800 tt vs. Speed 12

Discussion in '2000 Hennessey Viper Venom 800TT' started by bmwm3gtr200, May 8, 2003.

  1. Re: 800 tt vs. Speed 12

    If you, "know damn well what it is," then you would imediatly ignore the marketing claim that a longer pedal travel is like traction control. You also wouldn't assume that what works on 300 bhp cars will work on 900+ bhp cars. Who realy wants to drive around using only a quarter of the car's throttle at most anyways. The problem with cars that have this much power is that it has to be restricted somehow, either through traction control, or some other electronic device. If you can't lay the power down with out traction control, then why would you want that much power?

    If you were mearly relaying TVR's stance on traction control, then you should have mentioned their philosophy, not what an ad guy says. Their philosophy is that if you have to electonically limit the power to less than what the engine makes, then what is the point in having all that power.
     
  2. Re: 800 tt vs. Speed 12

    LOL, this 90% driveline efficiency thing again. Tell me. Where did you see this 90% driveline efficiency figures for TVR? Did you NOT read my post up there, where I showed TVR have been giving inaccurate hp figures for years? Why are you so ready to accept everything Peter Wheeler has to say. DESPITE the fact the evo article showed no dyno graphs, DESPITE the fact the Speed 12 has never been tested?
    I have seen TVR driveline ineffeciency anywhere from 25-30+ %!

    You said you've personally seen THREE of these cars? Really? Where?

     
  3. Re: 800 tt vs. Speed 12

    If you ignore the TVR's marketing claim about the longer pedal travel, then why not ignore TVR's hp claims? It's all bogus marketing, isn't it? Oh, I see. You believe wholeheartedly the rubbish they give about power figures, yet you selectively dismiss their philosophy about the long-action throttle pedal? Oh dear, how convenient!

    300 bhp in cars as lightweight as TVR's is still pretty sketchy. Besides, I was talking about the Red Rose Cerbera, which has quite a bit more than 300 hp. You don't see those leaving the roads ass backwards on a regular basis, do you?
     
  4. Re: 800 tt vs. Speed 12

    Yeah, I agree.

    A car that weighs 2205lbs. and has (if 90% of power got to rear wheels) 846 RWHP, would not be able to find any Street tires that could hook up.

    It would be like a truck, with a 502 in it, b/c no weight is on the back wheels (only the bed) it won't get tracktion.

    But the point of this thread was your first post:

    "The Speed Twelve may be the fastest road car ever...
    Can the 800 tt keep up? "


    But considering :

    ("The main reason for this was their problems finding tires that could handle the power it created. So it has to be taken as fact, it has been observed, documented, and can the results can be repeated. So until you can repeatidly test this car and prove that this car is not too insane for the street, and that there are street tires that hook up, shut your damn mouth.")

    So considering that there are NO tires in the world to harness the power of the car, meaning IT WON'T GET TRACKTION,

    Then how in the world would the car be able to beat an 800tt?
     
  5. Re: 800 tt vs. Speed 12

    Firstly I never said I saw them in person, I said I have seen three different ones. In car magazines, and on the internet.

    Where did you get your data? I already asked you this once before, and no reponse. The drivetrain in the Speed 12 is also completely different than any TVR car before it. So it will have totally different charateristics.

    I will also like to point out that the majority of cars use the same driveline, and get the same driveline efficentcy. The only time you realy see cars get higher than the norm is when they are supercars, or high end sports cars. The Speed 12 is the same car as the racecar version minus the restrictor plates, and a slightly softer suspension. It also has a complete interior. Seeing how the majority of racecars, esspecialy ones racing in legues as competitve as the British GT, get over 90% driveline efficentcy, I figureed 90% would be playing it more than safe. I have also read on a couple of websites that the racecar gets 94% driveline efficency. I did not use those sites as sources though because I felt there numebrs source was not documented well enough(A link to a website that didn't have info on the Speed 12, and no source for the other).

    As for the power numbers, read my post that I made in response to your post on that issue.
     
  6. Re: 800 tt vs. Speed 12

    Well, like i said b4, considering there are really no street tires in the world that can harness the tvr's 846 RWHP (if 90% driveline efficiency occurs)

    Then i don't see how it could be faster than a 800tt, i mean if the speed 12's tires will just spin. <A BORDER="0" HREF="http://www.supercars.net/emoticons.html"><IMG BORDER="0" SRC="http://speed.supercars.net/cboardhtml/emoticons/smile.gif"></A>
     
  7. Re: 800 tt vs. Speed 12

    Where do you guys get the 940 horsepower figures for the Cerbera Speed 12?

    Everywhere I read it says that the Speed 12 has 800 hp and 880 Nm torque (supposedly at the flywheel)
     
  8. Re: 800 tt vs. Speed 12

    Quote from bmwm3gtr200:
    "Firstly I never said I saw them in person, I said I have seen three different ones. In car magazines, and on the internet."

    Errm...you didn't simply say you saw three different ones in car magazines and on the internet. You said: "I've seen three different Speed 12's so far myself."
    Without reference to car magazines and the internet, that "myself" could very well be replaced with the word "personally".


    "Where did you get your data? I already asked you this once before, and no reponse."

    Where did you ask me? I didn't see it. I may have missed it, and if so, please show me where you asked.
    In any case, I get my data from a forum full of people who know a helluva lot more about TVR than you and me combined. They are TVR owners, rabid enthusiasts, and race fans. The links I posted show you my source, so why even ask?

    But if you want to see examples of TVR driveline losses at 25-30+ %, just say the word. I'll hook you up.


    Drivetrain losses. You seem to be forgetting that race cars also have heavier duty driveshafts, halfshafts, hubs & larger bearing surfaces. All of this contributes to drivetrain losses.


    "I have also read on a couple of websites that the racecar gets 94% driveline efficency. I did not use those sites as sources though because I felt there numebrs source was not documented well enough(A link to a website that didn't have info on the Speed 12, and no source for the other)."

    Then send us the link, so we can see this for ourselves.


    "As for the power numbers, read my post that I made in response to your post on that issue."

    Thanks for dodging the question.
    Your response was weak. What good is having a 450-hp Viper when you can't use even half the power anyway? Best way to launch a Viper certainly sure isn't at redline, you can chirp the tires from as low 2000 rpm. Yet Dodge sells 'em this way.
    The 800TT sure as hell isn't going be good for redline launches....yet Hennessey sells 'em this way. You could try launching a Red Rose Cerbera at half throttle...but you'd be met with nothing but tire smoke. Yet...TVR sells 'em this way.

    Point being: their explanation that it's undrivable is smoke and mirrors. They're in the business of producing lightweight cars with gobs of power, and there clientele is used to that. So the excuse that the Speed 12 would be undrivable just doesn't hold water.
     
  9. Re: 800 tt vs. Speed 12

    800TT.
     
  10. Re: 800 tt vs. Speed 12

    February issue of Evo Magzine (052). It has an article in it written off of the interview they gave to TVR's President Peter Wheeler. In that article he explained that since the engine has never been fully dynoed they added the power ratings for the two straight sixes that make up V12, since the two straight sixes make 470 bhp each, you get the magical number of 940 bhp @ 7200 RPM. I put a plus after the 940, aswell Evo does too, because the only time it has been on a dyno it broke the drive shaft of TVR's 1000 bhp rated dyno at 5700 RPM while making 660ft lb of torque. Plus the math on the engine says it should make 1000+ bhp, at least that is what Peter Wheeler said in a TV interview I saw of him.

    The 800 bhp rating is what people were assuming it made, and what TVR said the first version of the car would get. That is were many people get the 800 bhp number, but the newer version has a fully devoloped engine in it, and is said to be torqier also.
     
  11. Re: 800 tt vs. Speed 12

    Well, i don't think that arguing about Only a speed 12 being insane or not for the road, or having 940hp or not matters.

    This is a 800tt forum, AND thread aswell.

    What matters is comparing the two cars, not just arguing about one.

    Now IMO, i think we should all believe TVR and what bmwm3gtr200 say,

    b/c like i've said b4, considering (supposedly) there are really no street tires in the world that can harness the tvr's (supposed) 846 RWHP (if 90% driveline efficiency occurs)

    Then i don't see how it could be faster than a 800tt, i mean if the speed 12's tires will just spin.

    So to believe what bmwm3gtr200 and TVR say, means to believe a 2205lbs car has 846 RWHP, and that there are no tires to harness that power-to-weight ratio.

    And considering that, It means that off the line, the tvr will not beat a 800tt.(b/c the tvr's wheels would just spin, and not get tracktion, like tvr and bmwm3gtr200 say)

    So the 800tt is the victor here. <A BORDER="0" HREF="http://www.supercars.net/emoticons.html"><IMG BORDER="0" SRC="http://speed.supercars.net/cboardhtml/emoticons/smile.gif"></A> <A BORDER="0" HREF="http://www.supercars.net/emoticons.html"><IMG BORDER="0" SRC="http://speed.supercars.net/cboardhtml/emoticons/smile.gif"></A>
     
  12. Re: 800 tt vs. Speed 12

    Ok guys, I did some thinking at work tonight and thought of this way of looking at it. Look at what cars with similar numbers, this means 900+ bhp cars, around 1 ton, or 900hp/ton, and a racing tuned suspension. They run under 2.5 sec. 0-60, under 5.5 sec. 0-100, and have top speeds of 250+ MPH. All of the cars with those times though weich about 500-1000 pounds more than the Speed 12. So think about what happens when you reduce the weight, you go faster, you also loose some traction.

    Those two reasons also are likely why the Speed 12 can not get traction with any tires on the market at this point in time. If TVR could partner up with a tire sompany I am sure this would happen, but TVR or the tire industry seem to be dragging their feet. Hopefully someday soon they can get in gear and make some tires for this car.

    There is one other way that I have thought of for us to get are damn Speed 12's. We need to find about 500-1000 people with the money for one of these things, maybe even only 100-250. Have them all go to TVR at the same time and tell them they want to buy however many TVR's; and is cash alright? I gurantee you that TVR will crack and make the cars.
     
  13. Re: 800 tt vs. Speed 12

    yeah sure, if the money is right....how about an All-Wheel-Drive and twin turbo converted version of the Speed 12... Now that would be insane!
     
  14. Re: 800 tt vs. Speed 12

    ...but remember that it's more or less the torque that makes the wheels spin (with normal gear and rear axle ratios) and the Hennessey Viper has got more torque than the Speed 12.
     
  15. Re: 800 tt vs. Speed 12

    "Look at what cars with similar numbers, this means 900+ bhp cars, around 1 ton, or 900hp/ton, and a racing tuned suspension. They run under 2.5 sec. 0-60, under 5.5 sec. 0-100, and have top speeds of 250+ MPH. All of the cars with those times though weich about 500-1000 pounds more than the Speed 12."

    If you could name some of those cars that have the same (or less) weight as the TVR (2205lbs.), and 900+HP, do so.

    Because i've tried looking for other supercars with the same power/weight ratio as the speed 12 (or cars that weigh around 2205 and have 900+hp), and couldn't find any.
     
  16. Re: 800 tt vs. Speed 12

    Haha, and you still believe everything TVR says? Nice...

    And how about answering my questions instead of dodging out like you did in the "V12's: Do we still need them?" thread.
     
  17. Re: 800 tt vs. Speed 12

    I know that torque is the reason cars spin their tires. But how in hell is a car with 900+bhp/ton giong to get any traction? Even if it makes less torque, it still likely has a higher torque/weight ratio. With a higher torque/weight ratio the car is more likely to burn out. So TVR is likely right in saying they couldn't find any tires that could handle all that power.
     
  18. Re: 800 tt vs. Speed 12

    Firstly your links were to another forum, so that is not a valid source. Second hand talk about second hand talk is not going to cut it.

    Sorry about no reponse to that, that was when this site was being stupid again, and not letting me submit posts. You were talking about a net dyno versus bhp dyno I believe, and how TVR engines are rated higher than they should be. The only number you gave to prove your point was a number off of a rolling dyno, and then said they quoted to high of a hp. Hey, rolling dynos get less horsepower than bench dynos. If you want to say it was on a bench dyno, or the power at the flywheel, then why is the guy talking about putting it on the rolling dyno, then a flywheel number? I know you can get flywheel numbers off of rolling dyno numbers, but they are vague in there accuracy. So get some solid information, then come back and talk abut TVR over quoting their power because if they are I really would like to have some facts to back it up when I am talking with other people about TVR. I do not see how people talking in a forum is in anyway a solid source.
     
  19. Re: 800 tt vs. Speed 12

    "With a higher torque/weight ratio the car is more likely to burn out. "


    FIRST POST:

    "The Speed Twelve may be the fastest road car ever...
    Can the 800 tt keep up?
    I do not think so."


    And with that, you just proved yourself wrong.

    Considering if the TVR will just burn out, there's probably no way it could beat a 800TT. <A BORDER="0" HREF="http://www.supercars.net/emoticons.html"><IMG BORDER="0" SRC="http://speed.supercars.net/cboardhtml/emoticons/smile.gif"></A>
     
  20. Re: 800 tt vs. Speed 12

    Also, if the cars were making less horsepower than they are supposed to, then their performance numebrs would show it. Especially since I had my engineering budy run your numbers through his equation, and he told me that he got numbers that made your claim nearly impossible. He said that some of the test times I gave him would be impossible also. So as math goes, it is nearly impossible.

    Then there is the legal issues, and the talk about it factor. If they realy are over stating the power of the cars, that is false advertising. That would be illegal, and TVR would be getting fined and sued left and right. So there is one other reason why I am not likely to believe that they are doing this. If they were they would have likely been sued by now. It would also be all over the Car magazines that ther are doing this. They hear about everything, and talk about everything worth mentioning, a car manufacturer over quoting power numbers, especially as much as you claim, is big news.
     
  21. Re: 800 tt vs. Speed 12

    "Power at the flywheel"? Why are we talking about power at the flywheel? When TVR tests their engines for hp, there's no "flywheel" to speak of. There's only numbers from the crank, meaning this is pure GROSS hp we're talking about. No ancillaries, no flywheel, etc. So the numbers are not going to correlate well with *anything* from the rest of the automotive industry (just about everyone else uses either NET flywheel hp, not GROSS crank hp).

    What's the official power rating on the Cerbera 4.5? TVR Tuscan? Chimaera?

    Do you seriously think you know more about TVR's than TVR *OWNERS*? LOL, this coming from the guy who thinks the McLaren F1's engine is 10 years older than the S2000's.
     
  22. Re: 800 tt vs. Speed 12

    If you read the links carefully (and do a search on Pistonheads), you'd see that the issue of possible litigation over inflated power claims comes up over and over. Only a handful of TVR's customers ever really find out their cars make less hp than claimed, and those that do think their cars are already mad quick enough so why bother?

    Where are the *PROVEN* performance numbers for the TVR Cerbera Speed 12? What is its axle ratio? Its transmission ratios? What's its drag coefficient? You would need all of these factors if you're going to have anything resembling accurate modeling.
     
  23. #73 Guibo, May 26, 2003
    Last edited by a moderator: Apr 25, 2016
    Re: 800 tt vs. Speed 12

    OK, fine. To save you some trouble, I'll show you something (but for god's sake, man. Take off your blinders.):


    "So Cerberas are nearly 25% "over-estimated"...does anyone has any idea on other car(s)?"
    “forget all those official numbers for starters. All 4.5's so far on a dyno are between 320 and 350. I haven't seen a dynograph of one with more than 350 - this is corrected to flywheel numbers. 4.2s appear to be around 330 with less variation, though there are a few with quite a bit more.”
    http://www.pistonheads.com/gassing/topic.asp?t=7352&f=6&h=0
    THERE IS REFERENCE TO LEGAL MATTERS IN THAT ONE

    “After trying all of them I came to a personal conclusion that either a 4.2 or 4.5 was fine for me. There wasn't much between them. Performance difference is not noticable.”
    “-- it's well known the cerbie 4.5 doesn't do what it says on the tin.”
    http://www.pistonheads.com/gassing/topic.asp?p=1&f=6&t=9244&h=0

    "I do find it entertaining that TVRists will quote fantastic power figures when it suits and similarly ignore them if it suits."
    “TVR may well be quoting figures from what is known as an "optimistic dyno" it all depends on the manufacturer of the Rolling Road with some makes being well known as being "optimistic" and does not neccesarily indicate sinister doings on TVR's part (It is always best to quote the highest figures though and all manufacturers do it)”
    “The figures I've seen were mainly from AJP8 4.5 engines which are quoted at 420 Bhp. The best was 71 bhp down, the worst 107 bhp down!”
    http://www.pistonheads.com/gassing/topic.asp?t=2754&f=13&h=0

    “The Cerbera 4.2 was dyno tested at exactly 360 bhp (as claimed) by Autocar. However, this is an unlikely co-incidence and the strong rumour was that the press car was specially prepared and actually had a 4.5litre engine. There have been several people who have driven various of the press cars over the years and have said that they been noticeably quicker than the production ones....”
    http://www.pistonheads.com/gassing/topic.asp?t=803&f=13&h=0

    Here's a thread that deals with legal matters AND shows a drivetrain loss of 37 (!) PERCENT:
    http://www.pistonheads.com/gassing/topic.asp?t=30441&f=6&h=0

    Just take a look at some of the rolling road results from this dyno day they did:
    http://www.pistonheads.com/features/dyno.htm


    When TVR owners take their cars to the dyno, is that still second hand "talk" to you? Do you doubt these guys own these cars? Have you yourself ever dynoed a TVR? Why should we believe you anymore than we believe these guys?
     
  24. Re: 800 tt vs. Speed 12

    Oh, and on the issue of the number of Speed 12's made, it's well known in certain circles that only 1 (perhaps 2, at maximum) was ever made. So how you ever saw three boggles the mind. Did you ever see all three in the same picture at once? Did you ever see even two of them in the same picture at once?

    Take a look at the advertisement below. What does it say about the Speed 12?

    When the Cerbera Speed 12 was unveiled for the first time back in '99, TVR issued a press release stating they would produce one or two EACH MONTH starting in '00, to coincide with their British GT Speed 12 campaign. There should now be (at a minimum) 24 examples of the Cerbera Speed 12 in existence. Well, where the hell are they? Peter Wheeler said he drove the Cerbera Speed 12 and knew within 300 yards that to produce one for public consumption would be "silly." Yet, why would TVR then go out and issue a press release stating they would produce one or two per month? Does that make any sense to you at all? And to list the Speed 12 in its official literature as a TVR model you can actually buy....?

    Let me know when you think any of this sounds the least bit strange.
     
  25. Re: 800 tt vs. Speed 12

    I never said it wasn't true first off, just that I had not seen enough solid facts, and that until then I will believe what TVR says for several reasons why I felt they wouldn't do this, illegal, and the math doesn't seem to show it being possible.

    I am coming to one of two conclusions. First, that people are mixing up their rolling road dyno(Test of hp at the rear wheels) and a bench dyno/flywheel dyno/whatever(Test of bhp at the flywheel). All of the guys are talking about rollnig road tests. None of them seem to have had the same dyno done are their engine as the one used by TVR. The dyno system TVR uses seems to be standard industry practice also. Strip the engine down and give it a bench dyno. The Speed 12 doesn't have a/c, power steering, or any of that crap. The only thing that runns off of the engine, assuming they are running an electric radiator fan, is the timing belt, alternator, oil pump(May use an electirc motor), and water pump(May use an electric motor for). So what ever it gets on the dyno should be correct.

    The other conclusion is that TVR has some quality control issues to work out. It seems that there are at a few TVR's out there that get or exceed the power claims. TVR is also likely going off of the highest number that they have gotten. Since their engines are hand built, they likely are getting a large variation between the best engine, and the average engine. There was also some talk about a conversion kit that would get the cars up to snuff. What exactly does that conversion do if you know off hand? I would be interested in what things are done. I read in some very back issues of car magazines I found laying out at a friends house, that TVR had done some detuning from the prototype version and the version people would be getting for the 4.5. They also had what they claimed to be the first hp number given by TVR for the production version, it was 420 bhp.

    I am not sure which way to go, but if we can see a bench dyno number, that would be great. If there is one in the information that you posted and I missed it, please inform me. I did not read over it too hard core, I am trying to order some carbonfiber and kevlar so I can make my buddies fender for his dirt bike. Youi would think that something that is bullet proof would last him longer than 1 race.
     

Share This Page