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Discussion Starter · #1 ·
In my continuing search to rec

In my continuing search to recover the documented approx 10 rwhp lost at the well known poor flowing Ferrari airbox, I think I have found a possible solution. Much as the exhaust on the flat crank V-8 takes advantage of even pulsing per bank, so might the intakes.I am going to separate the the intake tracts into two separate intake airboxes or plenums. It just so happens that a Lamborghini Jalpa airbox does just that. As a matter of observation, all Ferraris from the 348 on separate into a plenum per bank.
Have discovered something interesting about the Jalpa airbox, not sure if it means anything - it has a large volume that is offset from the centerline of the barrels. It looks like it gives the air a path around the barrels to allow the back ones to not breathe from the fronts. Alfa airboxes are similar, actually.
The Ebay Jalpa airboxes I just purchased arrived - as expected, they are 'offset' to the outside of the engine allowing a flow space to the carbs (shown). The Jalpa DCNF spacing is wider, so am quickly CAD and machining up a nice fitted aluminum adapter piece (shown). In an amazing bit of luck, a RC-5000 filter designed for a GM throttle body almost exactly matches the measurements on each airbox snout, so will go with system below for cold air induction - not perfect, but it will be cool air from the scoop and up from back around the wheel well away from the engine. It looks like the height will probably be ok.
Should have the adapter piece in a couple of weeks - will post.



 
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Discussion Starter · #2 ·
I think you will have some suc

I think you will have some success Russ, because Lambos have generally over history, recieved more HP from simular volumetric sizes as compared to Ferrari. And as you noticed, Ferrari has split many Intakes to increase flow and reduce stalling and resonance of intake air. And if you go back to the Big Block Mclaren days of the 60's-70's you will remember that the Stacks were staggered in hieght to keep one Cylinder from robbing the next of air.

I don't know if you're familiar with Super Trap Exhausts (you likely are but others may not be) that had Addable/Removable Plates for Differing Track Layouts & Conditions, intakes have also had many variations on Air Boxws and Stack Lenghts for the very same reasons. In the Ferrari realm one of the main reasons the "95" 355's have more HP than the 96 & laters is INTAKE FLOW (95's have Twin Inlets).

I think you'll pick up even more HP as you progress along this line.
 
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Discussion Starter · #3 ·
Thanks JRV
I've been stud


Thanks JRV
I've been studying up on the small Lambos; I don't know if I would fit or not, but I really like what I read about the Urraco P-300.
Maybe I need to look at it more seriously - I really love mid engine 2+2's.
 
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Discussion Starter · #4 ·
JRV wrote: And if you go back

JRV wrote: And if you go back to the Big Block Mclaren days of the 60's-70's you will remember that the Stacks were staggered in hieght to keep one Cylinder from robbing the next of air.

I write: The staggered heights also result in a wider power band since 4 cylinders are tuned for (slightly) higher RPM power (short stacks) and the longer ones tuned to (slightly) lower RPM power.

Back to the question at hand: If r_turner could figure out a means to get only cold air to the intake (filters) this would prevent the engine from digesting warm/hot air from the engine bay. Something like an air box big enough for both intake cone filters to be enclosed (with adequate spacing around all components) would work well
 
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Discussion Starter · #5 ·
Well, not all my ideas work so

Well, not all my ideas work so good.
The Lambo Jalpa airboxes fit GREAT, but the forward one is too tall and the bonnet cannot close. The metal support beam in the bonnet contacts the box and prevents from coming all the way down. Back to Ebay for the boxs probably.

Not to be dissuaded, have designed a possible solution and will go to an aircraft a&p fabricator tomorrow. Here are the issues to solve for making this worthwhile to me:
1. One plenum per bank, easily removed and giving quick access for carb tuning and work ( where you don't have to remove the whole assembly like stock)
2. More open than stock allowing more airflow between the carbs to allow cooler running temps and solve intermittant fuel system heat soak problems I've had here in Texas.
3. curved plenum top like all 348 and after dual plenumed Ferraris
4.Offset side box with flow taper to better aid even flow and enhance flow velocity to carbs and mixture stability barrell to barrell using the Jalpa offset scheme and add a front to rear taper like in older Ferraris and some others.
6. Simple
7. Use/modify existing adapter plates ($)
8. Adaptable to readily available K&N filter set up.
9. The bonnet must close

Have enclosed photo of the Jalpa airboxes installed just to show you what they looked like on a carb Ferrari engine. I think they would have worked pretty well. Also shown is a picture of the adaptor plate showing how easy it is to work on the carbs once the airboxes are quickly removed by six nuts, and my current best attempt at a solution.

I apologize that the engine is so dirty - I've been driving it a lot in the rain this fall/winter and need to do a spring cleaning. It really does clean up nicely I promise.

All ideas and comments welcome. Hope this is interesting for the 3 guys left following this.

best

Russ



 
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Discussion Starter · #6 ·
Here are the roughed out dual

Here are the roughed out dual plenum intakes; The snouts will be refined but I must say the aluminum welding on the box is aircraft quality.
I've also removed the side vent and am working on an appropriate duct.
Note the space now between the carbs for cooling air flow. The Plenum tops can quickly come off to allow easy DIY tweaking.
It looks like the new ones will fit much better than the Jalpa boxes (for sale, by the way)
I was going to paint them black or red, but I may just leave them aluminum...
I have no idea if this will affect the sound.


 
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Discussion Starter · #7 ·
Hi Russ,
Did you get any wher


Hi Russ,
Did you get any where with this? I have my airbox off at the moment!

Off topic, would the colours your engine is painted be standard? My GT4 has gloss black cam covers - yours look so much neater!

Interestingly and purely by coincidence I knocked up a similar shaped airbox for my last car which ran twin side draft webers 40 DCOEs, Although it was aonly a 1300 Triumph it still produced 135 bhp which was quite impressive (the airbox was not the only mod)! If you can squeeze 135 out of a Triumph Spitfire lump, is it possible to get 290+ out of the Ferrari V8?

On the triumph, the setup was as follows:

Stage 3 Engine Ground, Stroked, Indexed, Tuftride Lead/Copper Bearings 010/010 - Bored, Rodded, Acid dipped. Whole rotating assembly balanced, including pistons and conrods the Flywheel was Lightened and balanced, AE Hepolite +030 Pistons Kent TH3 Camshaft with duplex timing set.
Manifold Triumph Tune 4-2-1 exhaust manifold
Cylinder -ead Triumph Tune Stage 3 unleaded cylinder head the Rocker gear Triumph Tune Roller Rocker assembly and lightened hollow pushrods with Twin Weber 40 DCOE carbs and Piranha Electronic Ignition

The engine was built by Williams racing for me and was truley awesome HOWEVER.. Surely most of this would be standard (not withstanding the differences between the two motors) on the Ferrari V8 taking into concideration its pedigree? (http://home.btconnect.com/ntruman/Spitfire/index.htm)


regards
Nick
 
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Discussion Starter · #8 ·
Nick
Thanks for the email - a


Nick
Thanks for the email - am waiting to pick up the final plenums this week. In addition, I am also picking up a modified side scoop with a new aluminum duct to direct air at the air filters and around the carbs to keep them cool. I hope to have everything installed this next week. The original factory engine finish was aluminum; these colors are as close as I could find to the factory when they powdercoat the cam covers.

It is interesting to look at the restriction of the original intake scoop duct. After a lot of **highly scientific** (using a floor fan) and different duct ideas, I settled on strong and simple. I may not be the absolute best, but it is quite simple and should lower engine bay temps as well.

Your engine looks fantastic - very well done. Anyone that puts out over 100 hp per liter, well, that is impressive.

Should have photos in a week or two I hope.
 
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Discussion Starter · #9 ·
Very Impressive HP output on t

Very Impressive HP output on the Brit. Especially considering the small valve sizes. Good going!
Russ, are you going to powdercoat the new housing? Perhaps a thermal coat? Might be a couple of ponies to be found there. I have been doing thermal coating on motors in the past, and note the ffactory did coatings on the F-40 intake.. Food for thought.
 
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Discussion Starter · #10 ·
Kermit - Actually, the powderc

Kermit - Actually, the powdercoating does sound like a good Idea - I will look into it tomorrow when the plenums are supposedly finished.

Part of this whole installation by neccesity is a new airscoop. The old Mondial sidescoop had been trimmed to accept a rubber duct to attach to a stock 308 airbox. Well, upon disassembly of the starboard side scoop, it has a smaller intake opening and is more complicated than you may think. The intake scoop opening itself is only about 1/3 of the total scoop area or less, about 4" x 3", with other air being ferreted off to cool in front of the front cylinder head and around the vapor recovery cannister. The big discovery for me was that the airscoop has a built in resonance chamber at the bottom of the airflow tract vented by two holes.

I removed the air induction piece and the rear vapor recovery scoop and replaced with an aluminum duct that points towards the two K&N filters for the plenums. It is simple, robust, well ventilated the filters once the car is moving and also blows cool air on the carbs in the engine V. I may be overselling the carb cooling thing I realize, but my gut reaction is that it will help on hot Texas days.

Will post some plenum photos tomorrow.


 
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Discussion Starter · #11 ·
Here are the unfinished, untri

Here are the unfinished, untrimmed and unsecured pieces in place.

Pic 1 is baseplate with stock airhorns. Since you asked, there is the same amount of upward clearence in the stock airbox, which is where the vertical dimension came from

Pic 2 is with the Durable1 shoet air horns

Pic 3 is the plenums in place

Pic 4 is Plenums with filters. What may not be visible is that the are sitting in front on the large airduct to the side scoop

I think I am going to shorten the ram tubes to the plenums just an inch or so. Don't ask me why, just a a vibration in The Force.

Will start it I hope by Sunday sometime.

Will probably leave the plenums aluminum, but am tempted to do crinkle black. Have a friend who suggested red matching the cam covers - any advice?

best
rt



 
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Discussion Starter · #12 ·
First drive:
I can't tell


First drive:
I can't tell if it has any more power as much, but it is a bit easier reving around 4500+ rpm and sems a bit smoother at higher revs. Purely objective of course. The sound is a bit bit 'harder' - much like it sounds with 4 separate air cleaners with a lot of induction sound and it seems you can hear the reversion a bit at low throttle. At full throttle she still jumps and pulls hard, and maintains a good amount of torque.
Will get a dyno later - will first put on the mobile LM-1 A/F meter to see if any mixture tweaks neccesary.
Cleaned up the engine a bit, and have one rubbing place I have to fix.:
 
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Discussion Starter · #13 ·
Looks Awesome!
Did you ever g


Looks Awesome!
Did you ever get rid of the lambo boxes - I think they would fit the GT4, more space above the airbox..

Regardfs
Nick
 
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Discussion Starter · #15 ·
Cool, i have sent an email to

Cool, i have sent an email to you asking for more details.

Cheers
Nick
 
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Discussion Starter · #16 ·
Awesome work! Do you have any

Awesome work! Do you have any measurement supporting your good feeling on engine torque response? Apart of the engine sound and lay-out improvement(the stock airbox is penalizing both )I wonder how the dual air boxes made on the spot can be very effective.Matching a continous air flow inside ducts to reciprocate machines ( the cylinders ) with variable speed means dealing with multiple waves streams. To get measurable improvement over the stock baseline would require an accurate study of the actual airflow path inside the box over the engine RPM range and air temperature.
Most of the advantage in changing the stock airbox would come IMO from reducing/removing the filter restriction ( simple velocity stacks ). Without airboxes the airstream would adapt his shape and find the most effective way to the stacks at all speed and temperature conditions ( a kind of adapted flow ) matching so far the engine requirements over the whole RPM range. Anyway your engine compartment looks now very appealing and professional.
CalMorr
 
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Discussion Starter · #17 ·
If as dicussed one of the issu

If as dicussed one of the issues with the stock airbox is the robbing of air between one cylinder and another (I asume this is across banks?) could a simple option be to divide the stock airbox in two? with a sheet of steel rnning between the banks?
 
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Discussion Starter · #18 ·
Have settled on the original a

Have settled on the original air horns for now; could not get Kermits low rise to fit as well (Kermit - will need a special version).
One of the things that is amazing is how open things are and easy to work around and inspect when compared to the original airbox. I am hoping that it will also help to increase airflow and keep the carbs cooler in the Texas heat.
The induction sound is now a bit more hard. Have not pushed up in high rpms, but low end is still very good. The one time I did run it up it seemed to catch and 'come on the cam' about 5,500 rpm and really pull. Perhaps that is a resonance point. Still all subjective and will get a dyno this fall when it cools down.
One option I had looked at was to splt the stock box and put a K&N cone filter at the front of the stock airbox.

Nick - I do still have the Lambo air boxes if you or anyone is interested.



 
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