Topend wars!

The Seca Turbo (a very low-mile '82 with the Power-Up kit) is almost ready for safe topend blasts. The opponent is a stock-motored unfaired '79 CBX (DG 6-1, K&N air filter, main jetting slightly too rich ) which is ready to go.

We have a fine venue for this, TRUE topends WILL be reached (with the blessing of friendly local law enforcement officials)! 8)

My best guess: 132 for the Seca, 134 for the CBX.

Should I start a poll??

P.S. Forgot to mention, these will be GPS-verified speeds, of course!

 

just a thought
H rated tires are good for 130

 

Don't know if i would want to go 130 + on a cbx. That is a whole lot of bike for some reason that went into a wobble kiss it good bye. I always loved the cbx rode one of the silver 79s handling wasn't its best feature by far. Great bikes for collectors for sure. Turbo seca much better street bike wouldnt feel so bad running the heck out of it. To me the honda feels like a big gyroscope. Just be careful . Brings back memories from when i was young going for every mph i could get

 

Guys, forget about the safety aspects. ALL of that is covered. That's ALL of them. (No, I'm not going to brag about my qualifications, just tell me what you think about the true top speeds if you will!)

 

How far into the redline are you willing to go??
The Turbo makes 90 HP, the CBX was 98 or so (guess)
They've both been worked on and tuned up, so I would guess a little higher.

And that 130 speed rating is for continuous use, due to heat build-up.
The tires ARE relatively recent, right??

Will you be adding air pressure, ratchet-strapping the front ends, (to reduce frontal area) , adding thinner oil, removing mirrors??

 

Well of cause it's fine with the power up kit, but a lot of turbo owners disable the wastegate, which make the boost pressure go from 7 to 14. (In fact it has a secondary wastegate opening at 14)
At 120mph it tends to get a little light at the front so take care.
Without stronger springs in the clutch it will be slipping - mine did and it's a well known problem.
If you wich to go that fast the steering bearings and the swinging arm bearings should be new and well adjusted with no clearance.
Use only top quality fuel.
Good Luck!

 

130? I figured those old cbx's would of had a lot more too end. Up in the 150's at least. I think the SECA takes the line but the CBX comes rumbling back.
Btw if he ever wanted to sell the CBX that bike is on my wishlist. It's hard to find a deal on them though.

 

Without stronger springs in the clutch it will be slipping - mine did and it's a well known problem.

 

this should be interesting, get some vids!

 

Will do. I'll probably get another rider to run one of the bikes so we can do some side-by-sides (probably from a roll, I'm not particularly crazy about abusing either one of these bikes out of the hole).

 

I'll be an interested observer to this race. I had my turbo out the other evening, after dark actually so I'm a bit more concerned about critters (read deer) at night.

Someone mentioned a secondary wastegate....doesn't exist, what the powerup kit actually does is to rely on the pressure relief valve to open at 14 to ACT like a wastegate but there's a catch, and it's a big one, by opening the bov or prv as it is more accurately called, you induce turbo stall. Yes, it effectively cuts boost but at the cost of being VERY hard on your turbine bearing and shaft. Much better solution to shim the bov to open at 21-22psi and install a boost controller. That way you can safely take your turbo all the way to near 20psi before the actual wastgate opens. Mine has been set to 18-19psi for a year now and still runs great, especially as the needle swings past 14-15 psi...things happen quite quickly to say the least!!

I seriously doubt you'll see 130 from a stock geared turbo.....I'll admit to never clocking mine but it seems to run out of breath much sooner then 130 but who knows, until you've done it with gps accuracy. My guess for both given 1/2 mile to 3/4 mile would be high 120's for both but depending on your turbo setup, the CBX should beat it in topend if the valve pops open and causes a hard ceiling on the top end.The CBX presents such a huge frontal mass that without a fairing, the same engine that developes such great power becomes a big, wide wind brake...sorry, just the way it is. When I used to road race, sticking my hand into the windstream at 170 would instantly chop 5mph so imagine what that engine will do.

Good luck and make a good showing for us turbo guys<LOL>!!

jeff

 

Stuck mine out a couple of times at close to 190 on Busas. Quite enlightening!

AMA, WERA??? I know a bunch of guys who raced quite a few years ago.

 

Thanks for info JeffK!
Could you describe your solution in details.

 

Oil---WERA Western,Eastern-----I was on Nigger Sammy's team, him and Ronnie Turner used to do most of the riding, I was the engine/bike builder. We raced a very heavily modified GT750 Zuk, water cooled 2 stroke(of course) triple. We spent the first year trying to get our H2 to hold together but with the inherent narrow transfers(it was originally intended to be a 650),it was impossible to get real power out of the engine without breaking the rules by building up metal outside of the transfer areas of the cylinders so we could reshape them. So the only other way to get power was to spin it faster. Stock R/L was 7,500....we turned ours at 10,200 to be competitive but I couldnt keep it together. You know the deal, cranks spun out of phase, broken cranks, spun bearings, broken welds..the works....the Buffalo was much easier to keep together but harder to get power from, Paul Dunstall made some parts for us(tranny, fairing) that helped in huge ways and a guy named Gordan Jennings provided some tech help....we had fun, didn't win much but came out of it with ourlives and a bunch of extra parts<LOL>

Pirok, I have some pictures of my boost controller setup, its pretty simple but for your turbo to produce 18-20psi, it has to be in VERY good condition. I rebuilt mine before running the kind of pressures that I run but so far, it's been bulletproof. If you pm me a email address, I'll send you the pics with some basic instructions to help you get it set up. I can promise you one thing....once you run 18psi, you'll wonder why yamaha delivered them with only 12-14!!

jeff

 

Did you ever put these two up against each other? I was real curious to soo what became of it....all in fun of course....seemed like a plan to me!!

jeff

 

Did you ever put these two up against each other? I was real curious to see what became of it....all in fun of course....seemed like a plan to me!!

jeff