260z How Does it Do? And, how does one do it?

[Ron Earp]

There is a 260z ITS car in my garage. Since it is there, I'm working on it getting it ready for tech next weekend and, since it is there and is a running car, unlike the Jensen, I place to race it at CMP in Feburary.

How are these things in the grand scheme of ITS?

I've driven it and it *seems* to have a reasonable amount of power. This particular car has been an ITS car since 1992 as far as I can tell and has run at a variety of tracks. It is built well, seems to have the right bits, and I'm just going through it correcting some issues and adding some safety equipment.

The motor is marginally larger than the 240z, but weight is up quite a bit too. How does one go about driving a Z car, in comparison to the only other car I've had on track, a Miata? Brakes are not up to Miata levels I'm sure, given the brake and weigh difference.

Thanks for any help,
Ron



------------------
Ron Earp
http://www.gt40s.com
Ford Lightning
RF GT40 Replica
Jensen-Healey ITS
My electrons don't care if they flow through OEM wires, do yours?

[dspillrat]

HI Ron,
You'll have a blast with the car. I've driven a friends 260z several times, and handling basically the same as 240z.....
In my limited opinion, the 260 should rank around 5th-7th on the "cars to have list" Of course I enjoy bout any kind of zcar!!!!!
Can't wait to see the Jensen on the track.

david

[Joe Harlan]

Ron the 260 should be a pretty good car. I think it will be down a bit in W/P ratio to the 240 mostly because the OE carbs a not real great. Headers exhaust and yes a muffler will be the biggest gains in the engine area. The setup will be very close to a 240 depending on what tires and diff you run.

[Ron Earp]

How about driving it, any tips?

Braking, I assume I can't dive deep in the corner like I can with the Miata?

Trail braking? I assume the Z car will not tolerate such foolishness?

4 speed tranny? Difficult to use or does torque set you free? 4 speed would kill that Miata.

I don't know how the car is set up so I can't comment on turn in and understeer, but I assume it'll get tail happy easily? I like being loose so that I think will be okay for me.

Rear drums, do they do anything at all?

Thanks,
Ron

------------------
Ron Earp
http://www.gt40s.com
Ford Lightning
RF GT40 Replica
Jensen-Healey ITS
My electrons don't care if they flow through OEM wires, do yours?

[dspillrat]

Originally posted by rlearp:
How about driving it, any tips?

Braking, I assume I can't dive deep in the corner like I can with the Miata?

Rear drums, do they do anything at all?

Thanks,
Ron



It'll brake with anything, with correct pad/shoe "carbotech" my choice...gotta swap out stock brake porportion valve w/adjustable to get drums to work. plenty of air blowing on front rotors, if more then 2-3 laps required at CMP or Road Atlanta.....as in most rides, smoothness pays off, on/off throttle and brakes...if in doubt mid turn, don't lift. CMP you'll need 4:11 or even 4.3 ...3.9 will work, won't need much of 4 gear. Enjoy!!

[Joe Harlan]

Agreed except Hawks are the pads to use. The cars are excellent on brakes be a little conservative until you figure out the brakes.

[kthomas]

Originally posted by Joe Harlan:
Agreed except Hawks are the pads to use. The cars are excellent on brakes be a little conservative until you figure out the brakes.

Which Hawks are you recommending and what do you mean by excellent?

------------------
katman

[Joe Harlan]

I sell mostly HT10 compound to my guys. I have a few that like the blues(9012) I say excellent compared to a few other cars I have raced. They don't last like an E36 or a second gen Mazda.

[kthomas]

Okay, HT10's. I miss the HT-9 terribly for Z's. Ron, pray for tracks that don't need a lot of brakes. If you must come to a Road Atlanta or Road America, you'll need HT-10's up front, Carbotech Kaelite Metallic shoes in back, perfectly trued rotors and drums (we also cryo treated ours), a proportioning valve and appropriate tuning so your rear brakes ARE doing their share (if the drums aren't turning blue you don't have enough rear bias), and more air to the fronts than you can imagine. We ran a 3 inch hose to the bearing area of the hub (plus synthetic bearing grease of course), a 3 inch hose split to either side of the disk, and another that emptied into a fabricated shroud that went between the caliper and wheel that blew air to the outer diameter of the pads. We also ran the parking brake to make rear adjustments during the race. That was on a 240Z, I can't imagine how bad another couple hundred pounds of car will be at a place like Road Atlanta. Brakes are by far the biggest regular maintenance item on a compteitive ITS Z of 260 vintage. Best of luck, they are a hoot to drive.

Driving tips: The fast guys treat the throttle like a switch- its either a "1" or a "0" baby! And when in doubt, stomp on the gas, the tail end is happier that way.

------------------
katman

[Ron Earp]

Joe, do you have the pads and shoes I need? If so, please let me know how to get in touch with you and I'll order up a set.

This car has a biasing valve and have the parking brake still connected. With any luck it has been setup right, but you never know. I'll drive it and adjust the thing so that the rears are doing as much work as possible.

Up front it has brake hats for cooling and I'll duct another vent to the caliper. Its already got air picks in the bumper, just no ducts to the caliper.

I'm looking forward to wailing around in it, even if I suck it seems like it'll be a fun drive!

Ron

------------------
Ron Earp
http://www.gt40s.com
Ford Lightning
RF GT40 Replica
Jensen-Healey ITS
My electrons don't care if they flow through OEM wires, do yours?

[grayracer]

Fun car to drive? Yes. Competitive? Doubtful. Reason: an extra 200 lbs, low comp/EPA heads, sorry carbs. The only reason you can make competive power in the 240's are with the SU style carbs and an E31 head...even the E88 in a 240 will put you down by atleast 10-15 hp. The brakes are the weakest link...just make sure you duct as much air as possible to the fronts lest you find yourself with no stopping power after 5 or so hard laps.

[specialtyautomo]

competitive? Chet whittels 240z i now own was the its record holder at road atl till he droke this past summer in his e36. he lowered the record by 1 second but did not run under that at this years arrc. Oh yeah he won the arrc twice in that car. It is running an e88 head to boot. As far as brakes, went testing a barbers motorsports track down the road and I must say the brakes were perfect turning 1.43's on a green track. If you do your homework on the brakes the are not much of an issue. btw That 240z is probably the legal front running IT car I have seen.

[specialtyautomo]

pardon the grammer. catching the phone at the same time.

[JeffYoung]

I know folks get nervous about dyno sheets, but I own half that car and it came with dyno sheets showing 236 hp at the crank, and 210 ft/lbs at around 5500 rpm I think. Motor LOOKS legal -- flat top carbs, etc. But that sure sounds like a lot to me out of 2.6 liters.

David S -- car was the silver 260z run by Jim Dunn at others at Road Atlanta up until 2002. Ever see it race?

[Ron Earp]

Hey, is that the same car I own half of? Holy sh^$!

R

------------------
Ron Earp
http://www.gt40s.com
Ford Lightning
RF GT40 Replica
Jensen-Healey ITS
My electrons don't care if they flow through OEM wires, do yours?

[JeffYoung]

Well, yes, once you actually pay me for the half you own, you will own half of it.

That's a joke.

[Joe Harlan]

Hey Ron, Yes I have pads shoes ect. I will be in the shop all day tomorrow. I just got a little lazy for a couple of days.

[Ron Earp]

Well, yes, seems I've been waiting on that part. I want to own the good half, the half that is reliable, and can't figure out which half that is until we get to the track.

Yes, the dyno sheets are somewhat strange on the car. On one hand the shop that did the build seems to be a respectable shop and all, but that is a lot from a 2.5L motor, unless of course it is a BMW 2.5L motor and then we're still short. Anyhow, as mentioned here those carbs are poor and after calling all around the country there was no good news on them nor any real way to do much about them.

Car doesn't feel like it has that much power but it does feel strong, however you can never tell just driving it up and down the street. Looks like the brakes are done right and sorted, I hope so.

------------------
Ron Earp
http://www.gt40s.com
Ford Lightning
RF GT40 Replica
Jensen-Healey ITS
My electrons don't care if they flow through OEM wires, do yours?

[JeffYoung]

No, Mark gets the unreliable part.

Maybe it doesn't fit the "racer" mold, but a sectio on this web page where people could post dyno sheets so we could have decent baselines would be interesting. Of course, it could also be a disaster (fake plots...).

[Ron Earp]

No special section but here is a thread with the plots I converted from the text data on the printout.

http://forum.improvedtouring.com/it/Forum3...TML/000210.html (http://forum.improvedtouring.com/it/Forum3/HTML/000210.html)



------------------
Ron Earp
http://www.gt40s.com
Ford Lightning
RF GT40 Replica
Jensen-Healey ITS
My electrons don't care if they flow through OEM wires, do yours?

[bobpink]

Before you give up on the carbs, give Eddie Radatz at E. Radatz Motorsports a call - 770.926.6609. He says he's made them work well in the past, but it can be expensive.

------------------
Bob Pinkowski
Atlanta Region SCCA
ITS Honda Prelude

[kthomas]

236hp at the crank? That must be a West Coast dyno......



------------------
katman

[JeffYoung]

That's what I thought Katman. It's some place in Atlanta, don't have the sheet in front of me, but sure sounds way high to me.

[Tom Donnelly]

Ron,

I ran a 3.7 diff at CMP. The twisty sections before the pit lane straight are an exercise in not hitting the rev-limiter. constantly in and out of 2nd and 3rd gear. There is a kink in the back straight that some folks brake at. Don't, just turn in slightly and keep your foot in it. To be fast in a z-car you are either foot to the floor on the gas or on the brakes. And if you aren't dialed in, the back end will try to pass you if you aren't careful. I would have liked to try a 3.9 at CMP but haven't yet. One thing about that place is there was plenty of runoff room when I was last there. The twisty switchback section was too much like Mario's grand prix or something.

Tom

236hp at the flywheel from an L-26 in IT spec? I have a feeling something isn't "quite right" there...especially with the flat top carbs.
Factory rated at 161hp and gain 75hp with what little is allowed in IT is a stretch.
http://Forum.ImprovedTouring.com/it/confused.gif

[Ron Earp]

No doubt and I think the same too. But, as I mentioned on the thread I think it was valid as a tuning tool, just forget the absolute hp number. They did about 10 pulls with lots of changes and eventually picked up a nice bit of hp over the baseline.

I'd guess the car would be able to make around 175hp at the flywheel in IT trim - but I thought the thing was rated at 139 at the crank from the factory, not 161hp.

------------------
Ron Earp
http://www.gt40s.com
Ford Lightning
RF GT40 Replica
Jensen-Healey ITS
My electrons don't care if they flow through OEM wires, do yours?

[kthomas]

Grimes, that explains the offset from reality in the raw numbers. An L24 will make 195-200hp at the flywheel in IT trim, but 175 is probably more typical. Peak torque at about 5400 rpm and peak hp around 6000 depending on the headers. I imagine an L26 would be a little stronger, especially down low with the longer stroke. Have a blast.

------------------
katman

[Prince Makaha]

Didn't Dan Bisone's 240 make 240hp at the crank back in the late 80s?

Not sure how legal it was but I last saw that car lapping about half the field at summit point in 1990.

I doubt that there has ever been an L-24 in legal IT spec making more than 220 at the crank.
Dan Bisone's motor was legal as far as anyone knows... it was protested on many occasions. I know, I was crewing for one of his competitors at the time. There were more than one protest on just his cam and mainly the cam tower shims, which at that time were in one of the "grey areas"

He was cheating in other areas, one of the main reasons he was so much faster than others is because he was using an R-200 with a Torson. His R-200 is now sitting in my shop, he sold it to Russ Thomas and I bought all of Russ' equipment after he passed away.

I'd be surprised if the EP L-24's are making much more than 240 at the crank with the LP rules limitations on carb and head work.

[JeffYoung]

One way NOT to go fast is to rebuild the carburetors in the hotel room the night before race weekend, leave a plug bolt loose and let it dump fuel all over the headers...POOF....we have one toasty 260Z but fortunately a safe and sound driver.

I have now driven the car, albeit with a miss that we corrected (temporarily) with the carburetor rebuild. It does NOT have 235 hp at the crank. I suspect that was a bastard motor with the round top carbs and L26 motor. Not legal.

With the flattops, and a race weight of 2600 or so, it feels quite a bit like my TR8 did last year, before I went to work on porth matching, getting the carbs set up right, headers, etc. The TR8 dynoed at 158 at the wheels, or about 180 or so at the crank, and that's what this Z feels like.

Anyway, just info to throw out there.

Great car by the way guys. Really like the smooth power delivery, and brakes aren't nearly as bad as I had suspected.

[Rick_htm]

So that was the toasty z car at cmp last weekend. Glad everyone was ok. Are you going to have it up and running by VIR?

Rick Harbaugh

[Ron Earp]

Hey Rick,

That was it. Really not that much damage other than a few crispy wires, a shaken rookie driver, and a discharged fire bottle that will take some cash to refill. Dang it.

The car does drive well though, although it looks a little on the ratty side. We'll rebuild the carbs, fix it up, and she'll be ready for VIR. We are hoping the JH will make VIR but I ran into a snag on the head and it is going to take a few days to correct so were still weeks away from firing the motor.

Fire bad.

Ron

------------------
Ron Earp
NC Region
Ford Lightning Tow Beast
RF GT40 Replica
Jensen-Healey ITS
260Z ITS - Just call me fireball!

[JeffYoung]

Rick, that was us. Ron Earp and I each own half of that car (the 260). We brought it to CMP to shake it down -- it was of course claimed to be "race ready." HA HA HA.

It was cutting out in right handers on Friday's test day. It literally would just die when you made the turn into the kink.

We took the carburetors apart back at the hotel Friday, and the float height was set wrong. That fixed the problem, for 3-4 laps, and then the plug worked its way loose and Ron had a fire to deal with.

Car is not in too bad shape. Mostly melted electrics and carb internals. Rebuild kits on the way.

We may bring it to VIR. We are hoping to have Ron's Jensen-Healey done by then so it can make its debut at VIR, but if not, we'll have him there in the Z. Fun car.

Really good to see the white/blue Z back out -- great looking car. How'd it run for you Rick? Are you going to run it more this year, or are you sticking with the 7?

[Rick_htm]

Thanks Jeff. I'm planning on doing the full CCPS in the Z if all goes well. It almost handled better in the rain than the dry. Still a few mothballs to clean out I guess. Can't wait to see the JH. Maybe We need to start a vintage ITS class.

[JeffYoung]

Vintage IT....a great idea.

Rule 1: No washer bottles.

Rule 2: Motec BAD.

See you at VIR.

Jeff

[RacerBill]

Vintage IT

20+ years old! Great idea! How about Club IT!

------------------
Bill Stevens
Mbr 103106
BnS Racing
83 ITA Shelby Dodge Charger

[lateapex911]

We've joked here in the NE about this. There is a clear line between the cars in ITA that have a chance, and those that don't. We race against Anthony Serra every event (he's the dude that got by, and drove away from Strech on the way to setting a lap record and winning the ARRCs), and there are quite a few guys who give him more than a run for his money...to say it's as fast as any other ITA group in the country is probably safe....and having fields in the 20 -30 car range means that getting a trophy is a fantasy for some well prepped and well driven cars. (Who pray for torrents of rain!)

We thought having "ITA lite" would be funny...and if we were smart, we'd register guys, collect money, make a rule that outlaws Hoosiers, and hand out trophies.

Cars like the Prelude, the 2002, the MR-2, the RX-7, etc fit the bill.

------------------
Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

[iambhooper]

Originally posted by rlearp:
Hey Rick,

That was it. Really not that much damage other than a few crispy wires, a shaken rookie driver, and a discharged fire bottle that will take some cash to refill. Dang it.
Fire bad.

Ron



I was working at 6 when you pulled off at 4. All I saw from the flag station was a cloud of fire extinguisher residue. Too bad. I'll see you guys at VIR, except I won't be flagging this time... I'll have the CRX out by then.

Glad everyone was ok!

Later!
hoop


------------------
hoop
Greensboro, NC
White ITC Honda CRX
Region 55

[Ron Earp]

Only thing I couldn't figure out is why they didn't flag me. Corner workers were looking at the car all through the techincal section and I ripped down the front straight full bore with fire streaming out from underneth (I didn't know). I was watching the tower for a signal because I was starting to suspect something was amiss but still got no flag. Do they have to call flags in or get persmission to show a flag?

It wasn't until the end of the front straight at turn 1 that I knew I had a fire and could see flames/smoke and smell smoke. I pulled the fire bomb and drove to the nearest station (missed station 2/3 if it was manned I can't remember, was looking at panel for fire handle and trying to see).

The station fellows were wonderful, one got the extingusher in the hood as quick as they could and the other started getting me out - all that flame extingushing stuff makes it hard to breathe, that is for sure. Good job and thanks a lot fellows!

But, all in all it is okay and we're going to run it again at VIR if the Jensen isn't ready. I'm pleased with the Z, on two of those laps before the fire it felt pretty good and certainly felt as if I could drive it about a 2:00 - a second slower than my class school Miata times. Still not ITS competitive with the Zs and the TR8 but I'm a new driver in a new car, gotta start at the bottom!

Best,
Ron

------------------
Ron Earp
NC Region
Ford Lightning Tow Beast
RF GT40 Replica
Jensen-Healey ITS
260Z ITS - Just call me fireball!

[kthomas]

CMP doesn't test the brakes. Let us know how you feel about them after a day at Road Atlanta.

Glad the damage was minor.

------------------
katman

[Ron Earp]

I'm new at this, but CMP seems like it is pretty hard on brakes. There are a few heavy braking zones there - turn 1 at end of front straight, turn 8 (9) before turning on the back straight (not too bad since you carry a lot of speed), and the big turn right after the kink turning into the technical section.

Then, in the technical section I feel if you do it right you've got a lot of sprints and hard braking there too, four right after one another before turn 14 and you're back on the front straight again. If you are aggressive through here you can pick up a little time on your opponents I think.

But, I don't know how Road Atlanta is so maybe it is a lot worse with the stopping and going.

Ron


------------------
Ron Earp
NC Region
Ford Lightning Tow Beast
RF GT40 Replica
Jensen-Healey ITS
1/2 a 260Z ITS - Zero

[kthomas]

Imagine the speed before braking for turn 1 at CMP, then point it down a hill and enter a much slower turn and you have turn 10a at Road Atlanta. If you're hard on the brakes anywhere else at CMP you're slowing down too much. Our Charlotte setup lasted exactly 6-3/4 laps at the current Road Atlanta configuration before completely vaporizing the pads and welding the caliper pistons to the pad backing plates. That was several years ago, we've learned much since. That was with a 240Z, a 260Z will be worse. Let me know if you ever make it to RA and I'll try to meet up and pass on some tips.

------------------
katman

[JeffYoung]

Katman, we will let you know when we make it down to RA. Will try the ARRC this year I think.

One question though (since I have a brake challenged car as well). CMP is hard on the brakes for me, for this reason. From Turn 11 through the "autocross" section, I'm not using the brakes all that hard, but I'm using them 4 times in a row. No time for them to cool.

This causes me problems, far more than VIR where I believe the braking for Turn 1 is a lot like 10a. About 130 mph down to 50 or so. At VIR I'm off of the brakes a lot, no real time to cook them.

So, what I'm getting is literally a melting of the piston seals in the caliper. I've got the brakes ducted to the rotors, but have not yet added caliper ducts.

At CMP when I use the brakes that many times in a row in that succession, I get too much heat in the caliper and the piston seal starts to go away.

Any thoughts/ideas/solutions? I've tried some things, including one thing that I ripped out because I decided it was illegal (a fluid recirculating valve), but no luck yet. Cooked the right front seal at CMP before I broke the transmission a few weeks back.

The only thing I haven't tried, other than caliper ducts, is hard metal pads that Kirk recommended. He thinks they will transfer less heat to the pistons. I will try this next if the problem continues, but again wanted the advice of (a) someone who obviously knows what he is talking about and (B) someone who has worked with brake challenged cars.

Thanks.

Jeff

[Joe Harlan]

Jeff, What pads are you running and how thin before you change them?

[JeffYoung]

Joe, when the problem started I was using PFC 90s. That compound has been discontinued , and I'm using Porterfield's recommended replacement, the ridiculously expensive Raybestos ST-42 (or 43, I can't remember).

I change the pads usually well before they have a 1/4 of their thickness left.

Thanks for thinking about this.

Jeff

[Ron Earp]

Fellows, anything you can suggest on the Z brakes would be helpful as well as the TR8 - both are about the same in specifications. The only difference in the cars right now is that the Z has full ducting - hat duct on the rotor and duct to the caliper, while the TR8 only has a hat duct on the rotor.

R



------------------
Ron Earp
NC Region
Ford Lightning Tow Beast
RF GT40 Replica
Jensen-Healey ITS
1/2 a 260Z ITS - Zero

[kthomas]

Originally posted by JeffYoung:
Katman, we will let you know when we make it down to RA. Will try the ARRC this year I think.

One question though (since I have a brake challenged car as well). CMP is hard on the brakes for me, for this reason. From Turn 11 through the "autocross" section, I'm not using the brakes all that hard, but I'm using them 4 times in a row. No time for them to cool.

This causes me problems, far more than VIR where I believe the braking for Turn 1 is a lot like 10a. About 130 mph down to 50 or so. At VIR I'm off of the brakes a lot, no real time to cook them.

So, what I'm getting is literally a melting of the piston seals in the caliper. I've got the brakes ducted to the rotors, but have not yet added caliper ducts.

At CMP when I use the brakes that many times in a row in that succession, I get too much heat in the caliper and the piston seal starts to go away.

Any thoughts/ideas/solutions? I've tried some things, including one thing that I ripped out because I decided it was illegal (a fluid recirculating valve), but no luck yet. Cooked the right front seal at CMP before I broke the transmission a few weeks back.

The only thing I haven't tried, other than caliper ducts, is hard metal pads that Kirk recommended. He thinks they will transfer less heat to the pistons. I will try this next if the problem continues, but again wanted the advice of (a) someone who obviously knows what he is talking about and (B) someone who has worked with brake challenged cars.

Thanks.

Jeff

Email me at [email protected] and I'll send you some info.

------------------
katman

[Joe Harlan]

Jeff/Ron,
We have dound it best not to run the pads below 50% if you want to avoid seal melting, I have in the past made up a spacer block to put between the pad and the piston when the pad gets worn to try to use up the last bits of the pad. (not worth the effort)

ON the Z keeping the front brakes alive requires constant adjustment of the rears to keep the balance and the pedal up. Ducting to the rotor shoud be a can the splits the air inside and out. Do not duct air to the caliper. Heat will travel to the coolest surface. If the caliper body is chilled the heat from the pad will travel toward the fluid instead of transfering into the rotor. You want the rotor to take the heat and transfer it to the air. I have never run the raybestos stuff so I am not sure what to offer there. I use the Hawk 9012 and HT10 compound for those cars and that is what all of my customers run.

[This message has been edited by Joe Harlan (edited March 02, 2005).]

[kthomas]

Originally posted by Joe Harlan:
Jeff/Ron,
ON the Z keeping the front brakes alive requires constant adjustment of the rears to keep the balance and the pedal up. Ducting to the rotor shoud be a can the splits the air inside and out. Do not duct air to the caliper. Heat will travel to the coolest surface. If the caliper body is chilled the heat from the pad will travel toward the fluid instead of transfering into the rotor. You want the rotor to take the heat and transfer it to the air.I use the Hawk 9012 and HT10 compound for those cars and that is what all of my customers run.

[This message has been edited by Joe Harlan (edited March 02, 2005).]

I agree with all that except for the suggestion not to run a duct to the caliper. The difference in temp between the source and the sink affects the rate of heat transfer, but you'll still get heat in the caliper regardless. I think airflow over the caliper outweighs the potentiol increase in transfer rate. That would make an interesting test, eh?

------------------
katman

[Joe Harlan]

Katman, I have actually done the test same day realife with heat paint and measuring fluid temp at the end of each session. The fluid temp went up when ducting the caliper. I did all of these tests about 5 years ago so the result could be different today with different fluids ect.

[lateapex911]

Joe, that is great stuff! I understand the temp paint for swowing max surface temps, such as on the caliper, but, how did you get the actual fluid temp? Drill a caliper and insert a probe?

Cool stuff.

------------------
Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

[Joe Harlan]

No we just measured the difference in the Master cylinder the test was head to head using fresh fluid each time and enough time for all parts to cool back to a similar a starting point. I had a couple of Z car guys melting seals and we just wanted to figure out why. The ideal way would be to make a small temp sender to thread into the bleeder hole to get exact data but that would be Kirk type anal.... http://ITForum.ImprovedTouring.com/smile.gif I would have to dig deep to find all of my notes but the end result was a set of cans the covered the largest amount of the lead edge of the rotor and forcing air over the top to the outside of the rotor.
No kidding we even tried different compounds inside and outside to try to equalize the surface temps....(waste of time)

[HounDawg]

Originally posted by JeffYoung:
We brought it to CMP to shake it down -- it was of course claimed to be "race ready." HA HA HA.

It was cutting out in right handers on Friday's test day...
I'm sorry to hear you guys had bad luck. I wish you the best with your 260. I, too have had carb problems and finally gave up on the flat tops. Since I wasn't competitive anyway, I got some round tops just to see what it would do, and it was like night and day. I'm building a 240 now. Someone else suggested having Eddie Radatz work on the carbs, and I'd second that. You need someone experienced with them and who might have some different needles he can try to get you leaned out some. Get Eddie to play around with them and try different things on the dyno.
Another thing you might want to check is your fuel pressure. The round tops seem to want 5-6 pounds at high rpms/speed, and the flats may be the same way. Of course your valves will have to be able to handle the extra pressure.
If you need any parts, I have some flat top carbs on my retired car. I had ripped out the stock wiring harness and built my own, so I can't help you out with any wiring.

Dawg

[Ron Earp]

Hey Dawg,

we need a set of flat tops, are you selling yours, how much do you want?

It is funny how people have had trouble with them - they are horrible carbs. But that being said I am determined to get them to work since I have to for the car to be ITS legal. Ain't nothing but a big motorcycle carb and I'm certain I can work something out - once I find a original set to learn on. Ours have been bastardized to the point where not much is left and they don't work well, so, I can't really tell which way is up. Reason I'd like to get an original set.

Our 260Z originally raced at 240Z weight and you can tell because that is crossed out in the log book. I think that someone was cheating with the car and passing it off as a 240Z. It also has on the VIN plate, convienently rubbed off, the section that tells what the car is....hmmmmmm, that and the weight in the log book being crossed our and re-written as a 260z seems to indicate to me something fishy was going on.

Ron

------------------
Ron Earp
NC Region
Ford Lightning Tow Beast
RF GT40 Replica
Jensen-Healey ITS
1/2 a 260Z ITS - Zero

[dspillrat]

Originally posted by rlearp:
Hey Dawg,

we need a set of flat tops, are you selling yours, how much do you want?

Reason I'd like to get an original set.

Our 260Z originally raced at 240Z weight
Ron



Ron,
I have a couple of 260s in the yard, If interested, I'll be glad to send you a set of carbs. See if they can be used, buy me a beer..... I'm cleaning out around the barn presently, so let me know, before the scrap yard gets em...
david

[Ron Earp]

Hey David,

We could use a set and we'll buy you some beers, that is for sure. If they are available and you can send them to us that'd be fantastic!

Ron Earp
132 Loch Pointe Drive
Cary NC 27511

Or if you are coming to VIR and could bring a set that'd be even better and probably easier. We'll have beer for you! If one of your 260s has that crazy plastic linkage ball we could use on of those too, getting hard to find these days. Thanks much,

Ron

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Ron Earp
NC Region
Ford Lightning Tow Beast
RF GT40 Replica
Jensen-Healey ITS
1/2 a 260Z ITS - Zero

[dspillrat]

Soon as the rain quits, I'll get you the carbs to the firewall...
BTW I drove a friends 260 at VIR couple years back into the 2:19s..I hope to be back in business by the MARRS/SARRC in May.
Good Luck
David


Originally posted by rlearp:
Hey David,

We could use a set and we'll buy you some beers, that is for sure. If they are available and you can send them to us that'd be fantastic!

Ron Earp
132 Loch Pointe Drive
Cary NC 27511

Or if you are coming to VIR Ron

[bobpink]

I mentioned Eddie Radatz in a previous post as a resource on the flat top carbs because he says he has made them work and work well. It's just a lot more work and more money for parts to get them functioning like the round tops.

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Bob Pinkowski
Atlanta Region SCCA
ITS Honda Prelude

[HounDawg]

Originally posted by rlearp:
Hey David,

We could use a set and we'll buy you some beers, that is for sure. If they are available and you can send them to us that'd be fantastic!


Problem is the carbs are at my mom's house in the back of parts car and it may be several weeks before I can get up there and box them up.
You can have them for the cost of shipping. Or if I can drop them off at Road Atlanta later this spring, that would be easier for me. But then if you need them to get ready for your next race, that wouldn't work for you.

[Ron Earp]

We're in no hurry and we'll take both sets you guys have, we'll cover the shipping and give you beers for the hassle.

Bob, we'll call Eddie too and see what can be done.

The funny thing is just about everyone that looked at the 260 at CMP said the same thing - never seen a 260 with those on it, everyone runs the round tops. "Just run the round tops" Well, there is that little problem of legality and we've got to have the car legal. Apparently a lot of people turn a blind eye to this issue but I'm sure it'd get protested sooner or later.

We'll talk to the folks in the know and take a look at the original carbs when we get them. They really are simple carbs and there has to be a way to get them to do something decent. It is a shame though the 260z carries with it a weight burden that is is excess of the small displacement increase it has. The weight coupled with the horrible carbs sort of makes it a non-competitive car but I'm hoping we can at least get around the carbs. 190 lbs additional weight for 185ccs displacement is a little steep!

R

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Ron Earp
NC Region
Ford Lightning Tow Beast
RF GT40 Replica
Jensen-Healey ITS
1/2 a 260Z ITS - Zero