Bradan twin turbo 355 build.

Just out of curiosity... what will adding a turbo do to the exhaust note of the car, which has long been one of the defining characteristics of the 355? Are you expecting there to be little difference, taking steps to minimise any impact in that regard, or anticipating an alternative aural quality for the car?

All the best,
Andrew.

 

Neat - if at all possible, it'd be very interesting to get a side-by-side noise comparison of the Braden 355 Turbo with a stock 355.

All the best,
Andrew.

 

Any reason for the stiffer valve springs? Only reason I ask is that the stockers can handle 9-10k rpm, do you plan to spin it higher? Are you going aftermarket cams or do you plan to widen the lobe separation at all to suit the boosted application? This is definitely an interesting project. Not my cup of tea but I can appreciate the engineering.

 

Boost doesn't have too much to do with needing more valvespring pressure. Approaching IVC, intake manifold pressure and cylinder pressure should be near equalized and as soon as IVC occurs you start the compression cycle.

So, pressures on the intake side effect valvetrain stability to a small degree but where stock valvesprings become a real problem on a turbo motor is EVC. When the exhaust valve tries to close against all of the exhaust backpressure (which on a responsive street based system can typically be 2x intake manifold pressure) it can bounce on the seat causing power to drop dramatically.

As for the cam timing, widening the LSA would likely just reduce horsepower (from the tests I've done). Just like dropping the compression ratio

 

I saw a pretty trick setup in a Caddi SVT. They had three different tanks. The regular gas tank, then a custom tank that held E85 in the trunk, and another smaller tank in the spare tire space for methanol.

 

Cool, good info. The reason I ask is I thought that overlap wasn't great for boosted motors, and the stock Ferrari valve timing has a pretty tight lobe separation and a decent amount of overlap. Granted, everything I know about boosted applications is on low rpm pushrod v8's so things may work a lot differently.

 

Many say that overlap is not good on a boosted engine and I once thought the same. My experience is with American V8's (many street cars and some approaching 1800hp/8500+rpm). I've tried several reverse split and wide LSA cams and from my testing, within reason overlap=power and the best turbo cams have very similar specs to what you would use on a naturally aspirated car. Any time I made no changes to a combination but reducing overlap with a wider LSA, power would drop. (and that is even with combinations that had more than 2-1 exhaust to boost pressure)

 

I'll get another F355 when this project completes. One of the most beautiful Ferrari's ever but could use a little more oomph!

$50K without a core? Seems pretty reasonable to me for a zero timed engine...

 

Apparently there isn't a lot of E85 in NJ stations - hopefully by the time this build is done there will be.

Erik

 

Inconel? For the love of God. We used monel and inconel in the primary systems of the nuke plant I worked at. Big $. What am I getting myself in to?! It would be cheaper to be a crack addict!

 

Yes it would. But you can't drive a crack pipe.

Not that I've heard anyway.

 

Well, the user might think they're driving the crack pipe.

I reckon this car would be a lot more fun though.

All the best,
Andrew.

 

Several valve train experts would state that both sides need attention. Many times however the stock springs are adequate when factoring in the additional boost. A plan for stiffer springs makes a lot of sense.

He's gonna need some serious injectors to keep up with e85 under boost.

Mark

 

Not a big fan of kevlar clutches, glaze them once and they are done. However, much cheaper way to hold the power when compared to a dual disc setup and much more street friendly than a super stiff pressure plate. So many different trade offs.

I am sure that you made the best comprise for your application. How much torque is that sucker rated for?

 

This project looks like a train wreck just waiting to happen. It will work, but for how long is the question?

 

Good work Braden...can't wait to see it finished.

 

I'm curious....What are you basing this on?

 

Hmmmm...
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I would have thought the same thing if I didn't know that Bradan is one of the best Ferrari shops in the U.S.

They know what they are doing.