clarkspeed
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Posts posted by clarkspeed
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Derek, I definetly see a Bill Coffey garage party award in your future.
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I have an ARE pan on the shelf. I could take some measurements if you want.
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Bilsteins are bulletproof. I can't blow them, and even if I did Bilstein will rebuild for $80 and valve any way I want.
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Bacically everything in suspension is compromice, some solutions are better than others, but not necessarily all ways. Are we talking about strut suspension. If so, within "normal" SAI-angles can be used angles somewhat zero and up. Or down, if you think about control arm. Remember measure angles by pivot points.
Widening track affects weight tranfers, and by that spring load and wheel rate depending suspension type. Widening both ends same amount is a safe way. If you not sure what you are doing.
Could not have said it better myself. Everything is a compromise. Especially with a strut suspension. You can really get wrapped around the axle looking for some perfection that is not there. And everything you change has at least a primary and secondary effect. So think about that when you start turning screws on those trick adjustable parts and drilling cross-members.
But with that said, I don't think there are any negatives to getting rid of bump steer......
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I think every rebuild I have done myself cost $1400-1500 in parts and machine shop. For budget, I say keep it stock and invest in intake and exhaust as required. A little "free" power can be had by port matching manifolds and blending the port into the valve seats on some heads.
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From my experience, large movement of the inner pivot makes the bump steer unmanagable. I prefer controlling the RC and camber by other methods. Then bumpsteer can be mostly eliminated with a very small vertical slot in the cross member of 1/4" or less.
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Those TTT control arms look just like the set I recently fabricated. I got the monoballs and pins from UB Machine.
My theory on bump steer is I dont worry about measuring it.....just try to get it as close to 0 as possible. No expensive tool needed. Just 2 pcs of plywood, piano hinge, 2 small screws that extend out to touch rim, and a weight to hold on ground firm. Remove spring and jack car through range of motion. Adjust until screws ride on wheel rim throughout range.
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Bumpstops and packers - the secret sauce for Chumpcar racing.
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Look up the stud kit number on ARP website. It links to their correct torque spec.
Not unusual for older block to have some corrosion in the threads if water ever set in there.
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I agree with stiffer spring rates. At 150mph my 425# front feels real mushy. Which also means you better not have any bump steer. In general, F&R toe in adds stability and doesnt scrub that much speed off.
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I watched it a couple months ago. I only began following racing closely after he was past his "prime" so I didnt realize what a good driver he really was. Nor did I know he raced full 10-13 race seasons with testing in between.
I tried to talk to him on the grid at Daytona one year when he was 60 or something. Thought he was a A-hole. But after seeing the movie, I realize how much fan/media attention he had to deal with. He actually ran over a photographer at Lemans.
Adam Carolla did the movie. Great footage and interviews with Bob Sharpe.
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That is pretty cool. But those rotor choices are enormous, heavy, and expensive. I am taking my setup from 12.19x1.25 down to 11.75dia on a 8 x 7 BC. Common as dirt circle track size, cheap, lighter, and more than adquate for my application. Still pretty cool they released those.
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nice car
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I am also in the middle of building a tube car. Not for the faint of heart! If you search the classifieds I think there still are some pictures of the partially finished shell I purchased from Chris Leone. He had already completed a full roll cage and front end. I ended up redoing most of the front clip and I'm now finishing up the floor, trans tunnel, firewall, etc. Slow going when you only get maybe 6 hours/week to work on it. Maybe some day I will start a build thread on Hybrid. Eventually it will become a IMSA GTU tribute car.
A lot depends on how much you need to replace. Most of the rear of my car was intact, but no floors, firewall, or front. If you can save/restore/reinforce the strut towers and frame rails I think it makes an easier project. Brace everything out before you start cutting out panels. That is assuming you are not building a race car. The project gets a lot more involved if you need to locate and square suspension mounts, then you need to build up on a flat plate. And you start thinking about all those compromises you might like to fix like Tube80z mentioned.
You can probably do it all with square tubing if you don't put in a cage. But I found I can lighten things up quite a bit since I have the cage providing structure. Either way plan way way ahead on what you want to do and don't "build as you go". And you had better know how to weld and how to identify a good or bad weld.
Google for the MGB tube build thread. Might give you some ideas of what to do and not to do. Like mentioned above, he built up the entire car and it came in at 2400# or something like that.
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It just takes more slip angle to make it change direction.
That is a clue. There can be a lot of difference between radial and bias. To dial them in will most likely will require some testing with different pressure, camber and toe settings. The difference in tire spring rates might also require a spring rate change. It takes a little time.
You can't trail brake effectively that way. So when you put a big splitter on the car and need to keep it flat on the ground in entry that will become important.
Dan did mention the car moving too much. Part of that may be too much suspension travel. From the second picture there's too much roll and that has decambered the outer tire. So even if the car feels great there's a higher level to be had. And these spring rates aren't stiff by any means. Starting points for slicks these days should be wheel rate equal to corner weight for no downforce and that can go up to 1.5 or higher. Add XP/EM downforce and numbers over 2 can be used. On radials .8 to .9 seem to be the norm.
On track cars running at higher speeds other ideas could be used.
I would expect some oversteer or instability under trail braking in that condition, but none mentioned. That's why I ask. And it didn't look like Dan is running a splitter. I've seen some strange things over the years and what works for some people may not work for others. Sometimes the answer is don't trail brake so much.
I think getting the tires to work is most important. If the overall grip is off, and you are "rolling over the tires" rather than "skating on ice", then stiffer is the way to go. I agree with your direction because tires are a lot gripper these days. Either pressure change )1psi = 60-80lbs/in) which you already tried, or spring rates. I wouldn't call 500/425 soft for a production based S30, but you should go higher if the car/tires are asking for it.
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That looks like a VW Golf trail braking! Dan is running a fairly stiff set up and looks to have a good deal of mechanical grip in the pic. Going stiffer might cure the problem, but always remember every change has a secondary effect. What is the real problem here? Oveall grip? Corner entry understeer or oversteer? Grip levels and getting the handling right are much more important than trying to cure the wheel lift. It works good for a VW, maybe it works for you too!
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A tech article from Driven Race Oils by Lake Speed their Lubrication Engineer talking about using ATF as an engine oil. It depends on how long you want to use it and load conditions.
http://www.drivenracingoil.com/news/dro/training-center/articles/oils-lubricatebut-long-conditions/
Also a good basic article on engine oils.
http://www.drivenracingoil.com/news/dro/training-center/articles/racing-oil-101/
They also have plenty of info on zinc and why you need or don't need it in other articles.
I heard Lake speak at the MSC expo last year and it was very informative.
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I use a Griffen double pass. It was from some Ford app that had the right width. I used aluminum tubing and silicone connectors from Silicon Intake Systems to custom plumb it.
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The lowest viscosity you can run to keep adequate oil pressure and protect the bearings from journal contact running is the oil that gives you the best power.
Absolutely.
I'm not a lubrication engineer by any stretch, but can only repeat what oil company reps and professional engine builders have told me. The oil cushion on start up is quite critical to bearing wear on both passenger and race cars. There really is no protection until the shaft is rotating and a wedge is allowed to form.in the bearing. A thiner weight oil provides enhanced protection during this period and is faster to form the wedge. That's why you see so many passenger cars moving toward the 0W-5W multigrades and most race cars running multigrades. Of course a sump heater would make a difference also.
BTW, I was also told there were only 3 synthetic oil base manufacturers, Exxon, Chevron, and BP. And only 4 additive manufacturers. The secret is in the mix of course, but it is not that big a secret. It's more of blending for a particular market or application. Diesel oils, like your Rotella, are blended with higher detergent additives. Race oils are blended more with additives that resist fuel contamination and the degregation that comes from it.
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I just read this post. Low pressure could have been the oil pump. Make sure to change it out on rebuild. As far as oil, there is plenty of info on the web. Bobistheoilguy. How hard you push it on track and how much you spent on that engine should influence your decision. I stay away from additives and straight weight oils. Most damage happens on start up. For a severe duty L6 stick with a multi-grade at least 40w or more for higher temps and to allow margin for some degredation. 40W oil turns into 35W oil when contaminates are introduced.
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This has me thinking again. What is the best way to quantify lateral g's? It's pretty much a normal distribution of data. At the Runoffs we saw almost identical G's from Hoosier R7 DOT's and slicks. Peaks at 1.8, but when I look at a smoothed plot the average is more like 1.25. And that is typically what I find when taking an average for 1/2 second or so continous loading.
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LNA in Greensboro. Sam will build you some power.
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I guess I just saw your earlier post, what RPM were you shifting at? It's not a trival task to have a 8k RPM engine with the big bore and stroke. Better to shoot for something that will deliver power < 7200RPM and use that big flat torque curve to your advantage coming out of the corners with a crappy ratio Nissan transmission. I'm sure it can be done if you pay attention to the details, and Rebello may report a high limit, but in the last couple of years I have seen 3 oversize engines wipe bearings when rev'd often over 7k. And one was mine. I know there are a lot of theories on this with vibration and all, but the simple solution is keep the rev's down.
ARE dry sump for L6 - Engine Drop
in Nissan L6 Forum
Posted
I finally got around to dragging it down. It may have less clearance than a stock pan! The "sump" is a 4"wide tray that runs the length of the pan on the drivers side. It measures about 3" from block to lowest point.