450 running a tad flat.

[Yatz]

Here's a query.
My y2000 Chimaera 450, which has recently been tuned, runs lovely and smooth, no dead spots or anything except that it is ever so slightly underpowered. The gentleman who tuned it said it ran great for a 4 litre but not for a 4.5. My immediate thoughts are, "cam" but could it be anything else? I don't want to pay for any unnecessary investigations but it might be worth knowing what else could possibly be causing this before having it looked at. Part of me thinks "if it ain't broke..etc" but one of the key attractions of these cars is their lively personality and one would wish to experience this to its full extent. All intelligent feedback gratefully received.

[Belle427]

What do you mean by tuned?
Did it have a rolling road print out?
Cams do wear out quickly, as standard the engine produced around 220 bhp, they were no where near the TVR quoted numbers.

[sixor8]

I know they exaggerated but that is a bit pessimistic IMHO. I had a 1996 Chimaera 4.0 litre with 60k miles on it that was measured with 214 bhp in Nov. 2018 A 450 should have at least 240 - 250 bhp.

ETA: Checking my records, I had a different W reg Chimaera 4.0 with 81k miles on it in 2015 that had 202 bhp before I had all the injectors ultra sonically cleaned, and also 214 bhp after. Both had no mention of a cam change in their histories.

Edited by sixor8 on Saturday 9th August 15:19

[Belle427]

They can vary depending on the rolling road used.
I have dug this out from a very well respected engine builder.
https://www.pistonheads.com/gassing/topic.asp?h=0&...

[sixor8]

It was this company on both occasions, when they were in Stourbridge. They had no reason to over do it (like I hear Surrey RR were prone to do), it weas their suggestion that I get the injectors cleaned, and on the 80k mile Chimaera, it helped a lot. Less so, my Cerbera.

https://hitechmotorsport.co.uk/

After they moved to Kidderminster, I had my Cerbera 4.5 on their rolling road in 2018 and it had a disappointing, but not untypical 347 bhp. I don't think they do 'book and turn up' customer power runs any more.

[Belle427]

A power run certainly helps you find out where it is, they hide small problems quite well.