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Author Discussion

Hollowpockets

5,603 posts

102 months

[news] 
Tuesday 7th August 2012 quote quote all
with regards to the 19" wheels, maybe you just prefer a heavier steering feel and thats what you are experiencing, the downside will always be, slower pick up time, braking and cornering response, reducing unsprung mass improves so many things about how a car handles, last week i was in a car the same as mine fitted with the carbon dymag wheels, 36 kg lighter than the standard wheels per set, the car tip toe'd around Spa with far less effort and much more precision than my car with speedline corsa's (8kg lighter than standard per set). sadly dymag wheels went tits up two years ago frown

I was led to believe the suspension parts on the sag are the same as the T cars, only mounted slightly higher and further out on the chassis to give the wider track and lower centre of gravity, i doubt the T400 bits would have been used but could be wrong of course smile

DonkeyApple

17,196 posts

55 months

[news] 
Tuesday 7th August 2012 quote quote all
Getsis said:
RedSpike66 said:
I can 100% confirm that TVR Power 'At the Wheels' figures match SRR 'Flywheel' figures.
So who is correct?
The people who have tested their car at both have apparently come away with SRR at the fly figure matching Power's at the wheel figure so the numbers are inline in that regard.

I think when you look at the numbers with open eyes/heart it seems much more likely that this number is more a reflection of power at the fly than at the wheels wouldn't you say?

But so long as we contrast SRR results v Power results in the right way we still have meaningful comparisons as to where each engine generates it's performance etc.

TVR_owner

3,349 posts

77 months

[news] 
Tuesday 7th August 2012 quote quote all
Hollowpockets said:
Maybe you just prefer a heavier steering feel and thats what you are experiencing, the downside will always be, slower pick up time, braking and cornering response, reducing unsprung mass improves so many things about how a car handles.
Correct.

Getsis

1,436 posts

102 months

[news] 
Tuesday 7th August 2012 quote quote all
DonkeyApple said:
Getsis said:
RedSpike66 said:
I can 100% confirm that TVR Power 'At the Wheels' figures match SRR 'Flywheel' figures.
So who is correct?
The people who have tested their car at both have apparently come away with SRR at the fly figure matching Power's at the wheel figure so the numbers are inline in that regard.

I think when you look at the numbers with open eyes/heart it seems much more likely that this number is more a reflection of power at the fly than at the wheels wouldn't you say?

But so long as we contrast SRR results v Power results in the right way we still have meaningful comparisons as to where each engine generates it's performance etc.
I always thought that a rolling road can only accurately measure "At wheels" at the fly is a calculate guess as each car has different loss factors to take into account. A rolling road will not know the power losses of each individual car.

I know the figures generated are the same at Power and SRR as mine was mapped within days of each other at each one. figures are only numbers it's how the car performs that is important! but is great to know that what ever comes out from a SRR session can be accurately compared to a TVRP run without one saying they are the more accurate than the other which did happen in the past.

DonkeyApple

17,196 posts

55 months

[news] 
Tuesday 7th August 2012 quote quote all
Getsis said:
I always thought that a rolling road can only accurately measure "At wheels" at the fly is a calculate guess as each car has different loss factors to take into account. A rolling road will not know the power losses of each individual car.

I know the figures generated are the same at Power and SRR as mine was mapped within days of each other at each one. figures are only numbers it's how the car performs that is important! but is great to know that what ever comes out from a SRR session can be accurately compared to a TVRP run without one saying they are the more accurate than the other which did happen in the past.
I've no idea on the dark arts of rolling roads biggrin So I agree that what is important is that the two seemingly most commonly used RRs can be compared/contrasted in a relevent manner even it means taking the fly from one v the wheels at the other.

The biggest issue with RR in general is that the one that reads the highest figures will recieve more business such is the way of us blokes and our number chasing. As such in that industry there are financial incentives to over read, so finding two that match must be a good thing?
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Hollowpockets

5,603 posts

102 months

[news] 
Tuesday 7th August 2012 quote quote all
I know rolling road comparissons could be argued all day long BUT, I think it seems a bit far fetched that two dyno's could measure roughly 50/60bhp out from each other on the same car, surely one of them is way out on its calibration/set-up. Also comparing at the wheels figures with flywheel figures makes no sense as one has assumed losses lumped on.

Dont flame me for this but looking in from a non TVR point of view I would say there seems a slight lack of transparency when it comes to tuning TVR's, as mentioned above its a money maker and within reason the tuners inputs can affect the outcome,

can anyone confirm for comparison purposes the results from an engine bench type dyno versus a rolling road calculated fly figure? for example with the nobles we map them on track'n'road dyno in essex, which has been proven to be within 1% of the mountune workshop dyno bench on a 600bhp engine flywheel power. It would clear up a lot of questions if there was a similar test with these, maybe there has been???

Graham

collingbroon

355 posts

77 months

[news] 
Tuesday 7th August 2012 quote quote all
Don1 said:
collingbroon said:
Just for comparison purposes my mate with a 4.5 power sagaris is getting 460hp at the fly, so really good for a 4 litre.
Really? I think a few people round here might ask where the rest of their horses have gone then! biggrin

Maybe he has been telling me porkies! Whats the average going figures for a 4.5 that others have seen?

Don1

Original Poster:

10,828 posts

94 months

[news] 
Tuesday 7th August 2012 quote quote all
collingbroon said:
Maybe he has been telling me porkies! Whats the average going figures for a 4.5 that others have seen?
This thread was created so people can see real-world horsepower of the different engine sizes, modifying bits etc. Modified S6 Wiki

Don1

Original Poster:

10,828 posts

94 months

[news] 
Tuesday 7th August 2012 quote quote all
Hollowpockets said:
I know rolling road comparissons could be argued all day long BUT, I think it seems a bit far fetched that two dyno's could measure roughly 50/60bhp out from each other on the same car, surely one of them is way out on its calibration/set-up. Also comparing at the wheels figures with flywheel figures makes no sense as one has assumed losses lumped on.

Dont flame me for this but looking in from a non TVR point of view I would say there seems a slight lack of transparency when it comes to tuning TVR's, as mentioned above its a money maker and within reason the tuners inputs can affect the outcome,

can anyone confirm for comparison purposes the results from an engine bench type dyno versus a rolling road calculated fly figure? for example with the nobles we map them on track'n'road dyno in essex, which has been proven to be within 1% of the mountune workshop dyno bench on a 600bhp engine flywheel power. It would clear up a lot of questions if there was a similar test with these, maybe there has been???

Graham
I completely agree - it is an idea that has been mooted before, but never come to fruition.
But as Getsis said earlier on in the thread (I think!), the Power at the wheel figure and the Surrey Rolling Road 'fly' figure are within 1 bhp of each other - on his car, the runs done a day apart.
We also have the problem of a 'home' rolling road operator not giving the car a full go (as has been alleged on here before) - so an independent shoot-out would be good.

OlberJ

13,964 posts

119 months

[news] 
Tuesday 7th August 2012 quote quote all
You should go down the vBox route instead. Much better to see what the cars can do rather than what they should be able to do.

Don1

Original Poster:

10,828 posts

94 months

[news] 
Tuesday 7th August 2012 quote quote all
That opens up other variables - tyres, gearing, driver, temperature of road.... At least on a RR you'd have some degree of control?

OlberJ

13,964 posts

119 months

[news] 
Tuesday 7th August 2012 quote quote all
That's a plus IMO. Again shows what a car can do rather than should do.

You're factoring in everything about the car rather than singling the one part (almost).

A few runs and a vBox average would be a better indicator of performance than an RR but people don't think in 30-100mph terms, they think in bhp and on occasion weight.

Hollowpockets

5,603 posts

102 months

[news] 
Tuesday 7th August 2012 quote quote all
This isnt about what a car can or should do, if your wanting to find how fast a car is overall then yes 'timing' of sprints/laps is most effective taking tyres and set-up into consideration but...

For the number chasers and guys paying lots of money, this is about finding out what the true power of these engine options are and which solution to the speed six rebuild is most effective power wise for your bucks.

As far as i can see theres no clear way of telling what the actual power is with the variance between the two. You may have a figure within 1bhp between the two srr and power rollers but is it the wheel power or the flywheel, or even both are wrong? you wont know unless someone (power/str8-six step forward please) puts a engine on a bench dyno to compare the actual with calculated - and till then the various companies will continue making claims and taking money for upgrades that cant really be backed up with evidence. smile just sayin...



Don1

Original Poster:

10,828 posts

94 months

[news] 
Tuesday 7th August 2012 quote quote all
Have a look at this thread. It states that the figures that Power gives at the wheels is the same (within 1hp) of the numbers that SRR give. This is from an independent.... http://www.pistonheads.com/gassing/topic.asp?h=0&a...

spitfire4v8

1,882 posts

67 months

[news] 
Tuesday 7th August 2012 quote quote all
When we ran the wilder 3.8 I mapped it on the engine dyno and it made just over 400hp. We expected to lose up to 20 hp on the install in the car and lo and behold it made 380 in the car. I don't think you can argue too much with numbers off a dyno dynamics dyno, they are widely regarded as amongst the more believeable within the industry.

Hollowpockets

5,603 posts

102 months

[news] 
Tuesday 7th August 2012 quote quote all
Don1 said:
Have a look at this thread. It states that the figures that Power gives at the wheels is the same (within 1hp) of the numbers that SRR give. This is from an independent.... http://www.pistonheads.com/gassing/topic.asp?h=0&a...
Right i see, so its just a case of ignoring the @ the wheels statement from Power? it goes against anything ive ever heard before about dyno's but ok. smile

SO has anyone commissioned a 4.3/4.5 bottom end with the FFF and VVT with either an MBE or Syvecs yet? has the idea even been discussed with Power/RG? Would be great to see what a modern day advanced S6 like that would do, with a nice 5 year warranty of course.

RedSpike66

2,194 posts

98 months

[news] 
Tuesday 7th August 2012 quote quote all
Hollowpockets said:
SO has anyone commissioned a 4.3/4.5 bottom end with the FFF and VVT with either an MBE or Syvecs yet? has the idea even been discussed with Power/RG? Would be great to see what a modern day advanced S6 like that would do, with a nice 5 year warranty of course.
I'm not sure the two companies are likely to work together to produce such a beast, and if they did, where on earth would the responsibility lie for any warranty claim....

  1. 1 Sir, fix the customer's engine please, your bottom end failed and our head damage is consequential
  2. 2 Sir, I disagree, you fix the customer's engine please, your head dropped a broken part into our bottom end
I think RG are considering bore/stroke increases, but are still concentrating on VVT.

It would take a brave person to buy all the bits and get their own specialist to put it together for them, which is the only way currently frown


DonkeyApple

17,196 posts

55 months

[news] 
Tuesday 7th August 2012 quote quote all
I think as well that stroking the engine won't favour the FFF head as it needs to be able to rev.

RG looked at increasing the cc but I think I'm right that the guy who designed the head said that it wouldn't deliver the gains you might expect.

RG still need to find the optimum intake and exhaust for the head first and then the VCT system will really come into its own and in theory give a bit more at the top end but most crucially fill in a load of torque at the lower revs off the cam.

At the same time their is Pascal's turbo conversion which I think they are seeing as the next product up from the completed VCT project.

Hollowpockets

5,603 posts

102 months

[news] 
Wednesday 8th August 2012 quote quote all
Understandable but surely an engine specialist can diagnose the initial failure which caused the engine to let go.

I went from the 3.6 to the 4 litre in my old car, it really disappointed me that it lost the reviness and exciting top end, yes the torque was good but it just wasnt the same drive and doesnt suit the car IMO, ultimatley other continueous problems led to a sale within 6 months of the re-build. Id imagine going from the 4 to 4.3/4.5 would be even worse in my eyes, (not convinced the turbo is a great idea on these, heat is already a major problem and based on my experience with the noble, it would be a nightmare with melting electrics, manifolds will crack unless made with inconel or the likes and oil will get too thin and cause more engine problems at a guess)

If Im ever in the position of needing a rebuild on one of these again it would probably be the 4+FFF with vvt and syvecs for the rev happy screaming S6 which it should always have been.

On a separate note, dont suppose the new owner of my old 'T' dislikes the carbon ACT airbox I fitted and wants to hand it back? Oh how I wish I kept that now! wink

DonkeyApple

17,196 posts

55 months

[news] 
Wednesday 8th August 2012 quote quote all
I came from a 3.6 and found the cars I tested just didn't have that same feel.

The 4 I have now revs better than my 3.6 did.

Re the heat issue, they have spent a lot of time researching how to dispose of the extra heat and so far have a test package which includes the higher output, ECU controlled brushless fans, a new type of engine coolant and a more efficient radiator.

A big benefit that the turbo has over the sc is that the boost level is optional via the ECU so you can run at different levels depending on your need.
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