[Gunnar804]

Ok so I am just finishing up a new build for my 2000 400ex. It is set up for tt racing so will be ran hard. The build is a 416 bore with a Wiseco 11:1 piston. Stage 3 Hotcam. Ported head, KnN air filter. AMR racing Stage 3 CDI and ignition coil, and a full Empire industries exhaust. My question is, what fuel should I run with this build during break in and on the track?

 

[rodp]

Can I ask what "TT" racing is. The TT over here is a road race around the Isle of Man. A very fast, dangerous and almost suicidal race at that.

 

[Gunnar804]

TT stands for tight track. It's a flat track race on dirt with very sharp turns throughout the track. Typical setups for this type of racing include lowering and widening your quad and swaybars

 

[MikeDawg46L]

With 11:1 compression you'd be asking for trouble running anything besides 50/50 blend of 93/110. I'd run straight 110 in it myself, but at $8/gallon you could probably cut it with 93 and be ok.

My 300 Fourtrax has a .040" over 10.25:1 Wiseco piston and I'm still getting a little pre-detonation with 93 non-ethanol when I've been riding for a few hours and get on the gas hard. Unfortunately, the only local station that sells race gas (Cam2 110 octane) has been out for a few weeks with no ETA on their next delivery.

 

[Gunnar804]

So you think 93 unleaded pump gas mixed with VP 110 would do the trick? Do they mix well? I don't know much about mixing the 2 if they would blend well or not.

 

[Nanook12]

100LL aviation would work. You might want to run something like TCP or cam guard to minimize the lead buildup. Probably @ $5.00 a gal.

 

[b52bombardier1]

All of these gasolines blend well and won't separate later. No worries there. But I'd buy them in the smallest practical quantities for reasons of freshness.

Rick

 

[TRX2fiveO]

416 with 11:1 you'll be fine on pump gas. 104 race fuel would be ok straight too. . . when you get into the 12:1 and up you'll need to run a higher octane.... Also be mindful of your need to jet the engine properly with the fuel you run. 100LL AV Gas works great and the shelf life is much longer than MO Gas. not to mention WAY cleaner. As mentioned using the additive for the 100LL will help some with deposits but it is LOW LEAD.. lol
I run Pump fuel in my 426 when trail riding. I like to dabble on the drag strip sometimes so I'll run VP110 or 104 too.

 

[jameslb]

When I learned TT it meant flat dirt track with at lest one right turn. Cheers.