cobramatt
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Posts posted by cobramatt
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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.
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Looking good buddy.
I really appreciate it.
Giving credit where credit is due. I dont know if everyone knows you work for TopSpeed. Our race shop. The brake ducts, radiator box, new tail light, exhaust inserts, hood modification, and a host of other items were all done by John. He is so busy working on my car that he hasn't touched his Z in two months. Your car is next............
Thank you for all your hard work and friendship,
Matt
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I wanted to also tell everyone how incredible AMP has turned out to be. I have been waiting for over two years to get this track built and it was worth the wait. Very technical. It has a nice fast section but all in all its on off on off on off. Going to be hell on tires. Been up every weekend for practice in a World Challenge Corvette. This weekend will be the first time in the Z. Thought I ought to post a picture from last Saturday that is never good to see but it happens. Blew the O2 sensor out of the down pipe. Happened right at the end of the front straight (at 150mph) in front of a crowd of people. Sounded like a gun going off. The only thing that went thru my mind was........"I hope that wasn't my brakes".
Matt
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UPDATE:
I'm taking her to the track (AMP) this Saturday. Just a shake down, set up and tech. VERY EXCITED...... She will then be going to VIR the following Sunday for a track day on Monday. Nissan North America will be there and they have no idea she is coming, so I think they will be very pleased with what we have done.
Been working on detail items. (pics attached)
1. Heat shields are in place.
2. Had a friend of mine machine me a custom gas pedal assembly that really came out great.
3. Took a picture of the remote Tilton reserviors for the brakes and clutch. Placed them under the cowl. Got rid of the old master cylinder.
4. Had to change the exhaust. She was just too loud and the noise restriction of 98 db was hard to overcome. We installed a MagnaFlow 2/1/2 and then did inserts. It really worked.
5. Brake ducts are in.
6. New transponder installed
7. She is going to get her wrap done next Thursday and Friday.
8. Battery box will go in tomorrow.
Now the push to talk system needs to be installed. The blower for my helmet installed, the NACA duct in the passenger quarter window. The smarty cams need to go in.
AND DAMN I THINK WE ARE JUST ABOUT FREAKIN DONE.............(theres always something that will need to worked on, such as our underbelly/splitter etc...)
I will be sure to post some video of her debut.
Matt
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Came across an old photo. This was taken in '79 and it was my 16th birthday. My mom bought me my first car as a present, '72- 240. It's crazy to think that it was only 7 years old then and I worked on it just as much as I work on my car these days, and it's over 40 years old now. I wish my mom was still around to see my z car these days.
Matt
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UPDATE:
I had a new strut tower brace fabricated. It ties in the shock towers on the new cage bars that we ran through the firewall. They know the paint scheme I'm doing so they got creative and did a little something extra. I think it turned out great.
Matt
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UPDATE:
Filled in back panel. Old exhaust port smoothed out. This gives the back end a very clean line.
Matt
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UPDATE:
Removed old roll cage and new one, Fabricated by Robinson Racing, installed. Great workmanship and its more roomy. They did a fantastic job in tucking all gaps. Very pleased, even though it was an unforseen setback.
Matt
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Congrats on the new family member. Is she bone stock or does she have goodies???
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There is an old saying......If you tell two gearheads that if they spend $2000 on the a few components they will get another 100 HP out of their engine. They will respond "Hell yea, lets do it". If you say hey you ought to spend $800 on a new helmet because the one you have has a small crack in the back of it, they say "This ones fine, its just a hairline fracture".
I made a list of items to be checked prior to going to tech inspection just to be sure all was in order. Got a call back saying they had some bad news and was I sitting down........ Lovely........ My rollcage had some fractures in the roof welds. My first thought is, "I know enough people and could get it through tech fairly easily". Now you see my reason for the opening comment. Two ways of fixing it, romove the roof or tear it out and start over from scratch. I opted to have Robinson Racing fabricate and install a new cage. It is much nicer than the one I had. We went through the firewall and installed front and rear strut tower braces. In the end it is not only much safer but adds to the strength of the car. Now we have to re-run all the oil lines, breathers, catch cans, etc...
I have these mature moments of clairity that actually surprises even me. I dont think I am getting any wiser, I think I'm just getting older.
The opening of AMP is this weekend and I was so looking forward to going. NO CAR. The solution is that I have rented a World Challenge Corvette. I dont know if its cheaper than anti depresants, but its a hell of a lot better for the soul.
Also please follow our car (GTR) this year in the TIRE RACK One Lap of America. It starts in a few days. We won overall for the last two years. Wish us luck. TopSpeedTuned.com
Matt
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Not a good day with the Zcar... For some reason the charging system still isn't charging the battery. Took it for a drive this afternoon and by the 3rd mile, the car was having "issues" due to electrical drain on the system. I don't quite understand what the hell is going on with this damned thing... 3 alternators later, still can't seem to figure this one out... I mean really, it's a single wire and power wire... On top of that, the car has a BAD shake in the steering at about 75mph... And ontop of everything else, the data logger isn't recording data. I'm pretty sure this is something I'm doing wrong, but yea, just another brick to the load...
Mike
I feel your pain. Was going over a few loose ends and making track debut (shakedown) this coming week, not really hot laps, anyway checked off some minor things to pass tech. Then I noticed that the welds in the ceiling of the roll cage have hairline fractures. Since I wasn't in the mood to tear the skin off the roof I had the old one removed and a new one installed. The guys at Robinson Racing did an incredible job on the new cage. I'll post some pic's over on my thread. I now have no car for the opening of AMP for members this weekend. I decided that I needed to get out so I've rented a World Challenge Corvette just to get some seat time. That's pretty desperate...........
Keep your chin up.
I also wanted to talk to you about the new battery........When we installed the no weight race battery in my car I had to keep it on a trickle charger ALL the time and it really didn't have the amps to restart the car if I stalled it, and in the pits with this clutch its pretty easy to stall. I dont want to spend $800 or more on one of the no weight high - high end ones. I was just thinking that I had to go with a red top. It might not have anything to do with it, but try your old (optima) battery and see if it helps.
Matt
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Matt, I didn't realize you were a member there. That being said, I know the guys running the event and they might want be open to having someone who knows the track available for instruction. If you are at all interested in that let me know and I'll run it by them. If I lived a little closer, I could probably justify a membership too. I'm going 'just for fun'. At the moment I don't have any plans for competition in the Z.
I would be more than happy to help out in any way. I just recieved an e mail from AMP and they have cancelled the Chin event this weekend as they want the members to be able to track their cars before anyone else. I really dont care who drives it first because I will be out there plenty. That makes your event the first event for non members. They are opening up the track for us this coming week Thursday - Saturday. They have contracted for the time being with David Murray Track Instruction to provide guidence to all members. Regardless of experiance this is going to be a lot of lead follow to determine run groups. Remeber 75% of membes have no track experience. I am in agreement with this decision as I really dont want to get out there with someone who might have an accident trying to catch up with their EGO behind the wheel. I hope I can have my car at a point to be able to run some laps,(LONG STORY). I also am going to have to buy some street tires as they dont want any slicks on the track for a month.
Why dont you call me and we can discuss further. Four zero four two one eight zero five eight eight.
Matt
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Matt,
I'm looking at doing some events at AMP with these guys (link below). I've run with them before and it's usually a pretty good time. Let me know if you are planning on going to any of their events and I'll try to get there to check out your awesome ride.
Zack,
I am not going to say I wouldn't love to come and join you but I am probably not going to spend a lot of money running events at a track I pay dues to run 180 days a year on. Like I said I am not saying no but the events I run and pay for will be at other tracks. This is where I am going to do my setup and practice at. We will see.
Feel free to call me and review the track prior to going for insight. It is a very demanding technical track that eats brakes and tires. Passing zones are pretty tight. Are you going just for fun run or are you in a competetive class?
Matt
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UPDATE......
1. Ive decided to wrap the car instead of paint it. Talking to a few guys about that now.
2. We have completed the fuel cell and oil tank surround with lightweight aluminum and it looks great. (photo attached)
3. I did some seat time and found out the power steering had no feedback. Our logic was that the more rubber on the road the more assist you need. WRONG....... We ordered a new pump with much less pressure and it seems much better. It had a larger pully so we had to get a new serpintine belt, which actually has better give. The other was real tight on the tentioner.
4. The Razor oil pump was leaking from the seal being oinched so we had to rebuild it......It was brand new.
5. Boxing in the radiator as we speak in the G-nose.
6. Atlanta Motorsports Park is opening up this next week for track time. They just sent out an e mail that they are going to keep all cars with slicks off the track for possibly up to two months. They dont want to tear up the track. I'm wondering if they consider my Hoosier R6's slicks? They are DOT approved tires. That's gonna suck if I can't even take it to the track I've been waiting for over two years to open up. I do have other events to attend but I was looking forward to setting up the car there. Damn....
7. Got the new front and rear sway bars installed.
Spent some time with Scott Pruitt up at AMP this past weekend. He has plenty of experience with Z cars. He won the 24 hour at Daytona in one, more than I'll ever say. He told me of when he was a kid his brother and he had a 260 that they tubo charged and would terrorize the neiborhood in it. He has alway's loved the form of a Z and it didn't hurt when he said he loved what I had done with my car and would love to drive it. That would be cool to have his data in my car and then compare my times against his. It might be hard to ever achieve what he can do but it would be cool to see the cars potential in the hands of a seasoned professional under race conditions.
All for now........
Matt
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Huge numbers... And how the hell did you get that thing sooooo light? WOW... Mine is a pig. We're still above 2600 even with all the work done to lighten it with component swaps...
I need to get mine on a generous dyno for some mega numbers...
Congrats!
Mike
I am not sure if that would be considered a "Generous Dyno", its just the numbers its putting out. I thought from the beginning the way the motor is built and all these numbers were right in line. I'm thinking they will probably increase slightly once we've gone through our break in period. It's the same motor that my frind has in his Corvette World Challenge car and it does the same in that car. He has a 2011 Camaro that he put it in and they put a supercharger on it and it puts out a 1000hp. Before you say anything...........I DONT NEED A BLOWER OR A SUPERCHARGER. I'm good.
As far as the weight. Remember that all the panels on my car, except for the roof and cowl is fiberglass. The interior is completly stripped and minimal. Carbon fiber dash, no gauges. All the suspension is Billet, The motor is aluminum. It was weighed without the passenger seat (if I'm racing solo I dont need it obviously). Even the battery is a no weight battery race battery. Add all those things up and this is what you get.
Matt
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Spent a fantastic day at the dyno. Working on the suspension. Got a few leaks we gotta work out but nothing major. Realized the brand new altenator from GM is toast. I was wondering what this faint noise was and when I looked the pully was not going aroung near as fast as the belt. I'm no brain surgeon but that seemed at bit off. We called the dealership and they will warranty it but they need a vin# off the vette it went in. I guess well just find a good random vette vin# on e bay tomorrow and run it up the flagpole and see if it flys. Hope you like the video, it sounds unreal up close. I actually am going to have to order different mufflers. Exactly like the ones I have but these are damn near hollow, more like resenators than actual mufflers. Its just too load. I love it but if its above 98 or pushing 104 DB it might sound great but your not going to get any track time around here. Well you might get a few laps before you see a big black flag.
Drove it around the industrial complex today to check the suspension set up I had done. MTI Racing did it for me. They are the ones who built the motor. Its got so much damn power listen to it bark the dyno in 3rd. To say that it is going to be a blast to drive on the track is an understatement. We had a pool at the shop. Everyone put in $5 and you guessed the weight of the car w/o driver. Well I didn't win but Doug Wilks hit it damn near on the money. The final tally..............2,248lbs. Doug guessed 2,250.
635Hp. 603Tq.
Link to Video:
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Matt, Seriously thinking about going with a Gnose/IMSA setup as well... Love the flow of the bodywork on your car... If mine doesn't sell, I may well convert it over the winter!
Mike,
A wise man said to me once, "dont keep working on all the little details with my build. Get it out on the track.........."
That was you who said that........
Ever since I had my first 240 33 years ago. I was always drawn to the shape of the Z car. When I saw my first IMSA race, I was blown away with the way the g nose changed the entire look of the car. Over the years I've come to realize that if a Z doesn't have IMSA flares that flow into the G nose it doesn't look right. In my opinion. The balance of making the car wider offsets the longer front end. Without the flares the nose looks out of place. I appreciate the comment.
Today didn't go quite as I had planned.............. Long story made short. Everything I touched today either broke, didn't happen, or just basically took a step backwards. To the point where I'm actually laughing. A true comedy of errors.
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Here is a side shot as she sits today.
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GT? I might need to sneek a peek at your ride, if you don't mind. I work at a shop close by.
Would love for you to. Won't be there tomorrow as I am taking her to Grand Turismo. Then back to finish some metel work. Give me a call 4042180588. What shop are you at?
Matt
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Took the day to assemble the front nose of the car. Over a year ago we molded some carbon fiber head light covers. I still need to work on them a little and I ran out of rivets. (Bad thing is...I can't find the box I had the glass ones we made the molds from. They were expensive as hell and I've missplaced the damn box).
Got the Air Dam on and all the Z tabs in place. I was really worried about how flimsy it seemed prior to installation. After brackets and all were in it's solid. Very surprised.
I had to cut a small section of the hood out to allow clearance of the LS7 altenator. I plan on doing a very small "Gurney Bubble" to cover it. I can't even see it from inside the car so I was happy about that.
I'll take the trailer tomorrow. I have an appointment to get the alignement done (Grand Turismo).
We got a sheet metal bender at the shop to assist us with the Fuel cell and oil tank cover/surround to meet regulations. It will make the job so much easier and look seamless as well.
Took a few pictures. She's a sexy beast.............
Edit:
Sorry.........I forgot to downsize the picture first.
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Lookin mighty fine.........
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Actually the Engineer stressed that the whole underside of the datsun Z does not lend well to a rear difuser. The lack of solid bottom panels front to rear add to the mix. He also advised us that working to get rid of dirty air in the engine compartment was futile. Both were better off left to "fill" to capacity, much like the interior filling up with air. As you mention, Jon, It's going to be hard. The engineer advised to spend attention elsewhere... closing off the front end, ducting the radiator, adding splitters and well balanced rear treatments...Matt clearly has the talent, but will it pay out in functional pieces or be a wasted effort?
I'll offer this much up, When My car is put in the tunnel I'll be happy to test ANY PART ANYONE can get to me before the test. We can put all the questions to bed by doing real tests and colleting real data, Again.
Mike,
What wind tunnel facility did you go to and where? I would also like to know what you paid if you dont mind me asking. Last time I checked it was around $4,000 per hour at a top notch facility with engineer input. I respect everyones opinion and appreciate even the fact that you take the time to comment on my thread. Our plan is to develop a splitter for the front. You mentioned 3/8 Tydex instead of 1/2 inch. I agree that 3/8 would be fine. Most every weekend racer program I know uses 3/8. I thought the 1/2 inch would obviously be more sturdy, every Sprint Cup team uses 1/2" Tydex for their splitters so I know that works too. My thought was the G nose is not flimsy but it is also not exactly sturdy. The 1/2" would help stabilize the lip of the air dam where it is the weakest. This would be one piece that works back to the lateral frame rail, that I cut out the stock one to allow more air to the bottom 2" of radiator. I replaced it with tube frame. The bottom of the car will be two pieces. One left and one right, I've attached a picture. I am going to have to leave the center open as the exhuast pipes need to breath. It will cause too much heat in the cockpit if not. After much research I have found this to be common practice with lots of flat bottom cars. There is even data that shows it to be helpful. The rear diffuser will be the challenge. I read lots and lots of data from other race teams and the equation for success is in trial and error. The slope should be around 14 degrees to start with. How far out the back it exits is a variable to consider. I know I can just take the car to the track and have fun with or without it. Our plan is to do laps and take our average without any of the aero items in place, (splitter, dive planes, wing vs three pice tail, underpanels, diffuser). Then start adding the pieces and see if it adds or takes away from performance. The car has an AIM data logger so this info will be fairly simple. Trying different combinations would be the next step. This is not about making the car look "street cool", this is about performance. A good friend of mine who is last years Grand Am champion with Brumos porsche, #59, is looking forward to driving the car and is excited to help me set it up. I trust my driving is good but he is a machine and during this process I need a constant in the equation. That's Lee Keen.
I will share all the pictures and results of this once we are finished testing.
Thanks to everyone for their helpful input.
Matt
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Matt, Let me give you a little advice... Don't let this car sit forever while you're sorting all the small details. If you can get the car out on the track and start de-bugging it (enjoying it) you'll be happier. Mine has less than 200 miles in 10 years of long, drawn out build. I'd get it on the track as soon as you can so you can chase down all the other "little" things.
I've been working with kydex for about two years now. You'll probably get away with about 3/8th inch kydex for the splitter. I'd also think long and hard about that rear difuser. We got some really good advice from the engineers when we were at the windtunnel in 2007. There's good reason why I've not bothered with it.
Enjoying reading about your build. Takes away from the frustration and Thousands spent on mine!
Mike
Mike,
After being at the shop today we have decided to go ahead and take it to the track and see where we stand before doing a lot of the "little things". We can sort out the aero and such when we have a better idea of how the car is balanced, where it gets loose and so forth. I appreciate your advice and agree with you. Car is going to alignement next week. We have to build the enclosure for the fuel cell and oil tank. Do some minor body work and we are off to the track. Also for the record..... I think is was someone elses comment about leaving porsches behind. I'm sure I'll have a few that are matched more evenly but to think I will be passing any cup cars is absurd. I'm fully aware of the porsches capabilities. Thats not to say that some porsche drivers wont stop and say "That Datsun is fast as hell".
Matt
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Ok, its time to start thinking about the Aero on the car. I am about to take the IMSA three piece tail off and purchace an AeroMotive S2 static wing. Lots of data and seems a very good application for us. Purchased carbon fiber dive planes for the front, fairly simple process. In all my reasearch I have yet to see or speak to someone who has a functional, durable splitter on a Z with a G-nose. We are going to use Tydex 1/2 inch and make it ourselves. We'll see how it turns out. I would like to panel the bottom of the car but we are limited as to how smooth we can get. It was never designed to be flatbottomed. We will do our best. I was goofing around on photoshop and mocked up a diffuser that has given me some direction on the way we want to go there. This is actually the hardest part of all the phases. I'm gonna need help with this. I actually love fabricating and doing a one off car so to say, but there are times when I wish I could just open a cataloug and look under Datsun Aero and it would all be right there. So much for that........
Is it just me or does it seem like the closer you get to finishing a project the more key components of a build pop up and take forever??? I'm about to say F... It and take her to the track.
My Dream LS7GTZ.......project underway
in S30 Series - 240z, 260z, 280z
Posted
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