Dalara Wheelbase

bpimm

Brian Pimm
Is there any documentation that talks about the Dallara in depth? Curious what the front and rear space frames were like but have never seen any pics and google searches only bring up pics of the exteriors.

How much longer was the wheelbase? I found a reference on wiki that the engine and suspension were mover back .45 inches but I have other comments that say the rear wheels were moved back 2". I have a Dallara body and when the rear quarters are roughly lined up it appears that the wheel opening is roughly 2" back.

I do plan on putting the body parts on sometime in the future and would like to see what Dallara did on the originals.
 
Can't help with the measurements, but... you have an Actual Dallara body?? Where's the pics, man?? :grin:
 
its just a pile of panels, front fenders, rear quarters, nose, hood, doors, engine cover and a roof skin, I'm missing the trunk lid.

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The wheelbase increase required is around 14mm. This can be achieved with a trick that is simple in principle but difficult to do!

If you look at the bottom ball joint and the wishbone where it is attached, you will see there is enough width in the wishbone flanges to move the ball joint's outer fixing rearwards, rotating about the inner fixing. Rotating the ball joint outer fixing by around 11mm backwards will move the ball joint axis itself around 14mm.

To do this you need to drill out the outer rivet and carefully grind off the welds, which is the difficult bit.

This should link to a photo of a modified wishbone...

https://www.dropbox.com/s/ih4sn8rqaoctdm3/22 nd may 2012 013.JPG?dl=0
 
I had to cut out the front of my arches to fit the wheel and tire

I will see if I have a record of it when I return home. I am traveling at the moment. I am pretty sure it was more than 0.45 but not where near 2". If i were to guess it was about 1". My panels were not trimmed they had all the offall and I had to cut to size. They came from Bayless about 1991 or 92. I will have to see if I have good photos of the 13" wheels. That may have only needed 0.45" but with my 15"s needed the additional clearance.




 
I see. Instead of dealing with that, I centered the fender over the wheel, checking full compression & full drop clearance. You can get away with 1/2" fore/aft movement & trim the panel as needed. It's going to depend in part on just how big your tire ID is, and your wheel offset.

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The fronts, you need to push the inner panel forward for tire clearance - can be achieved by flattening the inner inverted "V" where the panel is welded to the inner fender

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Rear inner front had to be beat a little - some tire contact at full lock. Again may depend on wheel/tire combo

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The rear panels are different - very different

The Greenwood panels (NEW) are designed to integrate into the existing metal fender. The originals are intended to replace the entire rear quarter. If you look the new rears have more of an abrupt cut into the quarter. For original flares you would have to completely restyle and build down the upper surface. For me I prefer the old panel look but with the front of the Greenwood. Given a choice I would not bond (or cut) the panel into the metal due to thermal expansion issues. Unless you put in a detail that compensates for the panel shift you will certainly get cracking along the interface. The new panel certainly works better for centering and is definitely a plus.
 
This may help explain the difference

You can see the highlight line pretty good in this photo:



 
your kit looks like mine

i have 15x10 in the back i made the rear fenders wider

front you can put 15x9

good luck with the project
 
Thanks rachalejf that looks like an easy adjustment, easier than moving the wheel arch on this style of quarter.
 
I agree I like the older style better in the back and the newer in front, Also agree on not bonding sheet metal to plastic. I have a few derelict bodies that suffer from cancer that will help to understand how to disassemble the fenders and quarters, I may use these panels to make a mold for complete replacement panels or maybe even clam shell style nose and rear end, haven't decided yet, these panels are the lightweight race panels, only one layer of mat, they wouldn't hold up well on a street car.

The Greenwood panels (NEW) are designed to integrate into the existing metal fender. The originals are intended to replace the entire rear quarter. If you look the new rears have more of an abrupt cut into the quarter. For original flares you would have to completely restyle and build down the upper surface. For me I prefer the old panel look but with the front of the Greenwood. Given a choice I would not bond (or cut) the panel into the metal due to thermal expansion issues. Unless you put in a detail that compensates for the panel shift you will certainly get cracking along the interface. The new panel certainly works better for centering and is definitely a plus.
 
Brian, go visit Charles in Salem.

He still has our Rotary powered X with the Dallara bodykit on it. You can look at it for the things which work and the ones which did not.

The biggest issue was the rear quarter panels were put on but never aligned with the wheels. So the wheel tends to fit farther forward in the wheel well. Not quickly noticeable, but it pisses me off every time...
 
Those are the wheel sizes I was thinking, how much did you widen the rear quarters?

at list 4 cm more i have 245/45r15 in the back on 15x10
im planning on getting wider wheels and tires

the front i think 15x8 or 9 with 195/45r15

so if you need wheels let me know !
 
Just some additional information

Its posted on here some time back but I recommend welding on brackets and bonding the panels to the brackets.

1) Weld brackets (pitch for me was either 100mm or 150mm)
2) Coat with Zinc rich primer etc
3) Bond with adhesive made for FRP to metal (I used a Ciba Geigy adhesive but there are there are others now)
4) Rivet till cured
5) Reinforce each bracket from the "B" side with resin soaked glass mat (sandwich it all together)
6) Drill out rivet and fill with resin and cabosil (micro baloons)

It has been since 93 and my panels are still bonded without cracking issues

I also put in intended slip flanges for the body to metal interfaces. Those eventually cracked (as expected) and I covered them with 3M body tape http://solutions.3m.com/wps/portal/...Aftermarket/Our-Brands/Scotchgard-Pro-Series/






 
I am running similar

I run 245s in the rear and 205s in the front. Just a comment if you decide to go with the larger diameter tires you will also need to update the brakes and springs:


It is a lot of rotating mass to slow up. I have Wilwood 11" rotors and I am running 300# or 350# rear springs and 225 # or 250# in the front. Just something to consider
 
Given a choice I would not bond (or cut) the panel into the metal due to thermal expansion issues. Unless you put in a detail that compensates for the panel shift you will certainly get cracking along the interface. The new panel certainly works better for centering and is definitely a plus.

I agree I like the older style better in the back and the newer in front, Also agree on not bonding sheet metal to plastic. I have a few derelict bodies that suffer from cancer that will help to understand how to disassemble the fenders and quarters, I may use these panels to make a mold for complete replacement panels or maybe even clam shell style nose and rear end, haven't decided yet, these panels are the lightweight race panels, only one layer of mat, they wouldn't hold up well on a street car.

I don't understand this rationale. Even if you create a full panel, at some junction you are bonding dissimilar materials, so whether it's a full panel or partial like the Greenwood, at some point you are bonding Fibreglass to steel....

The Greenwood street panels are three layer, so perhaps I have much more material to work with than you guys do/did with the versions sourced overseas? The bonding adhesives from Lord are specifically designed for panel bonding steel/plastics/fibreglass, so I'm not clear on the concern when properly bonded.
 
I don't understand this rationale. Even if you create a full panel, at some junction you are bonding dissimilar materials, so whether it's a full panel or partial like the Greenwood, at some point you are bonding Fibreglass to steel....

The rationale is that the coefficients of linear thermal expansion of fiberglass and steel are so radically different that over time if the car is not a garage queen and sees thermal variances something has to give. Whether the glass to steel bond will hold long term is the question.

My motorhome is Aluminum framed with an Aluminum roof skin with SMC nose cap and rear cap. After 43 years the Aluminum to Aluminum bonds are still good where the SMC to Aluminum joints are failing and needing re sealing.

http://www.engineeringtoolbox.com/linear-expansion-coefficients-d_95.html

The Greenwood street panels are three layer, so perhaps I have much more material to work with than you guys do/did with the versions sourced overseas? The bonding adhesives from Lord are specifically designed for panel bonding steel/plastics/fibreglass, so I'm not clear on the concern when properly bonded.

The new glues are far better than the old stuff and may hold longer but when one piece is stretching twice as much or more than the other whats taking up the movement?

by using tabs or a slip joint you can control where the shift happens which is one of the reasons I'm considering one piece nose and rear but that just isn't practical on a street car.

I'm sure that the design specs the engineers are shooting for on the glues has a design life in there so they are probably not looking for a permanent bond. Look back at custom cars from the past, the ones that were garaged all their life still look good where those that were in the sun and cold didn't fare nearly as well.
 
OK. I can understand the concern. I'm going to have to see how it goes DTR. I have to believe adding all the additional bonded support structures for the inner arches, etc., will limit how much or in what direction panels can shift - I would expect a panel bonded only along a single seam is more likely to present issues than one with much additional bracing, but time will tell.

Don't know about other brands, however the Lord Fusor epoxies come with a lifetime warranty on bond permanence (with properly prepared surfaces), of course most cars are probably only expected to be on the road 10 years or so...

Anyway, it's a done deal for me, so time will tell.
 
My bonds are still good but.....

My polyester panels have shrunk over the years and the edges are where you see the cracking. It has been managed to localized areas as Brian described. My panels were very very rough to say the least with random thickness, some areas were 1mm thick and others 7-8mm thick. It took me several years to get them fitting right. I have been surprised how well it has held up for 23 years bonded (17years painted) and many track events. It still looks good. I have had the fortunate experience to work with many auto show cars and prototypes so I knew what issues would pop up with the body. The one area that has not cracked is at the base of the rocker where I have a pretty thick build up of duraglass. I also kept the rivets intact along the rocker. A lot of guys keep a distinct line between panels to avoid the panel movement issue.
https://www.google.com/search?q=wid...hWHlZQKHSc-DcQQ_AUIBigB#imgrc=TG-4LhBewAolFM:

https://www.google.com/search?q=wid...=isch&q=widebody+Nissan&imgrc=ST6JwviPE2AqEM:

It got the 3m tape idea from the Nissan GT500 guys. I saw it on their race car and did the same on mine when the micro cracks started to appear. Just some additional info
https://www.google.com/search?q=wid...bm=isch&q=GT500+GTR+r34&imgrc=Se13L18s7imOxM:
 
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