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Re: Harv's FED thread
Posted: Sat Jul 09, 2022 12:37 pm
by Brett027
No 1 sons car is pretty speccy. Heard it coming several minutes before I saw him

Re: Harv's FED thread
Posted: Sat Jul 09, 2022 1:13 pm
by Harv
Never been under 9,000rpm. The child is hard on the gear.
No idea where he learnt that from
Cheers,
Harv
Re: Harv's FED thread
Posted: Sat Jul 09, 2022 8:19 pm
by Blacky
They look purty

Re: Harv's FED thread
Posted: Fri Jul 15, 2022 12:48 pm
by Harv
The diff is now welded out for it's brackets and anti-rotation bars, so pretty much ready to get shortened and beefed up. I best get a little more decisive about the rear-end ratio. The Toyota G-series diff has lots of ratios to choose from, so it should be interesting.
There is some guidance in How to Hook and Launch. It uses the vehicle weight, engine stroke (as an indicator of torque potential) and first gear ratio. It then lets you calculate an optimum rear-end ratio. The chassis builder estimates it will come in around 1300lb. The grey has a 3.125" stroke, and the Slide and Glide will end up with a 1.80:1 first gearset. Plugging these numbers in gives a 5.78:1 rear end. Possible (and not out of the ordinary in a dragster), but a quick check shows that the grey would be pulling 8700rpm at the traps. Suspect 8700rpm out of the old girl would soon turn it into a grenade.
I know some Group Na humpies running Repco heads regularly zing to 8000rpm. Possible in the FED, given it would only be for a few seconds at a time. That would need a 4.93:1 rear end. 7000rpm needs a 4.32 ratio. The further down I go, the less torque to start moving those 26" slicks. I'm figuring asking the diff builder for somewhere between 4.5 and 4.9:1, then seeing what crown and pinion sets he can realistically find.
Opinions, as always, welcome.
Cheers,
Harv
Re: Harv's FED thread
Posted: Fri Jul 15, 2022 1:00 pm
by BS
Hey Harv,
Are you able to send your hook and launch calcs?
Iām running 4.11s beacuase that is what is in the diff from the wreckers and I didnāt have the budget to change but with the 4 speed Toyota box itās a 3.278:1 first gear.
When discussing rear end ratios with they guys who have been doing it for years their advice to me was to work back from the finish line.
Sent from my iPhone using Tapatalk
Re: Harv's FED thread
Posted: Fri Jul 15, 2022 3:17 pm
by Harv
PM me your mobile number and I'll send some photos of the calculation.
Cheers,
Harv
Re: Harv's FED thread
Posted: Fri Jul 15, 2022 3:21 pm
by Dr Terry
BS wrote: Fri Jul 15, 2022 1:00 pm
When discussing rear end ratios with they guys who have been doing it for years their advice to me was to work back from the finish line.
Exactly right. We drag raced at Castlereagh in the early 80s & we used to calculate the rear end ratio & tyre size by aiming to go over the finish line at 1,000 rpm under our redline in top gear.
Dr Terry
Re: Harv's FED thread
Posted: Mon Jul 18, 2022 8:04 am
by Harv
Lined up some front wheels for the FED. These were originally owned by Brendon Murry in the US. Brendon is one serious competitor in top fuel (AA/FD) FED racing... 6 times world champion. The wheels then spent some time locally on a Mopar-powered FED running 155mph.
There are a bunch of IHRA requirements for wheels that I have to meet - approved racing tires only, no retreads, minimum 12ā diameter, 0.1āinch minimum diameter steel spokes, all spoke holes laced, maximum of 1ā offset front axle.
First-class pram wheels for a grey-powered FED

.

- front wheels.jpg (90.02 KiB) Viewed 1126 times
Cheers,
Harv
Re: Harv's FED thread
Posted: Mon Jul 18, 2022 9:18 am
by BS
Lots of people donāt get the whole nostalgia drag thing. Iām constantly getting comments about āwhy would you bother building something like thatā but to me the history of the parts, collecting them and the stories that come from that is what makes it fun and interesting.
Sure you could go buy a ls powered commodore, throw some giggle gas at it and run way quicker for a lot cheaper but I personally donāt see the fun in that.
I guess what Iām saying in a long round about way is cool wheels and nice history/story on them
Sent from my iPhone using Tapatalk
Re: Harv's FED thread
Posted: Mon Jul 18, 2022 11:02 am
by Blacky
BS wrote: Mon Jul 18, 2022 9:18 am
Lots of people donāt get the whole nostalgia drag thing. Iām constantly getting comments about āwhy would you bother building something like thatā but to me the history of the parts, collecting them and the stories that come from that is what makes it fun and interesting.
Sure you could go buy a ls powered commodore, throw some giggle gas at it and run way quicker for a lot cheaper but I personally donāt see the fun in that.
I guess what Iām saying in a long round about way is cool wheels and nice history/story on them
Sent from my iPhone using Tapatalk
Yup , preaching to the converted - if we weren't we wouldn't be on this forum in the first place

Re: Harv's FED thread
Posted: Sat Jul 23, 2022 11:36 am
by Harv
Some more goodies on order for the FED.
Front spindles are from Strange (S3453). These are different to a normal FB/EK in that they do not use a hub to mount the wheel... the fancy bicycle wheels just slide straight onto the spindle, like a billycart. These ones have dimensions similar to old &*#@ Anglias, and are referred to as Anglia spindles. Pretty common in dragsters and altereds, and assume they were used back in the day as they were a small, light spindle. There are alternative spindle mounts (e.g. some referred to as "Strange spindles" that are based on Camaro dimensions). I guess I could have hunted around for a set of original Anglia spindles to make this thing more authentic, but finding and then reco'ing a pair would not have been an easy task. The kids would give me that dissapointed look if I bought &*#@ parts home.

- Strange S3453 spindles.jpg (41.85 KiB) Viewed 1091 times
For the steering box, I'm using a Strange S3441S unit. These were designed off a Standard 10. Again, could have tried finding a Standard steering box, but they are like rockinghorse poo (try finding someone who even knows what a Standard was).

- Strange S3441S steering box.jpg (20.64 KiB) Viewed 1091 times
For the steering wheel, I am using a ProWerks C42-482-D. The handgrips on these are beautifully shaped, almost art-deco. It will use a Strange quick disconnect to allow the wheel to be removed (which will help get my broad backside into and out of this thing).

- Prowerks butteryfly steering wheel.jpg (9.44 KiB) Viewed 1091 times
Cheers,
Harv
Re: Harv's FED thread
Posted: Sat Jul 23, 2022 1:14 pm
by Errol62
Cool Harv. Whatās the steering wheel diameter please? Looks smallish.
FB ute fixer upper, EK van on rotisserie
Re: Harv's FED thread
Posted: Sat Jul 23, 2022 1:26 pm
by Harv

- Prowerks wheel dimensions.JPG (31.03 KiB) Viewed 1085 times
Cheers,
Harv
Re: Harv's FED thread
Posted: Sat Jul 23, 2022 6:20 pm
by Errol62
Thanks Harv
Sent from my SM-G781B using Tapatalk
Re: Harv's FED thread
Posted: Fri Aug 12, 2022 4:50 pm
by Harv
Rear brakes: VN-VS live axle disks, recoād calipers. Can probably find something lighter (read pricier), but this will do for now. The red calipers should be good for 10mph

- 152C3B36-6B1E-4623-A901-2B385D14973E.jpeg (3.44 MiB) Viewed 1042 times
Seat has been made, front axle done and front wheels in place. Fireproof suit, boots, undies and balaclava arrived, kids had a field day playing dress-up.
Cheers,
Harv