Some Basic tuning rules with Boost

[TurboKeith]

Ted - Thank you for sharing your knowledge on turbo engines. I'm running 3 yamaha head gaskets and Wiseco 10:1 pistons, still only running 10 lbs on 93 octane pump, guess I'm pretty safe. I want to install a wbo2 before I start raising boost. What wbo2 sensor and gauge fit with the RX-1 MCX rear mount, and where to get it?

Hows your throttle response after dropping the compression that much? The 3 Yamaha head gaskets are .030" each for a total of .090"? What elevation are you riding at?

I'm going to be running the Wiseco 10:1's and an .060" spacer with one Yamaha .016" gasket on my Apex so I'm curious about the potential bottom end performance loss. It should put my compression down to about 8.6:1.

 

[Ted Jannetty]

My opinion, lowering the compression below 9.5:1 would be counter productive.

I would rather run less boost and more compression than very low compression and more boost.

I am sure there will be arguments to this but trust me after 25 years building race engines I feel pretty strong about it.

The bottom line is the fuel your running is the biggest HP limiter, not the compression or boost.

 

[rxrider]

Ted - Thank you for sharing your knowledge on turbo engines. I'm running 3 yamaha head gaskets and Wiseco 10:1 pistons, still only running 10 lbs on 93 octane pump, guess I'm pretty safe. I want to install a wbo2 before I start raising boost. What wbo2 sensor and gauge fit with the RX-1 MCX rear mount, and where to get it?

Hows your throttle response after dropping the compression that much? The 3 Yamaha head gaskets are .030" each for a total of .090"? What elevation are you riding at?

I'm going to be running the Wiseco 10:1's and an .060" spacer with one Yamaha .016" gasket on my Apex so I'm curious about the potential bottom end performance loss. It should put my compression down to about 8.6:1.

Reliability was my very first priority when I built the sled. Second is the ability to trail ride it everywhere and putting in whatever gas there is available, I wanted it to survive at 10 psi running 87 if that was the only fuel to get. Third is gas prices at the pump... and then prices on race fuel (sunoco gt plus 109 RON) which is about $35USD a gallon around here.. you see the picture. But I'm am able to run whatever boost the turbo is capable of... that would be around 22 psi. I'm no drag racer so don't care too much about throttle response. I'm a flatlander driving mostly between 0-600 ft, we do our speedruns at the frozen fjord at 0 ft sealevel. I also want to be able to run WOT for miles and miles on the fjord and the lakes at 18 psi. We do not have much tight and twisted trails around here, but more of open wide trails where we run at high speeds for hours...

I'm running the silver at 100 and a 52/44 helix, HHs at 66.5 grams (not enough, hitting rev limiter) and a 35/101 yamaha spring blue-silver-blue, green holtzman springs in carbs, throttle response is better than it ever was with the ecp filter kit. When I hit the throttle it goes 12 psi initially and down to 10, that's where I'm at the moment. Supertips 65 gram weights are in the mail, can't wait to hold her WOT for more that 3 sec. Happy sledding .... :exc:

 

[Ted Jannetty]

TTT For thoughs who missed it.

 

[sledheadgeorge]

Reliability was my very first priority when I built the sled. Second is the ability to trail ride it everywhere and putting in whatever gas there is available, I wanted it to survive at 10 psi running 87 if that was the only fuel to get. Third is gas prices at the pump... and then prices on race fuel (sunoco gt plus 109 RON) which is about $35USD a gallon around here...

If you have that concern with fuel and running low octane with boost get yourself a boost controller and you can adjust accordinglly as you ride in different areas.

 

[rxrider]

Thanks for all input guys.

My problem is that I do have to order a barrel or more of racefuel to get it at a resonable price pr. gallon as there is noone around that have race fuel in stock. When we are out riding on a round trip it sometimes up to 100 miles between tank stops. Many small gas stations do not even supply 93 octane, only 89. That is my problem when I'm out trail riding. I do have a manual bleeder switch system to set different boost levels. I do have a boost meter so I know where I'm at.

I do trailride, no dragraceing for me this year. National championship is held only a 1000 miles away this year. Last year we did run my sled N/A in stock 800 when National championship was arranged by our racing club we stood no chance against the SRXs and F7s, they were way faster than us in the 660 ft.