How far to safely push a stock RX-1

[sledracer]

Asphalt racing is just around the corner. Im wondering how far I can safely push the boost on a stock 03 RX1. Ive got a Bender Stage 2. The smaller turbo on this guy can efficiently push up to 14lbs of boost. A friend and I are purchasing a barrel of VP - C12 fuel for this season. From what I understand C12 should handle 14lbs boost on a stock engine but what about the engine? Are aftermarket head bolts needed? Connecting rods? Stock timing a problem?


thanx all - Tyler

 

[hlmrx1]

Do you have a head shim installed in order to lower the compression? I ran a 03 RX1 turbo'd with a head shim and stock pistons at around 12lbs. with no issues. VP C12 should be ok, but if you don't have a head shim, I don't know if I would push it.

 

[sledracer]

nope no head shim or low comp. pistons. I think the calculator on here says its OK stock for 12lbs easy with C12. C12 VP rates the for nat. aspirated motor up to 15:1 compression ratios - its motor octane is 108 thats different from pump octane. Im really not sure about it though.

Heres what VP says about octane ratings.
1. OCTANE - The rating of fuels’ ability to resist detonation and/or preignition. Octane is rated in Research Octane Numbers (RON), Motor Octane Numbers (MON), and Pump Octane Numbers (R+M/2). Pump Octane Numbers are what you see on the yellow decal at the gas stations and represents an average of RON and MON. VP uses MON because this test method is more prevalent in racing. Most other companies use RON because it is higher, easier to come by, and sounds better in marketing messages. Don't be fooled by high RON numbers or an average -- MON is the most important for a racing application. However, the ability of the fuel to resist preignition is more that just a function of octane.

 

[sledracer]

No body?

How much boost on stock head studs? When is it recommended to go to aftermarket rods?

 

[Wildman]

I've seen plenty of stock motors last at 25#'s(drag racing ice\dirt only). On the other hand I've seen them kick rods at 17#'s for no reason other than a weak component.

There is no perfect answer here as every machine is different. 14#'s should be okay but keep in mind if it detonates it junk.

If you are going to push the limits of your octane get an engine blanket. Kicking a rod at 130 mph can be extremely dangerous or deadly depending on where the fluids go.

Or turn it down a bit & be safe, work on your clutching, skid set-up, 60'-330' area and enjoy racing.

 

[rxrider]

I've had head lift at 14 lbs on Stock cylinder bolts. Blew the gasket out, got oil in the coolant.
The Stock head bolts will take 51Nm of tork, above that and the bolt will twist, not good.
You may get in contact with Ted Jannetty at Jannettyracing.com - he's been running a lot of boost on a Stock RX-1 engine way back.