C3 Race Car Build

[Oneball]

Oneball - perhaps explain the rationale of going with diff cooling on your Vette for us mere mortals?

They just get hot. You’re either on or off the power in a race unlike on the road where you’re mostly coasting. Some road cars have diff coolers but most don’t.

The majority of heat is generated by the CWP interface and running a bit lower means less air too. In James Garner’s AIR’s first outing with their L88s they all dropped out with cooked diffs.

Look at a C2 Grandsport or a race E-Type and you’ll see a vent in the bootlid that’s for a diff cooler.

20mins races should be ok but any longer are apparently an issue. Too hot and wear increases and performance decrease. The back lash you put into a diff is to allow thermal expansion. The cooler pump will be switchable haven’t decided how to do that yet.

 

[Oneball]

That's an impressive engagement pattern you have there! As I said, not such great memories for me - or should I say my long suffering "diff guy"!

I know, I was pretty impressed with that!

The crush sleeve takes a lot of force to crush. I reckon I had a 6ft bar on it.

 

[Daytona Vette]

Oneball - perhaps explain the rationale of going with diff cooling on your Vette for us mere mortals?

What I want to know is where will the Cooler sit, below decks with ducting or above the bodywork, latter may not be within the Regs -?

 

[Roscobbc]

They just get hot. You’re either on or off the power in a race unlike on the road where you’re mostly coasting. Some road cars have diff coolers but most don’t.

The majority of heat is generated by the CWP interface and running a bit lower means less air too. In James Garner’s AIR’s first outing with their L88s they all dropped out with cooked diffs.

Look at a C2 Grandsport or a race E-Type and you’ll see a vent in the bootlid that’s for a diff cooler.

20mins races should be ok but any longer are apparently an issue. Too hot and wear increases and performance decrease. The back lash you put into a diff is to allow thermal expansion. The cooler pump will be switchable haven’t decided how to do that yet.

View attachment 6733

An interesting (and logical) reply Oneball - thanks for explanation!

 

[Oneball]

What I want to know is where will the Cooler sit, below decks with ducting or above the bodywork, latter may not be within the Regs -?

Just hung below the fuel tank, you can get fans if needed. Some people vent through the numbeplate recess but I’ll have a number plate there.

 

[Oneball]

Diff assembled.



And bolted in.



Major garage tidy after work tomorrow I think.

 

[Nick B]

I could eat my dinner off of that diff, looks brand new!

 

[Oneball]

I could eat my dinner off of that diff, looks brand new!

We like shiny

A while ago someone asked why I’d cut a hole in the boot/parcelshelf floor

 

[Daytona Vette]

Diff assembled.
View attachment 6734
View attachment 6735

And bolted in.

View attachment 6736

Major garage tidy after work tomorrow I think.

Looking Good Tim
UJs what do you use - is there a better quality / heavy duty ? - I may be in the market for some and beg your experience.

 

[Daytona Vette]

Just hung below the fuel tank, you can get fans if needed. Some people vent through the numbeplate recess but I’ll have a number plate there.

Thank you - Now I have been questioning - Oil Cooler for Engine, Oil Cooler for Diff, but I have never heard of a Cooler for the Gearbox which again in racing would be on and off with the stress loading - why no Cooler for a Gearbox?

 

[Oneball]

Looking Good Tim
UJs what do you use - is there a better quality / heavy duty ? - I may be in the market for some and beg your experience.

Id suggest using genuine Spicer ones, the sealed type without the grease nipple are supposed to be stronger. The only way to increase strength beyond that is to go up in size but that means new shafts etc.

I don’t have any experience of Corvettes though, so don’t think I’m an expert!

 

[Daytona Vette]

Id suggest using genuine Spicer ones, the sealed type without the grease nipple are supposed to be stronger. The only way to increase strength beyond that is to go up in size but that means new shafts etc.

I don’t have any experience of Corvettes though, so don’t think I’m an expert!

Cheers for your advice

 

[Oneball]

Thank you - Now I have been questioning - Oil Cooler for Engine, Oil Cooler for Diff, but I have never heard of a Cooler for the Gearbox which again in racing would be on and off with the stress loading - why no Cooler for a Gearbox?

You do get gearbox oil coolers and some people do run them on Corvettes but they weren’t homologated so no good for me.

Most modern race cars run a gearbox oil cooler and usually have a internal pump but you can do the same as I am with the diff and have an external pump.

Autos almost always have a cooler as the torque converter gives the fluid a hard time.

 

[Oneball]

Cheers for your advice

PS they’re sized 1310,1350 etc. They’re set sizes so if you need a 1310 any 1310 will fit.

 

[Daytona Vette]

You do get gearbox oil coolers and some people do run them on Corvettes but they weren’t homologated so no good for me.

Most modern race cars run a gearbox oil cooler and usually have a internal pump but you can do the same as I am with the diff and have an external pump.

Autos almost always have a cooler as the torque converter gives the fluid a hard time.

Yes Auto Boxes have them of course and now I know Manuals can as well, thank you

 

[Daytona Vette]

PS they’re sized 1310,1350 etc. They’re set sizes so if you need a 1310 any 1310 will fit.

cheers

 

[Oneball]

Properly bad week with the Vette and am getting worried it’s jinxed, which is not good for a race car. Need a new crank for the engine, doors are bleeding oil through the skin where the locks have been greased over the years.

Diff and suspension in but for some reason too much play in the stub axles.




So diff apart to rectify



Then go to put the spring on and the top leaf has been made too big with a sharp edge where it narrows so stripped all four bolts as I took up the tension. Fortunately I realised something wasn’t right before the bolts buggered the threads in the diff.

 

[CrispyCleen]

i wish my trailing arms looked as tidy as that. Did you add extra weld to the seams or is that a reinforced version?

 

[Nick B]

Properly bad week with the Vette and am getting worried it’s jinxed, which is not good for a race car. Need a new crank for the engine, doors are bleeding oil through the skin where the locks have been greased over the years.

Diff and suspension in but for some reason too much play in the stub axles.

View attachment 6747
View attachment 6748

So diff apart to rectify

View attachment 6749

Then go to put the spring on and the top leaf has been made too big with a sharp edge where it narrows so stripped all four bolts as I took up the tension. Fortunately I realised something wasn’t right before the bolts buggered the threads in the diff.

View attachment 6750

View attachment 6751

Bad times!

 

[Oneball]

i wish my trailing arms looked as tidy as that. Did you add extra weld to the seams or is that a reinforced version?

They’re new arms that have been seam welded and had a reinforcement welded along the top, along with stronger axles and half shafts.