how quick??

A

Anonymous

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new to the site but Ive gotta ask the question.
What quater miles are you guys pulling?

I've gotta TE Cortina thats having an engine rebuilt. Quick run down includes ported heads, 10.5:1 comp extractors 4bbl manifold with 650 holley, 200 long rods balanced 250 crank and cam that lifts approx 0.510. car runs a 4spd manual with a mini spooled 3.8:1 diff and McCreary rubber. Figure it should do somewhere in the 14sec mark.

Whats the best Nat. Aspirated time you have seen/pulled?
Whats the best Forced inducted(includes Nitrous) time you have seen/pulled?

Ill trust you to be honest my corty would pull 8s if I lied too.
 
My 4156 cc 250 gas XE Falcon does 16s flat at 140 km/h. But it was two up with 67 liters of propane. And that was done on the first 400 meters at the flat Info 2000 test strip in Dunedin, which is about 15 meters above sea level. I haven't any timeslips from Oamaru, Lawrance, Teratonga, or Levels where real drag racers hang down here. I'm scared I'm gonna snap my glass case BW 35! Just for interest, I 've calculated the power to be 130 kw (174 hp) at the flywheel, and have a dyno run showing 350Nm (258 lb-ft) at 2600 rpm. Theres some info beneath if you can handle it. :shock: :shock: :shock: :shock: :shock: :shock:

The car weighes 1635 kgs all up with two people and a full tank of gas.
Using the formuae:-

total start line weight with fuel and driver(1635 kgs) divided by net kW at flywheel ( dunno, but guessed to be 130 Kw) , all multiplied by 325, and then raised by the power of 1/3, gives the quarter mile time in seconds.

ie 1635/130 gives 12.58 kg per kw weight to power...that gets multiplied by 325, the constant for a big car with big torque, which gives me 4088.5. Then that gets raised by the power of 1/3...which gives 15.99, which is almost 16 seconds that I got. So 130 kw seems true enough!


Specs are:-

1. NZ Heatseaker extractor,
2. stock 47mm internal diameter exhast (yes,its gotta go, next on my list)
3. Stock Weber ADM relieved and gas flowed for #2300 4412 500 Holley 2-bbl throttle body on a Redline adaptor. 12 mm spacer plate to port mismatch the intake manifold and give enough space for the Holley.
4. Custom 2.375 inch tall alloy adaptor with top part 95 mm ID, faired into two 42.8 mm holes for the two Holley throttle buterflies. This hookes to a Impco CA 300 LPG carb and L-series convetor. Throttle link is VG Valiant Auto. Air cleaner is K&N and is open in the stock Impco carrier.
5. Runs 30 thou over ACL 4.1 pistons. Compression is 10.2 :1
6. Cam is previous owners Heatseeker HS 100 with 438 thou lft, and 253 duration.
7. Head is stock XE carby
8. Diff, trans, and crank all stock as a rock 4.1 XE GL
9. Dissy is set at 9 degrees, no change from stock at all. They didn't carry a lot of total advance.
10. Dyno tune at Auto Tune and Electrical gave it rear wheel torque of 1056Nm at 2600 rpm in second ( three point average reading).After dividing it by the 1.45 *2.77 overall gearing in that gear, and multiplying 1.33 for drive train looses, that's 350 Nm or 258 lb-ft! Pretty close to a multi point 4litre Cammer!
 
Thats not bad from a bit of a stocker in a falcon. The stock injected XE 6 in my corty wet 15 flat at 78MPH hitting full revs top gear 3/4 track (diff gears a bit low) Before it was pulled out to build a bit of a hottie!! you seem to be right on the money according to your calculator.
 
Down south, even further South than Dunedin, where the nights are cold and the sheep are scared, there is an Injected TE Aussie Cortina my friend owns. It was a stock Cortina 4 until the 4.1 XE EFI engine got put into it. The thing is stock as, and has a 5-speed Hilux trans in it. It sure is fun to drive. He doesn't drag it, but its engineer approved and weighes only 1245 kgs.

If a stock 4speed emmisionised Cortina 4.1 carby did 17.2 second quarters, then I'm quite sure his would get down into the low 16 second range. We don't have to run EGR or anti-pollution gear in the Shakey Isles.

Even Oz EFI XF Falcons, weighing 1480 kg's or more, did low 16.4's with a 120 kW 4.1 two up with a full tank. Only reson my XE does 16's is because its almost 50 kilos lighter, runs non emmision gear, and has a better intake, cam and exhast. My friends Cortina out drags it.
 
My quatrter junior says your XE is developing around 200bhp!
With the times and mass you gave.
So well done id say.
A7M
PS 221s dont have steel cranks LOL
 
ok i did a rough 400m close(within 10- 15m). took off slow(otherwise she wheel spins above2500rpm) i had my mate 80kg's a tank with3/4 and original rear suspension (really soft & old) and managed 15.8 and was hiting close to 5000rpm in fourth
 
Ah, XT's are nice and light, and are lovely machines. The first XT I saw was a 221 cid Falcon 600 Wagon that took this four year old to kindy! Never been the same since!

If you run with the stock XT BW 78 3.5: 1 gears, and a four speed with 245/50 14's, you'd get 158 km/h at 5000 rpm! Wow! Even if your car is only 1300 kg at the kerb, which it is likely if its a hot six, then you've got serious power there!

I run 2.77:1, 245/60 14's, and hit 4200 rpm at 140 km/h at the end.

aussie7mains says

My quatrter junior says your XE is developing around 200bhp!
Click to expand...

Can't see how my thing does 200 ponies. Sounds like a vacuum cleaner!

Can aussie7mains or somebody with one of those programs check out these? All figures by Lietz Correviet by Wheels, measured both ways, using two up (100 kg per person, and 68 liters of gas). I've added just 200 kg. May have been more during the tests

1. If a kerb 1480 kg 161 hp XF EFI Falcon S 4-speed does 16.4 seconds, then what does the quarter junoir say it has? All up test weight was 1680 kg (3704 lb)

2. If a kerb 1529 kg 220 hp EB S-XR6 Falcon 5-speed does 15.2 seconds, then what does the quarter junior say it has? All up test weight was 1729 kg (3812 lb )

3. If a kerb 1480 kg 186 hp EA SVO 3.9 Falcon 3-speed auto does 15.8 seconds, then what does the quarter junior say it has? All up weight was 1680 kg (3704 lb)
 
My TF was good for 14.1 all day. Good cam and holly combo with some mild head work on a 250 alloy Xflow. A mate with a TE is working on the 12's at the moment with triples and street tyres.
 
my rear gears are 3.23 and i run 225/65 r14 and i have a w55 supra box 3.55 first gear. what sort of power am i looking at having?
 
I used the formula used earlier (above). Answer is you've much more than 150 hp net at the flywheel 5000 rpm in 4th is 185 km/h, enough to do a 12 second quarter. Perhaps yer rev counter is out, or you got such bad wheel spin that the 450 odd hp that your not telling us about is having trouble getting through!!!!! :rolflmao:

Here are the calcs to you can see if I'm a bulls**ter or not!

Calcs:-

my rear gears are 3.23 and i run 225/65 r14 and i have a w55 supra box 3.55 first gear. what sort of power am i looking at having?
Click to expand...


(not by any of the formulas given in other books, this one is based on factual info from all reputable British car mags from 1970 until 1990, it allows for the reduction in tyre diameter due to wheel load which can be 4% on a Mini, to 2% or less on a large car with big tyres)

The fourth gear is 1:1, so Km/h at 5000 rpm is worked out this way


225*0.65+225*0.65+(14*25.4)= unloaded tyre height of 648.1 mm with full tread. Take off 2.2% for crush. Its a radial, how can the tyre balloon at 150 km/h? Actual loaded diameter is 634.1 mm.

Divide by 1000 to get meters, multiply by 60 to get the units (revs) into hours, and multiply by pi (3.1416) and divide by 3.23:1 (diff ratio) to get km/h in a 1:1 fourth gear.

Answer is 37.0 km/h in fourth per each 1000 rpm.
At 5000 rpm, that's 185 km/h
Ist is 10.4 km/h per 1000 rpm.

A 15.8 second quarter mile needs a minimum of 112 kw (150 hp) at the flywheel if an XT Falcon is 1320 kg ar the kerb, has 80 kg for one driver, and 3/4 of a 77 litre tank is 77*0.75*0.75=43 kgs. All up 1363 kgs.

The terminal speed for that is around 143 km/h.

For gearing to be optimised, car must haul through the traps at an rpm reading 10% above the point where maximum power is reached.

In most six cylinder 250 Falcons, red line can't exceed 5400 rpm, or sump surge, crank vibration and piston speed start causing problems. In most cases, a cammed 250 with more than 280 degrees of cam and a good head/carb will do 160 kw(215hp) at 4900 or less. A Falcon 250 engine can hit 112 kw at 3800 rpm, and 4200 rpm is the best change up point. So a flat 15.8 could be done with only a 3.5:1 diff ratio giving 34 km/h per 1000 rpm and only 112 kw!

Quarter Junior:-

The quarter Junior seems to over estimate things, saying you'd need 172 hp at the flywheel. With 3.23:1 gears, it'd be doing 3860 rpm through the traps in fourth.

For an XF EFI Falcon S 4-speed , thats 188 hp

an EB S-XR6 Falcon 5-speed 252 hp

an EA SVO 3.9 Falcon 3-speed, 214 hp
 
ok it wasn't right on 5000 but it was above 4200 and under 5000. the car is going so fast i didn't get a good look as i had to slow down quick but it felt as if it was neally maxing out and that i would need to change to 5th. i am sure i don't have 450hp and there is no way i could do a 12, i reckon low 14 is the most i will get. also does anyone now of any good dyno tunning places in brisbane ipswhich areas as my car is running really rough and i need the carb tunned and see what power she really makes. when is willobank open for street cars and how much is it? i wouldn't mind a actual print out of the 1/4 time. thanks Aaron
 
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