B2 Motorsports - Cliff Rosson All-Aluminum 331 SBF Build

[lippy]

The Webers certainly *look* good - especially on a Ferrari. There was a vintage Weber vendor at the Monterey Historics this year. He had one NOS Weber (for a Ferrari) that was going for $75k (!). My kid almost picked it up and I almost... nevermind.

[Rick Parker]

I ran a Barry Grant modified 650 DP Holley (not a Demon) for many years on my 289. About 5 years ago I installed 48 IDA's and went throught the normal tuning process.
Speaking first hand the flexability of the motor was greatly increased and seat of the pants torque really stepped up. It is possible that the absolute top end HP might favor the 4bbl but the increased flexability and torque are what make the car squirt from corner to corner. My guess is that is why they were installed by Shelby in the first place. As you all know, in Road Racing the engine spends 95% of its time between or in corners not winding out at or near its redline so the flexability would win out.

[ERA Chas]

Then, from Rick's experience, this should show up as superior lap times when Cliff does the testing.
Getting interesting-er!

[ERA2076]

Been reading Simon McBeath's stuff - the under carriage is a travesty and an ERA may be the worst. With ERA and it's rec tubing it should be easy to clean and accelerate air under the car. Can't help but wonder what a sheet of CF adequately fastened to the chassis would do for twist.

Look at the Shelby entered FIA's in the 64 Targa. Right idea but 5 (+?) years to early and lousy execution. Needed Hall to move the ship. Reading McBeaths study makes it apparent.

An Englishman's Cobra





On paper we should hit 155 at 7K in 4th and I believe we have what we need in power with some improved aero. We will have very good suspension, hopefully a rigid enough chassis and brakes. I watched an Audi Spyder with a V10 hit 155 at the end of the front straight at Portland over and over which I guess is around 600 yards once you are straight. I am thinking you need to carry near 80 off of the apex of 12. To watch and hear it is a lesson unto itself.

If I ever reach for 5th it will be with a very satisfying grin.

To do it at all -

with a set of Webers

Did you see this guy's areo experiment errr experience

Watch this LSR Honda Insight crash at 190 mph in the desert - Autoblog

[ERA2076]

Originally Posted by lippy

there was a vintage weber vendor at the monterey historics this year. He had one nos weber (for a ferrari) that was going for $75k (!). My kid almost picked it up and i almost... Nevermind.

..

[J.Jensen]

Very interesting build thread!

Did you ever get to compare the 4bbl and the Webers on the dyno?

[ERA2076]

Not yet, but still in the works. Ran the Mustang for the last time til next year. FIA goes back on the rack this week.

chr

[J.Jensen]

With the cam putting the power up as high as you have, whats the lowest revs you can maintain without bucking on part/minimal throttle?

[ERA2076]

Not really concerned about crawling. We are setting it up for road race and trying to build as lite as we can. I would like to be around 2300 lb full of fuel and me in it. Notice where the torque and speed is at 4600 rpm in 2nd gear. I am really concerned about throttle control and 400 rpm later it really gets interesting.

Of the three tracks we've run with a 3600 lb car and 100 hp less, I have not encountered a corner I cannot get thru at 53 mph. It takes 2nd to exit with any real haste and I use it all the time.

Depending on how well we can get it to corner, not sure it will be needed much, but 2nd is anything but foreign.

Work/Time - I expect a rocket -


chr

[J.Jensen]

I´d be expecting some fishtailing in second for sure. I´ve only been that slow on a track with street rubber - and that was a hairpin turn.

Your engine looks like what I´d want. In theory anyway. For autocross and track days, trailering it to shows and if the weather is really nice - a loud sunday trip on the backcountry roads.

But I do need to be able to get to 17-18mph (the speed limit from my house to the fun roads) without having to do a 3500rpm launch. With a 3.54 rear it would hold 2300rpm in first @ 18.

[blykins]

It would do that just fine...

[ERA2076]

Not sure I would pick this setup fir Auto-x, but I have never tried it. From what I have seen, my gut feel is I would want to move the torque down.

Brent - I had to purchase some headers for the 302. I have been toying with the idea of building a set of 3" straight pipes (just for the beauty - LOL!.)

Last night we grabbed the old side pipes and they fit the 302 headers perfectly- no modifications needed.

I am still toying with a set of straight pipes. I understand the noise problem so let's leave that to the side.

The pipes I have are from Stainless Specialties (?). The muffler section is 37" long - 3" into 4" - with some kind of baffling. At 25lb each I am looking to build something lighter, but the baffled will get me going.

A set of straights would take little fabrication. I am considering titanium tubing and I would take my chances with the noise. Portland allows 105db at track side. The loud ones run on the opposite side of the track.

I have spent a bunch of time studying this, but have found little info except optimum back pressure (could test) - and noise. There is no point in perusing if it is a really bad idea.

What kind of performance difference (penalty) would you expect between open and baffled? Any other cons (except noise).

x-chr

[J.Jensen]

Autocross would be just for fun, not to win. My biggest smiles come from hitting the perfect line on a fast track.

I´m no engine builder, but building a titanium exhaust might give some of the benefits coated exhaust has, with keeping the temp up on the exhaust gas due to its thermal properties - thus keeping gas velocity up?

[ERA2076]

Pretty much just looking at weight. If I were to build straight pipes I figured why not build them as lite as I could. I have yet to find anyone to bend them. It might be that they have to be welded pieces. I have been unable to find Ti 90's in the right thickness. It would be fun to run this engine on the dyno with both setups i.e. muffled and straight.

chr

[blykins]

Are you alive?

[ERA2076]

Ha HA - Was trying to find the guy building Jag IRS and I saw this. Yea still going. We have been buried in work so FIA got pushed to the back. We are going hard on it again. Lot's work left to do as I am still changing several systems on it. A lot of engineering research and then a lot of head banging trying to source parts.

Just finished swapping a new K member into the Mustang - we are going to run it in a couple of weeks - just have to bump steer and it is ready to go.

chr