[Race_Prep] Never Ending Race Car Build

[petert 588]

We've been working hard since the first round of our MRA series to improve the 205. The list of mods looks like this:

 

- fitted fully adjustable front wishbones

- moved top strut mount back for more caster

- fitted pedal box

- removed rear torsion bars

- replaced 350lb rear springs with 500lb springs

- fitted dry sump tank over LH rear wheel

- fitted full width full tank & surge tank

- fitted flex sensor and fuel lines ready for E85

 

We're hoping there will be a lot more weight over the LH rear wheel now. Previously we were at 138Kg & 189Kg, left and right rear wheels respectively.

[Kane 34]

Looking good Pete! If you don't mind me asking how have you managed to retain the arms with the TB's removed? Have you had the bars machined down so they're essentially just holding the trailing arms in place?

[petert 588]

Just the ARB with M10 bolts.

[petert 588]

Some pics.

[welshpug 1,661]

How do you stop the arms sliding side to side and wearing the seals out without the positive location provided by the torsion bars?

[blandy 29]

Love these threads plenty of inspiration there. Funny as done my camber yesterday and was wondering how people achieve move on the front and your pics answered my question lol

[petert 588]

That's approx -3.5 deg with 405 driveshafts.

[Mac Crash 78 1 Cars]

What were the corner weights over the front wheels?

[petert 588]

How do you stop the arms sliding side to side and wearing the seals out without the positive location provided by the torsion bars?

 

The axial loading on the torsion bars is only retained by two M8 double ended studs made of cheese. It's more of a moments question than a straight axial load.

 

 

305Kg L/309Kg R, giving a 47.5/52.5 diagonal split.

Edited May 18, 2016 by petert

[petert 588]

Mission accomplished. It now has a perfect 50/50 split, with driver and 35L of fuel.

 

Front 281.5/289 Kg

Rear 160.5/167.5 Kg

 

Caster +6 deg.

 

Looking forward to race day on Sunday.

[camgti 56]

Great work Pete. Have fun on Sunday, Wakefield?

[petert 588]

Yep, MRA Round 2, Sunday.

[camgti 56]

Awesome. Hope all the upgrades work well. Have you been doing leg presses to build up the muscles for the new pedel box! How did it fit? All good? Looks great in there as do the new positions of the struts.

[Kane 34]

What size or ARB are you running with the higher spring rate on the rear?

 

Is this the car your son races which blew the engine a while back? You'll have to let us know how it performs after Sundays event.

Edited May 20, 2016 by Kane

[petert 588]

Std ARB at the moment. It's just there to stop the shafts falling out. Yes, it's car that blew an engine. We've been running a mostly standard XU10J4 since while we build a new engine(s).

[JeffR 51]

Good luck tomorrow Peter. Hope the upgrades work well.

[petert 588]

Not as good as we'd hoped, but drove it back on the trailer at the end of the day (which is always good). We battled with the fine tuning of the new pedal box in practice and the first two races, then started to get it moving in the final race. Parry cleaned us up well and truly, along with most of the >2L cars.

 

John with his 2015 MRA Outright trophy and Parry with his 2nd place trophies.

Edited May 22, 2016 by petert

[camgti 56]

How did it feel to drive with the bew geo settings?

[JeffR 51]

Niggling issues can be a PITA on race day. Do any of the NSW tracks have the equivalent of Winton's Test & Tune Fridays? I find it handy when major changes have taken place.

Good thing as said-you could drive it back onto the trailer though.

[petert 588]

Yes, Wakefield has similar days. Eastern Creek too but considerably more expensive.

 

Car is easier to drive and do consistent times.

[petert 588]

A big thanks to Allan @ Bridgecraft for these fantastic rear arms.

[wicked 103 3 Cars]

Nice wheels!!

[petert 588]

Over the past 12 months I've slowly been gathering parts to build a new engine. I was fortunate enough to pick up two sets of pistons, so I thought I'd build two. Here's the first part of Engine B, as it will be known. These are pistons I purchased from JeffR. Wisco incorrectly machined the pin location, thus the piston pockets were effectively reversed. I needed the pockets deeper anyway, so I set about building a jig to hold a piston at 26º. During a quick dry assembly, I projected the centres for the valves onto the piston with a 7mm drill blank, inserted into the valve guides. I then made two programs for the CNC mill to re-cut the inlet and exhaust pockets respectively. I was surprised how far out the exhaust pockets were. It would have been fatal to use the piston as supplied. I wanted the pockets deep enough so they could be used with my best head, which is going on Engine A. So I gave up a bit of compression in the interests of compatibility.

[JeffR 51]

Would the exhaust valves still have fitted into the piston pockets or was it that they're at a 24° inclination hence the discrepancy?

[petert 588]

No, the centre was wrong, thus they would have collided on the side of the pocket. I was slack and made both sides 26 degs. I figured a steeper cut on the exhaust wouldn't matter.