Performance Upgrades Questions

[HuhReally]

To be more clear, the rest is assuming you have mashed the throttle to wide open and you feel the need for speed in your TR6. Engine A makes 131 HP and engine B makes 155 HP but they both make a constant 125 LbFt of torque. That last condition determines quite a bit. Namely, they both will accelerate at the same rate until engine A needs to shift. That engine B has a higher redline than engine A, approximately 1000 RPM higher. This illustrates that when we talk about HP (peak HP that is) for bragging rights etc, it is good to ask, at what RPM? Another example is why do people like supercharged engines? Because a supercharged engine can produce more torque at a lower RPM compared to a NA version of the same engine. That torque is esentially the grunt that accelerates you from that RPM.

Or for example, you want more HP in your TR6 engine? Get the all the parts finely balanced along with a steel fully counterwieghted crank from Racetorations, then you could safely spin it to 7K. If you changed nothing else, it would have quite a bit more HP.

[skootch13]

Exactly why I did GP2 and not GP3. When am I ever going to be at 5500 rpms in my 6? I was worried about gassy smell, startability, smooth running etc. Maybe the GP3 doesn't have those problems, but I wanted to be sure. Mine is quick enough for me.

[TRick6]

I have argued blue that it ain't the HP, it's the torque, that turns the earth when you let the clutch out.. In the auto performance world, too much emphasis has been placed on HP, but torque is the work quotient. I want a ton of torque. All earth moving equipment is operated a little above idle but the monstrous torque is development down there so that high RPM's are not needed. There is a HP to Torque relationship when the work is twisting but HP seems to have capture the attention of the auto industry. I guess when it changed over to the horseless carriage it is the animal relationship picturing 2 horses pulling your wagon as opposed to 350 ft.lbs of torque. What is a torque? A force placed on an object to rotate it. What? What does a torque look like anyway? A lower case Greek alphabet T. Heck, I can't relate to that. How does a lower case T move my carriage. It doesn't even look like a horse.

[tdafforn]

I think people are offering very sane advice.. think about how you drive the car and how you want to enjoy it.. these cars were never really intended as screamers but saying that they can be really good fun. I opted for the supercharger option when they were available from Moss.. Lotss of torque from low down so less need to change gear and great in the mountains.. but transmission had to be upgraded somewhat to cope.

[lfmTR4]

Well said. I’ve always thought of torque as what tears your diff mounts or bends your frame if you don't reinforce them when upgrading your engine. LOL

Seems like everybody sees performance as HP, but to get it you have to be able to apply the HP to the road hence suspension upgrades. Once that is done, then you have to stop it hence brakes. By the time you’re done you’ve built a new car. Kind of an expensive way to get “performance” as a system which is best and less expensive bought all together.

Best to just enjoy it for what it is. To me 50mph in a well driven 6 beats the snot out more HP in a straight line. It’s really how you drive it.

I have argued blue that it ain't the HP, it's the torque, that turns the earth when you let the clutch out.. In the auto performance world, too much emphasis has been placed on HP, but torque is the work quotient. I want a ton of torque. All earth moving equipment is operated a little above idle but the monstrous torque is development down there so that high RPM's are not needed. There is a HP to Torque relationship when the work is twisting but HP seems to have capture the attention of the auto industry. I guess when it changed over to the horseless carriage it is the animal relationship picturing 2 horses pulling your wagon as opposed to 350 ft.lbs of torque. What is a torque? A force placed on an object to rotate it. What? What does a torque look like anyway? A lower case Greek alphabet T. Heck, I can't relate to that. How does a lower case T move my carriage. It doesn't even look like a horse.

[L.O. Guvna]

I will add that it is nice that we continue to find a few hp here and there. It is great to catch up on the bits - what else can we do to the head and cam, for example. While Kai and WBC is dark and hiding, there are others continuing the work to improve the whole package. I still like thinking about the lightened crank - maybe 5 pounds, and how that rotation improved engine balance. We talked recently at a Dallas 6 gathering, about parasitic power loss - even the cam takes away from power, somewhat like an accessory tied in to the crank with a belt.

Good to see Al's vega pics - thanks for sharing those!

[TRMark]

I've been driving my '73 TR6 since 1975. I had three daughters and even bolted 2 lap belts to the shelf behind the seats. They are grown now themselves, but their excitement at being dropped off at the elementary school in Daddy's TR is the biggest thrill I ever had in my TR. Make sure you have pictures and video of your daughter. She will never forget it.

All of that being said, I always wanted more giddy up. Several years ago, I added Good Parts GP2 Cam, and shaved the head to 9.5 to 1 while getting a valve job. I freshened up the original carbs. Wow!!! What a difference! The idle quality is as good as it ever was, and the first time out on the interstate I looked down and was cruising at 90 mph without the overdrive. My experience has been that if the carbs are running badly and can't be adjusted, its usually the throttle shafts need replacing. My '73 TR6 has 200,000 miles and still ticking.

TRMark