Old track car project - new update

[mfain]

Originally Posted by Flash68

Hey Pappy, any updates on this?

Motor is finished. Just waiting on the harness for the Motec ECU so I can go to the dyno. Got the Forgeline GA3Rs (18X12 inch front/18X12.5 inch rear) and mounted a set of Hoosier 335/345 scuffs. I went with 8.5 inch backspacing on the front to get .375 inch of scrub (left a little to account for tire squirm under load), and everything cleared including the inner inside of the barrel (control arms, tie rod, sway bar, etc.) and the tire thru full suspension travel up to 30 degrees of turn. Whew. I've still got to move the firewall and motor back 5 more inches to get the dry sump pump to clear the aft pick-up point of the lower control arm. With the smaller Tilton bellhousing I will also be able to lower the motor another inch or more. I also got the Tilton 900-series pedals so I will complete their installation when I move the firewall. Still lots to do, but getting there.

Pappy

[mfain]

Jewelry......

[Vegas69]

That looks great Pappy.

I don’t know what your plan is for the water pump bypass, but I don’t see a port in the intake. I tried to run mine without it and it almost always developed an air pocket and belched out my over flow. I’m talking about each drive cycle.

[mfain]

Originally Posted by Vegas69

That looks great Pappy.

I don’t know what your plan is for the water pump bypass, but I don’t see a port in the intake. I tried to run mine without it and it almost always developed an air pocket and belched out my over flow. I’m talking about each drive cycle.

Thanks Todd,

In the past I drilled a couple of holes in the thermostat base circle and that seemed to work fine. I guess my other option is to drill and tap a hole in the face of the thermostat housing boss (below the thermostat) and add a small bypass line from there to the pump. Thanks for the observation.

Pappy

[Vegas69]

I don't think I tried that and I don't recall why, but the coolant from the factory returns to the pump under/before the t stat.

[mfain]

Decided that the C-4 Corvette based suspension was not going to be strong enough, and I wanted to get the half shafts out of the suspension business, so I took this out:



I am in the process of installing the Detroit Speed Decalink with a 3:73 Hammerhead differential. It was designed for a C-2/C-3 Corvette, but with some minor modifications it is going to fit the C-1 chassis fairly easily. Luckily the forward four-link provisions I had for the previous suspension fit perfectly (width and vertical placement with adjustment capability), so the conversion is going smoothly. I watched the DSE Corvette company car with the Decalink at last week's Goodguys autocross in Scottsdale, and I really like the way the rear was planted.









Pappy

[mfain]

Short update. The DSE Decalink install is almost complete. Even though it was designed for a C-2/C-3 Corvette, it went in the C-1 chassis fairly easily. Modified the cross member to fit the C-1 frame rails, added a front hoop to carry the front of the differential, and added 4-link-style, adjustable pick-up points for the forward links. The 345s on 12.5 inch Forgelines fit perfectly. The motor is done - just waiting to get it on the dyno.

Pappy

[WSSix]

Wow, that's awesome! Glad it's working well for you, Pappy. Good luck with it in this new year.

[rustomatic]

This looks interesting. So a C4-type suspension is also called a five-link, I think, and the DSE setup is called a "decalink," which sounds like a Bruce Jenner-style update (the Olympics version, not the modern one). It's hard to tell via DSE's site, but is there now some semblance of an upper control arm? Aside from that, it looks very similar to the C4 setup (with batwing!), which I recently learned was largely pirated from early Indy car-type setups (makes me feel better about my C4 stuff) . . .

Nice stuff!

[mfain]

Originally Posted by rustomatic

This looks interesting. So a C4-type suspension is also called a five-link, I think, and the DSE setup is called a "decalink," which sounds like a Bruce Jenner-style update (the Olympics version, not the modern one). It's hard to tell via DSE's site, but is there now some semblance of an upper control arm? Aside from that, it looks very similar to the C4 setup (with batwing!), which I recently learned was largely pirated from early Indy car-type setups (makes me feel better about my C4 stuff) . . .

Nice stuff!

It has an upper link, a lower link, a toe link, and two forward links - so you could call it a true 5-link. The axle shafts are free-floating with CV joints and are not part of the suspension like the C-4 set-up. The C-4 uses the axle shaft as the upper suspension link, but the Decalink does not. The C-4 is, therefore, a 5-link with the axle shaft serving as the fifth suspension link. I had a C-4 based rear suspension in the car earlier, but I pulled it in favor of the true 5-link (post 26 has a photo of the C-4 based system in the car). If you look carefully at the picture I posted of the DSE unit mocked up in the car (post 27) you can see the upper link. The axles are not installed in that photo. I debated going to upper and lower control arms, but I am fond of a multi-link that applies driving and braking forces through the forward links that are parallel with the car's axis - much like the old CanAm cars. The forward links also give you a much better range of anti-dive/anti-squat adjustments than control arms, and the lateral links (upper and lower) provide for a wider range of roll center adjustment. Thanks.

Pappy