Supra Forums banner

1 - 20 of 32 Posts

·
A State of Trance
Joined
·
2,695 Posts
Discussion Starter #1
Like the topic says, anyone of you thats using it? Post some pics and tell me what you tought/think about it :) Does it make any diffrence or ist just like stock?
 

·
Registered
Joined
·
1,317 Posts
They made a significant difference on my cousin's integra before the engine rattled itself to death, so I don't see why it wouldn't on the supra. The gain is minimal without the crank pulley though, so I wouldn't bother.
 

·
Registered
Joined
·
1,113 Posts
Its always an upgrade to do it. anything you do to lighten up the motor spinning, then its easier to rev up.

~~steven
 

·
Registered
Joined
·
620 Posts
Most 7M owners usually DONT use an undedrive pulley. Long crank motors, like the 7M, have inherent crank vibrations that the stock pulley is designed to dampen.
 

·
Registered
Joined
·
6,475 Posts
to add to Robbman post

the unorthodox is an undamped pulley. What this means is, the 7m and ALL inline six motors have lots of harmonics which if they go undampened will destroy a motor in short order. Now if the motor is 100% race I would not even fathom putting on an undamped pulley on the car. Asking for trouble. There is only one aftermarket pulley that is damped and is not underdrive and weighs 3 lbs lighter than stock. Comes from ATI :)
 

·
A State of Trance
Joined
·
2,695 Posts
Discussion Starter #6
Allright, thanks for the info :) Was near to order one acutally but now im glad i didnt.
 

·
Rock'n Death with Spikes!
Joined
·
155 Posts
I've been running one since '96 and I know someone thats had one on since '92(Cusco) when he bought the car new. I know what the books/Reg say and such...Maybe I'm one of the "lucky" ones? :x:
 

·
Registered
Joined
·
6,475 Posts
Supranaut said:
I've been running one since '96 and I know someone thats had one on since '92(Cusco) when he bought the car new. I know what the books/Reg say and such...Maybe I'm one of the "lucky" ones? :x:
Or not putting down enough power ;)
 

·
Registered
Joined
·
3,727 Posts
specs? pics?
 

·
Registered
Joined
·
6,475 Posts
Supranaut said:
I've been running one since '96 and I know someone thats had one on since '92(Cusco) when he bought the car new. I know what the books/Reg say and such...Maybe I'm one of the "lucky" ones? :x:
add to that "list" Dinan of BMW.
BMW AG also.
Toyota.
 

·
7m > 2jz > 1jz
Joined
·
1,518 Posts
ive just always heard that these werent that great for the 7m's.

-sean
 

·
Registered
Joined
·
3,877 Posts
it's just risky, the dampener is there to stop the harmonics from the engine. Inline 6's are inharently STABLE, meaning they don't need it THAT much, but anything that isn't balanced quite right in the engine (even from the factory the spec isn't as tight as you'd want), it will cause problems

Hell, on turbo motors there are all kinds of harmonics because of the turbo, so it's your call, personally I'd go with a lighter flywheel first, and have the entire rotating assembly spin-balanced together (that incudes the pulley and flywheel)...
 

·
A State of Trance
Joined
·
2,695 Posts
Discussion Starter #14
If i get the pulley and crank balanced together it must work? Sould i balance flywheel at the same time together with the pulley and crank? :)
 

·
A State of Trance
Joined
·
2,695 Posts
Discussion Starter #18
tookwik4u89 said:
I had my engine balanced as a set with the u/o pulley, no problems, no dynos but running in 12's.
Gonna do that me to then ;)
 

·
This Is Why I'm Hot.....
Joined
·
1,984 Posts
Supranaut said:
I've been running one since '96 and I know someone thats had one on since '92(Cusco) when he bought the car new. I know what the books/Reg say and such...Maybe I'm one of the "lucky" ones? :x:
figgie said:
Or not putting down enough power ;)
Hello Guys,
A UR pulley went on my engine in '98 when it was rebuilt. I did this before I was aware of all the negative press. Having already gone to the trouble, I decided to leave it on.

I did notice a harmonic mid-rpm, dissipating in the 3800-4000rpm range, which is precisely the reason for the dampened OEM pulley, to reduce noise. The 7M-GTE is internally balanced, which means it does not rely on external masses like v engines do. I acknowledge the 400MHz harmonic, but view it as more of a comfort issue, than one of inherent reliability. Heinz Heisler bears this out in his book Advanced Engine Technology, not bearing nearly the bad news that the Dinan white paper does. Heh, Reg is a longtime friend, and I know better than to bring up pulleys, LOL.

Anyway.....
Eight [8] years later, with ~70K miles on the rebuild: ~350rwhp for a couple years, then over 400rwhp for several thousand miles. Currently running DD on an HK$ Stage IV+ mod level just under FCO...awaiting me to schedule the ITS TO-4E, 550s, & AEM installs. Oh, the rebuild was stock, except for 0.5mm OS OEM pistons [~2990cc] & 3mm MHG. The shi+ was machined twice since I blew two [2] pistons @ 35K miles, LOL. FPR failure @ WOT.

Soooo, the engine failure allowed me to see what ~35K miles of UR underdrive pulley use did to the bottom end. Nothing. The bottom end was pristine, except for broken ringlands on #2 & 5 pistons. LOL.

At ~70K miles, my only complaint is throttle response from the thick-a$$ MHG. Other than that, my 7M-GTE engine on the UR pulley has been nothing less than a stalwart performer.

Take care.
 

·
make that blkGT4294 LOL!
Joined
·
827 Posts
This damned subject will be debated forever and ever... I plan on running one on my engine. There are reasons NOT to run one and no good reasons to run one. However the stocker looks like shit!
 
1 - 20 of 32 Posts
Top