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Further N/A Mod's


captint

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The FCON SZ has been superseded (some months ago now) by the iS.

 

The cost of installing such an HKS piggy-back EMS will be of the order of:

- £600 for the unit

- £300 for the ECU harness

- £150 for installation

- £400 for tuning

 

Expensive, yes. However, there is no doubt (in my mind) that due to its flexibility and more particularly, its resolution, it is broadly a superior (and extendable) unit to the UTEC and due to the non-existent tuning expertise with the UTEC in the UK, the choice becomes even more polarised.

 

As to whether it is worth that money to achieve 20 BHp gains is a moot point but one which is more easily justified if you have the longer F/I goal in mind :)

 

[Couldn't stand by on this thread - to avoid money being ill-spent :)]

 

 

I don't think the F-CON SZ (or the Is) has a higher resolution than the UTEC?? the V-Pro yes (with higher costs involved even) but not the lower specs one? please check.

 

It all depends on what type of tuning is required here: the HKS units will NOT be user tuneable (or tuner tuneable unless they are PRO dealers) or have multiple on the fly selectable maps. The UTEC has.

 

AND surely with a UK offical distributor for the UTEC, you are covered by warranty if anything goes wrong anyway?

 

I'll be the guinea pig sooner or later, although now my priorities have shifted a bit anyway.

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Don't know but they could be on about Wheel hp rather than flywheel hp my zed n/a reached 266HP at the fly and if IIRC it's about 17% loss for transmission etc which differs from car to car so wheel hp would be about 220 see dyno below

 

gallery_128_71_25585.jpg

 

Think ive remembered correctly I'm sure someone will correct me if not.

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Guest prescience

You do not generate the same torque (which is converted to power) at the rollers (which is where it is measured) as you do at the flywheel.

 

This is because the drivetrain (flywheel, clutch, gearbox, differential etc) cannot translate flywheel torque (Bhp) perfectly to the wheels with out some losses - its just normal engineering.

 

So, what do you is, measure the power at the rollers (wheels) and apply a 'best practice' conversion factor, which is typically 17% for FWD/RWD and abour 22% for AWD to estimate power at the flywheel - which is what you will see quoted in brochures, websites (cf the Z develops 276 BHp).

 

If you had an engine dynamometer (and the manufacturers and others use these), you can unbolt the engine from the drivetrain and measure the torque (hence power) at the flywheel boundary precisely -so no conversion approximation is required.

 

Furthermore, it is fair to say that some dynamometers, rather than using the 17% conversion factor, use a technique called coast-down whereby the time etc to coast down from a given wheel power (to a stand) with no gear engaged is measured - which can be used to determine the dirvetrain loss (so the theory goes) which is added to the wheel power to get the flywheel power.

 

Opinions vary as to whether this coast-down apporach gives a realistic result, because the engine is not engaged during this process. Thus since the coast-down loss would be precisely the same whether or not for example, your engine had a supercharger connected, the difference between wheel and fly Hp would be the same - which seems most unlikely to me; whereas applying 17% would be more consistent and logical.

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Guest prescience
Holy Smokes, Dorian, you should work at NASA. Ok, based on my lack of engineering knowledge. If this creates a 17% loss and Spill was posting 266 hp, then if 266 = 83% is his true HP 320? Or have I missed the point.

No you have the point except the wrong way around.... 266Hp is his flywheel figure (which is 10Hp down on stock, I know not why) and his WHp number is 220 BHp as he states.

 

Referring back to your earlier point, most US people use wheel power (as I would prefer to do since it is measurable and flywheel is estimated) so that is why they would be please with 256 wheel Hp which compares well to 235 wheel Hp (stock).

 

The situation is further confused however since US and UK dynamometers use different techniques in accounting for environmental changes (air pressure, density, temperature etc) which would lead to different results. I think the UK useds 'SAE' and the US 'DIN' but don't quote me - Id need to look it up and you can do that (try wikipedia)

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No you have the point except the wrong way around.... 266Hp is his flywheel figure (which is 10Hp down on stock, I know not why) and his WHp number is 220 BHp as he states.

 

back to the old debate n/a mods don't help this car, this dyno run was done with true dual exhaust, cats, plenum and modified air intake

 

This was one of the better runs BTW and the torque is effected by a TD so if your not going FI in the future stick with a y'pipe.

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Guest prescience

Yes I believe he is saying that, mid-range would be interesting though

 

here is a plot (referred to below, deleted and re-instated) , which compares my S/C number (power and torque) vs MY03, 06, 911-3.6 and Z43.0. my mubers were dynoed at Abbey Msport and IMO were overestimated (based on my research elsewhere) thus the ones shown are 5% LOWER than actually recorded by the dyno

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Pete

 

Are you saying your torque decreases witha true dual exhaust? Did you have a Piggy back ECU?

 

At certain rpm yes the single pipes seem to have a straighter line no drop off in torque, i've tried to find a dyno done at the same time to compare mid range but can't find it.

 

Piggy Back no, this was only fitted when I had the sc done

 

The biggest improvement I saw over on the day seemed to be AFR, but that would have been the plenum and that was back to back comparision with another TD but no plenum.

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Guest prescience

Pete,

 

I took mine down for now - it was rather busy and confusing. Your car does puzzle me as the above seems low as did your original numbers (on different dynos).

 

Checking again, up to about 5k** revs, your numbers are very close to mine (and consistently well above stock as expected) suggesting in the early revs the two S/Cs are performing similarly and the dyno comparison is valid (ish).

 

**Yours is actually marginally higher than mine at 4.5k

 

From 5k onward, my rate of climb is higher than yours and so the gap widens to about 20Hp at redline - maybe your blower is just slightly less efficient? [Edit-> the slope of your power increase flattens from the previous linear response above 5k if you put a ruler along it, mine does not, this is unexpected behaviour for a blower, that's the area and the question. Why?] What was your boost at 6500, mine was 7.2psi

 

 

ps

I am surprised you have values above 6500 rpm - did you get your rev limit raised?

 

You do have a completely separate Vortech set-up though to me, exhaust, fuel system, injectors?, EMS so its not like for like.

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Rev limit raised?? not that I know of, hope not!

 

Injectors still not in, once they're done I'm going for a retune then I'll post figures again.

 

But your right setups are a little different so can't compare totally, oh one other thing I had a split exhaust well the flexi pipe so that may be some of the difference, oh well we'll see.

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Guest prescience

Be interested to see that mate - good luck with it.

 

Leaks are never good for performance even on the exhaust side.

 

In summary, the plots are pretty similar, with a re-tune, I expect you to get over 400 B)

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