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Looking At a C4 Have Questions on the Build

Old 10-02-2018, 08:09 PM
  #21  
jayjones
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Originally Posted by MatthewMiller View Post
Don't get caught up in the torque-trumps-power BS. Torque at the crankshaft means nothing. The number tells you how fast your car will accelerate at any given speed is the power it can produce at that speed, period. All the talk about torque is mostly people who want to make this more complicated than it is. The ideal torque curve is the one that is as flat and wide as possible. That will make for an engine that has a wide useful range of rpm and is very flexible...
Personally I've always wondered why peak HP/Tq became the most used metric for engine output. It really tells you nothing about the car's acceleration potential by itself. Since looking at the whole power vs RPM curve is more useful, I think the total area under the curve would be an interesting way to compare engine performance.

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Old 10-02-2018, 08:57 PM
  #22  
MatthewMiller
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Originally Posted by jayjones View Post
Personally I've always wondered why peak HP/Tq became the most used metric for engine output. It really tells you nothing about the car's acceleration potential by itself. Since looking at the whole power vs RPM curve is more useful, I think the total area under the curve would be an interesting way to compare engine performance.
It kind of depends. For outright road racing or drag racing, you really only to look at the curve within the rpm range required by max-rpm shifts. That may be only 1500rpm or less (the amount the rpms drop with each shift). For an autocross car, you generally only use one gear (usually 2nd), so you would really like the widest, flattest torque curve possible. I'd argue that for street driving, you basically also a very wide and flat torque curve, because you obviously don't want to drive in the lowest gear possible most of the time, and it's nice not to have to row the gears all day just to get any acceleration.

Back in the bad old days (20+ years ago) a lot of sportbikes were tuned with super-narrow, high-rpm powerbands and were frankly awful to ride on the street. The LT1/4 are anything but that. In their day, they were the most flexible engines with the most linear torque curve around They had the added benefit of an extra 1000rpm (at least) available for any number of uses, and the same off-idle torque as an L98 (which is why the myth of the "torque monster" L98 is so much BS). That's always the way to go for a street motor, and since it doesn't sacrifice any peak power to get the flat torque curve, it's better for a race engine too. An L98 doesn't get off the line from a standing start any faster than an LT1. That's silliness anyway, because from 0mph in 1st gear, you're traction limited anyway - so who cares how much "torque" it has at 1000rpm? The reality is that you only start caring at around 2000rpm for a street engine with a manual or a stock torque converter. For a more race-oriented car, you can move that upward, depending on the application.

But anyway, a lot of that is beside the point to the OP. If the choice is driving the car with the TPI intake that came on it vs spending money for a different intake, then it's totally logical to save the money and wait - drive it like it is for now. But if the choice is to spend big bucks on a different TPI intake vs spending the same money (or maybe less?) on a good short-runner intake, it would be mighty foolish to spend on the TPI intake when it's demonstrably worse for both power and flexibility.
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Old 10-02-2018, 09:34 PM
  #23  
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Well I am making the 2.5 hour drive tomorrow to check it out and if I want it he will trailer to my town for gas money, so I may have a new car in the driveway tomorrow night! LOL

Converstions on torque vs. HP I think at times gets confused with low end power band being a car with a lot of "torque". In my 1947 chevy I have the 67.5 327 vette fuelie motor minus the fuel injection unit that originally put out 375 HP (crank) and I love the 327 high reving motor, it all comes down to what your driving style is. I just didn't know about the newer vette TPI engines so everyone was very gracious with information and opinions and insights.
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Old 10-02-2018, 10:47 PM
  #24  
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Originally Posted by TheAllusionist View Post
Converstions on torque vs. HP I think at times gets confused with low end power band being a car with a lot of "torque".
Exactly! And good luck with the scouting/purchasing trip. Please tell us how it goes.
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Old 10-04-2018, 03:53 PM
  #25  
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I decided not to purchase it at this time at least as it is too rough inside and outside and thus too big of a project for me to take on with the two projects I have going now as it is. I think it is more suited to being a race car for someone or a part out, looking at the reciepts he spent over $15,000 on the engine and transmission rebuilds in 2014, plus all the performance parts he has on it. If I had a vette from that error that was stalk and I wanted to build it up rather economically, this car is probably perfect for buying and transfering the engine, transmission and performance parts into it, but I don't have one that needs parts. Nice older retired gentleman who's health is forcing him to give it up, even has an enclosed trailer that he used to take it to the races...... Nice guy, wish it was a good match for me, but as is hard for me to justify it and if I am going to get devorced over a car, I would prefer it being in better shape! LOL
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Old 10-04-2018, 11:27 PM
  #26  
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Originally Posted by TheAllusionist View Post
I decided not to purchase it at this time at least as it is too rough inside and outside and thus too big of a project for me to take on with the two projects I have going now as it is. I think it is more suited to being a race car for someone or a part out, looking at the reciepts he spent over $15,000 on the engine and transmission rebuilds in 2014, plus all the performance parts he has on it. If I had a vette from that error that was stalk and I wanted to build it up rather economically, this car is probably perfect for buying and transfering the engine, transmission and performance parts into it, but I don't have one that needs parts. Nice older retired gentleman who's health is forcing him to give it up, even has an enclosed trailer that he used to take it to the races...... Nice guy, wish it was a good match for me, but as is hard for me to justify it and if I am going to get devorced over a car, I would prefer it being in better shape! LOL
Sounds like an interesting project for someone. Also sounds like you made the right choice for yourself, though.
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Old 10-09-2018, 06:33 PM
  #27  
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Dang that one sweet looking car, I wish I could find cars similar to that near me like that. I would remove the air pump.crap if it was a track car.

Hoping you find a sweet C4 that works for you, cheers.
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Old 10-10-2018, 01:13 PM
  #28  
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The car is much rougher than it looks in the pictures, top and body real rough with scratches and chips and the interior plastic was bad, fake carbon fiber applied and ‘go pro’ mounting holes on dash, etc.. What it had for it was a professionally rebuilt motor and transmission and performance parts, a lot there that could be transplanted into another car that is long in the tooth.
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