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Sitting in my amazon cart waiting for me to get the engine back together and need it is scale....I would love to know what this engine weights. I expect the eng/trans with everything I've done to weight about 800lbs, I'll be sad if its 1000 but that is certainly a possibility....but I'll get that number before the engine goes back in the car. This will help me decide what to do roll center wise whenever I decide to tear into the suspension for real.

Installed the trans is sitting 1/4" higher that stock....it was that or notch the already soft frame to clear the flywheel. The engines crank though sits 2" lower and 3" forward of the the V8s so even with the added height of 60deg vs 90 and added weight 12 v 8, I'm pretty sure new mass center is lower and f/r split similar to stock or at least to the V8 with big supercharger that came out....but what to do suspension wise has been on my mind since I first bolted the 80 or 100 lbs of blower parts onto the top or the V8 and I'm clearly still undecided.

New rear springs arrived yesterday, 8" to replace 10"



Siting with the adjusters full up so rear as low as possible here it is



Last time when I measured the front I was looking at the valance and getting about 4.5". last night I laid down on the floor and discovered 4.5" at the valance is about 3.25" at the frame so the front goes plenty low. Right now the frame in the back is at 4.5" with no engine. If the engine is 1000lbs with exhaust and everything and the spring 500lb/in each and nearly 1:1 motion ratio the rear will be 3.5" full low so I guess it works out as this might work at an autocross but is too low for street use.

I can rise it about 2" which would be just about stock or perhaps a touch over so these springs seem good length wise.

This morning I was out putting down weed&feed.  Its kind of earlier but last year while building walls, regrade, and such I really let it go so I decided to hit the show parts of the lawn now then the whole lawn in a month at normal time.  I like to do the fed&feed first thing in the morning when the grass is damp so the stuff sticks....don't know if it actually helps but I've always believed it does so I use the push spreader not to wake the family with the tow spreader making the job slow and boring and giving me an uninterrupted hour to pond Ferrari 308 chassis design and I believe I had an epiphany.....the frames are actually pretty well designed but aren't finished.

Let me explain.  If you look at the FSAE frame I posted its a space frame which means it made straight pieces of tubing and EVERY external opening is a triangle, EVERY node is supported in 3 dimensions.  This means all the frame member are in tensions or compression with virtually no bending loads, the only exception is the suspension mounts which weren't designed yet when I did the frame and honestly none of us were very sure about how to design it so I used heavy members there to allow freedom to make changes.Even the cockpit opening is a triangle which is important becasue removing just the 2 bars that go over the driver's shoulder to triangulate the cockpit reduced the frames torsional stiffness by a factor 3...so remove those 2 pieced the weight about 2 lbs and you have 1/3 the stiffness you started with.   So that is a space frame, wonderful for a race car but clearly worthless for a street car and as a result street cars do not have space frames.

Street cars, and here I mean older street cars that have defined frames all have a version of a ladder frame....2 main rails with cross members. Even most of the new monoque (stressed skin, no real frame) stuff uses ladder like supports.  A 308 frame is made this way.  With a ladder frame there really is no clever way to keep things in tension/compression so the only way to make it stronger is to just make all the part bigger and heavier....I had a '65 vette and its frame tubes were about double the width of the 308 frame, at least from memory.....the 308 frame is pretty spindly really and ferrari use the exact same frame in the 288GTO (just a 4" stretch in the engine bay) and and the same frame on the F40.....

.....why I wonder?  They had to know it was a POS when even a casual observer can look at it say WTF were they thinking? so why?

Racing rules.

Every sanctioning body has cage requirements that mandate, imho, ridiculously heavy cages built in semi-foolish ways.  They do that so its easy to tech and hard to screw up so anything you bring that meets the rules is safe.  Take a street car, remove nothing structural, add all this new stuff.  Everybody needs to follow the rules so it doesn't matter that all the cars are 200-300lbs heavier than they could be, the racing is fair and everyone is safe.

So what does Ferrari, a company who sell street cars to pay for their race program do?  They design a nice bottom section of a cage with very little consideration of street performance to make the frame as light as they can get way with knowing old men driving on the street will never notice the flex (this is no doubt also way the stock springs were so soft, to help hide the frame flex issues) and the racers will add a cage, finishing the frame, and have a lighter, faster race car than anyone starting with a car designed as a good street car who then is forced to carry the heavy street frame around the race track. 

So they were either incredibly competent  or incredibly incompetent. I'm going will they were brilliant.....doesn't help me with my flexi street car issues but it does make a lot of sense. For me, where a cage is not happening there is a bit of a challenge.  The front wheels are basically at the front os the passenger compartment so there is little to nothing to be gained up front leaving the engine bay and passenger compartment.  with both causing about 1/2 the flex. 

The engine bay I can cage.  Once the engine is back in I'll design something to bolt on top.  On the FSAE frame I reamed the holes and used shoulder bolts on ends of the engine access tubes and that working out pretty well so I'm thinking something along those lines but beefier to deal with the bending loads I didn't have then but will have now.

The passenger compartment.....the only answer is more metal.  There is lots of room in the rocker panels but I need to figure out what to do with the cross members....there is a double floor where I lost that steering bolt a couple weeks ago, for sure I can replace that with something quite rigid....I need to model it up and play with it....in my spare time......

The MAT effort was mentioned a bit ago and somebody sent it to me
http://www.mat.fi/projects/59
http://www.mat.fi/gallery/56

I looked through it but will need to spent a bit more time staring at everything. Pretty sure they are working with an older, '76 I think, chassis that is a tiny bit different from mine.

I think too, and I might be wrong, that they are working with the original homologation specs and saying they need to make changes because the FIA cage rules have changed.....which may limit what they are allowed to change. I say that because they have some obvious misses like they have a couple diagonals added to the side of the engine bay (red in pic below) but to triangulate the top or bottom so the side pieces add bending strength but little torsional stiffness because the flex just moves to the weakest link location. Similar issue up front although probably less critical since the front is shorter length but still I'd want to get what there is to get and they didn't it doesn't look like so I suspect a rules issue.

Something to note, the bodywork clearly does nothing on their setup other than look pretty, its not structural in any way so Targa or coupe body you'd get the same answer.

I've also been thinking about shocks a bit as part of the suspension work I want to do. With my $250/mon budget revalving the shocks is probably next year and AC the not until 2026 but a buddy was working on his and kindly shared his spread sheet which I added 308 stuff to to see where my shocks kind of are with the new springs. And mostly what I've learned is that I don't know a whole lot about setting up shocks...but luckily I don't have any money to mess with them right now and have a year or so to think about it.

ping pong back to shocks. I know many are running QA1 shocks including a buddy of mine who said 6/4 front rear on the clicks and shared the graph from the QA1 manual, this is the newer 18 click version so it looks like the red line is 0, so the blue and green line are likely 3 and 6 click respectively. the 6/4 was were is started to get harsh. I did a search and people with the older 12 click version were saying 4 clicks is harsh, so % wise about the same. His other comment was it also felt loose over anything



What really caught my eye here that rebound is nearly the same as compression. OEMs like about 1:3 ratio comp:rebound and my current shocks are just that as were the OEM konis which are also show on my graphs. That is a compromise for street use to let the bump move the wheel easily to make the ride feel softer but they jack up the rebound that you really don't feel as easily to help settle things. On the oem konis with the oem springs the average damping is exactly critical, meaning the system will settle with no additional oscillation.



The shop I bought them front basically said, you're not hating anything about the ride use they kept the compassion about stock and added more rebound to better control the stiffer springs. I am feeling more damping would be better and was thinking 20-50% more compression. The QA1 green line is just about exactly where I am now on compression so Ik could probably double what I currently have and now hate it as that would put me right about the QA1 blue 6 click line.

Rebound wise though, I'm already on the QA1 blue line at 1in/min, 0-2in/min is generally considered low speed damping, and the transition knee is usually right around 1in/min so by 2 its fully into the highspeed damping behavior. Low speed is small bumps like highway joints and and the pitch/roll/dive from driver inputs....so to make the car feel responsive you want to add low speed damping, but that will also make it feel every bump aka harsh. The high speed range is big bumps, track curbing and such and I'm at near full or nearly so on my current shocks with the new 800/500 springs and that feels ok.

So my thought for when shock make the top of the list is to ask for more like 50-80% more compression then maybe center up the rebound so full range currently closer to centered....but I still want to play with the spread sheet a bit more and see where the average damping is compared to critical damping...that seems importantish I can't just add lots of rebound as then the suspension won't actually rebound very well. I'm also still a little confused about preload...it doesn't play any roll in oscillation but does does change the spring force relative to the shock force....so I'm pretty sure less preload means it won't like being over the critical damping numbers as much on rebound as low spring rate high preload OEM setup will tolerate. I need to think on that a bit more.