gmsc.net goes to a page saying that the domain is for sale... What is it supposed to be?

OTTP/Powell Rotated Mounts FTW!

 

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^^ That explains it! Thanks.

 

I've spoken with the guys here and looked at the GM piece which Ryan and Matt are familiar with. You are technically correct in saying you can rotate the engine with the mount. I say technically because it reality, you cannot.

There are 3 transmission mounts and removing the slop as your doing allows less than 1 deg of engine rotation. GM does 22 deg. So in theory you could move something .1" and say you rotated it but in practice no significant rotation has occurred.

By holding things in tighter and 'rotating' the bushing you gain control which is why you eliminate wheel hop. Any poly mount accomplishes this as well but gives a lot of engine vibration which is what people have complained about and why ZZP did the Gen 2 mounts. The OTT piece uses a 'rotated' rubber bushing and they are doing something like this:

http://www.zzperformance.com/grand_p...les1.php?id=45 which we added to our site 5 years ago.

Instead of going that route, ZZP uses a solid rubber piece which we feel is a superior option to the rotated rubber piece. Our part in function does the same thing as the others discussed in this thread but it will take significant time and effort to re-educate the public on what this mod is actually doing. Consumers have a misconception about rotating the engine which isn't the proper way to advance the community.

 

zooomer then why did i still have hop all the time with a bwoody engine mount and poly inserts? as soon as i switched to the ott mounts there was absolutely no hop on the street. and the bushing itself is not rotated. the extra height is built into the mount itself

 

That is not the scientific method. There are any number of reasons one mount or setup could do something and another would not. I don't have all the parts here to analyze.

The fact remains that you cannot rotate the engine with any significance when you have 4 total mounts and only change one or two of them. This is just a fact that would apply to any solid object held by 4 locations. Sure you can remove one mount, loosen bolts and re-install the mount to eliminate slop and it may technically rotate the engine a fraction of a degree but there no benefit coming from rotating the engine because the amount is insignificant. The gains are from removing slop and changing the preload tension to engine torque. (the engine/trans can't bounce around or enter a harmonic)

My point is not to say that OTT's mounts don't work. I'm not implying that at all. What I am saying is that calling them a rotated mount incorrectly gives people the impression that they are rotating the engine to straighten axles and therefore do something similiar to the GM build. This is totally false.

 

Hmm.. interesting. This is exactly what i thought the OTT mounts accomplished -- straightening out the axles on cars that have been lowered with shorter springs.

 

WRONG. In the strongest possible terms Zoomer I MADE THE BUILD BOOK MOUNTS. I made the OTTP mounts. They do the same thing. The motor is rotated. HISTORY LESSON: John Heinricy coined the term "rotated mount" to explain to Grand Am officials what we were doing as he did NOT want them to think we were setting the engine back in the chassis, as we were not.

ALSO. The axle misalignment is 17 degrees and the Powell mounts made for Grand Am racing and OTTP correct that through rotation of the motor trans through the horizontal axis of the mid chassis mounts.

You say"it may technically rotate the engine a fraction of a degree but there no benefit coming from rotating the engine because the amount is insignificant. "

You are wrong. Go measure. For someone like yourself who prides themselves on speaking the truth from facts read what you say:
" I don't have all the parts here to analyze.

So how can you make these statements?
EZ. So you are wrong ; you dont have ...(wait for it) all the facts. Oh and Zoomer? ALL M 35 /F23 DELTA CARS HAVE 4 TRANS ENGINE MOUNTS.

we expect better from you.

GM does 22 Degrees? Gm does and did nothing They never made Grand American approved rotated mounts. I did, and after me, GBM to the same drawing/design I did. Made in Canada.

 

so which reduces wheel the best?

and who does it wiht the least amount of vibration??

 

^^^

So then I'm not crazy!

 

Well. Yes, but its not what you think. The axle goes from a slightly downward slope along the horizontal axis at OEM ride height with stock springs, to (depending on the drop) with lowering springs, a sharply upward slope along the horizontal axis, pivoting mainly at the plunge (inner) cv joint.

The cv joint can handle that pretty much. What it cant handle is vertical misalignment which it has (17 degrees from centerline) in the OEM config. Lowering springs dont affect the vertical misalignment.

If you know what a tractor pto driven bush hog is, cut grass with it, and while still rotating the blades lift the table on a sideways slope. Violent hop results. Thats what happens here


Hope this helps.

 

^^^^ no exactly what u mean!!!!

 

John knows what hes talking about...i have the rotated mounts, made a world of difference and even with the stg2 mounts theres hardly any vibes, i had poly inserts and snapped an axle still(and that was totally stock!) no problems yet with these mounts and thats with the TVS

 

QRL- Zoom is referring to the GMRacings forward rotation of the motor on drag cars when he mentioned 22 degrees.

What I would like to know is where you are coming up with this 17 degree vertical misalignment? Since parallel misalignment is typically measured as a distance, you would need to state the perpendicular span that you are referring to. In the case of a CV shaft, it should be safe to assume that you are referring to the center shaft angle compared to the yoke. Any Cobalt I have ever worked on has had nowhere close to 17 degrees of vertical misalignment. That would mean that if there is 17" between the pivot points there would be nearly 5" of misalignment! That sounds a bit high to me.

 

in for observation

 

I stand by my word that you are incorrect.

Clearly no consumers reading this thread have any idea what we're talking about, or what physics would play out or they wouldn't be so confused. That's why I'm saying it's misleading to tell the customers you are rotating the engine.

For you and others think about this example in your head: You have a piece of paper on your desk. You then connect each of the 4 corners of the piece of paper to the 4 corners of your desk using rulers. Each ruler is screwed into your desk with 2 screws. You then are instructed to rotate the piece of paper by unscrewing only one ruler and changing its size. it's impossible. you would have to change a minimum of 3 rulers. now you could loosen the screws on the other 3 rulers and tweak the paper just a smidge, then change the length of the removed ruler by maybe 1/8" but the paper rotation would not be visible. and this is what i'm saying.

open any hood with 'rotated mounts' and you will not be able to see the engine in a different location. open the hood of a car like Matt's 8 sec GP with an engine rotated 16 deg and the difference is HUGE! But this is the problem in a market where people are new and lack these understandings. They don't know what something is supposed to look like or how things would be different, they just know if the car is wheel hopping or not. So you can say or call something anything you want. in this case, incorrectly.

 

haha dude you quoted your own post... there is some good reading in here. kinda makes me laugh at times too lol

 

Hmm. I thought there was only 3 mounts. I guess I'm not sure where the 4th resides.

1 mount on the passenger side on top and 2 mounts underneath (Front and back). I replaced both the underneath mounts with the OTT mounts. With the two bottom mounts out, the engine was rotated a bit forward to get the new mounts installed.

Is this not rotated?

I understand the example posted above, but I don't think our engine is mounted the same way your piece of paper is to the table.

 

we do have 4 mounts. another is on top of the transmission. but i agree, i had to rotate the engine quite a bit to get my ott stage 2 mounts to fit

 

And to add to that.. I wish I had before and after pictures to prove this, but the distance between the front of my engine bay to the supercharger was decreased actually quite a bit. So much so that I had to re-route my coolant hose going to my Option B tank because the pulley on the supercharger was touching it. I had at least a good inch of room before the 'rotated' mounts were installed.

Just sayin'..

 

The axle misalignment is not 17 deg on Cobalts we've just measured, nor is it possible to rotate the engine anywhere near 17 degrees. I'd like to hear your math on this.

What is the measured misalignment?
What is the distance the motor would have to move to correct it?
What is the difference in length of your mounts to a stock one and how many degrees does that rotate the engine?

After doing the math, measuring the cars and watching this thread play out, I'm quite certain no one knows or has done the math or really has any idea what-so-ever what is taking place here. Not to say that they have to, in the end people just want parts that work. However, people should also want accurate descriptions of what is going on or we're all discussing non-sense and looking foolish to other communities that have outpaced this one drastically in the same time frame.

You have cases like this one:
https://www.cobaltss.net/forums/2-0l-lsj-performance-tech-47/hopping-issie-still-218064/
Where a guy with OTT mounts is still having wheel hop. The problem as I see it, is that if no one knows what the mounts do, how they function, if axle alignment is an issue, etc. then how can he or anyone else possibly be helped or continue in the pursuit of a fast ET?

 

Zzp stage 3 or go turbo.

 

well if this is the case i hope is doesnt make it harder to put in the tvs when i get it?

 

Zoomer I did the work in 2004. I worked with GM engineers. We did the math together. You somehow are challenging the GM build book now? I never said you rotate the motor 17 degrees. Wow. where do you read this. measure the centerline output of the trans shaft and the center line of the knuckle at rideheight. what you got? dont ask me for the drawings or the calculations You are in the same business. do it yourself. OTTP sell the mounts, you compete against them in the marketplace and you want to know the calculations behind their products? Nice work ifyou can get it.

I am not going to go back and forth with you on this. You say many things some right some wrong. I have no idea what car you are measuring but clearly the axle is misaligned. What did you measure?



the fact is that power hop is a consituent of many things, and this forum becomes tiresome with your posts challenging stuff. The last go round I hadwith you was on the Ion Redline intake . You know the one that OEM is 3 inches or more, that you say is not. I posted the pictures with measurements.

so please, take it away and forget this. I have the PM's from folks who resolve their powerhop issues and conclude the mounts did their work.

If they didnt people would not buy them.

thats what I think

I gotta call John Heinricy and tell him he was wrong to call it rotation. Coz zoomer says its not?

lets see. raise the back of the motor. Lower the front of the motor. Consumers can see that something moved. we call it rotation. Ugh.

sorry not vertical, read horizontal, my bad. I was tired last night. I apologise for the error. It is evidentally a parallel misalignment if that is the correct word, you look at it you can see it.

it does I am glad I have a Redline more room. Option B hoses are a bitch to route on a Cobalt as well the tie bar is so close.

I cant imagine getting to the hold down allen bolts on a TVS Cobalt. I would stud those right qwik...