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Rather than spamming the modified car thread, it’s probably better to lump this in its own thread…
So – after racing in Fuel Altered for a couple of years (see here), and messing around with a Nostalgia Top Fuel car prior to that, I took a few years out to recoup some of the money that was pissed down the toilet. A slight diversion back into AV meant plans changed and the return to racing was delayed. Finally I’m slowly getting back on programme, and the new race car is ever so slowly taking shape.
I’ll update this thread as things progress. Here we go…
Nostalgia Nitro Funny Car (what the f*** is that?) – warning…history lesson drivel…
In the last 15 years or so, drag racing has become financially crippling at the higher levels. As performance levels increased, as did costs. These days a big show spec Top Fuel car uses a fuel pump that flows 120 gallons per minute, a couple of 44 amp magnetos and a mutts nuts supercharger in order to make 8 - 10,000 horsepower. Bearing in mind that modern Top Fuel & Funny Car only race to 990ft these days (a safety issue after a fatality a few years ago, and the terminal speeds surpassing 335mph over the standing 1/4 mile), the cost of a run, without accounting for any damage, is around $8-10k. Destroying an engine is all too easy, and at $50-100k a piece, it soon becomes pricey.
Modern Nitro Funny Car (supposedly a Mustang...)
Nostalgia Nitro Funny Car (Plymouth Arrow & Chevrolet Camaro)
In the same way as most motorsports, the look of cars has become a little generic in recent years. Aerodynamics, efficiency and corporate sponsorship all had a part in taking away the fun and the identity from race cars. Back in the 1970’s, cars more closely resembled their road going counterparts. For most, it was the golden era for the sport. This, along with the cost implications mentioned above, meant a plan was hatched to build a nostalgia class, that recreated cars of that era, but with modern safety kit, and rules that were sympathetic to the engine technology of the period. What resulted was a class where Funny Cars look like they used to, but go quicker than the period they portray. Fuel pumps are limited to a flow of 21 gallons per minute, superchargers are limited to a 6/71 GMC style unit, driven at a maximum 18.99% overdrive. Cubic capacity is limited to 500 cubic inches.
The cars run on a blend of nitromethane and methanol. Nitromethane isn’t to be confused with nitrous oxide. As exotic fuels go, nitromethane is in its own league, and technically deemed a chemical rather than a fuel. Due to oxygen content within the fuel, less air is required to burn it, meaning 8.7 times more nitromethane can be burnt in one stroke. It’s also a high explosive, featuring more high explosive energy than TNT. The result of all this when injected into a combustion engine, is circa 3000-3500 horsepower in a rule restricted application such as this. The by-product of burning nitromethane is nitric acid vapour, hence why we wear gas masks during engine warm-ups.
As a rough guide to the ¼ mile performance figures; Elapsed times in the 5.7 – 6.0 second range, at terminal speeds of 240-260mph are expected.
Onto the car build…
The foundation of the car is a 426 Chrysler Hemi block, with its design roots dating back to the 1960’s. Rules stipulate that cylinder heads have to retain OEM architecture, so whilst the basic design cannot really deviate, the materials used, certainly can. The block is billet aluminium made by TFX, as will be the heads & crankshaft. As the rules limit the fuel pump size (21gpm @ 4k RPM) in order to maximise the volume available, it’s common to use a small capacity, higher revving engine combination. In this case, a sub 400ci build, that will rev North of 8k RPM. If the engine's turning at over 8000rpm, the cam driven fuel pump is spinning at more than 4000, hence more flow. Simples!
The maintenance regime for this combination requires the engine to be stripped down to the block after a run (pistons out, rods out etc), oil changed, spark plugs changed, possibly some rod bearings changed, and then re-assembled and fired up for the next run, in around 2 hours. This is regardless of damage incurred, as everything needs a thorough check, as everything works loose on a run, and minor damage is expected (you’ll often find aluminium shards in the oil pan regardless of doing no actual damage).
In the case of melted pistons or scuffed bores, the liners can be swapped out quickly (with some blow torch assistance).
The chassis is of chromoly steel construction, to SFI 10.5 (one step up from the required 10.1E). The chassis itself is identical to a current Nitro Funny Car chassis, the only differences being the tyre diameter and rear end gear ratio. Modern cars run a 36” tyre (17” wide) and 3.20:1 rear gear (direct drive, no transmission). Nostalgia cars run a 34.5” tyre and nothing lower than a 3.89:1 gear and a 2 speed transmission.
Bodies can be fibreglass or carbon fibre. To be honest, fibreglass R&D has progressed that much that the weight saving by using carbon fibre isn’t worth the extra outlay financially. In addition, bouncing it off the wall at North of 200mph, it’s cheaper and easier to repair glass than carbon.
I'll post some more photos when things get underway properly. At present the body is still in Philadelphia, the motor is in San Jose and the chassis is in Essex, logistical nightmare  ... |
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24-11-2019 22:32:47
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