I had my '86 951 on the track a few days ago-at an S2000 track event at Thunderhill, in Willows, California; and after two different half hour track sessions I was in the pit, reclamping the hoses, first from the turbo to the intercooler, then from the pipe that attaches to the throttle body.

The original factory German clamps just weren't holding the rubber connector hoses securely, and I replaced them with large US style clamps. This seemed to do the trick.
Anyone else experience this problem and have a better solution for securing the rubber pressurized hoses?

BTW, I'm running a standard K26, freshly rebuilt, with LBE, Weltmeister chips, shimmed wastgate, K&N air filter.

Steve Cooper

 

Try replacing the hoses with new pliable rubber. Before I did this, they would come loose and leak. Now I run over 20 psi on occasion (like when i turn the boost **** to far), and haven't had any boost hose problems.

 

Steve, aka 951 may be right, but that can be sort of expensive.

I have found that cleaning the turbo oil blowby off the surfaces helps. I use a quick dab of acetone on a rag and it doesn't seem to attack the rubber yet, but I don't slobber it on.

what sort of US style hose clamps are you using? Don't use the type that has slots punched all the way through the band to engage the screw, especially on the boot to the throttle body. That is thin rubber and it will deform into the slots and get cut.

Use the type that has a long flat (no slots) "tail" that wraps all the way around the inside of the clamp or the type where screw engagement ridges have been pressed into the band, not punched all the way through.

NAPA sells the inner tail type.

 

I don't know how much your on the track, but thats more common than you might think. Most cars don't stay full "boost on" for long periods of time on the street. At Thunderhill, you will stay boost on for long sections of the track, and a hose clamp that can hold 1 or 2 seconds of boost on the street may not be able to hold for 10-20 seconds on the track.

When I work on anything on the turbo plumbing I use new hose clamps every time, I save the old one for other things, but Turbo gets new. I run up to 18PSI with T03 hybrid turbo, and have not had the problem.

In my opinion the "Norma" factory hose clamps are probably the best hose clamps on the planet. They have the edge rolled up so they don't cut the hose, and the angle they tighten at is increased to avoid cutting the hose when they get very tight.

Was that the POC event at Thuderhill last week or was it green flag or what? I can’t remember.

wish I was there

 

Iceshark and aka 951,

I ended up improvising in the pits, scooted down to Walmart in nearby Willows and picked up the largest hose clamps I could find- 2". I needed to put two together to get a long enough clamp for each end of the hose that feeds into the throttle body.

The clamps are the type that have the slots all the way through, with the tail on top of the clamp, basic hardware store style. I'll look for a set of new Normas for all points with pressurized hose connections. Any good sources you folks could recommend? I'll check out NAPA to see what style of US clamps the local stores here have in stock.

I did a decent job of cleaning off the turbo oil, maybe today I'll try a little Naptha just to be sure. I replaced the four major rubber connections for the turbo and intercooler when I replaced my original turbo with the newly rebuilt unit.

fletch,

This was a streetcar day at Thunderhill orgainzed by one of my employees that runs the Honda S2000 web community. Most of the cars were S2000s, (one eaton supercharged version with about 310 hp at the rear wheel) a few hot NSXs, a Miata or two, a few M Bmws, a Viper, C5 Vette, a Testarossa, and a surprisingly fast AMG CLK Mercedes.

All of the A group was running race rubber, and a lot of the B group was as well. I am running Dunlop SP 8000 street rubber and was drifting heavily through a number of the hot corners.

I had a lot more power than most of the S2000s but was lacking grip. Combined with a few really hot full-power laps followed by some low-power blown off pressure hose laps, I didn't put on a very good show at the track. I think I won the award for heaviest tool box though :-)

I run Koni yellows all around, with H+R 200 lbs springs up front, stock non-M03 torsion bars, Weltmeister sways F+R. The Konis are at the stiffest setting and the swaybars are set-up with really stiff as well. Now I need a set of rubber.

Any feedback on what rubber to use on a second set of stock wheels for the track? Do 951 phone dials weigh a lot more than Fuchs that came on the 951? It seems like there are a lot of stock phone dials for sale on line.

One other feedback question- I just put in new Zimmerman solid rotors with stainless lines and 8 speedbleeders. I'm using new aftermarket stock Axis? pads on all four corners; after a few hot laps I was standing on the pedal to get braking into corners 1 and 10. Nasty fade! Any reasonably priced race pads that may be able to work on the street as well?

I'm smitten by the track. I'm looking forward to running a lot more events. And the 951 is a great affordable sleeper. Most of the other track attendees were thinking I was driving some old sub-capable Porsche. I really enjoyed walking away up the hills on 5 and 9, and loosing S2000s on the straights.

Steve Cooper

 

I had this same problem on mine after I replaced the intercooler and intercooler rubber. One of the factor clamps had a slight bend to it and so it wouldn't get a good, tight, even seal. It would eventually work loose under full boost.
I replaced it with an Ideal hose clamp and have not seen any problems since.