S2K on a rolling road

S2K on a rolling road

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JM-S2K

Original Poster:

64 posts

213 months

Tuesday 19th June 2007
quotequote all
Just had my S2K on Farnborough College's rolling road.

The readings gave 208 bhp at 8429 rpm/127 mph in 5th gear. A bit upset with that, although it was with the air con on and they did say that the rollers hadn't been callibrated.

I cant believe that my ride is running almost 30 bhp shy....
Is it likely that if the RR had been callibrated I'd be getting a figure close to the claimed 237 bhp?

Anyone else had there's RR'd, where and what figures did you get?

Think I'll have to go to the annual Japchat RR day at Surrey, to see how it does and put my mind at rest.

RobCrezz

7,892 posts

215 months

Tuesday 19th June 2007
quotequote all
Is that RWHP or BHP?

JM-S2K

Original Poster:

64 posts

213 months

Tuesday 19th June 2007
quotequote all
If it was at the wheels I'd be doing handstands!

RobCrezz

7,892 posts

215 months

Tuesday 19th June 2007
quotequote all
JM-S2K said:
If it was at the wheels I'd be doing handstands!
What was the rwhp?

as it was a rolling road and not a engine dyno the BHP is only a guess.

JM-S2K

Original Poster:

64 posts

213 months

Tuesday 19th June 2007
quotequote all
It showed 157.3 hp at wheels with power loss of 46.4 hp measured. All at 127 mph and 8429 rpm.
Apparently this equated to 208.0 bhp???
This is my first RR, so a bit lost with all the figures.

John57

1,853 posts

235 months

Tuesday 19th June 2007
quotequote all
How many miles has it got on it ? They get considerably better with age ! My MY05 has only got 11K on it so I have no intention of putting ot on a RR yet .....

I believe they usually put out 160-185 ATW ..... but every rolling road is different. Charlie (Vixpy) may be able to comment on common ATW figures for S2000's from his (Surrey) RR ?

Bibbs

3,733 posts

217 months

Tuesday 19th June 2007
quotequote all
Most should read 190 bhp @ wheels. I think the dyno may be out.

I had a few mods and got 195 @ wheels.
I added a charger and got 284 @ wheels.
I then tuned it with a stand alone ECU and got 316 @ wheels.

Edited by Bibbs on Tuesday 19th June 22:19

markiem8

76 posts

246 months

Tuesday 19th June 2007
quotequote all
4th Gear would have been better for the run.

I've had my chop with dyno's now they all read different, I've varied from 366 down to 290's back to 340's. I just pick a random number now when asked how many ponies you got.

havoc

30,895 posts

242 months

Wednesday 20th June 2007
quotequote all
5th is an odd gear to use.

Plus, IIRC, peak power is usually at 8,700rpm or so...so 208 at 8,400 might not be far off the mark.

And if the road hasn't been calibrated then it could be giving you the answer 'green cheese' and it would be as much use, in all honesty.

Lurking Lawyer

4,535 posts

232 months

Wednesday 20th June 2007
quotequote all
havoc said:
Plus, IIRC, peak power is usually at 8,700rpm or so
Peak power comes at 8,300 rpm.

JM-S2K

Original Poster:

64 posts

213 months

Thursday 21st June 2007
quotequote all
Its a MY04 and only done 19k miles, after speaking to them again I'm guessing it is their calibration being the problem. Hasn't been done and they had the same problem with a monaro (came back with almost 100 bhp less than it should have).
They ran it in 5th first and 4th for the 2nd run. First ran gave more, although I think that the 2nd run aborted as gave peak power at 7400 rpm ish (203 bhp). They thought that the gear ratio would have been closer to 1:1 in 5th gear so more likely to get a better reading? I had no idea so took it as though they knew better.
They added that they'd had the RR set to 8000 rpm when it was new, as before mine they never thought they'd need more hehe
I'll have to wait and see what Surrey RR brings in July.

mikey k

13,014 posts

223 months

Monday 25th June 2007
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My 05 S gave 188WHP and 243BHP @ TDI North in Warrington.
It now has a stock Comptech supercharger and aftercooler on and gives 264WHP and 318BHP.
I'm planing the next upgrade which is a smaller pulley, bigger injectors and a replacement ECU

PJ S

10,842 posts

234 months

Tuesday 26th June 2007
quotequote all
I take it you've already done the manifold and CAT-back?
That's bound to be good for gain since the a bog standard one with those swapped out is good for 12-15 bhp, if not nearer 20.

RobCrezz

7,892 posts

215 months

Friday 29th June 2007
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Also, why did you have the A/C on, that will drain a little power.

hondafanatic

4,969 posts

208 months

Thursday 5th July 2007
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RobCrezz said:
Also, why did you have the A/C on, that will drain a little power.
If i remember correctly, on wide open throttle (i.e. foot flat to the floor) the ecu will switch the condensor off, therefore it makes no difference.

RobCrezz

7,892 posts

215 months

Friday 6th July 2007
quotequote all
hondafanatic said:
RobCrezz said:
Also, why did you have the A/C on, that will drain a little power.
If i remember correctly, on wide open throttle (i.e. foot flat to the floor) the ecu will switch the condensor off, therefore it makes no difference.
Right you are, forgot about that.

ASBO

26,140 posts

221 months

Wednesday 11th July 2007
quotequote all
JM-S2K said:
Its a MY04 and only done 19k miles, after speaking to them again I'm guessing it is their calibration being the problem. Hasn't been done and they had the same problem with a monaro (came back with almost 100 bhp less than it should have).
They ran it in 5th first and 4th for the 2nd run. First ran gave more, although I think that the 2nd run aborted as gave peak power at 7400 rpm ish (203 bhp). They thought that the gear ratio would have been closer to 1:1 in 5th gear so more likely to get a better reading? I had no idea so took it as though they knew better.
They added that they'd had the RR set to 8000 rpm when it was new, as before mine they never thought they'd need more hehe
I'll have to wait and see what Surrey RR brings in July.
Will they be giving you an other run fro free then?

On the basis that you presumeably paid for a duff run

dan-t

53 posts

220 months

Thursday 18th October 2007
quotequote all
if there rollers werent calibrated they shouldnt be taking money off customers as your paying for a service that you wont be getting.

i say take it to a more reputable dyno company with preferably a dyno dynamics rolling road (like ours)

and as for the gearing mith there is no wrong or right gear to run any car in we are sick to death of customers leaving our shop then slating us on other forums saying that we didnt run it in the correct gear and going on like they know more than the operators simply because they have watched a few vids on youtube lol!

we run most cars in 3rd or 4th gear depending on the acceleration rates (4th gear for forced induction cars or highly strung n/a cars) but untill youve done a couple of runs in the car you wont know which gear suits it best as there is no rule book saying which is best for each car, this is only a myth made up by the invention of owners club forums where rumours get spread about like chinese whispers and then you get some guy coming in and basically trying to tell you how to do your job.

every standard car we have dyno'd has come out with the manufacturers quotes accept clio 172 and 182 models which always put out 164bhp and poorly looked after v-tec models which seem to loose a bag load of power if not looked after properly.

JM-S2K

Original Poster:

64 posts

213 months

Thursday 18th October 2007
quotequote all
I got the runs for free, my mates dad is head of the dept at the college. I helped him out when he had a bit of trouble with a car accident. Plus they used the graphs as a teaching aid to compare them with other types of engines.

I'm pretty sure the engines running well and the apparent lack of peak power was due to un-calibrated rollers/not being set for 9K RPM. The graph showed a very smooth torque and BHP curve and she's only done 20K now (18.5K at the time) with a full service history.
I may take her on another check up at another RR after xmas when I've changed the fluids & filters but in the mean time I'm content!

thetrash

1,849 posts

213 months

Thursday 18th October 2007
quotequote all
Could it be that honda are just optimistic with their figures? CPL dyno'd a standard CTR and it made 180bhp or 150ish whp. Now i've got 345whp biggrin