Venom Cobra Build - Page 4

stephen low · #61 (**permalink**) 10-06-2011, 09:49 PM

David

I'd be interested in seeing that brake information too.

Anything to improve braking is good in my book.

David Hodgson · #62 (**permalink**) 10-07-2011, 01:01 AM

I'll see what I can get from him.

David Hodgson · #63 (**permalink**) 10-11-2011, 04:05 PM

I managed to get hold of Chris last night re the Jag 4 to 3 pot caliper change. Turns out it was not as successful as he first thought. The main reason for the change was that in the go-whoa event we used to hold at West Wyalong, when all cars barring the DRB's ran Jag front and rear, they all demonstrated severe front brake bias. In fact some were so bad they appeared to have no rear brake at all. Chris's RMC included.
He did some calc's on pad swept area, F & R piston surface area, m/cyl surface area and proportioning valve bias. His RMC uses the plastic top ford m/cyl.
He doesn't think he still has the artcle he wrote for Snaketales as is was over 10 years ago.
Summary of changes were;
4 pot to 3 pot fronts - smaller pad(less friction) and different force acting on pistons
Different bore size m/cyl - to change applied force
Appropriate proportioning valve within the master cyl - one that did not over restrict rear brakes, from wagon or ute - he can't remember.

He found it vastley improved the bias under hard braking such as the go-whoa produces and for street driving but may have been too much rear for circuit where you may not have a choice but to brake on a bend.

Merv and Sharon · #64 (**permalink**) 10-11-2011, 04:31 PM

This sounds much the same as the Harrison set up. The rear brakes do little in standard form. There is also a previous thread on this started by Sambo I believe. What some of us have done is to fit softer pads on the rear and change to the Falcon wagon master cylinder (about $180 from Repco). It has a different F/R bias and transforms the braking, or it did so on mine for road use. See forward and back in the thread: Engineering tomorrow

stephen low · #65 (**permalink**) 10-11-2011, 08:21 PM

Changing the M/C sounds much easier than to 3 pot calipers according to Marty G at Kenmer.

Still when I get going again the one change I've have made but am yet to test was to insert a crack valve from a WB Stateman into my Ford M/C. The valve is supposed to engage the rear brakes sooner so that the braking distribution and hence performance is increased.

Bernie at Enkelmans suggested this when he passed my car for brakes but thought it could be made to brake even better.

sevenohms · #66 (**permalink**) 10-13-2011, 09:54 PM

Hi,

So after my joy at the torsional test, I got down to work on the turbo mountings. Tight fit on the drivers side, the passengers is good.

In regards to the brake performance, I have calculated the brakes from first principles, theres obviously a lot of variables to modify, but the main ones are pads and disc diameter, mc/slave sizes, the size of the tyre. One of the ones that can't be modified is how my car with a different weight split to I'd say most of the other replicas, with a Venom chassis and Ford engine, which carries and transfers its weight differently a "lightweight" Chev/302 with more of a ladder. I have the excel file if anyone wants it, its how I worked out which Wilwoods I wanted.

Modena · #67 (**permalink**) 10-14-2011, 04:30 AM

Turbos!?!?!?!?!

07cob · #68 (**permalink**) 10-14-2011, 01:44 PM

Quote:

Originally Posted by sevenohms

In regards to the brake performance, I have calculated the brakes from first principles .... I have the excel file if anyone wants it, its how I worked out which Wilwoods I wanted.

sevenohms

I would certainly be interested in your brake calculations. I will PM you my email address.

Cheers

Geof

sevenohms · #69 (**permalink**) 10-14-2011, 02:02 PM

Quote:

Originally Posted by Modena

Turbos!?!?!?!?!

Yep.

Twin T3/T4 turbos, same casing as the XR6 turbo, but smaller output (80%). Should be a wild ride!

sevenohms · #70 (**permalink**) 11-10-2011, 04:59 PM

Hi,

Update, i have build my manifolds and fitted the HEGO sensors, and fired it up last night, the youtube link is here:

Its ALIVE! - YouTube

Its running a bit off at idle, but I can hear each time it starts it gets smoother, so the ECU is working.

Zedn · #71 (**permalink**) 11-11-2011, 12:43 AM

nice work. I cant wait to fire mine up for the first time.

Looks like movember is going ok for you too.

renovationinnov · #72 (**permalink**) 11-12-2011, 10:13 PM

hey nathan just watched " it's alive " loved to see it fire up but was it with the turbos on
hopefully i can catch up to you soon
rob

Mrs flatchat · #73 (**permalink**) 11-13-2011, 02:21 AM

Sweeeeet ! crazy bastard

stephen low · #74 (**permalink**) 11-13-2011, 03:27 PM

loved the flickering blue flame as she idled

sevenohms · #75 (**permalink**) 02-28-2012, 02:47 PM

Hi All, a small update on my progress. I have been building the seatbelt mounts, which will also house the structure for the roll bars, so its pretty stout. Seats are bolted in, finished off a few little jobs, like properly bolting in the steering column, tone wheels for the ABS on the diff, brakes are functioning, building a linkage for the park brake.

sevenohms · #76 (**permalink**) 02-28-2012, 02:52 PM

Quote:

Originally Posted by renovationinnov

hey nathan just watched " it's alive " loved to see it fire up but was it with the turbos on
hopefully i can catch up to you soon
rob

No turbos in the photo, i fired it not long after the video with them on, but no video. The engine is out getting a rebuild to handle the BOOST!

sevenohms · #77 (**permalink**) 03-13-2012, 02:51 PM

Did some more engine building with my grandfather. We have sealed the engine, heads on, bottom end torqued, sump plumbed for return oil from the turbos, new bearings everywhere, upgraded head bolts.

sevenohms · #78 (**permalink**) 03-13-2012, 02:55 PM

And the Lokar handbrake is here.

sevenohms · #79 (**permalink**) 04-22-2012, 03:06 AM

Engine is back! In the chassis, turbos connected, side pipes on.

It's ALIVE no2! - YouTube

Outwest34au · #80 (**permalink**) 04-23-2012, 04:40 AM

Do those turbos really suck that much noise out? That sounds kinda quiet or is that a trick of the camera auto level thingy?