Show full size 924Board.org
Discussion Forum of 924.org
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
 Technical FAQ924 FAQ (Technical)   Technical924 Technical Section   Jump to 924.org924.org   Jump to PCA 924 Registry924 Registry

GRM Trashes the 931
Goto page Previous  1, 2, 3, 4, 5, 6, 7  Next
 
Post new topic   Reply to topic    924Board.org Forum Index -> 931 Discussion
View previous topic :: View next topic  
Author Message
Rasta Monsta  



Joined: 12 Jul 2006
Posts: 11332
Location: PacNW

PostPosted: Wed Mar 31, 2010 11:57 pm    Post subject: Reply with quote

ic932 wrote:
(which have sustantial + quality bearings, BTW)


Next time you're in Oregon you can look through my 2.5 roller junk box. I have some really ugly ones in there. . .heat and oil cause them to shed the seals, then they go dry and get crunchy in a hurry. . .fairly high RPM, and a decent amount of mechanical tension as well.

I'm not saying they need to be changed every six months, but they do wear out.
_________________
Toofah King Bad
  • Shaggy (1980 931) - Got Boost?
  • Red (1987 924S) - Pro44/Spec944
  • Weiße Scheiße (1987 924S) - In Progress
Back to top
View user's profile Send private message Visit poster's website
Joes924Racer  



Joined: 03 Nov 2002
Posts: 11965
Location: Oregon, Denver Colorado native!

PostPosted: Thu Apr 01, 2010 12:07 am    Post subject: Reply with quote

Rasta Monsta wrote:
ic932 wrote:
(which have sustantial + quality bearings, BTW)


Next time you're in Oregon you can look through my 2.5 roller junk box. I have some really ugly ones in there. . .heat and oil cause them to shed the seals, then they go dry and get crunchy in a hurry. . .fairly high RPM, and a decent amount of mechanical tension as well.

I'm not saying they need to be changed every six months, but they do wear out.


BANG is the noise mine made duringinnerwheel bearing failure.
It echoed thruout the car. Quite a loud soundsound. Any 1 else ex. this before.
_________________
1979 porsche 924 Na
1980 porsche Turbo 931GT Replica
Have u ever driven a turbo.
Back to top
View user's profile Send private message Send e-mail Visit poster's website AIM Address
ideola  



Joined: 01 Oct 2004
Posts: 15462
Location: Woodstock IL

PostPosted: Thu Apr 01, 2010 12:32 am    Post subject: Reply with quote

ic932 wrote:
What mickey mouse engineering would require the renewal of quality OEM seals every 2 years? Waterpump every 2 years? Rollers/tensioners (which have sustantial + quality bearings, BTW) every 2 years?

Dave, that's a ridiculous statement to make. Porsche is infamous for its onerous and expensive maintenance intervals. Ever looked at the valve clearance adjustment requirements on a 914? What is it Paul, like every 10K miles or something ridiculous like that?

The point is, the waterpump may not need replacing every 30K miles, but if the bearings seize at 45K miles you'll be cursing yourself (or your mechanic) for not taking care of it while you were doing the timing belt job. This is why conventional wisdom (whether recommended by Porsche or not) is to go ahead and do it because otherwise you incur the same expense twice to disassemble the front of engine components necessary to get to the water pump, and accept a relatively high degree of risk, financially speaking, given the consequences of a failed water pump on the 2.5L platform.

Granted, your experience and Paul's may not support the paranoid approach, but your view is no more empirical nor less anecdotal than the views of those who recommend, based on their experience, doing proper FOES every 30K miles.

Bottom line, some people like living closer to the edge than others. Maybe the risk of bent valves and doing a head job is no big deal to you, given your vastly superior wrenching skills. But I'd be willing to bet that to the vast majority of potential 924/944 owners, bent valves would be a catastrophic event that would likely result in the death of yet another waterpumper. And at the rate they're showing up in boneyards and at the scrappers usually due to bent valves, I'd say the anecdotal evidence supports my view.
_________________
15 981 GTS | 88 924S SE | 82 931 Holbert | 82 931 Rallye | 81 937 | 81 Euro 931 | 81 Weissach | 80 US 928 | 80 US 931 '941' | 80 US 931 | 80 931 GTR | 79 Sebring | 78 D-Prod Replica | 78 w/D-Prod kit | 78 Poli-Form | 78 Limited Edition | 77 Martini
Back to top
View user's profile Send private message
ic932  



Joined: 11 Feb 2005
Posts: 1104
Location: UK

PostPosted: Thu Apr 01, 2010 1:36 am    Post subject: Reply with quote

It's not ridiculous in the least. And again you are mistaken into the belief that this so called FOES has an official Porsche service mandate. Are you trying to compare a Porsche shedualed 10k valve clearance job in the same light as preventative wholesale engine component renewal based on the percieved wisdom of the online community?

I don't think you are comparing like with like on this point Dan.

There is a very good reason for a preventative FOES. Its to address negect Dan. Neglect isn't a good enough reason to add or subtract from an engine's basic design and performance.

On this basis, it has no place in a sensible debate about the 931 vs 944.
You must compare the 2 cars in stock form and in properly maintained condition. Neither model is a money pit on this basis. But both can be if you buy a lemon.
Back to top
View user's profile Send private message Send e-mail
ic932  



Joined: 11 Feb 2005
Posts: 1104
Location: UK

PostPosted: Thu Apr 01, 2010 1:42 am    Post subject: Reply with quote

Rasta Monsta wrote:
ic932 wrote:
(which have sustantial + quality bearings, BTW)


Next time you're in Oregon you can look through my 2.5 roller junk box. I have some really ugly ones in there. . .heat and oil cause them to shed the seals, then they go dry and get crunchy in a hurry. . .fairly high RPM, and a decent amount of mechanical tension as well.

I'm not saying they need to be changed every six months, but they do wear out.


Why would you keep a box of worn out parts lol. Yes, wear items generally wear out.. Pease post pics of your 2 year old (30K) worn out parts Rasta. This is the evidence I would need to join the FOES bandwagon.
Back to top
View user's profile Send private message Send e-mail
Rasta Monsta  



Joined: 12 Jul 2006
Posts: 11332
Location: PacNW

PostPosted: Thu Apr 01, 2010 3:32 am    Post subject: Reply with quote

ic932 wrote:
Why would you keep a box of worn out parts lol. . .Pease post pics of your 2 year old (30K) worn out parts


Don't know why I kept them, they went into a box while I was working and never got thrown out, I guess (there is a similar explanation for a lot of the clutter in my poor garage).

Unfortunately, I don't know how long they were on the car, so I can't help with that part of it.

Also, to clarify the level of my personal fanaticism, if I were starting at zero miles on a 100% fresh motor, I would refresh BELTS ONLY at 30-45k, and refresh rollers and water pump at the SECOND interval. I would also change shaft seals only on evidence of leaking, or at the THIRD interval.

But that's the rub, isn't it? None of us are starting with a zero mile motor, so some extra caution is warranted.
_________________
Toofah King Bad
  • Shaggy (1980 931) - Got Boost?
  • Red (1987 924S) - Pro44/Spec944
  • Weiße Scheiße (1987 924S) - In Progress
Back to top
View user's profile Send private message Visit poster's website
fiat22turbo  



Joined: 18 Jan 2006
Posts: 4040
Location: Portland, OR

PostPosted: Thu Apr 01, 2010 5:20 am    Post subject: Reply with quote

Cross-link to the GRM discussion with input from folks at the Magazine:

http://grassrootsmotorsports.com/forum/grm/the-porsche-924-turbo-folks-are-unhappy/20500/page1/

Hopefully some good info for you guys
_________________
Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)
Back to top
View user's profile Send private message Visit poster's website
Nein37  



Joined: 29 Dec 2009
Posts: 513
Location: New London, CT

PostPosted: Thu Apr 01, 2010 6:30 am    Post subject: Reply with quote

Truly the main benefit of the 931 over the 944 is the ability to easily make significant increases in horsepower. If this wasn't mentioned in the article than I'd say it left out a fairly important fact.

Keeping in mind that the US 931s ran less boost than their Euro counter parts. They were purposely detuned for whatever reason, maybe to allow them to run on 87 octane fuel or to ensure they didn't exceed US 911SC performance figures... who knows?

So your performance options include:

Stage 1: Take a stock 924 Turbo, get a boost controller and a boost gauge, turn the boost up to 10-11 PSI and you're over 170hp maybe more. Costs about $200 and takes about 1/2 hour.

Stage 2: Add an intercooler to that setup, turn the boost up another 2 PSI and you'll see over 200hp.

Costs vary... if you can manage to find a CGT intercooler expect to pay + $1500 for it or conversely spend about the same to fab up your own IC setup.

But...
Stage 3: If you get serious about it like some of the folks here, EFI it, add some goodies, optimize the tuning, and high 200hp figures aren't out of the question.

The 924 GTS CS output 275hp at 1.1 bar and this is most definitely achievable with an intercooler, boost gauge and a proper EFI setup.

And all of this can be done on the same bottom end. Its plenty strong enough to take it.

Compare this to a 944
Rated in US spec at 143hp ... it's often quoted as 150hp, certainly not all that impressive. Worse its VERY difficult to get any more power out of it. The question "how do I get more power out of my n/a", is asked over and over again on the 944 boards with the same answer given back... "if you don't have loads of money to spend you're stuck at around 150hp and even if you do have a lot of money to spend don't expect to crack 165hp".

This to me is a significant consideration when comparing the 931 with the 944, after all, they are SUPPOSED to be performance cars. The ability to quickly and easily get the 931 to perform respectably with the Stage 1 mods, far out weighs any perceived difference in its reliability compared to the 944.

Put simply, a slightly boosted (stage 1) US 931 can see 60mph in around 7 seconds. Thats respectable even in this day and age.

I'll take a 931 over a 944 any day of the week and I suspect there are a ton of 944 n/a guys who secretly dream about owning one too.

A note on reliability.

There are a few main issues that you will face with a 931.

Early cars can suffer from cracked exhaust manifolds... if this is not diagnosed and repaired it will cause you problems.

Later cars can have issues with their DITC (digital ignition control computer). This problem can create headaches and lots of dollars spent. A spare working unit will quickly rule it out as an issue.

Both can have problems with their CIS systems but once you understand how it works, that it doesn't like to sit for years and how reliable it can be once its properly sorted, its really not scary anymore.
_________________
1981 931 CGT replica, OEM CGT intercooler, .8 BAR WG spring, GTS Headlights, Innovative Wide band A/F, A/C delete, 16" Fuchs, Weltmeister 200lb lowering springs, Bilstein HDs front, Koni Sport rears.
Back to top
View user's profile Send private message
ic932  



Joined: 11 Feb 2005
Posts: 1104
Location: UK

PostPosted: Thu Apr 01, 2010 9:39 am    Post subject: Reply with quote

fiat22turbo wrote:
Cross-link to the GRM discussion with input from folks at the Magazine:

http://grassrootsmotorsports.com/forum/grm/the-porsche-924-turbo-folks-are-unhappy/20500/page1/

Hopefully some good info for you guys


Great info...."Grass roots motorsports". GRM - go figure!

I see, not the repected opinion that I thought! An there's me thinking that our cars were up for influential discussion
Back to top
View user's profile Send private message Send e-mail
ic932  



Joined: 11 Feb 2005
Posts: 1104
Location: UK

PostPosted: Thu Apr 01, 2010 9:50 am    Post subject: Reply with quote

Nein37 wrote:
Truly the main benefit of the 931 over the 944 is the ability to easily make significant increases in horsepower. If this wasn't mentioned in the article than I'd say it left out a fairly important fact.

Keeping in mind that the US 931s ran less boost than their Euro counter parts. They were purposely detuned for whatever reason, maybe to allow them to run on 87 octane fuel or to ensure they didn't exceed US 911SC performance figures... who knows?

So your performance options include:

Stage 1: Take a stock 924 Turbo, get a boost controller and a boost gauge, turn the boost up to 10-11 PSI and you're over 170hp maybe more. Costs about $200 and takes about 1/2 hour.

Stage 2: Add an intercooler to that setup, turn the boost up another 2 PSI and you'll see over 200hp.

Costs vary... if you can manage to find a CGT intercooler expect to pay + $1500 for it or conversely spend about the same to fab up your own IC setup.

But...
Stage 3: If you get serious about it like some of the folks here, EFI it, add some goodies, optimize the tuning, and high 200hp figures aren't out of the question.

The 924 GTS CS output 275hp at 1.1 bar and this is most definitely achievable with an intercooler, boost gauge and a proper EFI setup.

And all of this can be done on the same bottom end. Its plenty strong enough to take it.

Compare this to a 944
Rated in US spec at 143hp ... it's often quoted as 150hp, certainly not all that impressive. Worse its VERY difficult to get any more power out of it. The question "how do I get more power out of my n/a", is asked over and over again on the 944 boards with the same answer given back... "if you don't have loads of money to spend you're stuck at around 150hp and even if you do have a lot of money to spend don't expect to crack 165hp".

This to me is a significant consideration when comparing the 931 with the 944, after all, they are SUPPOSED to be performance cars. The ability to quickly and easily get the 931 to perform respectably with the Stage 1 mods, far out weighs any perceived difference in its reliability compared to the 944.

Put simply, a slightly boosted (stage 1) US 931 can see 60mph in around 7 seconds. Thats respectable even in this day and age.

I'll take a 931 over a 944 any day of the week and I suspect there are a ton of 944 n/a guys who secretly dream about owning one too.

A note on reliability.

There are a few main issues that you will face with a 931.

Early cars can suffer from cracked exhaust manifolds... if this is not diagnosed and repaired it will cause you problems.

Later cars can have issues with their DITC (digital ignition control computer). This problem can create headaches and lots of dollars spent. A spare working unit will quickly rule it out as an issue.

Both can have problems with their CIS systems but once you understand how it works, that it doesn't like to sit for years and how reliable it can be once its properly sorted, its really not scary anymore.


Bravo, then you can get real and compare your mods to a 944Turbo. Don't be silly now. Your sounding like Rasta and Dan lol...

I'll have a 944S2 or a 968 engine installed before you even change that wastegate spring
Back to top
View user's profile Send private message Send e-mail
Nein37  



Joined: 29 Dec 2009
Posts: 513
Location: New London, CT

PostPosted: Thu Apr 01, 2010 10:01 am    Post subject: Reply with quote

Why would I need to compare it to a 951??? I wouldn't argue that a 931 is a better mod platform than a 951... but its definitely better than a 944.

Of course if you tell us where you can get a 968 engine put in a 944 chassis complete and ready to go for $2000 you might have an argument... however I'm thinking it would cost closer to $7500 when its all said and done.
_________________
1981 931 CGT replica, OEM CGT intercooler, .8 BAR WG spring, GTS Headlights, Innovative Wide band A/F, A/C delete, 16" Fuchs, Weltmeister 200lb lowering springs, Bilstein HDs front, Koni Sport rears.


Last edited by Nein37 on Thu Apr 01, 2010 10:30 am; edited 1 time in total
Back to top
View user's profile Send private message
ic932  



Joined: 11 Feb 2005
Posts: 1104
Location: UK

PostPosted: Thu Apr 01, 2010 10:05 am    Post subject: Reply with quote

Because, a 931 is a Turbo-charged application of the 924. 951 is a turbo-charged application of the 944.

Listen, I'm just trying to stop these embaressing comparisons. And you are right, I can not get 968 engine for that price...but an S2 is £500 gauranteed..
Back to top
View user's profile Send private message Send e-mail
Nein37  



Joined: 29 Dec 2009
Posts: 513
Location: New London, CT

PostPosted: Thu Apr 01, 2010 10:15 am    Post subject: Reply with quote

ic932 wrote:
Because, a 931 is a Turbo-charged application of the 924. 951 is a turbo-charged application of the 944.


Really now!!! Now you learn something new everyday... don't cha. You inselaffens sure are smart. And in what way does this apply to a comparison between a 931 and a 944 n/a?

You're saying that since a 944 Turbo is better than a 931 then a 944 n/a is better than a 931??? Unfortunately this is not a logical argument.

Your logic would require this.

A 944 n/a and a 944 Turbo are equally good.

A 944 Turbo is better than a 931.

So a 944 is better than a 931.
_________________
1981 931 CGT replica, OEM CGT intercooler, .8 BAR WG spring, GTS Headlights, Innovative Wide band A/F, A/C delete, 16" Fuchs, Weltmeister 200lb lowering springs, Bilstein HDs front, Koni Sport rears.
Back to top
View user's profile Send private message
ic932  



Joined: 11 Feb 2005
Posts: 1104
Location: UK

PostPosted: Thu Apr 01, 2010 10:51 am    Post subject: Reply with quote

Stop being a prick and read & listen.

I've already said compare a 944 and a 931 (row) in stock form. I havn't even come off the fence on that one! I've just been countering asshole comments like you have just posted!

If you want to start talking about a "sorted" 931 then all bets are off. If you wanna boost your 931 then the nexy best comparison will be 951. Now what is so hard to unerstand about that?

I don't care for boyhood fanatics!
Back to top
View user's profile Send private message Send e-mail
Nein37  



Joined: 29 Dec 2009
Posts: 513
Location: New London, CT

PostPosted: Thu Apr 01, 2010 10:53 am    Post subject: Reply with quote

Give me a friggin break man. You're the one that started the poking... don't get all uppity now. Calling me a prick... WTF.

And to answer your post. A 951 is a superior car to the 931 I wouldn't argue its isn't. My post was simply a reaction to the GRM article comparing a 944 to a 931. It failed to point out what I consider a big check in the 931s favor, it's easily modded for more power. Some consider this important when deciding whether they want one over the other.
_________________
1981 931 CGT replica, OEM CGT intercooler, .8 BAR WG spring, GTS Headlights, Innovative Wide band A/F, A/C delete, 16" Fuchs, Weltmeister 200lb lowering springs, Bilstein HDs front, Koni Sport rears.


Last edited by Nein37 on Thu Apr 01, 2010 10:59 am; edited 1 time in total
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    924Board.org Forum Index -> 931 Discussion All times are GMT + 11 Hours
Goto page Previous  1, 2, 3, 4, 5, 6, 7  Next
Page 5 of 7

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group