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My Dream LS7GTZ.......project underway


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UPDATE:

 

What a long holiday weekend. We were able to take the car to the track and do some very needed setup on the car. After a two year build to finally get her out on track is a great feeling. No major issues. Just had an incredible time all weekend long. Whats really cool is to have her on the grid along with a bunch of new exotics and everybody wants to look at her and talk about the old school ways.

 

This is awesome. I can only imagine your feelings while breaking her in with big dog company along side !! Congrats !

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So how did it compare to the World Challenge 'Vette?

 

I ran a 1:29 flat in the Z. That's movin pretty quick for a Vintage car. The Vette runs a 1:26 and has its pro's and con's. The z is lighter and has the same HP as the Vette. They have the same exact engine actually. The z is almost as fast as the Vette in the technical part of the track but where the Vette is better is high speed. The Vette has a huge wing on the back, a splitter up front, canards, and is set up , balanced and very solid. The Z at this point does not generate enough downforce front or rear to compete at high speed. The faster the Z goes the lighter she feels and it really gets kind of dangerous. We will get to that point soon enough and start thinking about the aero on the car. We are still shaking out the setup at this point. We determined the ride height with the suspension. We determined that the brake pads that come with the Willwood 6 piston race set up are too hard for this car. the car is so light that it was hard for me to keep enough heat in them to generate the bite I need to slow her down. We are having some Carbotec pads that are a little softer overnighted to the shop. The engineer for them took all of the cars data and recommended these pads for our setup. We should feel more pedal and get some better initial bite.

 

I am very pleased with the way she is coming together on the track. I am torn in leaving the vintage three piece IMSA tail for historical value and putting a wing on her that would afford me more downforce. What is hard to keep in mind is that she is a Vintage car and does not compete with the WC Vette's or the Porsche Cup cars etc... She just thinks she does. Or is that me???

 

Matt

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Matt, I don't know if you're asking for opinions, but I'll give one anyway. I'd do the wing with appropriate bracing from it to the chassis, add a splitter, think more about that diffuser, the whole nine. I really have to wonder what kind of lift you're generating at speed now. Get yourself a decent aero package, and it wouldn't surprise me at all if you could keep up with the WC cars.

 

Besides, it's not like anything else on the car is vintage appropriate anyway.

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Matt, I don't know if you're asking for opinions, but I'll give one anyway. I'd do the wing with appropriate bracing from it to the chassis, add a splitter, think more about that diffuser, the whole nine. I really have to wonder what kind of lift you're generating at speed now. Get yourself a decent aero package, and it wouldn't surprise me at all if you could keep up with the WC cars.

 

Besides, it's not like anything else on the car is vintage appropriate anyway.

 

I will be doing the Aero that we have all been discussing for the past few years. We have good ideas on the splitter. I am leaning towards the wing and we did discuss numerous ways to mount it in the thread a while back. I will do some underpanels to smooth the air flow across the bottom of the car as best we can. The rear diffuser is going to be the last thing we do and after doing all the other first it will lead us in a general direction. I have run the car with the air dam on, air dam off. Ducts in air dam open and closed. I put duct tape in small openings and sealed up some drag elements. I am recording all the data to see what is actually going on when we make the changes. This is a slow but very fun part of this experiment. Now that we have her on track I am in no hurry to do it all overnight. I'm havin way too much fun.

 

As far as her outward appearance I was asked by NASA and SCCA to keep her as IMSA correct as possible for appearance sake when she runs in the Vintage class. I agree that under her skin there is little that is stock. I can keep the three piece tail for those events and run the wing when I'm looking to lay down the best time. I'm taking her tomorrow to have her wrap done. I am very excited to see her finally with her colors on.

 

Matt

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Got her all wrapped up and I must say " She looks incredible". It brings back the memories of watching Paul Newman and Sam Posey at Road Atlanta in the Camel IMSA GTU series. When I was 16 years old I dreamed of what it would be like to drive one of those machines. Now 33 years later my dream has come to life.

 

Matt

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That turned out killer Matt !

 

Thank you.

 

Took her to VIR for a Track Day with mostly Nissan GTR's and Porsche. She did incredible, looked amazing and was the talk of the day. Here are a few pictures. When I get the video together I will post it as well.

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Matt, What kind of times were you seeing on VIR's full course?

 

Mike

 

Mike,

After checking the data (Four 30 minute sessions), I was running around 2:06 average. I was actually faster in the early part of the day. Ran one 2:04 then as the day went by my times just got higher. Tires/brakes falling off and track heating up. All in all I was very pleased with the results. Our GTR set a new lap record for GTR's at 1:53 Lehman Keen at the wheel.

 

Here is some footage I took in the run group just after lunch. I just can't get over how good she looks going around the track.

 

Edited by cobramatt
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Hey Matt,

 

You know that annoying brake squeal that you think is just pads? It aint pads. Pull the front wheels off the car and look at how close the caliper sits to the edge of the rotor. The calipers need to sit a bit higher on the rotors. If you pull the caliper off the rotor and inspect it you will find that it is rubbing the outer most edge of the rotor. The more days you rack up the worse it will get. I finally had the aluminum bracket remade to correct the spacing problem.

Had it done in chrome mol;y. It doesn't flex any more.

This will never show up on a street driven car and maybe not a na straight 6 track car. You have a beast. Check it out. I may be wrong but it sounds like mine and it got worse quickly.

 

Let me know what you find. I've gone to a full floating set up on the front and have no more issues with brakes fading or rotors cracking.

 

Thanks for the video. It was awesome!! Love the sound.

 

heres the brakes.

http://forums.hybridz.org/index.php/topic/85165-13-inch-floating-rotor-set-up-with-pics/page__p__807332__hl__%2B13+%2Binch+%2Bfloating+%2Brotors__fromsearch__1#entry807332

Edited by mark
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Matt, Let me be the first to say holy cow... 2:04s around VIR in a Zcar is wheeling it and your times give me something to shoot for in my own car later this season... WOW...

 

Mike

 

I averaged 2:06. Lets not say 2:04's like I was peeling them off. I did (1) out of 100. I really feel with the right aero and seat time I could shave some time off that. The back straight at 158 feels like my world is coming apart. While in other cars that would feel quite safe and planted in this car it feels like death is eminant. I hope we can work out the details and get this car where it feels solid rather than a rocketship wrapped in cardboard. I just spoke with my chief tech at the shop and he said that he feels we might need to re engineer the rear control arms as the amount of torque and acceleration we have it has moved the diff and the rear is totally out of alighnment now and the control arms are bent and the front coil overs are loose where we did some turns. The alternator pulley as well is going to have to be changed. I'm thinking that it is too small and the engine is just wearing it out at high rev. It is melting the guts right out of it. There is melted plastic from the pulley all in my engine bay. We can machine a bigger pully to slow the spin rate down, but you see this little car is costing a fortune and were still developing things. I wonder if anyone that has used the "Track Pack" billet set up from Arizona Z Car has ever had these problems???

 

People at the track were all saying how incredible it was to see a vintage car like this out on track and how you just dont see them anymore. I look around and see all the GTR's and Porsche's and realize the reason for that is that there are very few foolish men like me that would rather have an old death machine instead of a reliable solid new racer. It's what I love and always wanted to build and thats what keeps me going. Crazy or not.

 

There is a NASA event that I am supposed to be attending in a few weeks at Road Atlanta (6/15 - 6/17). I'd love for you to come down and join me in the Vintage division.

 

Matt

Edited by cobramatt
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Hey Matt,

 

You know that annoying brake squeal that you think is just pads? It aint pads. Pull the front wheels off the car and look at how close the caliper sits to the edge of the rotor. The calipers need to sit a bit higher on the rotors. If you pull the caliper off the rotor and inspect it you will find that it is rubbing the outer most edge of the rotor. The more days you rack up the worse it will get. I finally had the aluminum bracket remade to correct the spacing problem.

Had it done in chrome mol;y. It doesn't flex any more.

This will never show up on a street driven car and maybe not a na straight 6 track car. You have a beast. Check it out. I may be wrong but it sounds like mine and it got worse quickly.

 

Let me know what you find. I've gone to a full floating set up on the front and have no more issues with brakes fading or rotors cracking.

 

Thanks for the video. It was awesome!! Love the sound.

 

heres the brakes.

http://forums.hybridz.org/index.php/topic/85165-13-inch-floating-rotor-set-up-with-pics/page__p__807332__hl__%2B13+%2Binch+%2Bfloating+%2Brotors__fromsearch__1#entry807332

 

Mark,

 

As always your knowledge is appreciated. I am printing this post and taking it to the shop tomorrow and checking things myself.

 

Thank you,

 

Matt

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Let me know what the fix to the death is imminent feeling is. About the coil overs coming loose, this has happened to me several times. There needs to be another red nut on the threaded collar or a set screw to lock these things

Again not something that would show up on a show or street car.

Edited by mark
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I just spoke with my chief tech at the shop and he said that he feels we might need to re engineer the rear control arms as the amount of torque and acceleration we have it has moved the diff and the rear is totally out of alighnment now and the control arms are bent and the front coil overs are loose where we did some turns... I wonder if anyone that has used the "Track Pack" billet set up from Arizona Z Car has ever had these problems???

I don't think anyone has posted pictures of damage on those control arms, but I've had reservations about the design of the arms and the mustache bar and have said so repeatedly. I'd like to see what happened to yours when you get them off the car, just to see if my ideas hold up.

 

If you're interested, I think I've designed a pretty good set of control arms. I have no intention of manufacturing them, but I think the design is solid, reduces bind in the suspension, and would be easy enough to copy. This thread has the whole discussion about how the arms bind and how to fix from start to finish and there are pictures of several different solutions.

 

http://forums.hybrid...rol-arm-design/

 

Here are the pics of my end result. I may still change the design so that I have studs welded into the arms instead of bolts going through the monoballs and into the arm on the inners, but I think most would probably just run the poly bushings on the inside (could cut up a set of 280Z arms to start with) and then that isn't an issue:

 

http://forums.hybrid...post__p__848687

Edited by JMortensen
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