North American Turbocoupe Organization



Here is a good question
Ryan H Offline
Posting Freak
#11
I've been told (but I have not confirmed) that the valves, HLAs, and rocker arms in our heads are different than the RR setup, and that the roller rockers from the RR setup makes it so the lift is virtually the same as the slider.
'88 TC Smile Walbro 255HP, Stinger FMIC, PIT BOV, Pro 5.0, Kirban, RR cam, FRPP strut tower brace, T3
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AerobirdMotorsports Offline
Banned
#12
Quote:Originally posted by russ c:
It's odd that many of the 25 fastest TC's have a "crap RR" and have times as good as they do.
Only 5 of the Top 25 use it, and only 2 of those are in the Top 10. Versus 8 A237's and countless stock cams.
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AerobirdMotorsports Offline
Banned
#13
I tell you what Matt, I'll go drag racing on March 30th when the track opens with RR and run whatever my car will go, then I'll stab the stocker back in and see how much faster or slower I go. Then we can all be happy again. :p

As far as my "outburst", his post IMPLIED that he was having power issues,

"I am trying to find the sweet spot. Under full load, the motor still misses from 3K to 5K and once 5K is reached the motor seems to run out of steam. I understand that the RR stops at about that RPM, but it just does not pull like the stock slider did in the D port head over the oval port with the RR set at -4*."

That sounded to me like he was trying to find some other issue to blame a power loss on, instead of seeing if it was the cam. And seeing as how HE mentioned the cam, and his percieved displeasure with it, I stand by my statement as NOT being unsolicited. I was throwing out the possibility that it's just too small of a cam for him since HE brought it up.

And Ryan,
That's 100% not true. Both the RR and the TC cams have the same base circle and a 1.6 ratio follower. The geometry is identical.
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Pete D Offline
Administrator
#14
Quote:Under full load, the motor still misses from 3K to 5K and once 5K is reached the motor seems to run out of steam.
That miss is most likely NOT due to the cam and could, possibly, affect the run out of steam issue also.The miss is a more important issue, at this point, than the run out of steam issue

This is not to say a RR does not run out of steam at high rpms. So does the stock slider. The RR is a truck cam, low lift, high velocity, lots of low end torque.
Pete Dunham


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Matt S Offline
Posting Freak
#15
He already knows the RR is not the same he stated it. He didn't ask if it was crap. He didn't ask if it was causing his high rpm torque loss (which it does all things being equal)

You fail to take into account the overall geometry of actual valve lift; your numbers are the dimension of the cam without regard the geometry of the followers and their effect on multiplying lift.

You try to justify your point by narrowing the number of people down to the top 10 who use it. You fail to state any torque gains achieved by the loss of 40 hp. Apparently you did not comprehend my calculations of how HP is measured. And your closed ended statement that it can't make power has people in the top 25 saying different.

Your opinion is a closed ended narrow statement that it can't make power and nobody should use it even when the 3rd fasted TC is using it. Your opinions and lack of understanding of cam/follower geometry have failed to provide sound justification for your view.

My unabated stance is the RR can be useful to some people's driving styles and performance requirements.

And so if anyone else would like to take this original question of wire problems and rpm miss (which have nothing to do with the cam) and post your experience with the RR be my guest. I am done in my explanations of what an insensitive, biased, infactual response you had.
Sold it Sad*
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AerobirdMotorsports Offline
Banned
#16
Hold on, because I'm not understanding here. I don't have any knowledge of geometry? So the ranger roller is magic because the valve length, rocker ratio, lifters, and base circle are all identical? How can it POSSIBLY create different actual lift when every single geometry number is identical? Could you possibly explain that? Because the way I see it it has to produce less actual valve lift then a slider because, well, it's smaller, and every other dimension is identical.

I stand by my statement that the cam is too small to provide the magical low end torque. Even on IHI RR TC's I've owned and driven it doesn't pull as hard on the bottom compared to a non-worn stocker, and YES, I've owned 2 identical TC's at the same time with only that difference and quantifiably raced them. Again, I say to YOU, that the sole and ONLY reason the RR is adored, is because it's CHEAP.

But that's OK, you have every right to sit here and do all the shouting at me because in the specs table I called your beloved cam "crap" even though I own a few. Like I said, I will go race my car and swap cams and put the issue to bed.
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AerobirdMotorsports Offline
Banned
#17
Now, for the spark problem.

Does the car miss at the RPM's indicated or is it just the timing light issue? If it does miss I'd look at the coil real quick. Just check the resistances with an ohm meter to be "sure". Pull the cap and see if you have any build-up on the cap or rotor preventing good conductivity. It's been my experience that misses in certain ranges and not from idle on up have nothing to do with the wires.
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