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S550 GT350R Race Car Build

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Got a report back from PAC on the broken valve spring. There was a very small inclusion in the wire — took an electron microscope to find it, but at least that means it wasn’t normal spring life:

CE7C7249-2445-40B5-8147-917EBE45E9E7.jpeg
 

TMSBOSS

Spending my pension on car parts and track fees.
There was a very small inclusion in the wire — took an electron microscope to find it,

Wow. The best part of the failure was that it did not drop the valve into the cylinder. You could have had “Inclusions” filling the pan.
 
@Tonymustang302 I believe they are no longer available. Part number is M-19515-M50
@Jet One Duane, I don't anticipate being able to measure any difference. I'm hoping it will lower temps on Cylinders #4 & #8, but any decrease there will likely increase temps on the other cylinders. Next engine teardown and Leak-down testing will tell.

Meanwhile, Got the Headers installed and got the Powertrain back in the car today:

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I'll get Watson to do the same Dyno Break-in that they did last time -- not long: 10-15 mins, followed by power pulls to get HP/Torque, then run the first track session at 80%
 
How well are you able to get the corner weights equal. No cross but at each front and rear axle?
@steveespo I didn't pay much attention, as I just wanted to get it right pre dyno and I'll fine tune with ballast, now I have the Dyno results. Last season front left was 87lb higher than right and rear left was 102lb higher than right at 50% Cross weight.

Car dyno'd up 3 rwhp peak and average rwhp after rebuild so I have to add an additional 24lb of ballast. The (much) better news is torque was WAY up (anywhere from 8-26 ft-lbs from 3,000-6,400rpm)
 

steveespo

Lord knows I'm a Voodoo Child
Moderator
@steveespo I didn't pay much attention, as I just wanted to get it right pre dyno and I'll fine tune with ballast, now I have the Dyno results. Last season front left was 87lb higher than right and rear left was 102lb higher than right at 50% Cross weight.

Car dyno'd up 3 rwhp peak and average rwhp after rebuild so I have to add an additional 24lb of ballast. The (much) better news is torque was WAY up (anywhere from 8-26 ft-lbs from 3,000-6,400rpm)
Thanks Nick, Those numbers are similar to what Ernie and I saw. He thought we could get left/right closer to equal but with my ballast on the left side no way.
Steve
 

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