Guest bastaad525 Posted November 25, 2003 Share Posted November 25, 2003 Bear with me... these are totally stupid, useless questions. And I'm bored, so I figure... why not For these questions, let's just assume that the 'car in question' is running just some normal every day street tires, nothing too fancy or sticky. Well... here goes: 1. Approximately how much hp/torque at the wheels does a car need to make, to be able to break the tires loose at will in first gear? From a stop? From a rolling (like 5mph) start? How about moving at like 15-20mph? 2. How much hp/torque would you need to be able to do this in second gear at speed? 3rd gear? 4th? 3. How much hp/torque would it take to be able to chirp the tires in 3rd gear. 4th? 4. Does differential or tranny gearing affect your hp/torque numbers when you are on a dyno? Would a 3.9 get you a higher dyno # than a 3.54? 5. How much HP/torque would a stock bodied Z (240) need to hit 150mph? 160mph? 6. How fast would a stock bodied Z with the stock front end need to go to lift the front tires off the ground? Hmmm... okay I think that's it for now... I may add some more later Quote Link to comment Share on other sites More sharing options...
Tim240z Posted November 25, 2003 Share Posted November 25, 2003 Well, I CAN tell you that a 1000hp TTV6 RX7 can break loose 335/35s at will at any speed in any one of the 6 ZF gears . It's especially fun at 75 MPH laying 2 black lines on the freeway (with a professional driver behind the wheel...my Dad). Tim Quote Link to comment Share on other sites More sharing options...
Guest ON3GO Posted November 25, 2003 Share Posted November 25, 2003 well i can chime in abit. my dads stock Z06 can chirp the tires HARD in 3rd. my boys Supra can roast his 315's in 3rd and chirp 4th hard as hell.. he has 658rwhp. my friends bone stock S2000 can chirp/spin the tires in 1st when Vtec kicks in... which is pretty cool. my other friends modded S2000 can really do it much better and roast the tires in 2nd. um i think thats it for me.. mike Quote Link to comment Share on other sites More sharing options...
z-REX Posted November 25, 2003 Share Posted November 25, 2003 even my 3200lb. saab 9000 turbo can rip third if i powershift and keep the revs up. that's around 200hp stock, damned if i know about the torque # but it is a 2.3 liter four, so take it from there. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted November 25, 2003 Share Posted November 25, 2003 ON3GO - okay that sux... I KNOW I'm making more torque at the wheels than a stock S2000, and pretty darn close HP wise I would think... and I can only get them to break loose in first when the turbo comes on, maybe 50% of the time. I was so sure that after doing the turbo swap and upping the boost that I'd be able to spin them all day long in first by just thinking about it. Another thing I dont get... with my N/A motor, which made 170hp and 170ftlbs at the wheels, I could easily chirp 2nd, 3rd, and sometimes even 4th! It was also extremely easy to do even a soft launch... 2000rpm and dump the clutch, and have the tires spin all the way thru first gear. Now, that motor ran thru a '75 5spd (really short 1st and 2nd gear) and a 3.9 diff. I know my turbo has got to be making more power and torque than the N/A, at 10psi, yet I am lucky if I can get it to chirp 2nd. This is with the same hard grabbing ACT 6puck clutch. It doesn't feel like it's bogging between shifts or anything... just doesn't hit hard either. That's part of why I asked that particular question... I"m again starting to wonder if my car is sick. I have heard from a couple people how the new Neon SRT-4's, which have like 220hp and around 250ft lbs of torque, have no problem breaking the tires loose even in 2nd, going straight. Anyways... dont let that side track anyone, I'm still curious about all the things I originally asked Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted November 25, 2003 Share Posted November 25, 2003 even my 3200lb. saab 9000 turbo can rip third if i powershift and keep the revs up. that's around 200hp stock, damned if i know about the torque # but it is a 2.3 liter four, so take it from there. I've been very tempted to powershift in this car but have been scared to break anything... I used to do it alot in my N/A and yeah I could get a lotta chirp in 2nd and 3rd. I must be losing a lot of boost between shifts.... it seems to come back up quickly enough and I am running a BOV. Quote Link to comment Share on other sites More sharing options...
Guest ON3GO Posted November 25, 2003 Share Posted November 25, 2003 dude its easy to break the tires loose in a FWD car... dude are you even launching in the Z? your boost should drop off between shifts, tipical of a turbo car if ur not taken ur foot off the gas between shifts. also what kind if tires are you running? you have LSD? you could have a boost leak.. you have a boost gauge? is it reading fine? does it taper off at higher rpms? im sure yur car is fine man.. mike Quote Link to comment Share on other sites More sharing options...
john kosmatka Posted November 25, 2003 Share Posted November 25, 2003 My dads saab 9000 aero can roast the tires in first and second. In first the tires will break loose around 10 mph when the boost comes on. Quote Link to comment Share on other sites More sharing options...
z-REX Posted November 25, 2003 Share Posted November 25, 2003 9000's are wild! but it seems to me that a lighter rwd turbo car should have a much easier time breaking loose than my car. maybe the boost and gear ratios aren't playing nice? could be geared too tall for low-end smoke shows? just throwing out ideas, but me being psychotic i'd try powershifting myself, hell i do it in the saab and they're not exactly made for that, but johan hasn't protested yet!!! 8) Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted November 25, 2003 Share Posted November 25, 2003 john k. - mine will do the same SOME times, not all the time. ON3GO - If I do a clutch dump launch the tires spin for like 1/2 second and the car bogs bad. If I do slip clutch launch, keeping the revs aroudn 2500-3000rpm, then when the boost comes I'll either screw up and not let the clutch out the rest of the way fast enough, the clutch will slip bad and the revs will jump way fast. If I let the clutch out right, then the tires will spin a bit, and usually chirp going into second. My tires are cheap, hard, $25 tires, with like NO grip, so they should break loose easier, I would think. No LSD. I've wondered about the boost leak thing... I know that the sound of air that comes out of the engine bay when I'm on boost sure sounds like a leak sometimes, but the other signs I'd expect to see, like rich running, or loss of power, aren't there. Boost gauge reads fine at 10psi by 2600rpm, and holds steady, no falling off even up to 6k. I'm running a '75 intake manifold so there's really not many places it could leak from and all I've checked have seemed fine. Damn but it is noisy when boost comes on.... whoooooooooooooosh! dont forget the other questions guys! Quote Link to comment Share on other sites More sharing options...
zguy95135 Posted November 25, 2003 Share Posted November 25, 2003 our 94 seville sts can roast the tires like nuthin. oh yeah, i was riding in my sister's friend's stock van and floored it coming out of the parking lot, she left a pretty long stip of black on the road You should have seen the guys face who was watching in his ricer Honda! Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted November 25, 2003 Share Posted November 25, 2003 9000's are wild! but it seems to me that a lighter rwd turbo car should have a much easier time breaking loose than my car. maybe the boost and gear ratios aren't playing nice? could be geared too tall for low-end smoke shows? just throwing out ideas, but me being psychotic i'd try powershifting myself, hell i do it in the saab and they're not exactly made for that, but johan hasn't protested yet!!! 8) That's what I'm thinking... '82 five speed and 3.54 rear end = VERY wide ratios. I'm keeping my eyes open for 3.7 LSD, if not I may go back to 3.9 rear, but I dont want it to make the car slower, just to be able to spin tires. That's why I asked if lower numerical diff would equal less torque to the wheels. On the flipside I also agree with you that my 2300lb car, with crap tires, should have no problem spinning tires.... Quote Link to comment Share on other sites More sharing options...
Guest ON3GO Posted November 25, 2003 Share Posted November 25, 2003 well still check for the boost leak.. also you really dont wanna spin the tires... the more u spin the less faster u go. you might have to launch it higher also. mike Quote Link to comment Share on other sites More sharing options...
z-REX Posted November 25, 2003 Share Posted November 25, 2003 not that i have nitto 555's an johan or anything... they're cooper touring tires and it's way more car than tire.... besides, you shouldn't have too much a problem with no top end if you gear it a little lower. boost is your friend! Quote Link to comment Share on other sites More sharing options...
Heavy Z Posted November 25, 2003 Share Posted November 25, 2003 Based on what I've read here on this site your 3.54 is the rear end you want for a turbo to help in building boost. A 3.54 will actually peel out easier than a 3.9 since it's gearing accelerates the wheel more(also from an old post). At 25 mph(2200 rpm) in my Z in 2nd gear, if I step on it my car won't start peeling out until I reach 35-37mph(3500 rpm). This is with 225/60/15 tires, 3.7 R200, and 1.94 2nd gear. DD2000 says I'm making 364tq at 3500, so in my case that's the limits of adhesion. Hope this helps. Quote Link to comment Share on other sites More sharing options...
denny411 Posted November 25, 2003 Share Posted November 25, 2003 well i can chime in abit.my dads stock Z06 can chirp the tires HARD in 3rd. my boys Supra can roast his 315's in 3rd and chirp 4th hard as hell.. he has 658rwhp. my friends bone stock S2000 can chirp/spin the tires in 1st when Vtec kicks in... which is pretty cool. my other friends modded S2000 can really do it much better and roast the tires in 2nd. um i think thats it for me.. mike In high school I drove a 74 super beetle with a 1600 dual port that I could chirp the tires going into third. Quote Link to comment Share on other sites More sharing options...
Guest ON3GO Posted November 25, 2003 Share Posted November 25, 2003 ive owned a bug and man o man i loved it.. was buy far my fav car to just drive.. it was a 69' bug... mike Quote Link to comment Share on other sites More sharing options...
80LS1T Posted November 25, 2003 Share Posted November 25, 2003 1. Approximately how much hp/torque at the wheels does a car need to make, to be able to break the tires loose at will in first gear? From a stop? From a rolling (like 5mph) start? How about moving at like 15-20mph? Well my car has about 350ish RWHP/not sure on the TQ...I can roast my tires all day long in 1st and 2nd, 3rd there is a little tire spinning and 4th there is a short chirp....From 5mph I can do the same....from say 15-35mph if I dump the clutch in 2nd or 3rd at about 3500RPMS I can get the tires to spin pretty easy! 4. Does differential or tranny gearing affect your hp/torque numbers when you are on a dyno? Would a 3.9 get you a higher dyno # than a 3.54? No since when you are on a dyno you should be in your "direct drive" gear in the tranny 1:1 ratio (for me 4th gear) for you it would also be 4th but for the auto tranny guys it would be 3rd (for most guys). Guy Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted November 25, 2003 Share Posted November 25, 2003 Difficult questions to answer but in general, the ones about HP and spinning tires have more to do with tire compound than it does with HP. Here is what I mean. Darius spin his tires at 65mph. If I do a 10psi on my 275/40-17 DRs, I guarantee I will spin them for at 330'. However, just the other night with 27x11.5 Hoosier QTP DOTs (same tread width as the DRs), I did a 15+psi launch, cut a 1.39 60' and had zero wheelspin. OTOH, someone with a 250hp Z and H-rated tires will roast their tires. As for a stock Z lifting the front-end, I do not know of any IRS Z that pulls the front wheels. I did not on my 1.39 launch but you could stand there and count the coils Hey, I like all that discussion about the Saab 9000s . Inspired me to proudly update my sig Quote Link to comment Share on other sites More sharing options...
Guest Nic-Rebel450CA Posted November 25, 2003 Share Posted November 25, 2003 I was actually starting to wonder the other day if this all can be mathematically calculated. Actually, I should say, how it would be calculated. It would have to be a factor of the following variables (plus a few): Current speed of vehicleCurrent HP at given RPMMechanical advantage (factor of gear ratios)Contact patch of the tireSome mathematical representation of the point that the tire would lose traction based on the weight on the tire and the amount of force to the tireRate of weight transfer I was thinking of this because I am thinking of writing a computer program that will be a Z Simulation. All of these complex mathematical calculations in the simulation would enable someone to learn exactly when to shift, and how much throttle they can give their Z to get the maximum acceleration and a near perfect quarter mile. Quote Link to comment Share on other sites More sharing options...
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