Love the 3D drawings. The concept to move the strut towers outboard by 3" is a great "thinking outside the box" idea too. Since you're going to be cutting them out and relocating them, it might make sense to raise them as far as you dare in order to re-gain some of the strut travel lost due to lowering the car. You also want to make sure that by moving the strut towers outboard that you're not going to run into strut/tire clearance issues too.
Regarding the extra room in the engine bay by squaring off the sheet metal in front of the struts, you might also consider going the other way and making more room ahead of the wheel wells instead. That's what I'm doing to make room for the side saddle radiators. Not sure what your plans are for the rad though.
Thanks Blooz. I have been considering the option of raising the towers as much as possible and you had mentioned in a PM or email that you might soon be sitting the rear section of your 355 body on your chassis in order to size up the rear structure mods required. That might be a great opportunity for me to have a look at just how high I can go. As well, while I said I am planning to reuse the stock towers, I am also considering the option to fabricate new custom towers that will better suit the new rear strut dimensions and location. The stock rear struts and springs are much larger diameter than the coil overs I am looking at and it just doesn't make sense to keep such large strut towers. I have a few ideas for replacing them that would have the required strength plus add a modern and unique look to the engine bay. Gotta keep up with the Jones's
With regard to perhaps using twin radiators forward of the rear wheels, I have pretty much accepted the fact that my rocker frame reinforcements associated with chopping my roof off have made that option impractical. I looked at several options but there just isn't enough room to do it right. So I'll incorporate some engine bay cooling air on one side and engine combustion air on the other side. For the engine rad, I'll just fit a good quality 4 core in the stock location.
note: edit typos
[This message has been edited by Yarmouth Fiero (edited 06-24-2014).]
The rear clip on the panels I sent you guys only has about 1" clearance above the strut towers. If you move them out as you are thinking, you will gain more room under the rear top raised section. Maybe an additional 2"?
As for moving the towers out, I made a plate setup that moved the strut out toward the frame rail. I essentially, turned the strut top around so the two outer mounts were now the inner mounts and made a flat plate setup to mount the third strut mount bolt to the outside. I kept the same angle etc. of the strut tower to not change the geometry and used coil overs on the struts. The coilover clears the inside of the upper rear frame rail by about 1/2" through full travel. The other item to make sure you do is to invert the mount bolts so you are tightening the nut from the wheel well as there is very little room on the top with the convertible clip on it.
A quick pic of how I made the strut top extension. Hopefully it comes through from Photobucket.
[This message has been edited by 355Fiero (edited 06-24-2014).]
Still working on the rear suspension posibilities, including selecting suitable brake and suspension components as well as modifying the rear structure of the car to suit the selected components.
To start with, I have been looking at possible brake components. I've narrowed the search to Wilwood products as they have a good selection, a good reputation and I like their website. For rotors, I am looking at the Wilwood SRP Drilled and Slotted 12.9" dia. x 0.81" thick with aluminum hat having the 5 x 100 bolt pattern and a 0.71" offset.
I've added these components to my 3D model to see how the parts fit. As suspected, the rotor interfers with a boss on the stock spindle casting. Part is colored red in the drawing. It should be a small matter to remove.
I have not selected brake calipers yet but I'm considering the Wilwood Forged Superlite 4 piston lug mounted model. First I'll draw them and add them to my model to see how they fit.
Here are a couple pics showing the assembly together with the wheel. Note, the drawing shown is the rear wheel which is 18 x 9 with 38mm offset.
As I had mentioned earlier, I have roughly set the rear track width based on the rear body panels that Blooz and I will be using. This results in an approximate 4" per side track width increase. My plan is to move the strut towers outward to compensate for the new track width. My dilemma is deciding if the struts should move outward the entire 4" or use some combination of strut offset bracket at the spindle and strut outward relocation. As can be seen in the last pic, the strut is going to be very close to the inside edge of the wheel if its bolted directly to the stock spindle. Any thoughts or experience to offer relating to this matter would be greatly appreciated.
As a final note, the drawing of the spindle casting surface is not 100% accurate although I think I've captured most of the important measurements and features. Also, the rotor and hat drawn have an 8 x 7" bolt pattern where as I am considering the models with 12 x 8.75". I'll update the drawing once I have made my final selection.
You will not be able to push the struts out the full 4" without impacting the upper rear frame rail. The most I could move mine out, with coilovers was about 3" so I needed to use a 1" spacer I built to connect the strut to the rear hub. You also then gain some needed clearance on the rim. My strut also hit my rim without the spacer but your offset is probably different than mine was.
Thanks Don. Looking at the chassis and my drawing I could see 4" was pushing it. I agree a 3" move will be the maximum and then a 1" strut spacer. Did your spacer also include a drop to lower the strut bottom as much as possible with regard to the spindle? You also mentioned maybe gaining some height by raising the strut tower but looking at photos I took last summer when Blooz and I put your rear body work on my chassis, I don't see alot of room to raise the strut tower. Am I missing something?
Are you widening the rear track by 4" on each side? For comparison's sake, I only widened my rear end 3" per side as measured from the wheel mounting surface on the brake hat to the center line of the car. By using 9" wide wheels with a 45mm offset my new half-track width (tire centerline to car centerline) is 832mm though, so if your wheels are different, then you'll need to account for that accordingly.
Take my measurements with a grain of salt though because I designed my rear suspension width using my old 355 body. But since we're going to be using Don's body as a plug for our moulds, and given that Don reshaped the rear fender openings significantly, my rear track may be a little too narrow now. I should know for sure sometime next week when I get back into working on the car.
Thanks Blooz. Yes, at this point I am just locating my suspension in the general area +/- 1" so I can get an idea of where my strut towers "may" need to go. I won't make any final decisions until we have a real good look at that body on your chassis. You had given me a rough measurement based on the outside edge of your tires and that was my starting point. Modeling the brake components is a safe bet at this time so that once we have the definitive dimension for rear track, then I can move ahead with the strut tower locations and then lower control arms. With the components modeled in 3D, I can move them around with little effort and try a variety of "what if" scenarios. Its a powerful tool but I spend a lot of time developing the drawings. You know all about that right?
With regard to moving the strut towers out more than 3", you are quite right Don ( 355Fiero ). Here is the 3" track width increase and the strut just clears the upper frame rail. If I require any more than 3" track width per side, I will either have to use an offset spacer at the spindle/ strut connection or cut into the upper frame rail. I think the use of a spacer at the spindle would be the easiest solution for sure.
Ha ha Had no reason to lie to you..... Just a joke.
If you don't use the 1" spacer on the hub, your rear strut geometry changes from oem during compression etc. so I sued the spacer to make sure the strut tower stayed the same angle. I didn't use the lowering in the spacer. That was one of the issues I had with the car was by the time I got the body on and everything lowered to where I wanted it, the rear cradle was only a few inches off the ground. I suggest you and Dave get your ride height to where you want it, put the panel son and then cut them up a bit more to lower the fender wells down a bit more to give a nice gap without slamming the frame to the ground to do it. The fender gap and ride height have always been one of the main issues with the 355 replicas on the Fieros.
Also, you are right. There won't be any room under the rear clip to raise the strut tower to help lower the frame much. It was pretty close at stock height under the body. You might get a bit more room if you move the strut towers outward like you were saying as there is a bit more room in the centre of the rear clip area. The engine cover lip was the limiting factor where it was only about 1" above the strut top inner edge.
Keep up the good work and looking forward to more update pics.
I have proceeded with removing the trunk sheet metal in preparation for moving the rear bumper assembly forward as per Blooz's build thread. Luckily all my sheet metal is still in good shape so there is very little fabrication of replacement parts required.
One of the issues we will have to address is whether we keep the plastic 5 mph honeycomb bumper as it will require us to move the rear steel bumper support that much further forward.
I guess the decision to either keep it and incorporate it into the 355 body or eliminate it altogether will depend on whether Nova Scotia laws require us to have it in place. The major benefit I see to eliminating it is that the steel bumper will not have to move so far forward thus retaining most of the OEM crumple zone.
I have added the rear bumper structure and most of the honeycomb structure to my 3D model however I will have to post images tonight from home as they are not on my work computer yet.
On a side note, I ordered my rear brake rotors and hats from Wilwood so once they arrive, I will post pictures of the equipment. I am still debating the caliper details so they have not been finalized yet.
Clean ? After I took these pictures and downloaded them on my computer, my OCD got the best of me and I ran out to the garage to ArmorAll the frame...again, before taking the pictures over. Unfortunately I forgot to take the new pics off the camera. So I apologize for the way the chassis looks here.
As noted by Blooz in his thread, the rear bodywork of our 355 body is going to clearly interfere with the stock location of the Fiero rear bumper structure. It then becomes a matter of deciding just how far forward to move the stock bumper and trying to minimizing the intrusion of the bumper into the trunk space while maximizing the use of as much of the stock bumper as possible. As Blooz had mentioned, moving the bumper structure forward 50mm or 2 inches seems to be a good compromise and allows for the stock chassis crumple zone to remaining mostly intact. The plastic 5 mph honeycomb bumper will likely have to be trimmed back prior to fitting the body but that is a minor sacrifice.
Here is a detailed drawing completed by Blooz and snatched shamelessly from his build thread. This shows a 50mm move forward of the rear bumper structure and how it will clear/ interact with the 355 body.
For my project, I will proceed to move the bumper structure forward 2 inches and secure it to newly fabricated flanges on the lower frame rails. As I plan to remove the stock strut towers, rework them and move them outboard atleast 3 inches per side as well as remove the majority of the trunk sheet metal, I need to get the rear bumper relocated and secured soon because it's pretty much the only thing holding the lower frame rails in position at this point in the build.
Here are a few pictures from my model showing the rear bumper in its new location
The graphics are amazing Graham. As we discussed when you were here, I think I'll be removing the thin webbing that holds the four parts of the honeycomb together and installing just the blocks. That webbing seems to contribute nothing except it was probably a convenient way for the production line to slap on the honeycomb in one step.
I agree Blooz. I will proceed with moving the steel bumper forward 2 inches and get my lower frame rails secured prior to removing my strut towers. I had planned on making new strut towers but I think I will try to reuse the stock towers and try to retain that OEM look in the engine bay as much as possible.
[This message has been edited by Yarmouth Fiero (edited 08-04-2014).]
Well then that would be an easy answer for me..........
I will have an adaptor for a Chev V8 (not sure if it is SBC or LT) to a Porsche G50 soon when I swap in my BMW V12 into the Countach........ Expensive transmission though. (came with my project or I wouldn't be using it either.....)
You would be better off to go with a setup like engineman where you use a fully complete engine trans already built by Audi. I know Jim Dinner did a Haltech engine management conversion on a BMW V12 in his Diablo build so it might also work well on the Audi if engineman can't get his sorted out. I think he is pretty close though from reading his thread. You would want want a better engine/trans frame mated to the cradle though. I personally believe engineman will have problems with is 1x2 trans cross bar. Look up motoracer838's build here or on Madmechanics and see how he did his back end frame. You could easily adapt what he did to the Fiero frame as he did a great job on his cradle updates.
Now is the time to do it though as you have everything cut away and ready to adjust the bumper so fit the engine/trans in and make sure everything fits..... (and this is why our projects take years..... upgrades and scope creep....haha)
[This message has been edited by 355Fiero (edited 08-06-2014).]
Just got home from two weeks of vacation on the road and had a nice surprise waiting for me.........two rear brake rotors, hats and bolt kits for our project. As described above, they are Wilwood 13" SRP rotors with aluminum hats. Here are a few pictures including a comparison with the stock 85 Fiero rotor and the rotor located behind the rear 18" wheel.
The black rotors are in keeping with the "all black and gold theme" for our build. I guess the rotor surface won't be black for long though davylong86.
The rear calipers will probably be the Wilwood 4 piston forged superlite as well as the Wilwood MC4 mechanical cailper for parking brake duty. I may order the MC4 just to see if there is going to be an issue with rattle as you had suggested Blooz.
Edit: The MC4 comes in black as well
[This message has been edited by Yarmouth Fiero (edited 08-15-2014).]
Taking advantage of the fast few days of my vacation, I thought I'd try to make some progress worthy of a thread update. Although it is kind of nice to post pics of new equipment once in a while.
As mentioned earlier, I plan to move my strut towers outward to allow the suspension to follow the 8" track width increase for this build. After removing most of the trunk sheet metal I realized the only thing holding the lower frame rails was the strut towers. At the same time, Blooz confirmed that out rear bumper was going to have to be moved atleast 2" forward to clear the 355 body we will be using. This seemed like a good time to move the bumper and secure the lower frame rails before any more chassis was chopped away.
So keeping with the planned 2" bumper move, I marked off the lower drivers side lower frame rail and proceeded to cut the required 2" of material off.
Originally, my plan was to make new flanges which would be welded to the shortened lower frame rail and allow me to secure the OEM bumper back in place. However, looking at what I had cut off and the fine condition of the OEM flanges, I decided to reuse them by removing the connecting sheet metal and separating them into two individual flanges. Not only were they in good shape, but they had dandy stiffeners already moulded into them which made them plenty stiff.
So I cleaned up the flanges and clamped them in place to see how they fit. I think they will be fine and once I have the passanger side done, I'll bolt them to the rear bumper to ensure they line up properly before welding them to the shortened lower frame rail.
Here is a pic of them clamped in place as well as a pic showing the difference in lower frame rail length with only the drivers side shortened so far.
Every now and then, I seem to get a little bogged down in design details, trying to figure everything out to three decimal places, hesitating to buy components once I seem to find what I want that will fit my design.................. such has been the case for the rear suspension. As I mentioned, I plan to move the strut towers outward to compensate for the 8" track width increase of the 355 and the design has been going pretty good, albeit slow-w-w-w-w. I decided that the struts would move outward about 2 1/2" and the last 1 1/2" would be completed with a custom bracket to connect the rear spindles to the lower end of the struts. I decided on QA1 Front Pro Coil Strut System and specifically the 82 - 92 Camaro / Firebird Coil Over Single Adjustable Struts ( 18 position ). They have the length I need with the travel I require with lots of adjustablility for fine tuning static length and dynamic response. I also ordered the camber / caster adjustment plates for the top end. So they are on order from my favorite speed shop.
Continuning on with the design of the new strut towers that will suit the forthcoming coil over struts, it became apparent that the stock lower frame rails of the Fiero were now going to be significantly inboard of where they should actually be in relation to the new strut towers. So I've been crawling in and out of the chassis looking at this issue from every possible angle and I have decided to remove the stock lower frame rails, cutting them at the point of the original 3" chassis stretch. Rather than try to reuse the odd shaped stock rails, I have decided to fabricate new rails that will run straight back, parallel to each other. I will probably use 4" x 1 1/2" x 1/8" HSS and run them all the way back to the rear bumper, while incorporating a wider section in way of the engine cradle rear mounts. I had planned on designing and building a new engine cradle anyway that better suited the SBC installation so I may as well make it a little wider and give myself as much room in the engine bay as possible. As you will see below, the new lower frame rails should also eliminate the usual interference of the SBC with the lower frame rail on the passenger side.
Here are a few drawings showing the stock lower frame rails in blue, the revised lower frame rails in purple and a couple close ups showing the relationship of the SBC with the lower frame rail ( roughly).
Stock Lower Frame Rails
Modified Lower Frame Rails
SBC Interference Corrected
And just when I think my plan is ready to carve in stone......... I get a suggestion from two different PFF members this week to consider going longitudinal. Back to the drawing board perhaps.
I saw your post in Blooz's thread. It's been discussed numerous times over at MM's. I don't think there is a transaxle option for a V8 that will fit in the 3" stretch longitudinally. Chrysler V6 is an option, but I don't think that is your direction. Obviously there have been several performance car options with the latitudinal engine. It's not necessarily the optimal, but obviously it can be done effectively.
[This message has been edited by RCR (edited 09-01-2014).]
The SBC is one of the longer V8's. I had done some measuring a few years ago with measurements I obtained from an 016 Audi transaxle into a 3" stretch. The 016 could withstand the SBC torque with the reinforcing plate by Jim Dinner and no clutch drops from the green lights...... The Audi 016 is the shortest transaxle between the bell housing face and the axle centre. I have a Porsche G50 but it is a couple inches longer between the bell house and axles.
I have drawings with the Audi lengths and widths etc. somewhere that I can send you Graham. I figured the SBC length, then the Audi transaxle bell housing face to axle centre put the axle centres about 1.5"-2" behind the suspension hub centres. That put a small angle on the axles and CV joints but nothing that would cause issues over the long term.
You would need to add in a box to the firewall upper portion to clear some of the upper SBC parts and you would need to remove the lower frame box that covers the fuel pipe etc. Or cut some out of the middle portion of the lower box. This is required to clear the harmonic balancer. You also need to use a custom low profile accessories setup that puts the A/C, alt etc. lower to miss the angled Fiero firewall.
It is tight and I am sure I missed some important interference areas when I was eyeballing it but with your full 3D cad, you can draw a transaxle and mate it to the SBC you already have and see where the interference will really be. The beauty of CAD.....
There are other, (better in my opinion), options for a V8 than an SBC unless you already have one ready to go though.
Good luck with your decision and I will track those drawings down and send off to you in email.
Thanks for the info Don. I got the drawings of the gearbox in my email. Very interesting option and one I will consider exploring. With regard to engine option, I don't have an engine yet but have been eyeing a nice Edelbrock Crate engine but its overall height as set up is a little concerning for the low deck of the 355 body.