SC and TT Characteristics Compared & Discussed
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skyrex
FORD GT OWNER
Sometimes when I have been reading this thread I feel like I am back in my old bartender days watching a couple of drunks argue about their girlfriends. "Well, your girl may have better knockers but mine has a better a$$!!!" and then they are rolling around on the floor. :lol
Your girl can have a better rear and mine can have a better rack, but as long as we are both happy there is no reason to be rolling around on the floor. :lol
........in case it is misunderstood this entire post is a joke and is intended to be used only by mature adults who realize that I think both systems are great. I made my TT choice based solely on my own personal driving goals. :thumbsup :cheers
Your girl can have a better rear and mine can have a better rack, but as long as we are both happy there is no reason to be rolling around on the floor. :lol
........in case it is misunderstood this entire post is a joke and is intended to be used only by mature adults who realize that I think both systems are great. I made my TT choice based solely on my own personal driving goals. :thumbsup :cheers
tmcphail
GT Owner/Vendor
BlackICE
GT Owner
Having ridden with Chip at Spring Mountain, I can attest to his TT having instant power when required, thus I feel that his configuration is quite adaptable to road course/track usage. The not-so-secret technique is to keep the engine in the power band - hence, he kept it above 3,500 rpm by using the gearbox, as he should do.
Similarly, in an SC car, one must also keep the motor in the power band - and, while our SC GT's have wonderful low end torque, that is not the optimal range of it's power band. The Ford specifications for a stock motor were 550 hp @ 6,500 rpm, and 500 lb-ft of torque @ 3,750 rpm. I believe that adding Whipples or pulley/tunes probably won't alter the nature of its curve very much, just the values which are reached. Thus, one would want to track an SC car keeping the rpm in a very similar range to that of the TT versions, or possibly from 3,000 rpm to redline. This, of course, is also done by using the gearbox to maintain the rpm levels.
It would thus appear that the only time the advantageous "low rpm" SC torque would be on the starting line of a race, or possibly when exiting a pit lane, although pit lane speeds are now controlled such that a TT car would easily be able to get into its power band. It would be more important, when racing a GT in either form, to have a set of final ratios which could be installed such that one could just achieve maximum power rpm in the highest gear on the longest straight section of the track, and selectable gear ratios to handle the lowest speed (probably the tightest corner) similarly.
Comments? (maybe Mark McGowan?, Roketman?)
Similarly, in an SC car, one must also keep the motor in the power band - and, while our SC GT's have wonderful low end torque, that is not the optimal range of it's power band. The Ford specifications for a stock motor were 550 hp @ 6,500 rpm, and 500 lb-ft of torque @ 3,750 rpm. I believe that adding Whipples or pulley/tunes probably won't alter the nature of its curve very much, just the values which are reached. Thus, one would want to track an SC car keeping the rpm in a very similar range to that of the TT versions, or possibly from 3,000 rpm to redline. This, of course, is also done by using the gearbox to maintain the rpm levels.
It would thus appear that the only time the advantageous "low rpm" SC torque would be on the starting line of a race, or possibly when exiting a pit lane, although pit lane speeds are now controlled such that a TT car would easily be able to get into its power band. It would be more important, when racing a GT in either form, to have a set of final ratios which could be installed such that one could just achieve maximum power rpm in the highest gear on the longest straight section of the track, and selectable gear ratios to handle the lowest speed (probably the tightest corner) similarly.
Comments? (maybe Mark McGowan?, Roketman?)
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Apollo
GT Owner
This was certainly the case when turbochargers first started to become popular. A lot has been done to mitigate this over many years of advancement. In fact, this is one of the main benefits of a twin turbo system. With twins, you can select turbos roughly half the size needed to get the job done at the top end. The smaller turbos spool much faster than a single, larger turbo.
Again, the TT's are not near as direct or "here and now" as the SC's. That's not what I'm saying. What I am saying is that the "push the pedal and wait" feeling has been significantly improved upon. I think Chip is saying that it was somewhat a pleasant surprise to him and I am saying the same thing. It is just a VERY strong linear pull. You can't help but to have an ear to ear grin!
Kingman
GT Owner
Has anybody included the stress/detonation of an engine in their thought process?
It appears from earlier threads that engine blocks are going to be very hard to find.
It appears from earlier threads that engine blocks are going to be very hard to find.
I've often wondered why nobody has looked into using small electric motors to spool up turbos at lower RPMs to eliminate the turbo lag. That could all be 'nannied' by 'peuters & such and, at least in principle, it OUGHT to work.
Mullet
FORD GT OWNER
I cant wait to show you all dyno graphs of a BIG Centrifical blower. I got 3 weeks to get it runninStock motor for now, just installed a dynojet 248 for my personal use, so im going to have alot of data.....
Personal dyno= super baller status (Chip you should change his forum title
)
Mullet
FORD GT OWNER
I cant wait to show you all dyno graphs of a BIG Centrifical blower. I got 3 weeks to get it runnin
Please define BIG
Personal dyno= super baller status (Chip you should change his forum title
Not a baller, got a killer deal
This big
TEXAS GT
2006 Twin Turbo
WOW! What a thread! It sounds to me like everyone is pretty much in agreement, they just don't know it.
I'm lucky enough to have the best of both worlds, one GT with a Whipple and another with a Heffner Twin Turbo set up. I can attest that they are indeed very different cars under hard acceleration but not so different under normal driving. I really can't say that I prefer one over the other. It just depends on how I plan to use the car that day, red light to red light or The Texas Mile. When I'm just driving one to work, the color plays a bigger role in which one I pick than the induction system. Some days I like red better, some days yellow. (I know, life can be tough sometimes.:biggrin)
Now, having said all that, if I were forced to sell one, the twin turbo would not be going anywhere.:thumbsup
I'm lucky enough to have the best of both worlds, one GT with a Whipple and another with a Heffner Twin Turbo set up. I can attest that they are indeed very different cars under hard acceleration but not so different under normal driving. I really can't say that I prefer one over the other. It just depends on how I plan to use the car that day, red light to red light or The Texas Mile. When I'm just driving one to work, the color plays a bigger role in which one I pick than the induction system. Some days I like red better, some days yellow. (I know, life can be tough sometimes.:biggrin)
Now, having said all that, if I were forced to sell one, the twin turbo would not be going anywhere.:thumbsup
Gentlemen,
The tough thing about evaluating a twin turbo Ford GT, is that it's almost impossible to test drive one in a manner that would allow someone to experience what it's really like. These are $200,000.00+ cars and no owner is going to flip you the keys and tell you to ring it out. Many people commenting on this thread have never driven one and are forming an opinion on the basis of theory and conjecture (well reasoned but largely incorrect). As such, the opinions of actual owners who either own both a TT and an SC GT, or have converted their SC GT into a TT and therefore have experience in each, are much more telling. I have never talked to a twin turbo GT owner that would even consider going back to a supercharger or who wished he had not made the conversion. There is one big bitchy down side to the twin turbo conversion and that is cost. It certainly isn't cheap. Kendall knew, before he did Terrys TT conversion, that the supercharger was probably the better deal.....in theory. More forgiving, more torque, easier to drive.....in theory. Now he's had a chance to drive a couple of them, and the only one of those theories that holds up in reality, is more low end torque. The TT car is more forgiving, and is easier to drive. Above 3500 rpm power delivery is smooth and rapid. And anybody that thinks that a supercharged car will give them an edge on a track because of more rapid power delivery will be sorely disappointed the first time you get on a track with a TT car behind you. At the mile, on a dragstrip, or on the track, the twin turbocharged GT will eat a supercharged car alive. You can lay out all the theory and conjecture and rationalizations about the advantages of a supercharger, but when you finally get your hands on your own twin turbocharged Ford GT, all the theory goes out the window. One could legitimately say that $35,000 is a lot of money to spend on a T-shirt. But after driving a TT GT on the track, I don't think anybody would attempt to claim that an SC car might be quicker. And we haven't even gotten into the power loss the SC cars experience after a few hot laps and they start pulling timing while the TT runs cooler and hauls ass lap after lap. That's my take on it.
Chip
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BlackICE
GT Owner
An interesting question for the experts on the FGT development team would be if the TT are so superior to the SC FGT why didn't Ford make it that way from the factory. I believe the option was considered but dropped for some reason. I believe that Ford could have made a TT FGT that is close to the performance of aftermarket TT system while still being in compliance with all Fed and State regulations. Do you think the reasons were cost?
I have never driven a TT, but have seen them in action. I wouldn't think I could out pull one with a Whipple unless I used some laughing gas.
I have never driven a TT, but have seen them in action. I wouldn't think I could out pull one with a Whipple unless I used some laughing gas.
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tmcphail
GT Owner/Vendor
Back at Rally 1 when my car first was assembled in TT form I was able to take a bunch of Roush engineers for rides including Curt Hill (GT Powertrain supervisor) and I was able to ask that exact question. Time frame, Cost, Fed regulations were a part of that. This is going from memory circa 2006 :biggrin
This is to say nothing about the superiority argument, but the SC was used on the car purely because the time frame was short and the 5.4L with a blower was a known quantity at a low price. I don't think there's any way in hell the Ford GT would have ended up anything but naturally aspirated if Ford already had a well mannered streetable 550 hp V8 on the books. With the cheap and easy power with the good street manners, the SC mod motor was the obvious solution. If you look at where Ford is going with it's engines from here on out, DI and turbocharging are the future. We're gonna get a couple more of these mammoth power SC cars, but I don't think they'll be around more than 5-6 years.
All he seems to be saying is that on a dyno the engine is at full throttle the whole run and the turbos are spinning faster at say 3000rpm than if the car was driving down the freeway at part throttle at 3000rpm. There will be more lag in the second situation.
The "so superior" part of this is an overstatement and I, for one, am not trying to say this about the TT. Even the stock car with the OEM SC is an un-real accomplishment and nothing other than an absolute hoot to drive. I'm not sure anyone would disagree. Add a pulley & tune or even a Whipple and the Hoot! is even bigger! If we move along this progression in terms of price, the TT is at the far end - and it gives some serious grins as well!! Chip is right in that I though that the trade-offs of the TT would be greater (too much lag, uncontrollable power deliver, etc and I was very pleasantly surprised that this wasn't the case!)
But as Shadowman said or reiterated early on in this thread, "to each his own". The SC's have superior low end capability. It's really hard to get caught off guard in a SC GT! However, if you're the kind of driver that is accustomed to grabbing a lower gear and getting the car up above 3500 quickly, well then the TT is going to deliver in spades. This thread was intended to be a discussion of pro's and con's and maybe along the way to dispel some largely historic notions about one config versus another. It really wasn't intended to say that there's one and only one solution that's best. That's up to you, your driving style, and your wallet !