I own a '04 roadster. The only thing keeping me right now from going with a crawford plenum is the strut tie bar issue. Since structural rigidity is much more of an issue with the roadster, I really don't want to compromise even a little on this aspect. Since the crawford bar is of a side bolt-in configuration as opposed to the stock 1-piece unit, it *appears* that it can still allow some pivoting/flex around the bolts. does anyone have any experience/opinions on this. Should I be concerned at all about this? Anyone know if the Stillen bar, which is a 1-piece welded design, will fit with the crawford plenum?

 

somewhere on this site are pictures of Doug Stewarts 350Z after one of his employees rolled it 3 times. The ONLY part of the car that wasn't bent was his strut bar! I think that speaks volumes for its rigidness. When I had one I was very impressed with the quality. I currently have the Stillen bar, due to my supercharger, and it would also fit with the plenum, but Doug's is a much better piece, imho, having owned both.

 

I'm really thinking more about how it is attached to the body of the vehicle. As I said, it is a 3-piece set-up that is bolted from the side, which would make me think that the assembly as a whole still has flex in it.

 

You should take a look at Doug's previous 350Z when it was totalled. The car flip over multiple times. Everything was bent, except for the engine bay and the bar/attachment points. You would think that this bar would flex under such conditions, but no.

 

I'm not referring to the bar itself. It looks very strong and of very high quality. I'm referring to the way it is attached, and how the way it is attached would allow the body to flex slightly as the ends of the bar pivot on the bolts. Imagine, theoretically, one side of the front of the chassis moving upward, and the other moving downward (viewed head-on). A one piece bar would prevent this from happening. Even if the Crawford bar was bolted in from the top, it would prevent this sort of vertical flex, but it is the fact that it is bolted in from the front such that the attachment loop of the bar is free to rotate on the shaft of the bolt during chassis flex that concerns me. In an accident, this may, in fact, help the bar to retain its shape as it is able to move slightly while the body of the car is taking a beating, but would still provide less overall chassis rigidity.

 

so get the stillen if you are worried about it. its an inferior product, but it will meet your concerns.

 

I have the Crawford bar and I know it works. The way it's mounted, I don't see how it could flex.

Victor

 

When Doug's car was wrecked, he took the strut bar off the crashed BabyI and put it on his new Z, BabyII.

The top of the mounting flange was damaged where it poked through the hood and was ground against the pavement. Other than a "battle scar', it fit perfectly. It looked to be the only part on the car that was not bent!

 

If you look at the metal the stock bar is mounted to (see pic), it is kind of a hack anyway. This is not an extemely secure mount to begin with, and you can tell it is a factory afterthought welded in at the last minute.

The mounting brackets are very strong, probably stronger than the mounting brackets welded into the inner fenders. You aren't going to get anymore flex. Plus, the factory bar has a curve to it in addition to having less strength than Doug's bar to begin with. A curve would be weaker than a straight bar (which is also thicker I believe).

 

The Stillen bar look solid, but the I dont like the fact there are welds everywhere on it. It looks strudy, but too many welds!

I am also torn...becuase I want the Crawford, but dont wanna give up the high speed stability that the stock bar tends to give.

I guess until someone does a before and after skid pad test or something, nobody can say which bar performs better in real world corner ability. It's ability to withstand a crash doesnt tell you if it wont flex under constant pressure.

Hey, can someone post of the pic of their engine bay with the Crawford bar attached? Closeups would be great as well.

 

Take your stock bar off and drive it for a few days. The factory bar really doesn't do as much as you seem to think.

 

Do your driving at 100+ mph and you will notice a difference without the bar. I did.

 

I have been tracking my car without the strut tower bar its really not that big of a difference and it felt fine on the ROVAL at cali speedway hitting 130ish soooo either way its a personal choice more than a strictly functional one. The onlly reason mines off though is because I have the crawford plenum and didnt feel I needed to buy their bar and still dont my car is very stable.

 

Here are my pictures in here

https://my350z.com/gallery/albus41

Click on the image twice to get a larger image.

 

Has anyone put the Crawford bar on a Greddy kit? Look at the above kits, and the location of the dipstick with that CAI, I dont think the the Crawford bar will clear the Greddy intake pipe.

Can someone confirm?


Regarding the struct bar and its effect on cornering...like I said...we need a skid-pad test to confirm its usefullness. I have no idea which strut bar, or for that matter, if any strut bar actually improves performance....or if it merely placebo effect.

 

Mannish - you are kidding right? The factory brace is franly nearly as good as it gets from a design and construction standpoint. As for noticing a difference, its a very relative thing. Given all the suspension mods I have, I noticed a bit les turn in response when I tried running without the brace for a few days (as it was hitting my aftermarket hood with the old Kinetix plenum on). High speed turn in was a particular issue).

Any brace that bolts together is an inferior design to stock......but thats in design only. From an execution standpoint, I am quite sure, given how stiff the chassis is to begin with (and hence why Doug's bar probably did not bend in the rollover ), you won't notice a performance increase nor decrease with the Crawford one. For pure sponosrship/aesthetic reasons, I now run the Cusco front strut brace on my car (a BIG bar that happens to have bolt attachments at either end), and te car behaves exactly the same as far as I can feel, to the stock bar. For me, the added bonus was that as big as it is, its actually a lower profile design than stock, so I now have zero hood clearance issues.

So in other words, don't let the brace swap steer you away from the plenum if thats a mod you want.

Adam

 

Did you get the whole engine cover fabricatrion done from suite G GraphX. Can I just call them, and tell them That I want "the engine cover to fit the Crawford Strut Bar?"

Thanks

 

You can disagree if you want, but look at the limited number of welds in the pic above and tell me that is optimal. In a lot of cars, the bars are attached directly to the top of the strut or shock mounts. These are not, they are hacked in with stands made as an afterthough (the G35C doesn't have this at all).

Again, if you look at Doug's brackets, they are very beefy, and they are probably much stronger than the welded in mounting plates Nissan installed.

As for skidpad comparisons without a brace vs with a brace, you could consider the G35C, which got as good or better skid pad number than the Z with no bar. Not exactly apples to apples, but close.

Also, in stock conidition with the understeer, you would generally losen the front or tighten the rear to make the car more neutral. Going without the bar might even help marginally with this.

 

Straight bar vs. pre-bent bar (stock), extremely thick mounting flanges and race-spec heim joints (as would be used in race car suspensions) make the Crawford bar a VERY sturdy piece.

The strut bars in my 240Z are also of similar design (straight threaded bar, heim joints, and thick mounting flanges).

Also, I've been told removing the strut bar helps reduce the understeer characteristics the Z displays.

The bottom line is that any brace is better than none as far as rigidity is concerned, but it would seem a straight bar would always be stronger under the extreme conditions this thread seems to be implying.

The fact that Doug's car rolled end over end (not sideways) three times is testament enough for me. In our 7 years of SCCA road racing, I never saw a car flip that way, or one so heavily damaged. This speaks well for the strength of the car and it's structural integrity. I'd hate to see my 240 after such an incident!

 

I did also...

Ran Roebling Road in Savannah, hitting just over 140 down the main straight.

Felt fine.

You been on a track yet?