Headwork or ECU?
Discussion
Think there's more to it than that though Peter...
In my experience, following Peters recipe will net you gains (50bhp perhaps a little optimistic though?
), by changing the character of the car and how it makes power - likely you will lose lower-down torque and gain higher-end BHP - within the limits dictated by your current cam profile etc.
In essence, the "character" of the power delivery will change, similar to what you might expect if you changed a cam for instance.
Changing the ECU will give you a different set of gains - but will keep the "character" of the car's power delivery similar to what it is now.
You may get some extra BHP (possible not guaranteed - depends on the accuracy of your current set-up), but you most likely get gains in part-throttle and mid-range - essentially optimising your current power delivery to get the most from it and enhance its character, rather than changing it.
I think the answer to your question depends on what you want to do with your car's current power delivery character...
HTH,
Dom
In my experience, following Peters recipe will net you gains (50bhp perhaps a little optimistic though?
), by changing the character of the car and how it makes power - likely you will lose lower-down torque and gain higher-end BHP - within the limits dictated by your current cam profile etc.In essence, the "character" of the power delivery will change, similar to what you might expect if you changed a cam for instance.
Changing the ECU will give you a different set of gains - but will keep the "character" of the car's power delivery similar to what it is now.
You may get some extra BHP (possible not guaranteed - depends on the accuracy of your current set-up), but you most likely get gains in part-throttle and mid-range - essentially optimising your current power delivery to get the most from it and enhance its character, rather than changing it.
I think the answer to your question depends on what you want to do with your car's current power delivery character...
HTH,
Dom
I'm in a different scenario as I have a 500, so should have good heads to start with. I have a new ECU to fit when I find the cash to get the extra bits, but this should at least make the car more of a pleasure to drive and give smoother delivery of power. At the moment it shunts something rotten. The new ECU will also do away with the AFM, which itself is a restriction to airflow (something you'll need to factor in). All this should make a difference to the mods I have already.
There are ways around the new ECU as Kits and Classics will now map 14cux and fit a larger 20am AFM. Handy if you're nearby. However, You really need to think about the ECU and mapping as a part of modding, so you get the most out of the mods you fit and the performance of the car.
There are ways around the new ECU as Kits and Classics will now map 14cux and fit a larger 20am AFM. Handy if you're nearby. However, You really need to think about the ECU and mapping as a part of modding, so you get the most out of the mods you fit and the performance of the car.
Chuffmeister said:
I'm in a different scenario as I have a 500, so should have good heads to start with. I have a new ECU to fit when I find the cash to get the extra bits, but this should at least make the car more of a pleasure to drive and give smoother delivery of power. At the moment it shunts something rotten. The new ECU will also do away with the AFM, which itself is a restriction to airflow (something you'll need to factor in). All this should make a difference to the mods I have already.
There are ways around the new ECU as Kits and Classics will now map 14cux and fit a larger 20am AFM. Handy if you're nearby. However, You really need to think about the ECU and mapping as a part of modding, so you get the most out of the mods you fit and the performance of the car.
Trust me your heads are far from good they are a sound base but thats all they still have massive guide protrusion where its not needed the intake valves are shrouded made worse by the BV's and the intake throats need attention, still its all good because you have un-tapped potential IMO a sound base for some stonking BV heads There are ways around the new ECU as Kits and Classics will now map 14cux and fit a larger 20am AFM. Handy if you're nearby. However, You really need to think about the ECU and mapping as a part of modding, so you get the most out of the mods you fit and the performance of the car.
I shall be following this thread closely. I too would like an upgrade (not £2k worth) to an otherwise healthy 4.5 pushing out 260HP and 300 LB FT at the moment.
I prefer bottom end torque to top end power personally, so not sure how much difference that makes in terms of upgrades spec and money...
I prefer bottom end torque to top end power personally, so not sure how much difference that makes in terms of upgrades spec and money...
Heads every time, they're the biggest limiting factor in getting more air and fuel through the top end.... go for the very best you can get/afford, this will make the most of all the other mods you do thereafter.... I did much searching on upping power from the RV8 when I had my BGT V8 and it was always heads then induction/exhaust mods to make the most of them and ECU to tie it all together as an efficient pump 
caduceus said:
I shall be following this thread closely. I too would like an upgrade (not £2k worth) to an otherwise healthy 4.5 pushing out 260HP and 300 LB FT at the moment.
I prefer bottom end torque to top end power personally, so not sure how much difference that makes in terms of upgrades spec and money...
Up the CR, and use 'cometic' MLS head gaskets to achieve this as they can be had in varying thicknesses and the thinnest is 27 thou'. In doing so you could get away with only a light skim of the heads leaving plenty of meat for the future if needed. Obviously some head work as discussed whilst they're off.I prefer bottom end torque to top end power personally, so not sure how much difference that makes in terms of upgrades spec and money...
Bobby Shaftoe said:
Are the standard 500 heads crap then? I was under the, perhaps misguided, impression that the 500's had BV heads as standard, or at least well ported heads.
I've got a couple of old 390se wedge engines and the heads were all pretty good from the factory, but running standard valve sizes. They had deshrouded and blended chambers, shortened guides, double valve springs and were fully ported from the factory, massive exhaust ports as well. I recut the seats for the 1.63" and did a tiny bit of fettling and they flowed more straight away than the Stage 3 head i've got from one of the RV8 tuners.
I guess the standards & attention to detail might have gone out the window at TVR once order volumes picked up and they were having to churn many more cars out per week, assuming there were any standards in the first place
No, the 500 head's are not crap they just have massive scope for improvment and are already BV, some of the earlier head's were prepped very nicely even the stock valves one's similar to what you have by the sounds of it.I've got a couple of old 390se wedge engines and the heads were all pretty good from the factory, but running standard valve sizes. They had deshrouded and blended chambers, shortened guides, double valve springs and were fully ported from the factory, massive exhaust ports as well. I recut the seats for the 1.63" and did a tiny bit of fettling and they flowed more straight away than the Stage 3 head i've got from one of the RV8 tuners.
I guess the standards & attention to detail might have gone out the window at TVR once order volumes picked up and they were having to churn many more cars out per week, assuming there were any standards in the first place
Edited by Bobby Shaftoe on Tuesday 7th April 21:34
Sardonicus said:
rust me your heads are far from good they are a sound base but thats all they still have massive guide protrusion where its not needed the intake valves are shrouded made worse by the BV's and the intake throats need attention, still its all good because you have un-tapped potential IMO a sound base for some stonking BV heads
Cheers Simon, I did notice the guide protrusion when I did the valley gasket. Are there some relitively straight forward mods that can be done with a dremel or is it definitely a job for the expert? What sort of guide price would you be looking at?The 500 heads are excellent, I don't know what you'd do to improve them really. I've seen lots of RV8 engines with heads from all the major players, the best 5litre power i've seen was on std 500 heads so far (375hp) .. I can't really see any trends in midrange either. If you've got std 500 heads I wouldn't go changing them or trying to improve them for the sake of it, no-one else's heads are any better from my experience.
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