Another option instead of the carbon plenums + div ECUs
Discussion
Geoff38 said:
Still gathering all the bits and pieces for this install , hopefully starting on monday.
Just collected the newly vapour blasted manifold
Well I'm no expert but I have studied this intake manifold and yes I know there is for and against TB inj no direct port inj etc etc ...... but I am convinced the one thing this will help is low speed running i.e the shunty dreaded 2k RPM area without the need to have to dial out advance and run slightly richer AFR's in that region like with the stock plenum Just collected the newly vapour blasted manifold
there is no big volume/plenum for all that nasty cross contamination/mixing that burdens the RV8 stock plenum with longer duration cams 
just my cents worth if you dont try these things you will never find out my hats off to you fella's attempting this 
the stock plenum is fine providing your using stump puller/short/soft cam durations or like Rover intendedEdited by Sardonicus on Friday 3rd March 11:31
rev-erend said:
My cam has a long duration and it ticks over very nicely at about 900rpm..
It's an M256, so just over 300 degress on inlet and exhaust and enough lift to punch holes in most pistons.
Its not the ticking over that is the issue though we dont drive at idle RPM It's an M256, so just over 300 degress on inlet and exhaust and enough lift to punch holes in most pistons.
and who dislikes that lopey/splashy idle? I dont for one 
Sardonicus said:
ts not the ticking over that is the issue though we dont drive at idle RPM and who dislikes that lopey/splashy idle? I dont for one
I'm with you Simon, the dual plane Edelbrock manifold is definitely the path to a smoother drive, but I wouldn't want to lose my port injection so some years ago I looked at welding 8 injector bungs in the manifold to effectively make it a port injection dual plane RV8 manifold. and who dislikes that lopey/splashy idle? I dont for one My idea was to fabricate a simple conversion plate to act as a base for the standard plenum mating it to the four bolt carb fitting on the manifold. The biggest challenge would be the fuel rails but there are some good universal rail blanks offered by the same people I found who offer those injector bungs I need.
Using the existing plenum with it's throttle body keeps the throttle mechanism and the overall under bonnet appearance standard too, in the end I decided while it was an interesting project there were no real guarantees it would deliver the results I wanted so there was a very real risk I could spend a chunk of money on a red herring.
I then decided it probably made a lot more sense to go down the Thor manifold rout, we know it works and there's a lot less fabrication involved to fit one, the only real challenge is solving the throttle body to bonnet clearance issue.
Since settling on the Thor idea and before I pull the trigger on it I've been studying air flow & behaviour which lead me to start investigating some other ideas, ideas that are well know drivability enhancers used by OEM manufacturers. One of these ideas is quick and cheap to try, it's also easily reversible so will be my next step.
Watch this space
ChimpOnGas said:
I'm with you Simon, the dual plane Edelbrock manifold is definitely the path to a smoother drive, but I wouldn't want to lose my port injection so some years ago I looked at welding 8 injector bungs in the manifold to effectively make it a port injection dual plane RV8 manifold.
My idea was to fabricate a simple conversion plate to act as a base for the standard plenum mating it to the four bolt carb fitting on the manifold. The biggest challenge would be the fuel rails but there are some good universal rail blanks offered by the same people I found who offer those injector bungs I need.
I agree that would be better still My idea was to fabricate a simple conversion plate to act as a base for the standard plenum mating it to the four bolt carb fitting on the manifold. The biggest challenge would be the fuel rails but there are some good universal rail blanks offered by the same people I found who offer those injector bungs I need.
these further developments all good to me Sardonicus said:
ChimpOnGas said:
I'm with you Simon, the dual plane Edelbrock manifold is definitely the path to a smoother drive, but I wouldn't want to lose my port injection so some years ago I looked at welding 8 injector bungs in the manifold to effectively make it a port injection dual plane RV8 manifold.
My idea was to fabricate a simple conversion plate to act as a base for the standard plenum mating it to the four bolt carb fitting on the manifold. The biggest challenge would be the fuel rails but there are some good universal rail blanks offered by the same people I found who offer those injector bungs I need.
I agree that would be better still My idea was to fabricate a simple conversion plate to act as a base for the standard plenum mating it to the four bolt carb fitting on the manifold. The biggest challenge would be the fuel rails but there are some good universal rail blanks offered by the same people I found who offer those injector bungs I need.
these further developments all good to me The way I see it the fundamental essence & character of a TVR we all love is thankfully the one thing that can never be fully removed, and that's super important to me.
However, its fair to say in its original form the Chimaera is somewhat of a rough diamond, so carefully and well chosen polishing of some of those rough edges can deliver great results and becomes a very rewarding exercise, indeed the car's 'so nearly brilliant' design almost seems to goad you into this polishing activity.
So given my TVR will always retain it's wonderful TVR soul that I love so much, I turned my back on the common power adding arms race activity and focussed my polishing work on smoothing out those TVR rough edges:
- Reliability
- Ride Quality
- Fuel Economy
- Drivbility
The thinking being by adopting this approch the car while never winning any horsepower competitions, will however deliver a much more refined and rewarding driving experience that should ultimately mean I use and enjoy it more.
This is a very interesting post and I'm in no doubt the OP will get some really positive drivability results from the throttle body injection unit on the dual plane Edelbrock manifold, I continue on the same path myself it's just my personal objective is and always has been to get the same results while retaining the more efficient multi point port injection setup that came as standard on the original car, but was just executed in a rather poor way.
Good luck to the OP on his excellent dual plane manifold & throttle body injection project
Edited by ChimpOnGas on Saturday 4th March 08:48
I`m liking this. Having run big cams in the distant past on RV8`s with a dual plane Offy manifold and Holley 390, 4 barrel carb i can vouch that shunting was zero with a super smooth drive. Probably due to a mixture of both the manifold and the carb as against that nasty plenum holding spewed out exhaust gasses.
I too predict good low down running and look forward to seeing the results.
I like carbs especially big 4 barrel ones.
I too predict good low down running and look forward to seeing the results.
I like carbs especially big 4 barrel ones.
It's fascinating that people are thinking of all sorts of round-the-houses expensive ways of modifying their cars to achieve smoother running, sometimes at the expense of power, when a far simpler route is open that doesn't mean any expensive one-off work or finger in the air experimentation. Fit a less wild cam.
Better driving manners, better economy, better emissions, slightly less top end power. Seems you can have your cake and eat it, just won't get the icing on top.
Better driving manners, better economy, better emissions, slightly less top end power. Seems you can have your cake and eat it, just won't get the icing on top.
spitfire4v8 said:
It's fascinating that people are thinking of all sorts of round-the-houses expensive ways of modifying their cars to achieve smoother running, sometimes at the expense of power, when a far simpler route is open that doesn't mean any expensive one-off work or finger in the air experimentation. Fit a less wild cam.
Better driving manners, better economy, better emissions, slightly less top end power. Seems you can have your cake and eat it, just won't get the icing on top.
It seems you've fallen into the age old trap of mixing your metaphors, which always dilutes and confuses a message, lets be frank here.... cake without icing isn't really proper cake now is it! Everyone knows a mild cam is the easy path to better drivability, sadly in life there are seldom any prizes awarded for stating the blindingly obvious, I prefer to take a more positive view towards those who seek to think of new ides.Better driving manners, better economy, better emissions, slightly less top end power. Seems you can have your cake and eat it, just won't get the icing on top.
The point you seemed to have overlooked is the very reason people are exploring different ways of going 'round-the-houses' as you put it, is they are trying to explore ideas that genuinely delivers our cake, and allows us eat it too. To be clear, the cake were looking to bake & eat here has excellent drivability combined with the top end benefits of reasonably progressive cam.
I don't actually see the interesting ideas muted on these pages as "round-the-houses expensive ways of modifying their cars to achieve smoother running", the truth is we all have a little of the frustrated engineer in us, some of us come up with a raised blended plenum base claiming horsepower gains at the top end with no penalties in the low end, others (lets call them the enthusiastic amateurs) are just having fun with their hobby by exploring ways of improving drivability while retaining a reasonably fast road cam grind.
For the record my 4.0 litre runs a V8 Developments Stealth cam which Rob & Ray describe as "a slightly more progressive fast road camshaft than the MC1 ideally suited to the 4.6 or 5.0 engine and the driver who is looking for a little more performance".
I'm also running an 18lb flywheel and burn a fuel that is so often vilified for delivering poor drivability characteristics, so as someone who has always obsessively sought a super smooth driving TVR you could argue I've already chosen to make my life overly hard for myself, but to me fitting a mild cam would have been too easy, and possibly completely unnecessary too.
Of course my Canems systems helps me tune out many negative behaviours that would be way harder to deal with if I was still burdened with the 14CUX and distributor, but I can assure you even with my less than perfect recipe, my cake (with icing) is absolutely delicious. Indeed the main reason I haven't bothered with my Edelbrock dual plane or Thor manifold ideas is because I've actually proved to myself it's totally achievable to (against all the odds) deliver unparalleled drivability while still enjoying the benefits of a more progressive cam using the standard single plane manifold & plenum arrangement.
So in the end and as it turns out, you can have your cake and eat it, indeed what I've discovered is the standard single plane manifold & plenum arrangement isn't actually the criminal we all make it out to be. Mapping work to correct some of the unwanted behaviours aside I've discovered there are actually certain things going on with air flow that can be super easily corrected absolutely for free, just by making a few simple tweaks to certain influencing components.
Indeed the biggest improvements I've implemented cost me next to nothing and have zero to do with an expensive after market engine management system or required the switch to different manifold design, this of course means those still running the 14CUX & distributor could enjoy them just as easily (and cheaply) too
One of the fun things about these cars is we get to play with different ideas, for most of us it's a hobby not a business so I'd like to encourage my fellow amateurs to keep trying new ideas, rather that taking the negative dismissive attitude of others.
I really hope the OP gets the results he's looking for, and there's some very good evidence he will. Lets not forget it's his money and his choice how he spends it, so I think I can speak for both amateurs & professionals alike when I say we'll all be following you over to the Wedge pages and look forward hearing how this interesting throttle body injection & dual plane manifold idea works out for you
Of course the very best way to add performance and drivability using the original single plane manifold and plenum arrangement....
Is to pressurise the thing
I won't get into the turbo vs supercharger argument, but the one Chimaera I experienced with a Rotrex supercharger fitted seemed to be outrageously flexible and indecently fast too
Pump up the jam, pump it up.....
https://www.youtube.com/watch?v=ifoy6_nARUc
I am clearly of a child of the 90's
Is to pressurise the thing
I won't get into the turbo vs supercharger argument, but the one Chimaera I experienced with a Rotrex supercharger fitted seemed to be outrageously flexible and indecently fast too
Pump up the jam, pump it up.....
https://www.youtube.com/watch?v=ifoy6_nARUc
I am clearly of a child of the 90's
spitfire4v8 said:
It's fascinating that people are thinking of all sorts of round-the-houses expensive ways of modifying their cars to achieve smoother running, sometimes at the expense of power, when a far simpler route is open that doesn't mean any expensive one-off work or finger in the air experimentation. Fit a less wild cam.
Better driving manners, better economy, better emissions, slightly less top end power. Seems you can have your cake and eat it, just won't get the icing on top.
For 85% of owners your probably right there Better driving manners, better economy, better emissions, slightly less top end power. Seems you can have your cake and eat it, just won't get the icing on top.
but then you will always have the rest who just wont leave well alone game on Sardonicus said:
or 85% of owners your probably right there but then you will always have the rest who just wont leave well alone game on
15% innovators...... and the rest just buy stuff off traders... of course they're then left praying the traders promises' aren't hollow but then you will always have the rest who just wont leave well alone game on Kind of makes you realise why some choose the innovator path, of course the truth is many of the traders are really just enthusiastic amateurs anyway, sometimes it would be nice to see the qualifications that make them a professional.
Or is the definition of a professional simply an enthusiastic amateur who's turned his hobby into paying work
At least when you take on the work yourself there are no false idols and no false hopes, so if it doesn't work.... you've only got yourself to blame.
That's got to be better than paying good money for BS power adders.... only to find they fall way short of their promises
Edited by ChimpOnGas on Monday 6th March 06:57
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