Results of Austec SP6 De-Cat & Re-Map

[S5TVR]

I thought I'd share the results of the recent re-map and then de-cat performed on my T350 by Paul at Austec. I did things a bit arse-about-face as I had the car re-mapped first and then decided that I would have it de-catted, which then necessitated some minor tweaks to the original re-map. However, as the results were all measured on the same dyno, it gives I think a good indication of the benefits of re-mapping and de-catting independently. In summary (figures quoted at the crank):

Original peak power: 363 bhp at 7,135rpm
Original peal torque: 281 lb/ft at 6,370rpm

Re-mapped peak power: 365 bhp at 6,845rpm
Re-mapped peak torque: 294 lb/ft at 6,170rpm

De-cat & Re-map peak power: 371 bhp at 6,790rpm
De-cat & Re-map peak power: 303 lb/ft at 6,120rpm

Although the peak power and torque gains are good, have a look at the gains through the rev range and in particular the improvement in torque at low revs. At 1,800rpm the torque has increased from approx 150 lb/ft to approx 215 lb/ft. Below 4k rpm it feels like a different car:
- Much more grunt
- I can drive in a higher gear now at lower speeds so I can hear the stereo !
- Much better throttle response so the engine doesn't feel a bit lifeless which I think SP6's tend to at under 4k revs

Also, look at the torque and power gains between 4k-6k rpm - the acceleration is now phenominal and it was hardly shabby to begin with (363 bhp for a standard SP6 was good to start with).

Just to pre-empt the debate on using crank figures rather than at the wheels figures, firstly I don't have at the wheels figures for torque and secondly Paul has tested his rolling road dyno against his bench dyno and the two agree to within 5 bhp !.

[pic][/pic]

Edited by S5TVR on Saturday 21st July 10:06

[Daftlad]

Very interseting. Peak power occurs earlier and more power and torque throughout.

Whose decat pipes were used?

[S5TVR]

Daftlad said:

Very interseting. Peak power occurs earlier and more power and torque throughout.
Whose decat pipes were used?

They were Austec's own pipes - I don't know if these are any different to anyone elses out there ?.

[T40ORA]

Apologies for my niavity, but are there any negatives to having a re-mapping done?

Also, what sort of money are we looking at for this work?

OK - just found it on other thread.

Edited by T40ORA on Saturday 21st July 23:00

[tuscandom]

yes how much and any downside to the power increase (i cant find the other thread ) cheers

[S5TVR]

T40ORA said:

Apologies for my niavity, but are there any negatives to having a re-mapping done?.

Edited by T40ORA on Saturday 21st July 23:00

Apart from the wallet-lightening, I can't think of a single downside. It would be fair to say that some people might get worse or better gains than I have as much will depend on the quality of the car's mapping to start with. Having said that Paul has shown me a number of SP6 re-maps that even to my untrained eye did benefit noticeably from the re-map. My car's ECU was carrying a standard map from TVR and contary to what I've read elesewhere these standard maps appear to leave a lot to be desired even though SP6 engines make closer to their quoted peak power figures.

[tuscandom]

how much was the decat and remap.cheers

[S5TVR]

tuscandom said:

how much was the decat and remap.cheers

Best check with Paul at Austec for a firm price, but the re-map is £750 + VAT and the de-cat is around £200 + VAT.

[tuscandom]

cheers

[yzf1070]

S5TVR said:

Just to pre-empt the debate on using crank figures rather than at the wheels figures, firstly I don't have at the wheels figures for torque and secondly Paul has tested his rolling road dyno against his bench dyno and the two agree to within 5 bhp !.

[pic][/pic]

Edited by S5TVR on Saturday 21st July 10:06

I may be misunderstanding something in this (I am no expert, so I hope someone who is, out there, will correct me) It looks to me like they have dialed in 31.36% transmission losses?!? 87.5 BHP difference between 279 at the wheels and 366.5. (87.5\279*100 = 31.36%) or is not as simple as this? Also I believe the corrected BHP at 370.5 based around barometric pressure above sea level?

Someone please enlighten me?

Anyway the main thing is you are happy with the results and the car drives much better.

Cheers
G

[T66ORA]

Graham
Not sure how you do your maths i only have an "O" level

I make it approx 23.9%, (366.5 minus approx 23.9% = 278.9)
This falls in line with the 20 to 25% average?
I`m no expert either, so maybe you could ring Autocraft to explain

[S5TVR]

T66ORA said:

Graham
Not sure how you do your maths i only have an "O" level

I make it approx 23.9%, (366.5 minus approx 23.9% = 278.9)
This falls in line with the 20 to 25% average?
I`m no expert either, so maybe you could ring Autocraft to explain

I also would base the transmission loss figures as a proportion of the corrected power (crank) rather than as a proportion of the wheel power figure.

[S5TVR]

yzf1070 said:

Anyway the main thing is you are happy with the results and the car drives much better.

Cheers
G

Spot on !.

[yzf1070]

T66ORA said:

Graham
Not sure how you do your maths i only have an "O" level

I make it approx 23.9%, (366.5 minus approx 23.9% = 278.9)
This falls in line with the 20 to 25% average?
I`m no expert either, so maybe you could ring Autocraft to explain

Tony,

I would have hoped that you learned with that O level that mathematics is all about playing with numbers...!

I based my calc on what I have read in a Forced Induction Tuning book I have.

To arrive at a fly wheel BHP figure you must obtain a base number to start with and a Chassis dyno can only give the Wheel BHP. You run the car on the chassis dyno and obtain the rear wheel BHP. The computer takes this wheel bhp and calculates the flywheel bhp from that, based on the transmission losses dialed in. To use the math this way 279 Wheel BHP * 31.36% = 366.5 Fly wheel BHP.

This is why I posted the query and I didn't even look at the intermediate figures. Re S5TVR he is happy with the car as it is obviously performing far better so he got the result he was hoping for and as I said that is what matters. I just hoped that someone could explain how the figures work, as 31% transmission losses are rather high, unless he has an automatic box !

[S5TVR]

yzf1070 said:

unless he has an automatic box !

Not an auto box, but did I mention those power runs were done in reverse gear !

[PeterT]

I know it's really bad to compare different dynos ... in fact it's bad to compare the same dyno on different days, but this really makes me pleased when comparing my recent re-map. ... Please see http://www.pistonheads.com/gassing/topic.asp?h=0&a...

I was happy using 20% taking mine to 374bhp, but if the multiplication factor is more like 24% then that takes it to 386bhp and if 31% to 408hbp!

So what do you believe?

Regardless of the actual numbers, I am also happy the driving experience and the smooth delivery is seriously better after a good re-map.

[Mr Freefall]

S5TVR said:

yzf1070 said:

unless he has an automatic box !

Not an auto box, but did I mention those power runs were done in reverse gear !

Simon, as a bench mark, my 4.0ltr red rose T350c made 310bhp at the wheels. My Cerb made 350bhp at the wheels 430BHP at the fly.

Nice results, basically 3.6RR power.

Mr F

[S5TVR]

Mr Freefall said:

Simon, as a bench mark, my 4.0ltr red rose T350c made 310bhp at the wheels. My Cerb made 350bhp at the wheels 430BHP at the fly.

Nice results, basically 3.6RR power.
Mr F

Thanks Mr F. Am I right in thinking your Cerb is at Austec's at the moment - having it tweaked are we ?

[HarryW]

Ah Mr F what did it come out at then, has it 'loosened' up then


Re the results as already said the proof is in the driving and whether the owner thinks there is a difference.



[footnote]
But I will say the RR in question is a top of the range MAHA one (look it up). Yes the losses are measured on coast down and do vary from car to car (mine actually on its last run displays an extremely low loss for cerb less than 35hp or something). It is not a % guess associated with simpler/cheaper dyno's. It is calibrated to ISO standards and is within a whisker of the bench dyno output, simply you will not find a more accurate chassis dyno. If you want it more accurate then take the engine out and put it in the load cell next door

[Mr Freefall]

S5TVR said:

Mr Freefall said:

Simon, as a bench mark, my 4.0ltr red rose T350c made 310bhp at the wheels. My Cerb made 350bhp at the wheels 430BHP at the fly.

Nice results, basically 3.6RR power.
Mr F

Thanks Mr F. Am I right in thinking your Cerb is at Austec's at the moment - having it tweaked are we ?

Yes, I could swear at the moment, but I wont, suffice to say that the car is testing my patients right now. But, it’s in the capable hands of Austec, so all will be well soon.

Update was custom a stainless steel exhaust (other one was falling apart) made at Haywood and Scott, 2.5 bore to the boxes, 3" from the box out with extra silencing (101 db at 4000rmp).

Harry, you will need to speak to Paul, he didn't tell me the final mapping roller figures

Mr F


Mr F