woodhouseporsche

I'm experiencing some driveability problem w/ my 964 Turbo. When I downshift from any gear at a high rpm, the car pulls to the right somewhat when I release the clutch. Any ideas on what's happening? It's not bad when I'm downshifting and the rpm is below 3000, but very noticeable above 3000. It feels somewhat unstable at times.

I recently added 18" wheels, so last night I checked to make sure the lugs were secured properly (96lbs). Your help is appreciated much.

Kiwi Carguy

I'm experiencing the same thing in my 964T. I think it's the engine moving on it's mounts. You can change them to semi-solid mounts or solid mounts depending on what result you are after. I may be wrong? Any guru's out there feel free to correct me

ZAMIRZ

Are you rev-matching on downshift?

woodhouseporsche

What is Rev-Matching on down shift?

The car seems to slightly lunge to the side on the downshift.

Kiwi Carguy

Amir...yes certainly. I notice it more in my 964T than I did in my 993 C2 even though they mention the RS engine mount mod allot more on the 993 board than here on the 964T board. I don't have to be overly aggressive either for it to happen. But it's obviously allot more noticable on the track going flat out.

Woodhouseporsche - Rev matching is when you blip the throttle on the downchange so that the rev's match approximately what they will be when you engage the gear your changing to. Does that make sense

With the engine mounts the theory is that if there's too much movement in the engine mounts the motor "shifts" unbalancing the car. I believe our engine mounts have a bolt going through a large rubber "bush". The race mounts are solid which eliminates movement but will increase vibration and noise. Anyone feel free to correct me if I'm wrong

SonnyV

Rev-matching is when you blip the throttle (while the clutch is disenage) to bring the rpm up to match the speed of the next lower gear when I shift into it.

Regards,

Sonny

Kiwi Carguy

Solid mounts - http://cgi.ebay.com/ebaymotors/ws/eB...spagename=WDVW

Factory mounts - http://cgi.ebay.com/ebaymotors/ws/eB...spagename=WD1V

To be safe I would suggest a Porsche specialist check the rest of the car over just in case it is something amiss. You mentioned your 18" wheels and lugs. If the lugs weren't tight that'd result in a bad vibration not usually what you've described. It would also be constant and not just on a downchange.

woodhouseporsche

Is it safe to drive until I can get it repaired? I have a 200 mile trip planned today and I do not want to damage the car or myself if I shouldn't be driving it.

I checked the lugs, they are tight enough and don't seem to be the cause of the lunging.

woodhouseporsche

BTW: the car just started doing this w/in the last few days. If there was this problem before I certainly did not notice it...but now it's very noticeable and annoying.

Staffan

Thanks for the information about the engine mounts.
Just what I was looking for.
Anyone using this brand ?

Kiwi Carguy

Woodhouseporsche - It's too hard to say over the internet without obviously seeing it. I would suggest getting it checked before you leave as it may be something else. How handy are you to a competent mechanic. If you do go just moniter if it gets any worse and if so pull in somewhere and get it checked. I can't think of anything else that would be showing the same symptoms unless your shocks were absolutely stuffed and the car is diving as your downshifting unsettling the rear. If it is the engine mounts if they're stuffed the motor can't go anywhere so you'll be fine to drive apart from the fact the you'll have to take care when downshifting at speed to control the car. It all comes down to your timeframe, how bad it actually is and your access to mechanical help.

Staffan - Glad I could help. Think of it as a return favour for the seat instructions I'm not running fixed mounts yet but do intend to. The shift we're referring to isn't bad enough on the road for me to worry about just annoying on the track. I'm not sure on brands although I know Porsche do there own for the RS's. If you search on the 993 forum you'll find more on it. It's a relatively easy DIY job from what I've read and you can also do the gearbox mount as well. I would imagine any of the ones on ebay would be o.k as they're a pretty straight forward design from an engineering point. The downside is increased engine noise and vibration. But is that a bad thing

woodhouseporsche

Thanks for the info. I wonder if the shocks are bad...I'm also experiencing a lot of "wandering" on the road now that I've switched to he 18"s. The car is really all over the road at times, unless it's a perfectly smooth flat road w/out any ashphalt ruts. The car has 71K on it, could the shocks be done?

How long do shocks usually last?

Can I replace the motor mounts easily myself on my 91 Turbo? I'm not all that handy, but I can do simple jobs.

Thanks!

cobalt

Regarding the solid engine mounts. I used a set I picked up from Kelly Moss on my SC. The plus.....made for a very nice crisp shift in the old 915 trannys. The minus.....very loud internally all engine noise and vibration is transfered through the car. OK on the track but not at all useable on the street. Just my .02.

JBH

This is sounding more like a suspension problem. I think you can expect shocks to last 50K miles or more. Lift the car, let the wheels hang - a bad shock will show leaking fluid down the tube.

This sounds like a good opportunity to go through the entire suspension and replace worn and tired parts. If you haven't installed stiffer and shorter springs, you could do it now. Replace and upgrade bushings, check wear on CV joints, check the steering rack, change/replace shock mounts, change replace motor mounts, and replace the shocks with RS or better.

cobalt

The turbos were actually known for worn shocks as early as 18k miles although they can last as long as 50k depending on driving habits. The Boge's were not so great and failed early. It is possible you lost a shock, It might be the best place to start looking. Also a good time to upgrade.