had a lot fun at the quater mile last time but always looking to go faster I am running a 355hp sbc with a125hp nitrous system (witch wasn't full this runs - so it could be faster a little more) tranny is a th350 rear ratio is a damn long 2.56:1 (locked) and I'm running hurst slicks so would you change anything - and what??? - - the video: http://www.dropshots.com/day.php?userid=32957&cdate=20060924&ctime=111416 - - the result: 12.8@110mph with a 0.45 reakt. time -- yes yes I'm a sleeper at the line ) - - Dragrace2000 Software 2006.09.25. Rendezvényen elért kvalifikációs eredmények 6. oldal A6 Autó 5000 Special Red Bull Gyorsulási verseny Fertõszentmiklós Kategória: - ------------------------Reakt 60 feet 1/8ET 1/8 Km/h 1/4et Km/h 941 Rainer Averspers-0.4513 2.3191 8.4818 145.14 12.8113 176.96 849 Peter Brunner-----0.5627 1.9091 8.4099 134.64 12.8805 177.5 929 Franz Kreitzünger-0.3595 2.2289 9.0353 130.93 13.8420 162.61
I'd probably put a mid 3's gear in it and call it good. Seems to leave good and pull pretty strong from what I can tell from the video. I'd wear a helmet. Never can tell when something's gonna break, or somebody is gonna mess up in the other lane. But that's just me.
You need to weigh the car(massen) , tell me what the camshaft is, Duration @ 050 and flat tappet , hydraulic or roller and I will give you the proper gear ratio . That will be the biggest improvement you can make . I also need the tire diameter or height. Don
the car weights 2540 slickshave a diameter of 28" and here's the engine - - Displacement: 5.7-liter (350 c.i.d.) Engine Block: 10105123 Four Bolt Main, Cast Iron Compression Ratio: 10:1 Pistons: High silicon aluminum piston with offset pins, 10159436. Crankshaft: 12556307 Forged Steel Camshaft: Hydraulic roller tappet (#10185071) Valve Lift (Intake/Exhaust): .474/.510 Duration (Intake/Exhaust): 208°/221° @ .050 tappet lift Valve Lash (Intake/Exhaust): Zero/Zero Cylinder Heads: Aluminum, 58cc chambers, 12556463. Valve Diameter (Intake/Exhaust): 1.94/1.50 Valve Springs: LT4 chrome silicon, 12551483. Rocker Arms: 12495490 - Kit, 1.5:1 ratio, self-aligning, stamped steel, 10089648 single replacement rocker arm.
Car will et best with 3.91 Almost as good with 3.73 and within a tenth of that with 3.54s (11.58 vrs 11.47/11.48) shift point is between 5300 and 5550 whatever works best. Engine power peak is there with that cam I ran this also with your combo and got within .005 what you ran so that ist die ueberprufen for this calculation. Have fun Don Don
Sounds like Dolmetsch is gonna give you a lot better specific advice, but.... Edit: He responded while I was typing! I think the et seems high for that mph. I'm running 12.8 at just under 105 mph, and my 60 ft. times are up in the 2.10-2.20 range. That's why I think gears would be your biggest/ easiest improvement. Do you mind changing gears to go to the track? Or do you need a set that is going to be a comprimise for daily and track driving. At 110, on 28 in. tires and a 1:1 top gear 4.56's's are spinning the motor at just over 6000 rpm. I don't know how comfortable you are at running the motor up to 6500, but that would get you to 118 mph, and pull a lot harder on the slow end of the track. But 4.56's aren't going to be much fun on the highway to the track. Cruising speeds will be cut way back. I have two sets of gears. Same size tires for street tires and a set of 29" cheater slicks for the track. I have 3.55's and 4.11's. 3.55's would put you at just under 3000 and 3.73's at 3100. If I was gonna go with just one gear ratio, it would be one of these two. Okay, having said all that, I just went to look at your engine combo again. I realized that you are on the NOS. That explains why your top end is so much better than your 1/8th. Somebody can probably answer this part better, but I think you can improve the breathing of that motor. The intake lift and especially duration seem low to me. That may very well be perfect for NOS, though. I don't know anything about NOS. What brand are the heads? 58cc on a 350 seems like it would be higher than 10:1 compression, with flat top pistons. And the 1.94/1.50 valves seem small for that motor. I think 2.02/1.60 valves would really wake it up. Again, maybe it's safer to have the small valves with the NOS. But that's the main thing that I'd look into as far as making more power. If it were me, I'd change the gears and run it like that for a while. See what it does to your times and mph, and how you like it on the street. Later on, you can dig in to the motor if you still want more. You will, but it's easier to do it in steps.
thanx guys for taking the time to answer -the engine easy would make +70hp with changing the camshaft/rockers and big valve heads - but it's a zz4 engine - so the parts are not really cheap - around $2000.- (and till their are over here in austria they are twice expensive with all the taxes....) - I think changing the rear ratio would be easier - a good comprimise for autobahn/strip would be 3.23 or something like that - the only thing is, I've to change the whole carrier because there are no other ring and pinion avaidable for a 81 trans am rear end with the 2.56 -
Intake duration controls RPM a sure as if it was a limiter Extended exhaust duration can fudge it but only slightly. Most important valve event is intake closing , period. nothing happens till that takes place. You could change a lot of cams long before you would need new heads. Camshaft is essentially the engines "program" Either way you will still need to change gears. Can you not get a aftermarketgear for that from Richmond or Summit ? Funny thing, you are the second guy from Ostreich i have spoken to today. The other was 57 caddy owner Martin Grosse from Thumersbach just a few minutes ago. Of course the other was "auf deutsch" Don
First what size of tires? What width of rim? Should start out at 28 psi no less than 25 psi Very important correct rim width to tire and also very hot dry burnout to allow even heat thru tread surface. Cody
okeeay I ride em with 10 psi - but I tryd a lot - but I have better traktion now then with 15 to 20 psi my hursts are 7-1/2" wide, 28" tall,on 15" x 8" rims here you can see em here I ride the tires with around 15psi with a 2sec burn out befor -- as said the first 50feet are a big problem with traktion - but as you can see we don't have strips with a lot of rubber or glue on them
Running those air pressures is not recomended. That tire is steel belted and will fail eventually running too low of air pressure.When you run low air pressure in a steel belted tire you flex the steel until it finally will break the belts . Steel belted tires rely on weight and air to work properly. Unlike a bias non belted contemporary "wrinkle wall" drag slick Cody
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