Confused on BHP
Discussion
TOV!E said:
Hi all, I am looking for a sag at the moment and I am a bit confused, speedsix/8 have two for sale with 390 BHP, and all the others for sale are quoted at 324 BHP, am I missing something...?????????????????????????
The Sag was first sold "with" 406bhp , Most decent "S" spec(Tuscan S , Sagaris ) make around 380bhp fly, don't know where they are getting the 324 from though.Unfortunately, you aren't going to know till you buy and do a power run.
Redspike has it right on that.
Pursyluv said:
Reading previous threads on this subject and in no way pretending to know what I'm talking about, but is it not 380 at the flywheel equating to 324 at the wheels allowing for a 15% loss?
At the end of the day.... we just don't know for sure. Expect a standard 4.0 to have 360-370 bhp at the fly. That is the general consensus, no matter what people say.Don1 said:
Redspike has it right on that.
I know the numbers are a bit unclear, I just thought that 380 less 15% worked well, give or take 1% Pursyluv said:
Reading previous threads on this subject and in no way pretending to know what I'm talking about, but is it not 380 at the flywheel equating to 324 at the wheels allowing for a 15% loss?
At the end of the day.... we just don't know for sure. Expect a standard 4.0 to have 360-370 bhp at the fly. That is the general consensus, no matter what people say.
I have always assumed that BHP figures are from the flywheel. AFAIK, it is only TVR Power that quotes at the wheel BHP - but some say those at the wheel figures actually tally with flywheel figures when other rolling roads are used!
With that in mind, I have a very strong suspicion that when I get my Tamora rolling roaded after the 4.3 upgrade, and after the running in period, the BHP at the fly will be near the 360-380 tops mark, and not 420.
ETA - However, looking back on these very forums a decade ago, when I first bought a Tamora, there was a lot of RR results, and most showing near as damn it the factory figures, some even a little higher!
With that in mind, I have a very strong suspicion that when I get my Tamora rolling roaded after the 4.3 upgrade, and after the running in period, the BHP at the fly will be near the 360-380 tops mark, and not 420.
ETA - However, looking back on these very forums a decade ago, when I first bought a Tamora, there was a lot of RR results, and most showing near as damn it the factory figures, some even a little higher!
Edited by chris watton on Saturday 22 February 13:32
chris watton said:
I have always assumed that BHP figures are from the flywheel. AFAIK, it is only TVR Power that quotes at the wheel BHP - but some say those at the wheel figures actually tally with flywheel figures when other rolling roads are used!
With that in mind, I have a very strong suspicion that when I get my Tamora rolling roaded after the 4.3 upgrade, and after the running in period, the BHP at the fly will be near the 360-380 tops mark, and not 420.
ETA - However, looking back on these very forums a decade ago, when I first bought a Tamora, there was a lot of RR results, and most showing near as damn it the factory figures, some even a little higher!
Chris, I appreciate that the larger S6 engine upgrades are about torque more that BHP, but if I paid for a 4.3 upgrade and only gained 10-30bhp I would feel short changed mate.With that in mind, I have a very strong suspicion that when I get my Tamora rolling roaded after the 4.3 upgrade, and after the running in period, the BHP at the fly will be near the 360-380 tops mark, and not 420.
ETA - However, looking back on these very forums a decade ago, when I first bought a Tamora, there was a lot of RR results, and most showing near as damn it the factory figures, some even a little higher!
Edited by chris watton on Saturday 22 February 13:32
Ant. said:
Chris, I appreciate that the larger S6 engine upgrades are about torque more that BHP, but if I paid for a 4.3 upgrade and only gained 10-30bhp I would feel short changed mate.
Well, this is exactly what some of the guys posting on the S6 forum are suggesting. This is why it is confusing for me. On the one hand, I know well and remember the threads from a decade ago regarding the S6 power output. The consensus then was that the RV8 TVR's were always way down on power from the factory figures, but the S6 engine TVR's were always more or less on the button for factory figures.A decade on and I am now reading that the S6 in whatever guise - 3.6 or 4 litre never really made the manufacturers figures - I based my above post on what I have read on the more recent S6 forums. It is strange for me - before I left the TVR fold, these engines were regarded as flawed, but great and spot on for BHP figures, and now I'm back in the fold, I am told that the S6 would be hard pushed to reach 350 at the fly for a factory 4 litre. At least, that's the general vibe I got.
Now, if the 3.6 is supposed make around 350bhp, the standard 4 litre 360 and the Tuscan S and Sagaris even more, pushing 400 I assumed (before I ventured into the S6 forums), and it seems reasonable to me to think that a 4.3 should be making around 410/20 BHP and 350/60 at the wheels - if the factory figures were/are correct.
The only way I shall truly know is book a before and after RR using my local-ish RR, and not any of the TVR-related RR's. The power from the 4.3 isn't the be all and end all for me, it's the reliability and warranty, with the extra power and lower down torque a bonus.
When I get the results you can be rest assured I shall post them, good or bad.
ETA - I am in no way, shape or form an expert on stuff like this, I just go with what others have said in these forums, including the engine builders.
Edited by chris watton on Saturday 22 February 21:03
chris watton said:
Well, this is exactly what some of the guys posting on the S6 forum are suggesting. This is why it is confusing for me. On the one hand, I know well and remember the threads from a decade ago regarding the S6 power output. The consensus then was that the RV8 TVR's were always way down on power from the factory figures, but the S6 engine TVR's were always more or less on the button for factory figures.
A decade on and I am now reading that the S6 in whatever guise - 3.6 or 4 litre never really made the manufacturers figures - I based my above post on what I have read on the more recent S6 forums. It is strange for me - before I left the TVR fold, these engines were regarded as flawed, but great and spot on for BHP figures, and now I'm back in the fold, I am told that the S6 would be hard pushed to reach 350 at the fly for a factory 4 litre. At least, that's the general vibe I got.
Now, if the 3.6 is supposed make around 350bhp, the standard 4 litre 260 and the Tuscan S even more, I assumed (before I ventured into the S6 forums), and it seems reasonable to me to think that a 4.3 should be making around 410/20 BHP and 350/60 at the wheels - if the factory figures were/are correct.
The only way I shall truly know is book a before and after RR using my local-ish RR, and not any of the TVR-related RR's. The power from the 4.3 isn't the be all and end all for me, it's the reliability and warranty, with the extra power and lower down torque a bonus.
When I get the results you can be rest assured I shall post them, good or bad.
ETA - I am in no way, shape or form an expert on stuff like this, I just go with what others have said in these forums, including the engine builders.
After a while of owning my Tamora I was confident that the engine wasn't about to pop, I went down the benchmark RR measurement route.A decade on and I am now reading that the S6 in whatever guise - 3.6 or 4 litre never really made the manufacturers figures - I based my above post on what I have read on the more recent S6 forums. It is strange for me - before I left the TVR fold, these engines were regarded as flawed, but great and spot on for BHP figures, and now I'm back in the fold, I am told that the S6 would be hard pushed to reach 350 at the fly for a factory 4 litre. At least, that's the general vibe I got.
Now, if the 3.6 is supposed make around 350bhp, the standard 4 litre 260 and the Tuscan S even more, I assumed (before I ventured into the S6 forums), and it seems reasonable to me to think that a 4.3 should be making around 410/20 BHP and 350/60 at the wheels - if the factory figures were/are correct.
The only way I shall truly know is book a before and after RR using my local-ish RR, and not any of the TVR-related RR's. The power from the 4.3 isn't the be all and end all for me, it's the reliability and warranty, with the extra power and lower down torque a bonus.
When I get the results you can be rest assured I shall post them, good or bad.
ETA - I am in no way, shape or form an expert on stuff like this, I just go with what others have said in these forums, including the engine builders.
Edited by chris watton on Saturday 22 February 20:56
At first it would only make about 335 on Joolz RR in Chesterfield. We found that it was strong but weakening AFR at higher RPM.
We tried to give it more fuel in this range through the map, but it had no effect.
I went away and checked fuel pressure through the range, and found it was solid. I popped the injectors out and had them serviced, result, when I went back on the RR the reading was now 349.5......however the torque is slightly down from where I expected it.
So TVR S6 engines don't make the power they are supposed to, mine is missing 0.5 BHP !!!!!!!
Go to the S6 forum and look at the modified engines wiki. All bar one result is accurate, we believe, as well as being backed up by evidence.
The full take is.... No established modified engine from FFF, Power or Str8-Six will leave you short changed. The FFF needs extra breathing mods to make it work to its potential. The Power and Str8-Six 4.3 is less BHP and torque than the FFF, but much less cost.
The 4.5/5.0 from Power will give you more torque but less bhp than the FFF. Horses for courses.
All have the same warranty.
You willl hear bad press about every rebuilder, but only one comes on here, posts and stands up for himself. (Dom, thank you). Some garages really haven't helped themselves in this case.
I think that's it....
The full take is.... No established modified engine from FFF, Power or Str8-Six will leave you short changed. The FFF needs extra breathing mods to make it work to its potential. The Power and Str8-Six 4.3 is less BHP and torque than the FFF, but much less cost.
The 4.5/5.0 from Power will give you more torque but less bhp than the FFF. Horses for courses.
All have the same warranty.
You willl hear bad press about every rebuilder, but only one comes on here, posts and stands up for himself. (Dom, thank you). Some garages really haven't helped themselves in this case.
I think that's it....
Ant. said:
After a while of owning my Tamora I was confident that the engine wasn't about to pop, I went down the benchmark RR measurement route.
At first it would only make about 335 on Joolz RR in Chesterfield. We found that it was strong but weakening AFR at higher RPM.
We tried to give it more fuel in this range through the map, but it had no effect.
I went away and checked fuel pressure through the range, and found it was solid. I popped the injectors out and had them serviced, result, when I went back on the RR the reading was now 349.5......however the torque is slightly down from where I expected it.
So TVR S6 engines don't make the power they are supposed to, mine is missing 0.5 BHP !!!!!!!
This is exactly what I expected from a S6, making the stated figure, more or less - which is why I am now starting to believe TVR Power. It seems that since the LS3/7 conversions became popular (a conversion that will cost around £24k from one of the specialists...), we are seeing a lot more posts about how crap the S6 is for power (again, that's just the general 'vibe' I get, so could be totally wrong). But I go back through my posting history, and I am convinced that all of those nigh on spot on for factory figure RR results for the S6 can't all be wrong. Your latest results help confirm this.At first it would only make about 335 on Joolz RR in Chesterfield. We found that it was strong but weakening AFR at higher RPM.
We tried to give it more fuel in this range through the map, but it had no effect.
I went away and checked fuel pressure through the range, and found it was solid. I popped the injectors out and had them serviced, result, when I went back on the RR the reading was now 349.5......however the torque is slightly down from where I expected it.
So TVR S6 engines don't make the power they are supposed to, mine is missing 0.5 BHP !!!!!!!
Hell, I even had a thought cross my mind that some are dissing the S6 so more will be convinced to have the LS conversions - but that's tin foil hat territory...
m4tti said:
The king of the hill is the fff at 440 independently rolling roadbed at srr. Every other speed six that's been measured at srr doesn't get close.
If you have a 3.6 that can do 350 I'd keep it!
I intend to, would like to free up the breathing via the backbox and have Joo/Brendans airbox fitted and Joo map it.If you have a 3.6 that can do 350 I'd keep it!
Reckon 370-380 would be achievable, and it it ever goes pop I will rebuild it myself.
Ok, FWIW my view;
Not an engine with a blocked nose although if you are taking the 4/4.3/4.5 to high revs then you will need to open up the breathing a little bit. The FFF gets a lot of positives on here but frankly what is the difference? I am not convinced it all comes from the head modification, specifically the removal of the finger followers and addition of buckets. I think, no maths involved, that the reciprocating mass is around the same.
The lively response of this FFF engine, in my humble experience, comes from the reduced mass of the timing gear not the buckets Vs followers. If you nick a shed load of weight from the rotating parts you will use less energy for the same effect, so it spins up quicker, noticeably.
If you want more torque increase the lever arm, stroke. The limitation here is the piston speed but more maths needed so being a thicko as I never really went to or paid attention at skool I will leave this to others but.... you will have more torque, will leave a little old 4ltr standing and actually have less mechanical stress per buzz as well as the benefit of a warranty.
Clean injectors, good fuel and good pressure for the same are needed. Change your gearbox, diff and engine oil and feel the difference, think these did make the money when they were new so with simple TLC you wont be far off now.
J
Not an engine with a blocked nose although if you are taking the 4/4.3/4.5 to high revs then you will need to open up the breathing a little bit. The FFF gets a lot of positives on here but frankly what is the difference? I am not convinced it all comes from the head modification, specifically the removal of the finger followers and addition of buckets. I think, no maths involved, that the reciprocating mass is around the same.
The lively response of this FFF engine, in my humble experience, comes from the reduced mass of the timing gear not the buckets Vs followers. If you nick a shed load of weight from the rotating parts you will use less energy for the same effect, so it spins up quicker, noticeably.
If you want more torque increase the lever arm, stroke. The limitation here is the piston speed but more maths needed so being a thicko as I never really went to or paid attention at skool I will leave this to others but.... you will have more torque, will leave a little old 4ltr standing and actually have less mechanical stress per buzz as well as the benefit of a warranty.
Clean injectors, good fuel and good pressure for the same are needed. Change your gearbox, diff and engine oil and feel the difference, think these did make the money when they were new so with simple TLC you wont be far off now.
J
Chris - I had my old 3.6 on 2 different rollers and had 361 and 366 at the fly so pretty healthy one could assume. My 4.3 I've not had tested BUT the difference in power and torque is soooo noticeable and much greater than before. There's no way it's only a 5-10 bhp diff at the fly. Are you going to at Burghley? If so try mine, I think you'll be very pleasantly surprised...
Zippee said:
Chris - I had my old 3.6 on 2 different rollers and had 361 and 366 at the fly so pretty healthy one could assume. My 4.3 I've not had tested BUT the difference in power and torque is soooo noticeable and much greater than before. There's no way it's only a 5-10 bhp diff at the fly. Are you going to at Burghley? If so try mine, I think you'll be very pleasantly surprised...
..But if I try yours, I will want the upgrade there and then, as I have the mental age of a 12 year old when it comes to these cars When/what is Burghley?
Thank for posting those figures - it isn't me seeing the past via rose tinted's then....(no - just re-checked posts from 'back in the day'....)
chris watton said:
..But if I try yours, I will want the upgrade there and then, as I have the mental age of a 12 year old when it comes to these cars
When/what is Burghley?
Thank for posting those figures - it isn't me seeing the past via rose tinted's then....(no - just re-checked posts from 'back in the day'....)
Chris !!!!! TVRCC season opener When/what is Burghley?
Thank for posting those figures - it isn't me seeing the past via rose tinted's then....(no - just re-checked posts from 'back in the day'....)
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