Discussion
oh dear, little englanders at it again 
Left = power (PS DIN)
Right = torque (Nm)
Top curve = power
Lower curve = torque
You'll see that the top red line peaks at a nice round number '300' at 6,000 rpm, which incidentally is 40 bhp above where it was before (blue line) at this rpm. 'Before' power peaked at 274.
Better?
Left = power (PS DIN)
Right = torque (Nm)
Top curve = power
Lower curve = torque
You'll see that the top red line peaks at a nice round number '300' at 6,000 rpm, which incidentally is 40 bhp above where it was before (blue line) at this rpm. 'Before' power peaked at 274.
Better?
Only 300 Verms then
So, is the difference solely down to the new dizzy? I fitted a 123 dizzy to one of my MG's a few years back, and it made a very noticeable difference to starting, running and (better)fuel economy. It's telling me the standard dizzy is not keeping up, or is there more to it?
Chilli
So, is the difference solely down to the new dizzy? I fitted a 123 dizzy to one of my MG's a few years back, and it made a very noticeable difference to starting, running and (better)fuel economy. It's telling me the standard dizzy is not keeping up, or is there more to it?
Chilli
900T-R said:
My 430 before and after mapped ignition by way of the 123tune distributor. Power run 'after' only between 5,000 and 6,000 rpm as a final check of sorts.
Seems to have done the trick, then.
You must be pleased with that result. Some questions: How much for the distributor, cable, drive wheel, software, etc? And did you fit a new coil?Seems to have done the trick, then.
Only difference between 'before' and 'after' is indeed the dizzy and the stupid thing is the advance we ended up running above peak torque rpm is still within TVR specs for the OE dizzy (33 degrees, where TVR service literature either calls for 32 degrees at 3750 rpm or 34 at 4000) as the second map we were running at 29 degrees max advance for 95 RON fuel didn't really show a significant loss of power, if at all.
From the results it's quite clear the dizzy was holding the engine back all along, as the final result now fulfils the best expectations one would have from the configuration. And the 123 product does indeed feature clever stuff like spark balancing. But what exactly makes the huge difference compared to the Lucas dizzy if not the spark timing (max advance)... well so far I'm stumped really. Will investigate this further
From the results it's quite clear the dizzy was holding the engine back all along, as the final result now fulfils the best expectations one would have from the configuration. And the 123 product does indeed feature clever stuff like spark balancing. But what exactly makes the huge difference compared to the Lucas dizzy if not the spark timing (max advance)... well so far I'm stumped really. Will investigate this further
davep said:
You must be pleased with that result. Some questions: How much for the distributor, cable, drive wheel, software, etc? And did you fit a new coil?
Coil was & is the Bosch item from ACT I've been using for a couple of years now.No crank wheel/sensor or wiring changes (actually there is one extra wire on the distributor for switching between map 1 and map 2). Programmable with any Windows XP compatible laptop using a standard (but ideally shielded) USB cable.
I think retail for the Rover V8 unit is 505 euro over here.
900T-R, if your 430 is standard those curves for the 'before' Lucas set-up are nothing to sniff at either. Assuming those increases are apparent across the lower rev range, I'd say you've grabbed yourself a bargain there.
I've found a UK supplier (Southern Carbs) that does the Rover V8 post SD1 unit for £399.95, and I must say I'm tempted.
You mention elsewhere a misfire at 1200 rpm, did this arise after fitting the 123 dizzy? And did you fit a new dizzy drive wheel?
I've found a UK supplier (Southern Carbs) that does the Rover V8 post SD1 unit for £399.95, and I must say I'm tempted.
You mention elsewhere a misfire at 1200 rpm, did this arise after fitting the 123 dizzy? And did you fit a new dizzy drive wheel?
davep said:
900T-R, if your 430 is standard those curves for the 'before' Lucas set-up are nothing to sniff at either. Assuming those increases are apparent across the lower rev range, I'd say you've grabbed yourself a bargain there.
I've found a UK supplier (Southern Carbs) that does the Rover V8 post SD1 unit for £399.95, and I must say I'm tempted.
You mention elsewhere a misfire at 1200 rpm, did this arise after fitting the 123 dizzy? And did you fit a new dizzy drive wheel?
Engine is not standard (fairly elaborate rebuild with reliability & performance enhancements, still standard capacity and standard non-BV valve sizes as heads were rebuilt according to 'fast road spec' by CTM Performance in Dagenham), it has an ACT carbon twin throttle plenum & intake hoses, 45 mm ported intake manifold (by yours truly) and carbon trumpets, thermal gasket, ACT performance exhaust manifolds, Vectra injectors and 3.0 bar fuel pressure.I've found a UK supplier (Southern Carbs) that does the Rover V8 post SD1 unit for £399.95, and I must say I'm tempted.
You mention elsewhere a misfire at 1200 rpm, did this arise after fitting the 123 dizzy? And did you fit a new dizzy drive wheel?
I had the existing drive wheel refitted to the new distributor as I feel it makes no sense mating a brand new drive wheel with an old one in the dist/oil pump drive mechanism...
Misfire at low revs was noticed after the install (it was heavy kangorooing at first), we were still playing with the vacuum advance mapping to eradicate it when we got sidetracked by a starter motor that wouldn't play ball anymore
so getting it out and to a starter motor/alternator repair place became first priority and it was 6 pm when I was able to hit the road again... Standard issue CUX14 with big-a55 Bosch airflow meter from a BMW V8 (frankly, you're better off using the ACT/Mark Adams Bosch meter as it's a known quantity and won't pose an airflow restriction until the mid-300s bhp level at least), fuel pressure regulator squeezed to give 3 bar and custom mapping.
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