Something funny...[Nitro Funny Car build thread]
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.
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Modern Nitro Funny Car (supposedly a Mustang...)
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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).
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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 data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7... Look forward to reading more on the progress.
Really need to get my backside back up to the Pod. It's been far too long since I drove home with nitro fumes in my nostrils, tyre smoke in my hair & a big grin... This is fascinating thank you for taking the time to post!
I have one simple question, what the hell does it feel like accelerating with such force it must be difficult to comprehend until you have experienced it. One way to find out:
Santa Pod Raceway - 2 Seater Dragster There's the Flame & Thunder event in a couple of weeks, though IMO the weather's turned so it might be a washout, we were spoilt in September, so the weather needs to balance its books somehow data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7. That'll be it for the year then, resuming next Easter. SHUT UP AND TAKE MY MONEY!!! No problem at all data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7
The two seater experience that Crocodile mentioned is a good window into the quick cars (7.9 @ ~169mph generally) - not the cheapest 7 seconds of your life thoughdata:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7.
What I found in terms of how acceleration felt, was that launches feel quite sedate until you get into the low 1.1 second zone to 60ft. Shorter wheelbase cars like Altereds and Funny Cars become a different animal when they launch a tenth or so harder. Most quick cars have toe loops on their throttle pedals to help keep your foot on the pedal as they'd be pushed off it otherwise.
Often you'd find that methanol burning cars will get to the 1/8th mile every bit as quickly as their nitro equivalents, but they run out of steam and don't put on big mph in the 2nd 1/8th. A nitro car is just getting into its stride by then, as the clutch should be fully locked in and full power delivered to the rear wheels.
Deceleration tends to be where the most G-Force is applied though. It's something like minus 5G when the chutes blossom, which gets your attention, mostly because it tends to get the rear of the car airborne briefly. It's been known to cause injuries in modern Top Fuel dragster, when harnesses haven't been done up tightly enough and the hit of the chutes causes broken ribs for drivers.
The only damage I ever did relating to chutes was on my licensing run when I was a bit late on the chutes, having had a face full of oil and couldn't see where I was going. I'd run 209mph, but was at closer to 220 when I finally got the chutes out. The shutdown area was quite bumpy and it launched the car into the air. When it came back down, it cracked the body and a couple of chassis uprights tried to punch their way through the bottom tubing. The tubes were sorted and gaffa tape took care of the cracks in the body data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7. I've spent far too many cold/wet/both days on the muddy banking at the Pod for firework specials. You can't even huddle together in the warm glow of an afterburner in the barn any more! Quick update: Not a lot to report, the short block assembly is progressing. The custom grind camshaft being dialed in after the gear drive and associated bits arrived.
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Next up will be the simple assembly for the rest of the block, which is then buttoned up over the winter, as I'll be switching focus to getting the chassis together in Q1/Q1 next year. Engine wise the next thing will be getting the cylinder heads and valve train together, which is relatively straightforward, but prohibitively expensive //static.avforums.com/styles/avf/smilies/facepalm.gif. Is that a new 426 block or is the basis for this (barely) controlled explosion a forty five year old elephant engine? I'm also intrigued if any of the qualities that make the 426 a great engine on conventional fuel translate under these rather more extreme ones- ie is the 426 better than the Chrysler 440 of the same period (or Ford 429 or GM 454) or are there just more bits for the 426?