Early vs late TR7 axle strength
Hello,
I'm in the process of building a Ford 302 powered GT6. I've built a new chassis from the front suspension back, and have designed it to use 4 link bars and a solid rear axle. I got a Ford 8.8 rear, shortened the housing, and had axles shortened, but came up on a roadblock in getting appropriate brakes, bolt pattern etc. I've decided to ditch the Ford axle, and use a TR7-8 axle instead. I've located one nearby, and will be going to take a look at it next weekend. It is a 1976 in a four speed car. My question is, does anyone know what sort of power that axle, and the later 5 speed axle can handle? I don't suspect that I'll be making more than 250HP, 300 tops, and I've outgrown my smokey burnout years. Any advice or links to information on the subject would be appreciated. Thank, John. |
Re: Early vs late TR7 axle strength
John
stay far away from the pre 77 rear ends they are spitfire/ gt6 axles If they survive one burn out I would be amazed In racing gt6;s in the early 60;s it wasn't until we came out with modified corvair axles that a 160hp race car finish a race. They are bad news. The 77 and later diff's are I beleve either rover or jag . |
WedgeWorks1 Mike Perkins Ellicott City, Maryland (460 posts) Registered: 07/06/2008 08:07AM Main British Car: 1980 Triumph TR8 3.5 Litre Rover V8 |
Re: Early vs late TR7 axle strength
John,
I would go back to the 8.8 Ford Rear Axle. The stock 4-Speed Banjo axle (3.27:1 or 3.73:1 ratios) is junk. It has very weak bearings and the housing lack any strength for real torque applications. The brake are tiny drums. The later 5-Speed Tube axle (3.90:1, 3.45:1 & 3.08 ratios) is sufficient up to about 250 hp but unless you buy one and have it gone through; tubes welded to the gear housing, new suspension mounts, possibly shortened, all new bearings, Quife LSD, and a new drive shaft hub. This rear have slightly larger drum brakes but not much better! The Ford is what Woody Cooper @ The Wedge Shop & Tim Lanocha @ Lanocha Racing use. Tim has a few cars of 300+ horse that the Ford 8.8 handles really well. Take the Ford rear back to the machine shop and get the GT6/Spitfire/TR7 95.25mm pattern drilled in the hubs. You can use the rear disc brakes if it has them with a larger 15+ rim or get the brake set up from a Mustang SVO and newer Mustang/Thunderbirds to put on the rear end. You can adapt the rear disc brakes to work with you emergency brake lever and rotors drilled with the lug bolt pattern. One last thing the choices for ratios are endless and cheap and its a Posi! Ford 8.8 narrowed & new TR7/8 suspension mounts Michael Edited 1 time(s). Last edit at 07/20/2008 08:17PM by WedgeWorks1. |
Re: Early vs late TR7 axle strength
Short answer....YES. If your using the factory chassis I'd strongly recommend a GM 60 degree V6. You'll save yourself a lot of engineering.
I'm a bit hard-headed, and ignored my brother's advice to go with the V6 because it wasn't as COOL as a V8. If I'd gone V6 I'd be driving the car by now. Also, look for the 60 deg for several reasons. It is more compact than the 90 degree engine, and runs with less vibration due to the firing order of a V6 being equally divisible in a 60 deg setup, but not in a 90 deg. Too much to go into here, suffice it to say that all 90 deg V6's are inherently rough, and you'd really fell that in a 2000 lb car. The GM engine was used in Camaro's, Firebirds, S10 trucks and also in earlier Jeep Cherokees'. Here's a link to a guy who did a 2.8L V6 conversion, very clean. My hat's off to him: [www.britishv8.org] Here's a pic of my chassis, it's an old pic, and I've done a lot since then, but it'll give you some idea how hardheaded I am.... |