my recommendation: Drive the pi$$ out of the cars when they are brand new. Really take them hard. The exact opposit of what the manual tells you. After that the engine either blows on you (then it would have anyhow a few thousand later) and you can get it replaced under warranty, or the engine will be used to strong driving and will be set for its full potential. Babies learn a whole lot in their first months. Engines do too. This is based on hundreds of Miata engines I have "tuned" for my customers in the early 90s.
BTW I also think that if the F1 is not set 100% you will have a higher loss from flywheel to wheels. If it is just a little lose you can decrease your output at the wheels dramatically. My F1 feels different than the 6 speeds as well. To really check you should probably take the measurments at the Flywheel and with CATs removed.
Using a portable chassis dyno at the race team, we've measured about 8 different 360 challenge cars about 20 times. I havent used the system myself, but did provide the operator with all the relevant information to plot the corrected figures, including ratio's, altitude, barometric pressure, temperatures etc etc Every 360 challenge car we tested had over 380BHP corrected flywheel figure. Some had up to 395BHP, with cats removed and a few different exhausts tested etc. There is no 1:1 gear ratio, so adjustments need to be made for that. We never did more than 2 on any one day. The operator calcualted a less the 10% transmission powerloss in 5 th gear. The best use for dyno's is simply running in engines and transmissions and doing comparative tests on the same vehicle, same day. Actual measurements are open to too many variables to be of any consequence. Remember.....Horsepower wins friends, Torque wins races
Newbie here! I might be out of place here, but Ill comment since Ive made several hundred dyno runs and just by osmosis I learned a few things on the way Generally speaking, the dyno will account for gear ratio on its own. Gear ratio will have little effect on power produced. If gearing could change power (assuming there is a constant load on the engine as load can affect power produced, especially on turbo cars), then wed have little fractional hp motors powering cars. Wed also be able to use an Energizer AAA cell instead of a nuclear power plant Gearing only changes torque produced. The way the dyno accounts for that is with the indcutive pickup on the spark plug wire. If the dyno knows engine speed and dyno drum speed, it can easily calculate an effective gear ratio. This effective ratio takes into account everything from tire diameter, final drive ratio, to gear ratio, etc, etc. The actual torque produced during a dyno run might be 2000 or more ft lb to the wheels depending on the gear used. That being said, I will say that most of the Ferrari dyno plots I have seen seem to show a larger than expected difference between whp and manufacturer rated crank hp. There is really also no reason (short of trying to see if the manufacturer is remotely truthful) in calculating back to crank hp. There will always be an extrapolation in doing so that is riddled with assumptions. (For instance, what is the driveline loss? Is it linear? Is it some sort of exponential function? Does the driveline loss vary with speed/load/gear?) To keep it simple, a fixed driveline loss is usually assumed (i.e. 15%, or 18%, or whatever one chooses). Most people who have done testing in this area seem to feel that the true driveline loss is comprised of portion fixed and a portion that varies with increasing power level.
sorry fellas...I think the 360 series is putting out about 380 horses, maybe even less...and the 355 about 350 at best...Think about a true 375-385 HP engine (f355 claimed) actually dropping only 280 WHP...thats a 100 HP LOSS!!!
AH - the very person I was waiting for - all the discussion based on numbers from a single car seemed to be wrong - however it seems that your finding support the common understanding 360 Engine - ~380hp flywheel measured with standard engine - ~395hp flywheel measured with cat removed, freeflow exaust and re-mapped ECU?? I assume all cars use racing gas - are the engines blueprinted?
if you do me a favor and lookup the HP, torque and weight numbers in your EU user's manual and contribute them to this discussion all this discussion is about the difference between HP measured at the rear wheel of a US CS versus the published numbers by Ferrari at the flywheel of the CS engine - flywheel HP are measured on an engine test stand and basically represent the raw output of the motor (without gearbox, some of the engine components, ...) - rear wheel HP is measured by putting the complete cars on a dyno - the wheels are on rolls and have to accelerate a known mass - the numbers include losses in the transmission, differential, ... Car companies love flywheel HP because numbers are larger than the rear wheel numbers - most of the dicsussions center around how to compute the flywheel HP from measured rear wheel numbers - which is next to impossible since it depends on so many variables - however it is fun to speculate (15%-20% difference are typically seen) Ferrari claims 409HP (flywheel) for the US CS and I have measured 320HP (rear wheel) - it is physically impossible that the gearbox, differential, tires, etc. absorb 89HP - this would generate an impossible amount of heat - so another part of the discussion centers arund why Ferrari stated 409HP (there are many standard ways of how to measure HP (DIN, SAE, ..) and typically manufacturers select the best one for them) or if my car is simply does not generate the 409HP because of bad US gas, problems with engine control, etc. At this time of the discussion nobody has a good answer – we would have to dyno a number of cars in the US and EU to get a better understanding about this issue (on the same dyno) – fat chance that that happens .. can you plssss get us the numbers for your EU CS out of the ower’s manual!
Yeah, they marketed a figure 15hp higher *twirls finger in air* Hardly in the same category as Ferrari! When you put these cars on a scale, they weigh what is shown on the door and shown in the Driver's manual. Put them on a dyno and they are much closer to factory specs. Ferrari will lose this particular pissing contest over and over again. 15bhp is nothing to fret over from Jag when your making 400lbs torque from a 3,750-4,050lb GT.
Rob, the weight is a disappointing factor since its really what made people want to buy the Stradale in the first place besides the exhaust. The highest money to performance ratio is when weight is taken into the picture. Martin, that is so true regarding engines. Its very possible this engine needs more shakedown time and the factory break in phase wasn't enough. Factory optimal conditions are hardly what we find out in the real world. I hope Ferrari learns a lesson from this, however unlikely.
could be a bad tank of gas..could be the dyno operator screwed up.. Could be your engine and the pcm needs a good whipping. With Vettes we find if you drive them harder they perform better both at the track and the dyno..(as compared to the guys who care so much for their cars they don't rev and run em hard) they usually dyno lower too... could be carbon build up? Could be a knock sensor? Tons of variables that the simulated dyno testing might not be totally accurate. JMO
Great description, Thomas. One point you didn't mention is the different dyno types. Most of the commonly used ones are chassis dynos, that measure horsepower to the wheels, but in different ways. Personally, I wrote off ever using a Mustang dyno when both a dyno operator and a factory representative thru email tried to explain to me how the weight of my car and it's wind resistance would affect the horsepower readings. (no comment on the weight of the CD, of course...) Dave
15-20% driveline loss seems very generous. In the Viper/Vette world 12% is the rule of thumb. Check out this dyno of my Viper SRT-10, rated at 500 hp and 525 tq: http://pathcommunications.com/dyno.jpg It has also been my observation that pushrod engines seem to be very consistent in stock form and vary by only a handful of hp, whereas overhead cam engines can vary by a good degree depending on how they are broken in and driven. As someone earlier suggested, running them aggressively at their peak hp/tq rpm range, on a regular basis, can work wonders for these engines. At one time I owned a 405 hp ZR1 that dynoed at 362 hp (stock). Its LT5 (dual-overhead cam engine designed by Lotus) redlined at 7,200 rpms and you could drive it all day long between 5k-7k rpms. Go to this link and scroll down to the 1993-1995 years (405hp) and note the differing dyno results for the stock ZR-1s. They tested from 334-364 rwhp in stock form: http://www.zr1.net/ZR1_performance.html Happy Holidays!
Interesting, I cannot understand this ... but have no proof, thus commenting. It makes no sense to me that an overhead cam engine with fewer parts (especially between the cam and the valve) would require MORE running in than a pushrod engine with the cam follower, it's location, pushrod, rocker and rocker shaft, and then location of all to said valves. Thus plenty more places for tolerances to get in the way. It might have something to do with more extreme cam profiles and thus valve/cam timing needs to be more precise ... ???, maybe ... but still makes little sense to me. Pete
Think Italian tune up. ECU's that adapt to driving style. Throwing in high octane gas and not disconnecting the battery forcing the ECU to relearn and use new mixture settings based on the new octane. Don't look at it from a purely engineering standpoint. There are cars that fall apart and cars of the exact same model that take abuse on the chin and wear you out driving them before you wear them out. How else can we explain these differences? They should get faster as they are broken in. If they never go through this breakdown period, which owner is doing more harm to their engine? Identical twins if separated at birth are only identical on the surface once exposed to different elements. Identical engines are the same way, once you start driving them, exposing them to "normal" operating temperatures, etc. When I eventually get an F-car, I want a well used well maintained one. Keep your 10k garage queens. I want a car that sees redline all the time. Its only a rebuild vs breaking things and costing you more money because it was pampered. Sunny EDIT: Here's an example, my best friend's '95 XJR has just under 70k on it. They are pampered miles. Mine are not. He's the second owner like I am, we bought them a year apart with the same mileage and I've been constantly creeping ahead by 500 miles or more each month. I have almost 98k on my car though its not a force fed beast like his. He started mimicing my driving style and things started breaking. He discovered he had a heating problem. His water pump was in bad condition but working, and coolant mixture was off. His intercooler was COMPLETELY plugged, he needed a new s/c pulley, he needed the s/c topped off on oil, he's still has traces of carbon build up. From a green light or full stop, given an identical launch from idle to WOT, I can keep up with him up to 90mph and he's only 1/3 of a car length in front of me. This starts to widen after 90mph and becomes a full car length at 105 and creeps ahead. He used to not be able to pull on me. His car is running good now that he's using it. My car is put on a lift once a month and my mechanic is amazed at the condition of everything. All I do is change the oil, drive the snot out of it every day, and take great care of the paint and interior. I told someone redline is there for a reason. Use it.
JaguarXJ6, I agree with all your post, but this has nothing to do with the comment on a previous post saying that PUSHROD engines break in better than OVERHEAD cam engines. This was what I was commenting about ... I may have completely mis-understood the post I was questioning though, you never do know I am 100% in agreeance that a car is a machine that needs to fully used Pete
I for one was willing to give the Stradale a chance. I said many times before, that it looked much better than a 360, i love the interior, and i thought it would finally have performance to match. At first it was a toss up between it and a Gallardo..... now there is only one choice. Ferrari disapoints, yet again.
I hope they can get at least 400 RWhp in the next iteration...I assume they will, they can't afford to lose to the competition like this, and lets not forget that for some reason, everyone picks the gt3 (yes, i know, Naturally Aspirated blah blah!) when the REAL comparison is to the gallardo and the GT2.... But if the 360 replacement has good power, I know the handling is said to be topnotch...
Well that's a personal issue and choice. I personally could not see spending 200$k on a celica lookalike either.
I agree, my post has nothing to do with your post regarding break-in differences between the two. I must have been too high on caffeine at work Sunny
Gentlemen, I would not write off the Stradale just yet! Reasons why: If you look at the post where the GT3 has been dynoed at 348.4 RW HP and 262.4 TW lb/ft. I have also heard that the (2004's) GT3's have been in the 350 to 360 rear wheel range when they are dynoed...so I do not believe that this dyno was a fluke. If you do the 15 % flywheel rule then the Porsche GT3 is around 410 to 415 HP and 305 lb/ft. These numbers make perfect sense because the GT3's are testing is just as quick in a straight line as the 996 Twin Turbo that has 420 HP with 420 lbs ft. Note: the turbo curb weight is about 250 heavier. I believe Porsche is understating the GT3's numbers because it would affect the sales of the more expensive ($30,000 US) Turbo Now with all that being said... the only way to truly see what the numbers on the dyno means is if you get all the cars together and dyno them on the same day, same gas, same everything.... Here is another perspective: Car & Driver results: Testing Numbers: HP/lbs** 0-60MPH 0-100MPH 0-150 MPH 1/4 mile Weight lbs Porsche GT3 '04 ** 380/284 ** 4.0 *** 9.3 *** 23.9 ***12.3 *** 3219 Porsche 996TT ** 420/420 ** 3.9 *** 9.4 *** 23.1 *** 12.3 *** 3470 Ferrari Stradale ** 425/275 ** 4.0 *** 9.5 *** 23.9 *** 12.5 *** 3152 Viper SRT10 '04 ** 500/525 ** 3.9 *** 8.5 *** 22.4 *** 12.1 *** 3408 Ford GT 2005's ** 500/500 ** 3.3 *** 7.6 *** 16.9 *** 11.6 *** 3429 I understand that thomas dyno results are showing only 320's in RW HP...but, those are just numbers on a chart. The real numbers are the results on the street/track. Looking at the Stradale's number against all of the above except Ford GT (which is almost as fast as an Enzo !! with only 500 HP, eha right ) and the Stradale can hold its head up high. If you read into the article from Car & Driver they say that the Stradale was the only car they ran a top speed on because the car was so "buttoned down... with nary a white knuckle". The Stradale has very good down-force for stability reasons which in turn would slow the Stradale's 130 - 180 MPH speeds down at the same time. I believe this is a good trade off When it comes down to it is what does the car feel like to drive? How does it make you feel? The way I look at it is that any of the above cars would make me a happy camper, but which one would I love the most
Spyderman - I completely agree. The CS is still pretty quick. 0-60 4.0 0-100 in 9.5. It does however raise your eyebrow a little when a 380HP car that weighs more (read the GT3) is pretty much equivalent performance wise than a 425 HP car that is lighter (read the CS). One is either sandbagging or the other is too optimistic. I think the Gallardo was 3.9 0-60 and 8.8 0-100 if I remember correctly, so at this level, performance is getting real close. I think it then boils down to the overall driving experience, feel, balance etc. I personally would still opt for the CS over all mentioned. Also the GT3 is basically as quick as a TT. The GT3 is an awesome car - no doubt.
All our tests have been with shell optimax pump fuel. 98 octane. Apparently the Mobil 8000 is very slightly better, but optimax is our series control fuel so that's what we use. You lose easily 5% peak figures by using 91/92 Octane.
excellent I will try this - I never thought the effect that big in NA engines I am wondering based on this how much the CS increased compression can be a reason for missing power - I understand the basic mechanism of the knock control in the ME 7.3 ECU the question is how active the knock control is - is it realistic that it never reaches the normal operating curve, i.e. ignition point is always late? the system would constantly try to advance the ignition point and reset after each knock occurence - it would never reach the normal operating condition - feasible?
Bear in mind the different octane measures in the US vs Europe/Australia "Regular" is "95" in Europe and "Super" is "97/98" - in Europe Porsche TT specifies 97 min and 360 95 min. This is not higher octane than the US just a different way of measuring it. Here's an old thread talking about US 100 Octane race fuel... http://ferrarichat.com/forum/showthread.php?t=517&highlight=octane I would expect US 93/94 to make a small difference over 91/92.
