95 Berlinetta weight reduction and modifications.

Was this after the dyno? Reason I ask is your dyno cutoff is same rpm as stock and Felix was unable to raise my rev limiter. Would like to shift mine at 9k so if you can ask Felix to burn you another set I'm in your debt

 

Not sure why I keep posting anything as this is another round of don't do what I do.

Thought I noticed some wheel bearing noise when I drove the car to dyno it, so I took it apart and found the wheel bearing grease was dried up solid.

Cleaned everything with solvent and re-assembled with swepco 101. Are there better options? Maybe but that's what I found and used. No visible wear on anything and super smooth after reassembly so seems good for now.

I had installed lightweight inner cv joints from superformance which were trash and binding. Absolutely nothing machined correctly, total junk. My original inner cv's were no good also.

The F355 cv axle shaft is solid steel which is rather heavy so I tried to order gun drilled shafts but didn't work out so tried to find oem hollow shafts.

Figured out 360 modena shafts are hollow and much lighter but also 29mm shorter.

Ended up putting it back together and re-greasing everything with the 360 hollow shafts and 29mm aluminum spacers with titanium inner cv bolts and titanium outer cv nut.

Had to cut the crimped outer cv shield to remove it/disassemble outer cv's.

Has an o-ring seal. I drilled through it into the outer cv housing to re-assemble with small fasteners.

In the end, saved 2.3lbs per side.

Then of course the inner cv heat shields were too short. I had superformance carbon fiber shields and I used those along with making aluminum brackets 29mm longer and attaching with solid rivets. Saved half a pound or so.

Original brake rotors are rather heavy for their size. You can buy front Girodisc. They would not make rears to match. Soooo, I used some parts from Wilwood to make some stock rotor replacements with aluminum hats. Had to drill the hats for F355 bolt pattern and re-arc the parking brake discs for slightly smaller rear hat diameter. Just saying what I did and trust when I say you don't want to do it.

The brake rotors resulted in a 24lb weight reduction.

Next thing I want to address is the wheels. They are heavier than I expected. (stock wheels). Front with tire- 44lb Rear with tire- 51.5lb.

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Those are the wheel bearings. All of them (front and rear) were dried up like that.

 

Awful video I know. Just made a quick bracket to mount my phone to check bypass operation and I guess it was a bit flexible.

It was sunny and 50 but still too cold for good traction really so it spins in first and hits the limiter. (from a roll)

I welded a threaded boss to the bypass valve so I can adjust the closing position. (I wanted idle/cruise slightly louder)

 

Thanks guys. I've been enjoying the car so much I think the other ones are getting jealous. Every time I go to the garage with intentions of driving something else I just keep grabbing the F355. Not sure if my underdrive/bigger power steering pulley would even change anything (I wouldn't think so) but even with all the weight reduction the steering feels great to me. No longer have any ambitions of modifying that.

A while back I added a Setrab trans cooler part number ‎50-113-7612. Used the stock trans cooler lines and banjo bolts but needed adapters to match the thread which are ‎Setrab 22-M22M16

(and made a small aluminum shroud for airflow)

Also was going to repaint the silver on the plenums and center part but liked the black look after sanding it off so just wet sanded and polished that surface.

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Correct offset yes. Rears were blank so I drilled the rotor bolt pattern. Had to re-drill the fronts. Re-arc parking brake shoes and clearance things to fit. Add hub centric rings and machine to correct depth.

I'm obsessively chasing weight reduction so that's why I did it. Don't recommend it to anyone else but it is working great including the parking brake.

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I tapped in some vacuum/pressure gauges to see how things were working. 1 testing exhaust backpressure. 2 going to a throttle body on each bank, the last going to crankcase pressure (valve covers)

At high rpm-

It pulls a slight vacuum on the crankcase so that's perfect.

Just barely comes into a tiny bit of vacuum at high rpm on the throttle bodies. Maybe slight room for improvement with larger blades.

Exhaust however, I'm seeing over 2psi backpressure at mid and high rpm.

If you recall I made the muffler from a C5 z06 titanium system and thought the tubing sizes would be ok as that car is rated at 405hp but apparently not.

I'm removing the muffler tonight to cut it apart and revise with larger tubing.

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Original configuration vs revised.

The tailpipe pieces were 1.75 od but seem a bit crush bent as there were some sections that measured as small as 1.7 x 1.5 od.

The two primary inlets went into 2" diameter perforated sections.

The two primary outlets had 1.75 perforated sections.

The bypass section terminated into two 1.75 tubes.

I gutted the muffler and changed it to-

2.4" primary inlets with no perforated sections and offset internally.

I moved the 2" perforated sections to the primary outlets.

All four outlets changed from 1.75" to 2".

I'll test again on the dyno to see if there is any improvement.

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Not sure if my wife would agree it's a wise use of time but I'm glad that things are turning out well as a result of my obsession.

Before this latest round of modifications the car made 340rwhp and 250rwtq. At that time it was 2,980 lbs and ran 12.4 @ 116.8mph in the 1/4 at the dragstrip.


Most recent dyno was 372rwhp and 246rwtq. Based on how it feels with revising the muffler I would guess it will do slightly better than that but need to get it on the dyno to verify.

Current weight is 2,835lbs.

With an additional 32 rwhp and 145lb weight loss I think it should break 120mph in the 1/4 mile. I will bring it to confirm.

 

I did another small change. Not sure if it will help or not but noticed that the tube in the top airbox was slightly smaller than the maf and because the screens were removed from the maf there was a step in the transition from airbox to maf.

After the maf was the corrugated tubes of course.

I ported the air box tube to slightly larger inner diameter than the maf. Took a long time to do accurately as there isn't much material to work with.

Then used a carbon tube to make an insert to fill the step transition from airbox to maf.

Used same carbon tube to connect maf to plenums. (end pieces are just cut off the original corrugated connectors). Original clamps at maf and plenum. Stainless wire at carbon tube connections.
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