As most know I have both a Z and G35c. I autocross the Z. Last autocross was a 2 1/2 hour drive, so we took the G instead, since it can hold 4 race tires inside.

The G (without a strut bar) has a tendency to go into a 4 wheel drift when going hard into corners.

The Z (with a strut bar) pushes, even with 4 tires of the same size installed.

My next autocross is going to be in the Z without the bar.

 

It was developed off site at a performance race shop that specializes and builds Spec Miata cars(but not limited to just miatas). They know their stuff.

On a side note, Nissan has confirmed on more than one occasion that the STB was an afterthought, but still functional to say the least.

 

Keep me posted on the results. nice job!

 

Well, finally we are hitting on the real problem that most have with the Crawford. I would like more of a 4 wheel drift effect when driving, kinda miss it. But I am not willing to give up any structural rigidity in the front of my car to do so. Now, getting the rear strut bar tighter is of huge interest to me.......

OK, so you guys are telling me that structurally, the car feels the exact same with the stock strut bar as it does with the Crawford strut bar??? Any stiffer or looser?? I haven't actually felt the Crawford of course, cause I don't have it on my car. But I plan to have my car for a long time, and I don't like a loose chassis. If you guys say it is the same, then I might have to find out for myself since I am not that far away from there.

 

Two reasons.

1) Racing cars does not a chassis engineer make.
2) Crawford has already commented on the extensive engineering that Nissan put into the car. Now they are going to minimize this engineering to sell more of their own product?

Come on guys.

I'm not goig to remove my front strut bar. I'm not alone in wanting to keep the front strut bar. There are other upgrades to reduce understeer. Putting a negative spin on the stock bar without solid engineering facts doesn't fly for me. Just LOOKING at the Crawford bar it looks like all the stress points are out of whack. Anyways, attacking my opinion isn't going to make me want a Crawford product any more.

And I will wait for a unit that works with the stock strut bar. You know, I don't even care about the cover.

 

think a lot of people are trying to say.. if thye dont have to remove the stock bar they would prefer not to.. where are the results??! =P

 

Well it's obvious the #1 purpose of a strut bar is to increase structural rigidty. If it also increases understeer, then that's a bonus (if that's what you're looking for). But the reason many cars have these bars is for primarily for rigidity.

That is why I will NOT be removing my strut bar completely. Consider somebody else's bar as a replacement? Sure, if it appears functional. But remove it completely? Not on your life. I don't want a sloppy twisty car in a couple years (or even sooner).

There are lots of ways to induce more oversteer. Completely removing the strut bar seems like changing the radio station by throwing a brick at the dials.

I don't have any problems trying out a different strut bar, but some bar will always be on there.

 

A point that has been avoided, I would really like to see how to make the rear strut stiffer. That would allow for the 4 wheel drift, plus make my car that much more rigid.

 

Seriously guys... this pissing match is over RIGHT now. This will be my ONLY post pertaining to this subject.

Here are some facts about our replacement bar...

To start off, our brackets were made using 1/4" steel. This will stop ANY flexing or leveraging that might occur with the bracket.

The stock bracket on the other hand, is made using .08 sheet metal, certain portions have been reinforced by using .12 for added reinforcement. Note even at its THICKEST point, it's still only three-quarters as thick as ours.

As for the lateral movement, the aluminum bar is completely straight. We have modeled these after our TC bars, which have been in our racecars for the last eight years. TC, better know as tension compression is a vital variable in putting ANY aftermarket suspension component together. From LOOKING at our bar, one could easily observe the stock bar will NOT hold as much compression... based upon the bends that were ALSO made in their bar. They too made compromises to make everything fit.

I truly do feel your concern in wanting to keep everything stock, and not wanting to compromise anything to gain something. Unfortunately, in your quest to perfect your Z... you are going to find many hurdles which will cause you much discomfort.

I personally invite you, if you are ever in the Nashville area to come down to our shop and I will show you exactly how each piece is developed.

Let me develop the performance parts... and I'll let you continue developing software. We each have our expertise, with that I won't dare dispute any form of coding you have assembled.

The community at large has applauded EVERY product we have released. Unfortunately you have "trolled" a HUGE handful of posts on this board. Everything from gains of parts, to sounds of exhausts, to my products... personally I have seen NOTHING constructive out of you.

For those of you who have my products, and are prowling the streets of your areas with added performance... I thank you. As for individuals as such, my opinion has to be voiced and the argument ended as it only continues to further discredit something that has already earned its merits.

 

"Can't we just all get along???", Rodney King

Dude, I know you weren't talking to me, but I will say any of my comments were not to say anything bad about Crawford. I am on your site a lot and respect your work. I live relatively close to you guys, and that is GREAT for me. Most of these guys are in So Cal, and it is SO neat to have a tuner elsewhere who knows their stuff.

My only problem with the bar was how it is not in a direct straight line from the top of the left to right wheelwell. I don't mean to infer that the bar is crooked, I know it is not. But it is not a straight line from each side of the wheelwell, and as an engineer, in my stress classes from college, the perpendicular forward location of the bar would move at least some of the stress from the middle of the strut bar to the bolts and extensions.

Now I do acknowledge that I don't know the materials and such that were used with the Crawford. From what you said, the materials are alot more heavy duty, which should make up for any dimensional inadequatices. Since the materials are more heavy duty, I do wonder, does the bar that Crawford puts on the car feel more heavy duty than stock??? That might be a good thing to me cause I don't plan on tracking my car much, so I am not as concerned about push as I am rigidity.

 

Don't get too stressed out. Some people will always want it made slightly differently. As long as you have a waiting list of customers, then you've done a pretty good job...

thanks for sharing your work with us,
rob

 

I will be Auto-xing my Z on the 10th of Aug. As you can see from my SIG I have ALL the CRAWFORD PERFORMANCE parts plus others.
This will be the first Auto-x with all the toys on the Z. I am VERY pleased with everything DOUG has built.
I will give an update after the 10th.
Thanks Doug for all your hard work.

 

any idea if they will fit the g35 coupe or sedan?

if not, will they be adapted to fit?

 

Show me the DYNOS!

 

Has the intake been on the dyno yet? IMHO the intake might show some positive numbers higher in the rpm band.
Correct me if I'm wrong, but from studying the picture, it seems that the runners have constant diameters. If it had a decreasing diameter going towards the intake port (hence higher air velocity), I think it might show some nice gains in the lower rpm. But then I'm not a mechanical engineer. Just an opinion.

 

hea doug, you mentioned that your steel backing is more than twice as thick as the stock bar. but what about weight? it looks like that your bar is thiner than stock so that might help the weight, but im interested to see the weight differences. also, do you know if the shop that built the bars did any rigidity tests on the bar (or the stock one) during development?

 

Wow this thread got hijacked somewhere along the line. When did this become a ***** measuring contest between Crawford and lsdunique (not personally ofcourse) over some stupid strut bar.

Ofcourse there is going to be some stress transferred from the bar when you move it forward with an extender. It's physics. But it's not like you're moving it 2 feet forward. The materials can withstand the amount of stress transferred.

But I thought we were talking about lsdunique's plenum in this thread. I'll just tell you that I like lsd's because it is aesthetically pleasing, well crafted, and it doesn't require the replacement of anything if you don't want to. I like that it is completely re-engineered. Let's see how much power it puts down.

Dan

 

Doug's bar is an aluminum cylinder that is straight, vs a arc'd stock bar. Is it easier to flex a straight rod when pushing on the ends, or one that already has a curve to it?

You need to see the two in person together to probably understand. I'm sure tests would prove it out.

Also, he was talking about the brackets being thicker + higher quality metal, not the bar itself. Weight differences would probably be minimal.

(I'm not speaking for Doug, btw, I've just seen both together).

 

yes thread hijack aside, how is the progress on dynoing this thing going. It sure looks hot!

 

quick update on the progress. We are THOROUGHLY testing the design and making minor modifications to it. I know some of you are anxiously waiting for some numbers and they are coming. I have put much of the design and fabrication time on the backburner for about a week though because I have a couple customers who are also anxiously waiting for their custom equal length headers (one "shorty" version and a long tube version)

Don't expect any hard numbers on the plenum until these sets of headers are completed, just wouldn't be fair.

So, bad news is...you will have to wait.

Good news is.... you will see pics of our headers sooner than later.

Sorry about posting the pics before I should have.