Bar for 87-95 S4/GT/GTS

Posted: Mon Dec 29, 2025 2:52 pm
by maddog2020
Online store is updated with the strut bars.

https://928-innovations.mybigcommerce.com/

Re: 928 Innovations Aero Strut Bar for 87-95 S4/GT/GTS

Posted: Mon Dec 29, 2025 2:53 pm
by maddog2020
I can't post these on RL because I'm not a sponsor. I'm checking into it but due to the holidays I haven't heard back from them yet & I may not be able to afford it if they do get back to me.

Re: 928 Innovations Aero Strut Bar for 87-95 S4/GT/GTS

Posted: Mon Dec 29, 2025 3:48 pm
by worf
Yeah, Rennlist has completely jumped the shark on anyone posting anything about selling anything unless you're a sponsor.

I had a PM deleted from my inbox this morning (after I read it an got out of it what I needed...)

Re: 928 Innovations Aero Strut Bar for 87-95 S4/GT/GTS

Posted: Mon Dec 29, 2025 4:37 pm
by maddog2020
it doesn't help that I told hacker to go f*ck himself on facebook. lol

Re: 928 Innovations Aero Strut Bar for 87-95 S4/GT/GTS

Posted: Tue Dec 30, 2025 4:44 pm
by JMW928
worf wrote: Mon Dec 29, 2025 3:48 pm Yeah, Rennlist has completely jumped the shark on anyone posting anything about selling anything unless you're a sponsor.

I had a PM deleted from my inbox this morning (after I read it an got out of it what I needed...)
They're reading your PM's? I assume they must have if they deleted it. I can understand no selling on the forums unless you're a sponsor, but private communication should be just that - private. Glad I didn't renew my membership.

Re: 928 Innovations Aero Strut Bar for 87-95 S4/GT/GTS

Posted: Tue Dec 30, 2025 4:54 pm
by maddog2020
they do have access to your private messages.

Re: 928 Innovations Aero Strut Bar for 87-95 S4/GT/GTS

Posted: Tue Dec 30, 2025 8:10 pm
by worf
Yup. They have always had access to PMs.

What's "new" though, is apparently, a "push button" means to delete an account along with every post, PM (in or out) and any post with reference to the username/email address for that account and certain keywords. (Not, really hard to do. But, better test it in a sandbox, lol.)

There's a thread on the RL 718 forum that has lost ~25% of its posts.

It's like if every post on the 928 forum that mentioned "strut bar" suddenly vaporized. You'd kinda notice a big hole in the universe and all of a sudden many things would stop making sense.

Re: 928 Innovations Aero Strut Bar for 87-95 S4/GT/GTS

Posted: Wed Dec 31, 2025 10:53 am
by Geza-aka-Zombo
If the use of 7075 is a major cost factor, I suggest changing to 6061 T6/T651. This item doesn't benefit from the increased strength properties of 7075 as is not a high stressed member, but is a stiffener. The mechanical property which determines stiffness is the modulus of elasticity (Young's Modulus), and all aluminum alloys have about the same modulus - about 10 million psi. Thus, making the part using the same design with a less expensive aluminum alloy will not impact the performance for this application but may reduce cost.

Setting aside the material, the shape of the cross section of the strut is also critical to its stiffness. The strut stiffness (as it is used here) is a function of the width of the strut and the thickness of the strut cubed. Basically if you double the width you double the stiffness, but if you double the thickness you increase the stiffness 8 times. You want to maximize the thickness to maximize the stiffness. Just something to keep in mind.

Re: 928 Innovations Aero Strut Bar for 87-95 S4/GT/GTS

Posted: Wed Dec 31, 2025 6:57 pm
by JMW928
worf wrote: Tue Dec 30, 2025 8:10 pm Yup. They have always had access to PMs.

What's "new" though, is apparently, a "push button" means to delete an account along with every post, PM (in or out) and any post with reference to the username/email address for that account and certain keywords. (Not, really hard to do. But, better test it in a sandbox, lol.)

There's a thread on the RL 718 forum that has lost ~25% of its posts.

It's like if every post on the 928 forum that mentioned "strut bar" suddenly vaporized. You'd kinda notice a big hole in the universe and all of a sudden many things would stop making sense.
That's pretty authoritarian IMHO. The only real problem I have with not being a member is losing access to my PMs. Haven't needed to access any in a long time, but when you need it, you need it. I guess I'll cross that bridge if/when I get to it.

Oh, and my apology to Maddog for mucking up his thread. :biggrin:

Re: 928 Innovations Aero Strut Bar for 87-95 S4/GT/GTS

Posted: Thu Jan 01, 2026 11:56 pm
by maddog2020
Geza-aka-Zombo wrote: Wed Dec 31, 2025 10:53 am If the use of 7075 is a major cost factor, I suggest changing to 6061 T6/T651. This item doesn't benefit from the increased strength properties of 7075 as is not a high stressed member, but is a stiffener. The mechanical property which determines stiffness is the modulus of elasticity (Young's Modulus), and all aluminum alloys have about the same modulus - about 10 million psi. Thus, making the part using the same design with a less expensive aluminum alloy will not impact the performance for this application but may reduce cost.

Setting aside the material, the shape of the cross section of the strut is also critical to its stiffness. The strut stiffness (as it is used here) is a function of the width of the strut and the thickness of the strut cubed. Basically if you double the width you double the stiffness, but if you double the thickness you increase the stiffness 8 times. You want to maximize the thickness to maximize the stiffness. Just something to keep in mind.
I'm well aware that 7075 T6 is overkill, but I've had some boneheads on some of the facebook group question the strength so I bent a factory bar and tore in in half with my bare hands after fold it over and made a video to prove a point. the width of the aero bar is over 2 inches and the thickness at the thickest point is thicker than the stock thin wall tubing for the factory bar. The factory bar wall thickness is only 1.23mm. I very seriously doubt that the 928ms bar or Jerry Feather's bar comes close to this bar in overall strength.

Re: 928 Innovations Aero Strut Bar for 87-95 S4/GT/GTS

Posted: Sat Jan 03, 2026 3:31 pm
by TheDeckMan
That is a great looking strut bar :beerchug:

Re: 928 Innovations Aero Strut Bar for 87-91 S4/GT

Posted: Mon Jan 05, 2026 2:41 pm
by maddog2020
have some great news on the pricing. We were able to get in on a large bulk purchase of 7075 T6 and get some fantastic pricing so I'm dropping the price on the pre ordered bars to $549.


After they are made the in stock price will be around 650.

Re: 928 Innovations Aero Strut Bar for 87-91 S4/GT (PRICE DROP~!)

Posted: Mon Jan 19, 2026 8:35 pm
by maddog2020
Strut bars are in production
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https://928-innovations.mybigcommerce.com/