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

[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.

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Bob Pinkowski
Atlanta Region SCCA
ITS Honda Prelude

[kthomas]

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



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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.

[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.

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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.

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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

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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!

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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.

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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


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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

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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.

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katman