Stealth cam - remap required?

[Dr Mike Oxgreen]

Very quick question…

It’s cam change time for my 450, so I’m considering my options.

Will a Stealth cam work well without any ECU or mapping changes? I’d prefer not to go down that rabbit hole if I can avoid it.

I appreciate that you might be able to squeeze a bit more out with a remap, but does it run well enough without?

My engine is a completely standard 450.

Thanks!

[Classic Chim]

I think cam changes were going on before after market ecu or mapping changes became the norm so yes it should be ok that’s assuming your engine is otherwise healthy.

[Dr Mike Oxgreen]

Cool. Yes, I should have said that my engine is very well-behaved with no shunting or other running issues.

Charlie at Surrey Rolling Road said the fuelling looks fine, it just runs out of puff toward the top end. It produced 278 bhp last time I had it at SRR (admittedly 6 years ago), but this time just 241 bhp.

[Belle427]

I don't think it's critical but probably best to maximise it especially at the top end where these cams shine.
Below 3500 rpm the lambdas will make adjustments. (Think that value is right)

[blitzracing]

The fact the ECU uses an AFM to measure airflow makes the system reasonably adaptable as if you draw more air it simply moves down to a another load point. Before you worry about the pain of remapping, all you need to do is plug a test meter into the lambda output to measure the output voltage under load. it should be in the region of 1.2 to 1.4 volts all the way from 3400 rpm to peak. If you find it drops below this you need to look at remapping or you may have another issue with fuel delivery. I can lend you a cable and test meter a passenger can read while to run a test if you want? I will add simply due to the shear performance of a TVR under full load tests on a public road can be "interesting" to say the least.

[Dr Mike Oxgreen]

Thanks Blitz!

I think fuelling is okay on my engine - the AFR during its recent dyno run at Surrey Rolling Road settled down to a reasonably flat line between about 12.8 to 13.5, and if anything was getting richer after about 4000 rpm.

So from people's replies it seems that an otherwise healthy RV8 with no running issues (other than a worn cam) should be able to accommodate the cam change.

[Dougal9887]

I have a Stealth camshaft with about 1500 mls on it available, if you're interested, as I changed to a trackday camshaft.
Dougal