4.3 1993 Chimaera - Little help
Discussion
Good day all!
I have a 1993 chimaera 4.3 and it is bog standard. On paper it should have 280 hp and 305 lb tq. Now I appreciate these numbers may be a little optimistic but I just been on a rolling road and it produced 160 hp and 200 lb tq. He said it was losing power up the rev range.
The car has 70k miles on, full service history with no modifications.
Could anyone please shed some light on how to regain most of the power it has somehow lost?
Many thanks
ChrisB
I have a 1993 chimaera 4.3 and it is bog standard. On paper it should have 280 hp and 305 lb tq. Now I appreciate these numbers may be a little optimistic but I just been on a rolling road and it produced 160 hp and 200 lb tq. He said it was losing power up the rev range.
The car has 70k miles on, full service history with no modifications.
Could anyone please shed some light on how to regain most of the power it has somehow lost?
Many thanks
ChrisB
A leak down test on the cylinders will be on everyone's list of things to do.
Probably, like so many RV8s, the camshaft will be a good place to start looking as well.
Though I can't speak directly on RV8s on this, I have breathed a lot of new life into higher mileage v8 engines with a 'simple' valve grind.
If you are fortunate, a few 4.3 owners will be able to give you their actual HP/torque figures.
Probably, like so many RV8s, the camshaft will be a good place to start looking as well.
Though I can't speak directly on RV8s on this, I have breathed a lot of new life into higher mileage v8 engines with a 'simple' valve grind.
If you are fortunate, a few 4.3 owners will be able to give you their actual HP/torque figures.
Thanks for your replies 
!
It's not to ratty or anything, I actually thought it was an okay motor. I'm gonna go buy a camshaft and the hydraulic tappets, I just ordered some upgraded ht leads, distributor cap and rotor arm.
The chap did put a oxy sensor up the exhaust and said it was running weak at the top end, he said to take the injectors out and get them cleaned up. He said there were no misfires, it had a service 1000 miles ago.
Yeah was very poor but it still takes the speedo to 155 on a nice long stretch of motorway!
!It's not to ratty or anything, I actually thought it was an okay motor. I'm gonna go buy a camshaft and the hydraulic tappets, I just ordered some upgraded ht leads, distributor cap and rotor arm.
The chap did put a oxy sensor up the exhaust and said it was running weak at the top end, he said to take the injectors out and get them cleaned up. He said there were no misfires, it had a service 1000 miles ago.
Yeah was very poor but it still takes the speedo to 155 on a nice long stretch of motorway!
PapaButch said:
He said it was at the flywheel...what does this mean for the wheels?
Flywheel figures are what TVR will have quoted (as said often optimistically)If yours is only making those figures at the flyhweel, transmission losses will mena your "at the wheels" figure will be even lower.
My old 430 with a new camshaft made around 195 at the wheels/ 240+ flywheel to give you some idea. Add to that the fact that some rollers will give different figures.
Sounds very much like a worn cam if it's still on the original. Make sure there's no restrictions between the air filter & engine etc too.
Sounds very much like a worn cam if it's still on the original. Make sure there's no restrictions between the air filter & engine etc too.
It's possibly just had LR ignition timing?
Check the ignition timing first, TBH I would have expected the RR to have tried that?
Somebody may well have put a LR cam in, even a badly worn original cam would be likely to give closer to 200, 245 is probably average for the used 430.
Also worth popping the rocker covers off to check the valve springs (they should be doubles) ~ broken valve spring will give dramatic power loss.
Check the ignition timing first, TBH I would have expected the RR to have tried that?
Somebody may well have put a LR cam in, even a badly worn original cam would be likely to give closer to 200, 245 is probably average for the used 430.
Also worth popping the rocker covers off to check the valve springs (they should be doubles) ~ broken valve spring will give dramatic power loss.
LMFAO!!! Yeah I cant wait to see what an extra 100 horsies is going to do lol! I did wonder why when i put my foot down in 2nd gear for instance, on a damp road...nothing happens except gliding along effortlessly. No wheel spins, i thought these cars were to eat me up!
Ooo like my dirty wife eating cream off meh...im excited now :P
Ooo like my dirty wife eating cream off meh...im excited now :P
Losing power higher up the rev range but feels quite alright when just driving about - sounds like a worn cam to me. Mine lasted 106,xxx miles but when it was removed in the course of a rebuild two lobes were pretty much round. as far as I could tell, the engine was fine before... 
My numbers for reference -
After rebuild (lightened & balanced rotating assy, extensively ported/flowed heads but standard valve sizes) with std 38 mm intake manifold, 'home blended' trumpet base & 72 mm plenum = 257 hp @ 5800
As above plus decatted w/ACT manifolds, ACT twin throttle plenum, 45 mm carbon trumpets on 45 mm ported intake manifold, ACT intake hoses, Vectra inj's = 274 hp @ 5500
As above plus 123tune mapped ignition = 300 hp @ 6000
Engine builder reckoned with everything else standard, the engine would develop about 15 hp more than the std TVR item, but with potential for more... in the end he was right.
Indeed, I'd expect 240-250 hp from a std 430 in tip top order, maybe 10-15 more for a BV.
My numbers for reference -
After rebuild (lightened & balanced rotating assy, extensively ported/flowed heads but standard valve sizes) with std 38 mm intake manifold, 'home blended' trumpet base & 72 mm plenum = 257 hp @ 5800
As above plus decatted w/ACT manifolds, ACT twin throttle plenum, 45 mm carbon trumpets on 45 mm ported intake manifold, ACT intake hoses, Vectra inj's = 274 hp @ 5500
As above plus 123tune mapped ignition = 300 hp @ 6000
Engine builder reckoned with everything else standard, the engine would develop about 15 hp more than the std TVR item, but with potential for more... in the end he was right.
Indeed, I'd expect 240-250 hp from a std 430 in tip top order, maybe 10-15 more for a BV.
just thought I would add my figures,
the car is fully decatted, carbon trumpets, smooth bore intake & running original tvr chip.
max power at flywheel was 279.8 at 6124rpm
max torque at 4622rpm was 261.7lb ft
max power at wheels was 234.6
no history to speak of with the car so couldn't tell you what else has been done or what cam its running im afraid.
that dyno run was just a quick power run on a vw golf shootout day as they couldn't get enough cars together, so no adjustments made on the day.
hope the figures help, enjoy the fact you have a 4.3, theres not many of us about.
the car is fully decatted, carbon trumpets, smooth bore intake & running original tvr chip.
max power at flywheel was 279.8 at 6124rpm
max torque at 4622rpm was 261.7lb ft
max power at wheels was 234.6
no history to speak of with the car so couldn't tell you what else has been done or what cam its running im afraid.
that dyno run was just a quick power run on a vw golf shootout day as they couldn't get enough cars together, so no adjustments made on the day.
hope the figures help, enjoy the fact you have a 4.3, theres not many of us about.
loud430 said:
just thought I would add my figures,
the car is fully decatted, carbon trumpets, smooth bore intake & running original tvr chip.
max power at flywheel was 279.8 at 6124rpm
max torque at 4622rpm was 261.7lb ft
max power at wheels was 234.6
no history to speak of with the car so couldn't tell you what else has been done or what cam its running im afraid.
that dyno run was just a quick power run on a vw golf shootout day as they couldn't get enough cars together, so no adjustments made on the day.
hope the figures help, enjoy the fact you have a 4.3, theres not many of us about.
Thats healthy the car is fully decatted, carbon trumpets, smooth bore intake & running original tvr chip.
max power at flywheel was 279.8 at 6124rpm
max torque at 4622rpm was 261.7lb ft
max power at wheels was 234.6
no history to speak of with the car so couldn't tell you what else has been done or what cam its running im afraid.
that dyno run was just a quick power run on a vw golf shootout day as they couldn't get enough cars together, so no adjustments made on the day.
hope the figures help, enjoy the fact you have a 4.3, theres not many of us about.
thanks simon,
it does seem to be, ive not got a lot of history with it, the power it makes seems to suggest big valve heads, but I don't know for sure, its pretty lumpy round town & is very rich while on tickover but a friend of mine has a played with 4.6 & it kept up with that till he put a H404 cam in it. like I said it was just a quick power run I had done, it would probably benefit from a proper set up & aftermarket ecu.
it does seem to be, ive not got a lot of history with it, the power it makes seems to suggest big valve heads, but I don't know for sure, its pretty lumpy round town & is very rich while on tickover but a friend of mine has a played with 4.6 & it kept up with that till he put a H404 cam in it. like I said it was just a quick power run I had done, it would probably benefit from a proper set up & aftermarket ecu.
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