When "Excessive" isn't enough... the IMSA 348

Plugzit is looking for his screwgun and 3" sheetrock screws about now... yellow zinc plated of course.

David, as slow as I am I need something to make downforce at a brisk jogging speed, they will just have to make due without.

 

Noooo, comparison purposes only, I just pulled it out of the coffin to look at the mounting struts and template the bottom mount shape.

I am having a dickens of a time finding a visually appealing wing mount to build. I have enough aluminum airfoil wing strut material but it is too narrow and would have to be cut lengthwise and widened for this cord width. I have already rolled out doubler plates to attach to the ribs that fit the lower wing contour but what will the vertical mounts look like? Twin wide mounts? Outer mounts? Single center mount ALMS type? I think I will need to replicate something on the line of the 355 wing mounts for it to look proper and then need to design an attachment of those to the doubler plates that is adjustable.

I needed a project to go to on the car when I get frustrated or sidelined on the engine. Yesterdays sideline was thinking through the Shower injector mounting, calculating the stack length and which pulse wave I want to capture. That leads to the shape and design of the cold air box, snorkel, rear deck lid cut outs, locate stacks of the right shape and length or build from aluminum or carbon.... and.... WALK AWAY and work on a wing mount I am unable to visualize yet. Lots of notes and calculations but little hard progress yesterday. I did on the other hand, reach the end of the Net while researching the above.

I was just about set to walk away from the Shower injector design, conceed to giving up a little and keep it simple and then the above trouble maker sent me this http://www.youtube.com/watch?v=oFm0m6sbOi8&feature=related He takes pride in seeing me stumble around mumbling nonsense and knows I am a sucker for a good video

 

Yup, cussing our GA brother all day Thursday. Spent Thursday evening machining shrink fit aluminum plugs for the throttle body injector ports. If they are plugged and the bores polished out to remove the injector boss I will not be tempted to use the std ports and will be forced into overhead mounting.

This is going to get real complicated, real quick but how can you not have THAT?! Full rolled edge 180* velocity stacks located and ordered this AM, there's no turning back now!

 

Remember that dweeb in the back of the classroom that would near tip over his desk jumping up and waving his hand frantically when the teacher asked a question he knew the answer for? Way over the top brown nose little shlt?

Someone in a crowd yell's HOE or Chicken Shlt..... "Right here, Right here, that's me!!!!! How can I help you"!

If it under steers hidiously because the rear is so stuck..... The smaller wing next to the car in the photo is a left over high mounted front wing from a Brabham F2 car. When one isnt enough, throw "Excess" to the wind and glue on another!!!!! They outlawed moveable feathering wings in CanAm, not in GFRT. You could be 1/3 a lap behind and still pull a draft off of this brick. That extra hydraulic line to the front brake master.... Ohh, that, that's just for a spare brake light sending unit... no worries.

See, you guys have no need for concern about this car... Its all a non issue, non starter from the get go where I can be allowed to do anything what so ever to it I can dream up... all show, no go, just a stock 348 with a fancy paint job. Have the Vegas odd's gone up against this brick yet?

 

Same place we spoke about. They are just aluminum not CF... so much for bling, I will have to polish them to a high shine (after I get done welding on them) or get ridiculed by those on both coasts.

 

Just woke up Kris with the obligatory 4:30 AM playing of the video... no sense of humor these women. "Where did you find that video?" Bruce..., it was Bruce that sent it to me.... SOLD!

Getting a little sidetracked again but... I get such a kick out of watching the vapor clouds appear at the stack openings at WOT. I can remember watching and getting a kick out of the BBC CanAm cars coming out of a tight turn with 8 little rain clouds hanging above the Hilborn stacks as the engines came up on cam. It looked like those big lumps would suck in the little clouds one by one when they lifted for a shift and then they would reappear again at WOT.... so fun!

Just got me to thinkin... if I ran the stacks a bit short, somewhere between the 2nd and 3rd tuned wave length with no snorkel... fuel stand off from 330*+ cams with top mounted injectors.....a single spark plug hidden behind the Wickerbill of the upper element of that wing.... I bet I could hold the number of times I am lapped down to zero. There are showmanship points applied in GFRT and fresh paint on the front of the pretty boy 358, sure hope the resin is dry on that spoiler!!! If one stands no chance of making it with the Race Track Queen waving the checkered flag... go for Shock and Awe points. Thinking out loud has now convinced me I need hollow wing mounts..... I prefer to think of that as "Good old Cheat'en'', not Cheating. Sometimes it is worth giving up a little power and gaining an unfair advantage. Time to bribe Finnerty onto the IMSA car team and have him find a way to bleed off a little of that wings upward flow to out and downward.

 

http://www.youtube.com/watch?v=oDTTcvftInw&feature=related

7-12 is a bit off but I see the makings of a cold air box and snorkel. Could be there is a need for an F1 shifter behind the IMSA stink maker.... I need to focus, I am falling into the trap Bruce set for me knowing I would never make the grid if I kept "what if 'ing". I made one for the DSR with starter solenoids quite a number of years ago... Hmmmm.

But I just have to have one of these! http://www.youtube.com/watch?v=5OS_k0V8Bvw&feature=related

 

I walked away from the intake/injection design issues to think those through a bit further and went onto the wing mounting design. Half a scratch pad later... My final drawings of the wing mount are a hybrid between a Top Fuel dragster and the Chaparral 2E, utilizing 2 hydraulic cylinders from the forward section of a 355 Spider top (for fitment adjustment only, of course) to stay with my want to use Ferrari parts where possible. As this is such a special car, I am also burdened with the requirement to make all of this reversible so not to forever change an important car. A hole here or there can always be welded up and race cars by their very nature are constantly evolving... Evolve, this one will but I am unable to work up the courage to cut the rear engine lid in half for the wing mount. Four small oval holes in the rear of the lid, 4 aircraft pip pins and a quick disconnect hydraulic coupler appear to solve that issue... on paper at least. Walk away and think on that a bit longer!

Intakes.... As wise old Plugzit eluded to, 355 ITB's will be used as the bore spacing aligns perfectly and the bore shape and size are very close. The 348 head's intake mounting flanges are set at a 10* angle. My initial plan was to angle mill the adaptor plates to correct for this but after thinking about it a bit further.... The port shape is set for this 10* angle and points the airflow directly at the face of the valves. The velocity stacks inside the 355 Pentium are also angled and if reversed side to side will point at one another. Depending on the lengths of the stacks, the height of the phenolic spacers, the length of the TB's..... I might be able to run a single central fuel log between the two banks of stacks much like on the cursed video Bruce sent me. The injectors would be staggered right, left, right... due to the offset of one bank to the other.

The problems:

Will the 355 ITB's, phenolic spacers and 355 stacks all add up to the correct tuned length given the cams I am using, the planned RPM range and the port size of the heads on the Enduro engine?

I am questioning if I need to run a pump pressure line to each end of the rail and a return from the center to lessen pressure surges in a common fuel log feeding this many injectors.

Will oval tubing for the fuel log, set on its side allow enough width to get each bank of injectors to the respective stacks given the 10* angle and the curved stacks

Can the injectors be mounted off set from the stack opening so they point at the throttle plates and not at the sidewall of a curved stack

Mount the injectors so they enter the stack at the outside radius as opposed to the bell mouth opening.

What is the spray cone pattern width of the injectors I have on hand now? I can get different spray cone pattern widths with the same flow specs as what I currently have (think they are all the same and you just need to match pounds spec's?) but that would burn up a very limited budget very quickly. If too wide it will condense the atomized fuel on the sidewalls of the stacks and TB's at anything less than WOT.

The 355 intakes are designed with a constant taper from the stack bell opening to the throttle plate to increase the velocity of the airflow, 2.5mm in the TB's alone. It is going to take some flow testing on Gary's bench to answer some of these questions. The other questions will be answered with a string line and line of sight on a mock up of the above.

Crap can the central fuel log and 355 tapered stacks (already ordered) idea and go back to the straight stacks (already ordered) and twin top mounted fuel rails and rely on the snorkel and cold air box to create positive pressure. Good thing I have a large wing as the snorkel will be disrupting some of the airflow across the roof.

And so goes the designing and building of a race car. Building a Production car into a Race car.... I refer to it as the ultimate exercise in compromise as you are burdened with using the shapes and dimensions you are given. The RV mirror will have to be mounted in front of the passengers seat to be of any use at all. A budget? Sure...!

 

Reference
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How fun is THAT!!!!! It just took an absurd project to light his fire, welcome back!

 

Great stuff Mitch! I wish I was well versed on the CAD/CAM and FD's but alas, as went the dinosaurs goes myself. These days I consider it a high class problem to be too busy to learn yet another speciality field such as these. It will be fun to run some of my guesstimate numbers past you to see how the programs like them.

What is intriguing is we are approaching it from different directions with different reasoning but.... our math comes within eye sight of one another. In my calculations I place a heavy point on cam size and intake air temp but have little experience with plentium volume, shape or placement. Everything I have experience with in my past has poorly shaped velocity stacks hanging out in the wind. Moving the injectors up to the top of the stacks on the Hilborn/McKay systems was done only because we couldn't afford quality injectors that would atomize properly. My experience was mostly limited to Triage modifications due to lack of budget than anything having to do with properly designing a system from the start.

This project is fun for me because I am trying to correct mistakes I have made over the years (a do over if you will), using parts on hand, seat of the pants reckoning from past experience and the same limited budget I have always had while building the race cars for myself. This engine is a know commodity we ran it in the Plugzit/Vince 358 for a number of years and it originated as the Enduro engine for the IMSA 348. I held this engine to a 8500-9000 limit and it has proven quite reliable with Big power at those numbers albeit the intake was a limit at that point. The cams in this engine have a bit less lift than those on the Sprint engine and as such, the cam belt lives a season or two as opposed to 4-5 hours of that on the Sprint engine.... I now know how much is TOO much for a "Fun effort" race car.

Once I get the intake system underway I will pull this engine apart and decide if I use this bottom end or do a 'bitsa' effort using parts of the Sprint and Enduro engines in the build up. I still have one virgin set of the Cosworth pistons, one more set of Carrillo rods and boxes of shiny valve train parts waiting for spare time. This engine saw a 5 digit RPM missed shift when in the 358 and was removed to be dealt with another day.... That day has come.
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