Lower Stress Bar

[itzbob46]

Is anyone familiar with this item. Supposedly can be homemade from 3/4" or 1" aluminum and installed for less than $20. Stiffens the rear plate that ties the rear subframes together. This is supposed to be a super improvement on the track with no downsides. I'm wondering if it is practical and has a noticable effect on agressive street driving. I won't be getting on the track, but would like to tighten and improve the 986's handling if it can be done for less than $20. Like, why not???

Seems like if it were really as good as they say, there would be numerous offerings for a bar and everyone would want/have one.

Bob

[rick3000]

There is an entire post about this on 986forum. I am planning on doing this aswell, you can't loss for $10-20.

[djomlas]

i put this as well. had a bar in garage from other projects, so free mod.

you really can feel the difference in turns, street driving, haven't tried the track yet.

[itzbob46]

I'm hoping to get some replies from 986ers that don't frequent the other forum so much. Especially comments on street performance improvements.

Sort of amazing that Porsche couldn't figure out that this cheapie bar would help the handling of the car. I find that it's very hard to judge the improvement that such a mod makes because of the physiological or placebo effect when an mod feature as added. For that reason, I would like to hear from as many as possible who have installed the bar.

Thanks to all,

Bob

[rick3000]

(I misread the above post, so this post commenting on it has no merit or value to this thread)

Edited November 7, 2007 by rick3000

[smartrepair]

Is anyone familiar with this item. Supposedly can be homemade from 3/4" or 1" aluminum and installed for less than $20. Stiffens the rear plate that ties the rear subframes together. This is supposed to be a super improvement on the track with no downsides. I'm wondering if it is practical and has a noticable effect on agressive street driving. I won't be getting on the track, but would like to tighten and improve the 986's handling if it can be done for less than $20. Like, why not???

Seems like if it were really as good as they say, there would be numerous offerings for a bar and everyone would want/have one.

Bob

Can somebody send a photo of this mod?

Cheers

Kare

[RFM]

This rear plate is not an ordinary plate, she is a cooling item for the gear box!!!

[itzbob46]

I don't understand why you dislike people who visit other forums. 986forum is not a bunch of racer we are mostly regular boxster owners, who talk about, "street performance enhancements," and other Boxster stuff.

If you want to get information on this mod then you are probably going to have to go over to 986forum, because that is were everyone who has done this has posted there opinion, and review of this mod. I don't know were you are getting this idea of people being too amazed by a $10 mod, that there sense of it's effects are biased. And there are not many people who have installed this bar, so you won't be hearing to many comments about it, especially on Renntech, because this mod orginated on 986forum.

Hey, rick3000.......I read every word on the 986 forum. There was not too much comment on street performance of this mod, so I checked the RennTech forum to see what other comments may exist and didn't find much. So I asked to get opinions on the mod form different people in order to get as many inputs as possible. A different forum input may contain different opinions from the first.

Where do you get the wild idea that I dislike anyone on that forum???

And do you mean that you don't think it's odd that the greatest performance car mfg in the world never thought to and a $10 item to the Boxster that would give it more fame on the track, or offer the accessory???? And it is difficult to hit every bump and curve exactly the same before and after a mod, unless you are an expert driver on a track with some fancy recording equipment. I'm not that driver....are you?

I don't have to explain anything to you, but I thought it a good idea to explain my thinking to other readers. I suggest that you calm down.

[rick3000]

I would like to apologize. I misread your post. It just sounded like your were saying you didn't care about the opinions of anyone except the renntech users, and you didn't want the opinion of people who visit different forums. I also read the entire 986forum post, and saw a few comments on it adding improvements to everyday driving, so that information is in there just not as in-depth.

I am embarrassed that I got so worked up, Sorry!

[itzbob46]

I would like to apologize. I misread your post. It just sounded like your were saying you didn't care about the opinions of anyone except the renntech users, and you didn't want the opinion of people who visit different forums. I also read the entire 986forum post, and saw a few comments on it adding improvements to everyday driving, so that information is in there just not as in-depth.

I am embarrassed that I got so worked up, Sorry!

Apology certainly accepted, Rick. I probably could have phrased my post a bit better so it could not be easily misinterpreted. I really respect the opinions of all contributers, but usually want to feel that there is substantial concensus before parting with my money. Thank you for your reply.

Bob

[rick3000]

Anyway, back on topic.

I agree about not parting with your money until it has been tested. This mod is actually just a DIY version of the $130+ strut braces you can buy. I am planning on doing it in the next month so hopefully I can give some insight into the improvements it makes then. But anything that keeps the chassis from bending is going to improve cornering ability.

[Topless]

Insite is a forum member here and has the original Ernie bar from Mantis. He has some really good hard data on this from G-timer and GPS on board instrumentation, and driving impressions street and track. From what I understand it just eliminates rear end flex in a turn and maintains negative rear camber for best tire contact patch during hard cornering. I don't think there is a downside in terms of ride quality. I have not yet added this as it will bump me out of street stock class in my region. Maybe next year an Ernie bar and Comp tires. :)

[Bristol]

I've got the lower stress bar installed along with the two additional bars I came up with. I've also got my car lowered on Gemballa springs. Otherwise the suspension is a stock 2000 S setup with 17" OEM rims. I didn't comment much before because I had been laid up with a broken foot and had some trouble operating the stiff clutch on the Boxster.

Well I can drive a little better now and have some feedback, but it's kind of limited. Basically I think that with the lower stress bar the car's handling is well beyond anything you can reasonably throw at it on public roads. I don't drive at 10/10ths on public roads, that's just stupid. At most maybe I'll push it to 8/10ths if I know the road well and there's no traffic. I feel that with the setup I've got now I can only really push the car to 7/10ths or so before I lose grip - grip that is between my butt pucker and seat. I've thrown my car into some gnarly 90 degree bends as fast as I can and the suspension is planted rock solid. Adhesion from the wheels doesn't even come close to slipping, but I get thrown out of my seat and am holding onto my steering wheel for dear life! I think that the lower stress bar (and possibly the lowering springs) has just raised the handling performance of the car well above what is reasonable for street driving. The limit now for taking turns any faster would be the seat and seatbelt. I would need to go to a race seat and at least four point harness to be able to corner faster, so that I don't get thrown around the car.

So I think that for street driving the Boxster is already a superb handling machine. The lower stress bar just pushes the limit of handling that much higher and beyond what's reasonable. Now track work might be a different story, but I'll have to wait until my foot is completely healed (or is it heeled?) before exploring the limits on a track.

Kirk

[itzbob46]

I've got the lower stress bar installed along with the two additional bars I came up with. I've also got my car lowered on Gemballa springs. Otherwise the suspension is a stock 2000 S setup with 17" OEM rims. I didn't comment much before because I had been laid up with a broken foot and had some trouble operating the stiff clutch on the Boxster.

Well I can drive a little better now and have some feedback, but it's kind of limited. Basically I think that with the lower stress bar the car's handling is well beyond anything you can reasonably throw at it on public roads. I don't drive at 10/10ths on public roads, that's just stupid. At most maybe I'll push it to 8/10ths if I know the road well and there's no traffic. I feel that with the setup I've got now I can only really push the car to 7/10ths or so before I lose grip - grip that is between my butt pucker and seat. I've thrown my car into some gnarly 90 degree bends as fast as I can and the suspension is planted rock solid. Adhesion from the wheels doesn't even come close to slipping, but I get thrown out of my seat and am holding onto my steering wheel for dear life! I think that the lower stress bar (and possibly the lowering springs) has just raised the handling performance of the car well above what is reasonable for street driving. The limit now for taking turns any faster would be the seat and seatbelt. I would need to go to a race seat and at least four point harness to be able to corner faster, so that I don't get thrown around the car.

So I think that for street driving the Boxster is already a superb handling machine. The lower stress bar just pushes the limit of handling that much higher and beyond what's reasonable. Now track work might be a different story, but I'll have to wait until my foot is completely healed (or is it heeled?) before exploring the limits on a track.

Kirk

Thanks Kirk.... In summary, would you advise this mod for street drivers that occasionally do some tight cornering to the point of some tire slip?? I'd liokely just do the ernie bar.

Incidentially, with the upper 30 temps here in New England now, it's doesn't take much to make good summer tires slip, but that's another story....it's almost moth ball time for the Boxster!!!

Bob

[Bristol]

Thanks Kirk.... In summary, would you advise this mod for street drivers that occasionally do some tight cornering to the point of some tire slip?? I'd liokely just do the ernie bar.

Incidentially, with the upper 30 temps here in New England now, it's doesn't take much to make good summer tires slip, but that's another story....it's almost moth ball time for the Boxster!!!

Bob

Sure I would recommend it for street driving if you're getting slip. It's going to tighten up the rear end and help with cornering. I feel it helped with my cornering as the car feels solid and I don't get slip (unless the road is wet). Basically, for the price how can you go wrong???

Kirk

[djomlas]

I've got the lower stress bar installed along with the two additional bars I came up with. I've also got my car lowered on Gemballa springs. Otherwise the suspension is a stock 2000 S setup with 17" OEM rims. I didn't comment much before because I had been laid up with a broken foot and had some trouble operating the stiff clutch on the Boxster.

Well I can drive a little better now and have some feedback, but it's kind of limited. Basically I think that with the lower stress bar the car's handling is well beyond anything you can reasonably throw at it on public roads. I don't drive at 10/10ths on public roads, that's just stupid. At most maybe I'll push it to 8/10ths if I know the road well and there's no traffic. I feel that with the setup I've got now I can only really push the car to 7/10ths or so before I lose grip - grip that is between my butt pucker and seat. I've thrown my car into some gnarly 90 degree bends as fast as I can and the suspension is planted rock solid. Adhesion from the wheels doesn't even come close to slipping, but I get thrown out of my seat and am holding onto my steering wheel for dear life! I think that the lower stress bar (and possibly the lowering springs) has just raised the handling performance of the car well above what is reasonable for street driving. The limit now for taking turns any faster would be the seat and seatbelt. I would need to go to a race seat and at least four point harness to be able to corner faster, so that I don't get thrown around the car.

So I think that for street driving the Boxster is already a superb handling machine. The lower stress bar just pushes the limit of handling that much higher and beyond what's reasonable. Now track work might be a different story, but I'll have to wait until my foot is completely healed (or is it heeled?) before exploring the limits on a track.

Kirk

can you post a pic of your drop with Gemballa springs?

i will be installing a set this upcoming Sunday and would like to see the drop.

thx

[Bristol]

can you post a pic of your drop with Gemballa springs?

i will be installing a set this upcoming Sunday and would like to see the drop.

thx

Djomlas, how'd the spring install go? I checked on my computer and don't have any side shots of my car. I tried to get one this weekend and just got wrapped up in some other stuff. I did get out a ruler and check my ground clearance with the Gemballa springs though. I've got about <0.5" gap still above the wheels (stock 17") and edge of fender and I've got 3.5" of ground clearance. Honestly I was pretty amazed at the results. I think the car looks much nicer and sportier dropped. It was more of a visual impact than what I had expected it would be.

[fitsintite]

Hi Bristol, You forgot To show photos of your assistant :D

Regarding the bar it does tighten the rear end and for the cost i didn't give it a second thought and made one ;)

[Bristol]

Hi Bristol, You forgot To show photos of your assistant :D

Regarding the bar it does tighten the rear end and for the cost i didn't give it a second thought and made one ;)

Hopefully I'll have up some photos of my assistant later this week. I ordered some fancy racing heim joints that USPS tried to deliver on Saturday, but I was away at a Work on Cars Day in Sacramento. I should have the package today, so tonight I'll make a new, super duper lower stress bar with adjustable heim joints rated for over 4,000 lbs each. Unfortunately my assistant has to work tonight, so I may have to take photos without her. :angry:

I'm doing all three stress bars in the back with this new setup. I also bought some parts to see if I can use these heim joints with special spacers to make sway bar drop links (one of mine has a bad seal).

Stay tuned more to come later this week...

[Stefan]

I don't have the lower brace but I have front and rear upper braces on my Boxster. With the above braces, the handling is definitely improved. The car handles much more coupe-like. However, the ride is most definitely harsher. Now some of the chassis flex that used to soak up some of the road irregularities is gone. I have a ROW M030 suspension. So one possible reason that Porsche didn't include this was that it reduces drive comfort.

It's worth the tradeoff to me but perhaps it's not for everyone.

I'm guessing that the lower brace has a similar effect. If not, forget everything I said. :)

[Bristol]

Here are some quick pics of my new and improved lower stress bars (all three). The large main bar ties the left and right sides of the car together. The two smaller bars then tie the left and right sides to the support in the middle/rear of the car, thus triangulating the three bars together and giving extra stiffness.

Basically I've been running with a homemade setup like this for a couple months and really appreciate the improvement. Now I've taken it a step further by upgrading to light weight and stronger racing components. I'm going to take these parts to work tomorrow and weigh them before I install them. But they're really very light weight. The rod ends or heim joints are three piece (not the cheap two piece) units made out of hard anodized aluminum. Each heim joint is rated to hold over 4,000 lbs! The bars and locking nuts are all aluminum too. Man this is a slick setup. I can't wait to get them on the car!

Oh, and by popular demand, my assistant is back to show off her goods... er... I mean the goods.

Kirk

[Bristol]

Them are some good looking... uh... bars.

[Bristol]

The three bars, as they are laid out under the car.

[Bristol]

A closer look at the heim joints (also called a rod end).

[itzbob46]

Thanks for the last 2 pictures. I hadn't noticed the bars that you made in prior photos.