THE BASTARD - 944 LS1

[chris_f]

Yeah, I was getting worried about you buddy. 

Talk soon ok......

Thanks Dean, no worries here - Just happy to have the 1000km done with no major issues. Hopefully all of the niggles are ironed out now... when I have total confidence in the car I'd still be keen for a Sydney road trip

And we thought you didn't like us anymore

haha... this is the only forum for me!

[TINGY]

Chris what happened to the 3.0litre engine out of your car?

[chris_f]

Chris what happened to the 3.0litre engine out of your car?

That was sold to Buchanan Automotive about a year ago.

[Blue964]

sorry to hear about the accident, but good to hear you're back on the road. would love to see this car in person some day...i know the sound of an ls1 coming from a 944 would do my head in...in a good way:)

[chris_f]

sorry to hear about the accident, but good to hear you're back on the road. would love to see this car in person some day...i know the sound of an ls1 coming from a 944 would do my head in...in a good way:)

Would love to do a road trip to Sydney...  it has done 1300km now, so feeling more confident in its reliability. I'll see what I can do about getting some drive-by videos in the mean time...

[chris_f]

Here are a few quick shots of the car with it's second set of wheels after a brief drive up Mount Tamborine. I just missed the sun unfortunately but will make an attempt at a proper photo shoot soon...

Keeping the engine in 2nd and 3rd gear up steep inclines was a good test for it and no overheating issues to report. The cooler mountain air would have helped quite a bit.

The wheels were purchased from a PFA member (nath) - thanks mate! They are Volk Racing TE37 - a Japanese wheel by Rays Engineering. Not to everyones taste perhaps but I have a soft spot for them. They were originally silver and looked very out of place on the car so I decided to have them professionaly resprayed in satin black by The Alloy Doctor (wheel repair specialist here in Brisbane). They also machined off the centre cap lips on the front wheels - they won't clear the hubs otherwise. Very happy with the way they look in the end... will mostly likely paint the dust caps black too.

More so than the wheels, the tyres have completely transformed the car. The Pirelli Trofeo Rs are in a totally different league compared with the 6 year old continentals I've been running on the RUFs. They're just what the car needed. 1st gear is usable now and no more breaking traction half-way through second gear. Will have to wait until the cars first track day before testing their limits around a corner.

Wheel specs:
18x10" +42 offset with 295/30/r18  (8.7kg vs. 10kg for the 17" RUFs)
18x8.5 +49 offset with 235/40/r18  (8kg vs. 10kg for the 17" RUFS)

Definitely a gamble with these widths and offsets on a late offset 944.. Timm guessed they would just fit, and he was right... they clear by 1mm in the rear. Some healthy negative camber definitely helps in that respect.

Other additions since the last update include: Joe Toth front splitter. (Plasti-dipped for now... still deciding on the paint), Perspex foglight protectors, VDO head unit.

Satin black for the front splitter? or stick with the rubberised look? hmmmm

The new VDO head unit looks much more at home than the ugly Sony X-Plod unit.

[LeeM]

Wow mate, that looks amazing! Love the rims too

[clutch-monkey]

leave the splitter rubberised but paint the bolts, it really bothers me haha

[MFX]

leave the splitter rubberised but paint the bolts, it really bothers me haha

+1. Bolts need to be black, the rest looks great. At least if you leave the splitter like it is, if you bump it, it won't crack or scratch paint.

[Plugger2]

Do you need the 18" wheels to clear the brakes. or is it basically an aesthetic choice?

[Blue964]

Satin black for the front splitter? or stick with the rubberised look? hmmmm
 

 

 

Nothing wrong with those wheels--they look great. Love the stance

[Plugger2]

Nothing wrong with those wheels--they look great. Love the stance

I wasn't being critical of the appearance, it's just that Porsche did issue a service bulletin a while back that advised against > 17" on the 944 series... the stock suspensions (even MO30 options) just weren't designed for them, apparently. While I suspect for everyday cruising use 18" wheels would be a non-issue, for a track car I'd be more circumspect. The advice was that larger wheels resulted in compromise in both safety and performance, IIRC.

Edit: Here's the text of the service bulletin

ARTICLE BEGINNING

TECHNICAL SERVICE BULLETIN

INSTALLATION OF 18" WHEELS NOT APPROVED

Model All Porsche Models
Group 4
Bulletin No. 9305
Date April 15, 1993

Concern:

Retrofitting 18" wheels on Porsche vehicles which do not have 18" wheels as original equipment is NOT ALLOWED.

General Information:

Endurance tests have shown that equipping certain Porsche vehicles with 18" wheels in an application not already approved by Porsche Cars, N.A. may result in loosened bolts and /or threaded connections on the front wheel carriers. This, in turn, may cause fractures in these components. Fractures may also occur in the front strut mounts and in the body in the area of the rear suspension as a result of the installation of 18" wheels not already approved for installation for this specific application.
Such damage can occur without warning and the vehicle may become very hard to control/steer as a result of the improper installation.
Porsche dealer personnel coming in contact with a vehicle that has been retrofitted with 18" wheels in an application not approved by Porsche, should inform the owner of the potential for damage to their vehicle and loss of steering control. Porsche Cars, N.A. should also be notified of any vehicles retrofitted with 18" wheels.

END OF ARTICLE

[clutch-monkey]

Surely if the overall diameter is close enough it would not be an issue? They look great 

[Plugger2]

Surely if the overall diameter is close enough it would not be an issue? They look great 

It's not the diameter of the rim that's the problem, is the height of the sidewall. 1" doesn't sound like much when considered as a proportion of the rim diameter, but it's a much more significant decrease as a proportion of the sidewall height.

Personally, I would think that cruising around town with urban speed limits, 18" wheels would really be a non-issue , practically speaking, but for me, fanging it around a track would be a different issue.

[chris_f]

Do you need the 18" wheels to clear the brakes. or is it basically an aesthetic choice?

It was a tyre choice above all else. These came with 295 section Trofeo R's which work well with the cars power level. I'd like to run some Michelin Pilot Super Sports next and they also start at the 18" sizing. As for brakes, the front RUF's barely clear the stock S2 Calipers (spoke clearance)... so nice to have some room to move in the future.
 

 

I wasn't being critical of the appearance, it's just that Porsche did issue a service bulletin a while back that advised against > 17" on the 944 series... the stock suspensions (even MO30 options) just weren't designed for them, apparently. While I suspect for everyday cruising use 18" wheels would be a non-issue, for a track car I'd be more circumspect. The advice was that larger wheels resulted in compromise in both safety and performance, IIRC.

Edit: Here's the text of the service bulletin

It's a fair point but I will say this:  I've come accross this bulletin quite a few times on various porsche forums (rennlist, pelican parts). It's important to keep in mind that it was issued in 1993. Since then, countless 944 owners have daily driven and/or heavily tracked their cars on 18" wheels and I'm yet to see anyone report issues directly related to the size of the wheels . The Te37 are significantly lighter than the 17" RUFs and the overall diametre of the wheels + tyres are essentially identical.

My guess is that Porsche based this reccomendation on the weight of existing 18" wheels, including their own. For example, a 16", 9" wide D90 wheel is 10kg. An 18", 10" wide 993 RS Speedline is 13.5kg.

Wow mate, that looks amazing! Love the rims too

Thanks Lee!

leave the splitter rubberised but paint the bolts, it really bothers me haha

I just found some black anodized 1/4 turn fasteners on ebay... I'll see how they look
 

+1. Bolts need to be black, the rest looks great. At least if you leave the splitter like it is, if you bump it, it won't crack or scratch paint.

I have a more permanent rubberized coating to try next... the plasti-dip rubs off too easily for my liking.
 

Surely if the overall diameter is close enough it would not be an issue? They look great 

Thanks! Thinking they will be fine

[Plugger2]

My guess is that Porsche based this reccomendation on the weight of existing 18" wheels, including their own. For example, a 16", 9" wide D90 wheel is 10kg. An 18", 10" wide 993 RS Speedline is 13.5kg.

Interesting thought, but if you think about it, you will see that the weight of the wheels can't have any effect on increasing the forces that would lead stressing the strut towers leading to fatigue fractures, etc. Heavier wheels just make the car slower.

In any case, I would be very surprised if the heaviest 17" wheels Porsche offered at the time would have been heavier than their lightest 18" wheels (e.g,. their 18" hollow spoke Turbo twists.) As I suggested above, I think you'll find It's the reduced sidewall height leading to additional stresses on the rest of the suspension that is the issue. If Porsche had meant that wheel weight was the issue, they would have simply mentioned wheel weight, rather than wheel diameter. German engineers tend to be like that.

But carry on. I was just curious about your choice of wheel diameter, and thought I'd ask. No criticism implied; I like your car (and the vision to achieve what you have with it) very much.

[Timm]

Maybe it was just Porsche covering their arses in case something did happen?

I don't think running 18's causes any issues at all. People have run 18's on the 944 chassis for ages and I haven't found a single reported failure of the strut towers.

In any case, one would think that harder suspension would be more of a concern than reduced sidewall height.

 

[Plugger2]

Maybe it was just Porsche covering their arses in case something did happen?

I don't think running 18's causes any issues at all. People have run 18's on the 944 chassis for ages and I haven't found a single reported failure of the strut towers.

In any case, one would think that harder suspension would be more of a concern than reduced sidewall height.

 

Reduced sidewall height _is_ a harder suspension.

As for fatigue at suspension points in the 944 chassis, there are lots of examples of this from people tracking their cars. Larger wheels, in combination with other suspension mods, would unlikely to be the _sole_ cause of failures. But that is not say larger wheels wouldn't be a contributing cause.

After all, Porsche claims to have run their own "endurance" tests leading to these failures. That would have been with just changing the wheels on a standard factory suspension. I can't see them just making this stuff up. If they were seeing these problems emerge in those tests, it would be fairly safe to assume that larger wheels + stiffening up the suspension further without compensating strengthen mods to the chassis would be making things even worse. 

[chris_f]

Interesting thought, but if you think about it, you will see that the weight of the wheels can't have any effect on increasing the forces that would lead stressing the strut towers leading to fatigue fractures, etc. Heavier wheels just make the car slower.

In any case, I would be very surprised if the heaviest 17" wheels Porsche offered at the time would have been heavier than their lightest 18" wheels (e.g,. their 18" hollow spoke Turbo twists.) As I suggested above, I think you'll find It's the reduced sidewall height leading to additional stresses on the rest of the suspension that is the issue. If Porsche had meant that wheel weight was the issue, they would have simply mentioned wheel weight, rather than wheel diameter. German engineers tend to be like that.

But carry on. I was just curious about your choice of wheel diameter, and thought I'd ask. No criticism implied; I like your car (and the vision to achieve what you have with it) very much.

Thank you, and definitely not taken as criticism, all good!.. it's an important topic to bring up / discuss - I know many others would be having similar thoughts. Interesting about the sidewall leading to additional stresses too - could very well be the case. That variable would be tyre dependent though and tyre tech has come a long way since '93. Maybe modern 18" tyres have been designed with more compliant sidewalls and that's why no one is reporting issues on their cars?

But hey... nothing I've done to this car would be reccomended by Porsche...

Having said all of that, I do still prefer the appearence of 17" wheels on the car but you do miss out on the best tyres compared to what's available in 18".

Here is a good reference regarding wheel weights. OEM porsche wheels are all suprisingly heavy compared to a modern forged Japanese wheel like the Te37: http://www.944racing.de/wheelweights.php

The heaviest OEM Porsche 17" is the Cup 1. in the 17"x9.5" size they weigh 12.5kg
The OEM Porsche hollow spoke 18" x 10" wheel is 11.4kg (40 offset) or 10.6kg (65 offset)

Te37 in 18"x10" = 8.7kg
Te37 in 18x8.5" = 8kg

They are actually lighter than the 16x8" (9.9kg)  and 16x9" (10kg) D90 wheels that came with the car originally.


 

[Plugger2]

Thank you, and definitely not taken as criticism, all good!.. it's an important topic to bring up / discuss - I know many others would be having similar thoughts. Interesting about the sidewall leading to additional stresses too - could very well be the case. That variable would be tyre dependent though and tyre tech has come a long way since '93. Maybe modern 18" tyres have been designed with more compliant sidewalls and that's why no one is reporting issues on their cars?

But hey... nothing I've done to this car would be reccomended by Porsche...

Having said all of that, I do still prefer the appearence of 17" wheels on the car but you do miss out on the best tyres compared to what's available in 18".

Here is a good reference regarding wheel weights. OEM porsche wheels are all suprisingly heavy compared to a modern forged Japanese wheel like the Te37: http://www.944racing.de/wheelweights.php

The heaviest OEM Porsche 17" is the Cup 1. in the 17"x9.5" size they weigh 12.5kg
The OEM Porsche hollow spoke 18" x 10" wheel is 11.4kg (40 offset) or 10.6kg (65 offset)

Te37 in 18"x10" = 8.7kg
Te37 in 18x8.5" = 8kg

They are actually lighter than the 16x8" (9.9kg)  and 16x9" (10kg) D90 wheels that came with the car originally.


 

Thanks for the link to that list of wheel weights! Very interesting. I'm running 17" Boxster 1 (986) twists on my S2, and look like a surprisingly good weight comparatively speaking according to that chart.

You're point on tyre tech since 1993 is well taken, Conceivably, advances there could well mitigate the original problem, at least to some degree.

Isn't it nice we can have a civilised discussion putting forward differing viewpoints without everyone getting touchy? So rare in forum discussions these days.

 

[Timm]

Thank you, and definitely not taken as criticism, all good!.. it's an important topic to bring up / discuss - I know many others would be having similar thoughts. Interesting about the sidewall leading to additional stresses too - could very well be the case. That variable would be tyre dependent though and tyre tech has come a long way since '93. Maybe modern 18" tyres have been designed with more compliant sidewalls and that's why no one is reporting issues on their cars?

But hey... nothing I've done to this car would be reccomended by Porsche...

Having said all of that, I do still prefer the appearence of 17" wheels on the car but you do miss out on the best tyres compared to what's available in 18".

Here is a good reference regarding wheel weights. OEM porsche wheels are all suprisingly heavy compared to a modern forged Japanese wheel like the Te37: http://www.944racing.de/wheelweights.php

The heaviest OEM Porsche 17" is the Cup 1. in the 17"x9.5" size they weigh 12.5kg
The OEM Porsche hollow spoke 18" x 10" wheel is 11.4kg (40 offset) or 10.6kg (65 offset)

Te37 in 18"x10" = 8.7kg
Te37 in 18x8.5" = 8kg

They are actually lighter than the 16x8" (9.9kg)  and 16x9" (10kg) D90 wheels that came with the car originally.


 

Those wheel weights make me feel better about my Meisters...I always thought they were pretty heavy, but at 10.5kg they are as light, or lighter than all of the comparatively sized Porsche wheels. Not as light as your te37's though, 8.7kg is damn impressive for an 18x10.

 

 

[chris_f]

Thanks for the link to that list of wheel weights! Very interesting. I'm running 17" Boxster 1 (986) twists on my S2, and look like a surprisingly good weight comparatively speaking according to that chart.

You're point on tyre tech since 1993 is well taken, Conceivably, advances there could well mitigate the original problem, at least to some degree.

Isn't it nice we can have a civilised discussion putting forward differing viewpoints without everyone getting touchy? So rare in forum discussions these days.

 

No trouble! The boxster twists are a nice upgrade for the S2. I have a feeling that the weight of oem Porsche wheels speaks to their strength and rigidity. Often overlooked in lightweight wheels that are made in a cheap low pressure casting process. Brands like Rota copy the designs of forged wheels without the material strength needed for the design.

The KW V3 Coilovers may help too. They use a valving technology which allows pot holes / sudden bumps to be absorbed with more compliance. 

Very true, this forum is great like that!

Those wheel weights make me feel better about my Meisters...I always thought they were pretty heavy, but at 10.5kg they are as light, or lighter than all of the comparatively sized Porsche wheels. Not as light as your te37's though, 8.7kg is damn impressive for an 18x10.

10.5kg is not too bad at all for a pretty 3 piece design like that. Lower offsets tend to increase the weight of the wheel too for some reason? Compare the Meisters to the simirlarly designed Speedline wheels... they are 11.5kg / 12.2kg.

[Timm]

10.5kg is not too bad at all for a pretty 3 piece design like that. Lower offsets tend to increase the weight of the wheel too for some reason? Compare the Meisters to the simirlarly designed Speedline wheels... they are 11.5kg / 12.2kg.

Yeah I'm surprised the RS Speedlines weigh so much...I think the Meisters might save some weight by having lighter barrels? I believe they are spun forged, so might be a bit thinner than the speedline barrels. The centres are low pressure cast alumium though.

FYI, low pressure casting, while obviously not as good as a forged wheel, is still better than normal gravity casting.  I'm not saying Rotas and the like are good, but there are some great quality cast wheels out there that are popular with the track guys such as Enkei RPF1 and OZ Allegerita. I really wish the RPF1s came in 5x130 so I could get them as track wheels.

[chris_f]

Yeah I'm surprised the RS Speedlines weigh so much...I think the Meisters might save some weight by having lighter barrels? I believe they are spun forged, so might be a bit thinner than the speedline barrels. The centres are low pressure cast alumium though.

FYI, low pressure casting, while obviously not as good as a forged wheel, is still better than normal gravity casting.  I'm not saying Rotas and the like are good, but there are some great quality cast wheels out there that are popular with the track guys such as Enkei RPF1 and OZ Allegerita. I really wish the RPF1s came in 5x130 so I could get them as track wheels.

That would actually be a fun project to look into... I've been thinking about the possibilities of rebarreling certain wheels. Upsizing 16" BBS RS to 17" for example.

I had the processes mixed up... gravity casting is the most basic like you said.

From tirerack.com: https://www.tirerack.com/wheels/tech/techpage.jsp?techid=90

GRAVITY CASTING
Gravity casting is the most basic process of pouring molten aluminum into a mold utilizing the earth's gravity to fill the mold. Gravity casting offers a very reasonable production cost and is a good method for casting designs that are more visually oriented or when reducing weight is not a primary concern. Since the process relies on gravity to fill the mold, the aluminum is not as densely packed in the mold as some other casting processes. Often gravity cast wheels will have a higher weight to achieve the required strength.

LOW PRESSURE CASTING
Low pressure casting uses positive pressure to move the molten aluminum into the mold quicker and achieve a finished product that has improved mechanical properties (more dense) over a gravity cast wheel. Low-pressure casting has a slightly higher production cost over gravity casting. Low pressure is the most common process approved for aluminum wheels sold to the O.E.M. market. Low-pressure cast wheels offer a good value for the aftermarket as well. Some companies offer wheels that are produced under a higher pressure in special casting equipment to create a wheel that is lighter and stronger than a wheel produced in low pressure. Once again in the quest for lighter weight, there is a higher cost associated with the process.

Enkei seem to use a more advanced process again for the RPF1 and other MAT wheels: http://enkei.com/engineering/

I also found this funny: http://jalopnik.com/knockoff-wheelmaker-rota-warns-of-knockoff-rota-wheel-1137837262
 

[Plugger2]

The KW V3 Coilovers may help too. They use a valving technology which allows pot holes / sudden bumps to be absorbed with more compliance. 

Also a good point. And you don't have to sell me on the KWv3s -- by far the best money I ever spent on S2. Totally transformed the car in terms of ride and handling. Far superior to the old 1980s Bilstein tech the car came with originally -- chalk and cheese.