Turning a Porsche 944 Turbo into a Spyder

NASTYZEN · Jan 16, 2011

A friend of mine had a great idea,turn his ordinary 944 into some thing special and quick.I love doing things that are different so I obliged.This project was realized in the winter of 06.
The first thing I did was put the car on jacks as level as possible so as to not be left with a twist in it when I was done.
I then planned where it would be cut to be able to blend it all off after it was cut.

NASTYZEN · Jan 16, 2011

The next step is to locate the drivers seat.This will guide where everything else goes.Once that is determined it's on to the floor anchor plates for the cage,in this case for the weight of the car aprox. 16 sq.inches of 3/16 mild steel plate for each anchor point.We removed the doors and installed fiberglass ones to save weight,this also guides us with tube placing.Because we took off the roof and windows we need to re engineer strength back into the chassis.
Still more to come.

930dreamer · Jan 16, 2011

Wow, that's a big project. Will the roll cage make up for the roof being removed as far as chassis strength? Any drawings of the final look? Keep the pics coming.

NASTYZEN · Jan 16, 2011

The final product is stiffer than it was with the original roof.The owner has made several hundred laps with it so far and is very happy with the tighter handling.He gets better lap times with less drag from not having a windscreen to push thru the air.

NASTYZEN · Jan 17, 2011

A few more showing the structure.I also welded up all the spot welded seams with mig welding to get as much stiffness out of the original body structure as possible.
Once all that was taken care of it was time for the sheet metal part of the job.I started with the rear deck by fitting the outer perimeter and then the center.Rolled a crest in it with my English wheel to get stiffness out of it.There is two removable access panels under the main roll bar.Built an adjustable seat brace to bolt the seat to the cross bar.
Also had to mount a rear carbon fiber wing with 1/8 alu.plate.The bottom had to match the radius of the deck and bracing was built underneath to put up with the wing loads and vibrations.

Bulldog13 · Jan 17, 2011

Your not gonna leave that wing on there are you.....? Please don't...it burns my eyes

weegaz22 · Jan 17, 2011

i had one of these years ago, loved it, dont get the logic/reasoning behind making it a spider, but do realise the work involved and can appreciate that

SM Racing · Jan 17, 2011

You should add a couple of forward down bars from the main hoop to the low front hoop. It would stiffen that chassis significantly and it will make the cage safer for the driver. copy the SCCA rules for open top cars. Look the common style cages on the Porsche 914s, Fiat X-19s, and other targa/******* cars.

NASTYZEN · Jan 17, 2011

Did I mention this project was done in 2006!!? :headscrat

It's been out of my shop for 5 years now!
The owner insisted to have the lateral bars the way they are.Besides they would of needed a bend in them to clear the driver.This car is really stiff anyway like it is.It would be safer to have them further forward to keep wheels n other cars out of the cockpit thow,I agree.

NASTYZEN · Jan 17, 2011

Here's a little more.Hard to tell from these pics. but the cage is tied to the front shock towers.

ZTFab · Jan 17, 2011

Nice job!!

NASTYZEN · Jan 17, 2011

ZTFab said:
Nice job!!

Thank you ZTFab.It' nice to hear from someone who does nice work like you do.

Here's a bit more.The car before at Mosport.

NASTYZEN · Jan 17, 2011

This car is not to SCCA spec but can race anywhere in Canada.It is used mainly for club racing.
The owner tells me it used to lap at 1.57 min. at Tremblant before we cut it's roof off and now he gets 1.46 min.lap with slicks and 1.47.8 with Hoosiers.Please note I am only the fabricator in this build.The owner did all of the mechanical and someone else painted it.

Benw455 · Jan 17, 2011

Nice work!

BlackSheepSpeedShop · Jan 17, 2011

I am not a Porsche guy and that is cool! Great work!!

NASTYZEN · Jan 18, 2011

Benw455 said:
Nice work!

Thank's

BlackSheepSpeedShop said:
I am not a Porsche guy and that is cool! Great work!!

Thank you,you might like this one even more.
Here are some pictures of the other one we did.

NASTYZEN · Jan 18, 2011

And some more.Note the floorboards with the Porsche logo on them.

NASTYZEN · Jan 18, 2011

In order for a 944 to perform more on the track,it needs to have the suspension lowered.This is a problem with the front lower A-arms that were not designed to run this low.They tend to bottom out and break the outer ball joint,witch is not a good thing at any speed!
I have modified the original aluminum A-arms outer ball joint cage to accept a regular spherical bearing that turned out ok.But developed a cro-moly tubular adjustable version that I feel much more bullet proof.Along with replacing the rear metalastic body to trailing arm bushings with Aluminum plugs.Makes for far more rigid parts and tighter steering response.
Another thing we did was to make the steering links adjustable along with the rear dog bone toe links.
Yet another safety mod was the stainless removable fire bottle bracket.
And finally for those who want to hang on to there roofs, a bolt on cage kit.
Enjoy! :beer:

SM Racing · Jan 18, 2011

So why are these guys taking the roof off so frequently on these 944s? Wouldn't it be better to start with a Boxster or something like that? This is not a common thing here, not sure if it is because PCA doesn't allow it or what.

Nice job on the lower control arms. Are you raising the spindles to fix the suspension geometry that gets all screwed up on a strut car when you lower it?

NASTYZEN · Jan 18, 2011

I don't think it's a common thing anywhere.!The logic behind it is that you can get a 944 for as low as $4500.00 and with a relatively low investment,get some thing that blows the doors off of some factory $300,000.00 cars.I know I would get a kick out of beating a Ferrari to the line with my unconventional budget racer. :lol_hitti

As far as the suspension goes.It's a Porsche and the engineering is already pretty good to start with so there isn't to much goofiness to deal with. More a matter of binding when bottoming out.These are clubbers and get a lot of track time.Adjustibility and robustness is why we went cro-moly.
I'm a fabricator and if someone has an idea and money and is happy with his project,that makes me happy.People have me build the strangest things sometimes. :wtf:

That's the greatest thing about metal working for me.One day I'll make something for the aviation industry the next for a giant wind turbine a wheelchair after that...Never know what challenge that next phone call will be.
Cheers
Zen

weegaz22 · Jan 18, 2011

NASTYZEN said:
This car is not to SCCA spec but can race anywhere in Canada.It is used mainly for club racing.
The owner tells me it used to lap at 1.57 min. at Tremblant before we cut it's roof off and now he gets 1.46 min.lap with slicks and 1.47.8 with Hoosiers.Please note I am only the fabricator in this build.The owner did all of the mechanical and someone else painted it.

i bet he could have got that time with the roof on too, looks like a lot of weight in all that bracing, didnt like it at first in the fab pics but once it had paint and could be seen screaming round a track it looked a lot better :thumbup:

e-tek · Jan 18, 2011

The paint on the second one is RADICALLY cool (if that's a phrase?)!!! Great fab work too for sure!

What is the purpose of the sleeves over the tubes in the shot with just the cage? For strength or to take it apart?

Thanks for sharing these!

NASTYZEN · Jan 19, 2011

e-tek said:
The paint on the second one is RADICALLY cool (if that's a phrase?)!!! Great fab work too for sure!

What is the purpose of the sleeves over the tubes in the shot with just the cage? For strength or to take it apart?

Thanks for sharing these!

Thank you e-tek,yeah, I like the look of the second one better two.The white for sure is paint but I think the rest is all decals.
Yes the tubes are to take the bar apart.

NASTYZEN · Jan 19, 2011

weegaz22 said:
i bet he could have got that time with the roof on too, looks like a lot of weight in all that bracing, didnt like it at first in the fab pics but once it had paint and could be seen screaming round a track it looked a lot better

Thanks
If you consider the weight of the roof,the doors,electric widow mechanism,the windows,the hatch back,all the interior trim,all the sound proofing then the bracing weighs in much lower than all that other stuff.
11 seconds faster than with the windshield on.In a 20 lap race, that's reaching the checkered flag 2.2 minutes faster than before...

Jazz · Jan 20, 2011

Very nice

NASTYZEN · Jan 21, 2011

Thank you Jazz.

weegaz22 · Feb 10, 2011

NASTYZEN said:
Thanks
If you consider the weight of the roof,the doors,electric widow mechanism,the windows,the hatch back,all the interior trim,all the sound proofing then the bracing weighs in much lower than all that other stuff.
11 seconds faster than with the windshield on.In a 20 lap race, that's reaching the checkered flag 2.2 minutes faster than before...

but if you were turning it into a dedicated track/race car like you did all that stuff would get tossed out anyway, window mechs, interior trim, soundproofing would all be removed, glass replaced with polycarbonate versions etc, the only extra weight i can see would be the roof and boot lid structure, and whatever you had'nt gutted from the doors.

I'm not knocking what you have done, apologies if it comes across that way, its just there are many ways to skin a cat as they say, i probably would have went a different route, but can see some advantages to it like having no blindspots and a full field of view

dont suppose you had it weighed/corner weighted?, would have liked to see what it was compared to a stock 944 turbo.

NASTYZEN · Feb 11, 2011

Hey Weegaz22,I've been doing this for so long I take criticism well don't worry.

I'm a fabricating ***** of sorts,they tell me what they want and I try to deliver as best as I can.You could see the design evolved a little from the first too the second one and if they ever want an other I would do things a little different to try and improve even more.Thats what evolution is all about.Ultimately the owner is forking out the dough so he chooses what he likes to have done.I always try to give different build scenarios for them to choose from.Where I am not flexible is safety considerations.
I'll have to get in touch with the owner to see if he has weight comparisons available.
:beer:

RossABQ · Feb 12, 2011

Nastyzen, are you on Rennlist?

NASTYZEN · Feb 17, 2011

RossABQ said:
Nastyzen, are you on Rennlist?

No I'm not.But I believe both car owners are though,or used to be.

NASTYZEN · May 10, 2011

You can get in and enjoy a few laps on board at Le circuit Tremblant and ICAR as well as others here.
http://www.clubvirages.com/

:beer:

NASTYZEN · May 7, 2013

Bump for the new members who haven't seen this thread yet.
Enjoy.
:beer:

Big-Foot · May 7, 2013

Nice work!

I raced a Porsche 924S in SCCA and NASA for a few years.. Great cars and almost bullet-proof engines.. Bastards to put clutches in though....

CNGsaves · May 7, 2013

Thanks for the bumped thread . . . nice work on great affordable race car when done.

Enjoyed ride along in 944Turbo spyder at the Glen video of hot laps. The little turbo was passing some 911's . . . . not too shabby !!

Back in the 80's, watched local racing here in midwest with SCCA small tracks around small lake roads. The Corvettes, Mustangs, and Porsches were racing locally here and it was great to watch. Many a time the Porsche 944Turbo's would finish 1st/2nd and then the Vettes and Mustangs. Cars roaring through the water-filled steel barrels was great to witness. Hairpins could get within 10 feet back then which put you right in the action as a spectator.

Zelatore · May 7, 2013

Thanks for the bump - I hadn't seen this before.

I totally get it - PCA guys are among the few clubs that are serious about racing, and the 944 is little more than a beater to most average Joe's these days. But it's still a lot of bang for the buck. Why not cut it up and make something interesting!

But...I'm also in the camp that's a little dubious about the performance increase coming from removing the windshield. Yes, you might have saved a little weight vs building a standard club racer out of it, but I wouldn't be surprised if it were actually more aero-efficient with the stock tin in place. It would have been interesting to see a top speed comparo before and after (assuming no engine changes) as that's about the only way an average Joe can compare drag.

But hey, regardless it's about 100% cooler than it was as a coupe and he's getting around the track faster now so it's a win-win!

racingtadpole · May 8, 2013

Zelatore said:
But...I'm also in the camp that's a little dubious about the performance increase coming from removing the windshield.

I used to have a Leyland Moke that was logged as an open sports car. Removing the windscreen makes a MASSIVE difference.

Hey Claude, thanks for the bump, I'd not seen this thread before. Cutting the lid off a 944, you get all the good jobs.

Turning a Porsche 944 Turbo into a Spyder

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