The Never Ending Search for Extra Horsepower

[IC]

It could be said that it is human nature for people to be never truly satisfied with their lot - the search for extra horsepower seems to be a continual topic on this forum, however it seems that some people are satisfied with their upgrades with increased torque and acceleration and driveability (at a price!).

On reading a thread in this section somebody has not checked the output of their car on a rolling road after getting an upgrade, people may not be happy in retrospect to find that their cars may not be producing the bhp that was claimed, however some members are just happy with their cars' increased performance (people with AWD cars do have a problem in that there are the serious implications of putting an AWD non-Haldex on a rolling road which has been discussed many times on this forum). How do we recognise how much bhp our cars are producing on a day-to-day basis? Maybe somebody would produce a bhp meter that we can put in the cabin and then the driver can see what bhp the car is producing in all conditions – would that satisfy people in their quest ;-)

When you buy a product it is quite reasonable to expect the product to perform according to the specifications that the vendor has described and there must be a cooling off period so that if the buyer is not happy with the performance of the product the upgrade can be returned with the guarantee of the customer's money back. It is acnowledged that some providers offer this money back policy.

Why do we want cars to go faster? – how important in the scheme of things is this preoccupation with bhp and being faster and more powerful? In the end if an individual is truly happy in his/her own mind with the increased performance of their car after an upgrade because there is a perceived increase in bhp the upgrade had done its job, however increased bhp is not the be all and end all – real performance increases (backed up by benchmarked performance figures whatever value these figures have in peoples’ minds (we do need to have bhp and torque performance figures, however how do these figures relate to driving a car in real road conditions on a day-by-day basis?)), value for money, long term reliability and product support are. My point being that it is all well and good that a product is advertised as producing so many bhp under optimum conditions - what does this mean in the real World?

How many times are the conditions going to be just right for a car to perform to its maximum efficiency – the equation continually changes depending on weather, engine condition – the list goes on....as does our quest! All in all it is all down to personal satisfaction of what we want and how we perceive what we have and don't have. The search for Nirvana goes on :-)

Very well written! I agree with what you say, but there is one important factor that needs to be mentioned and that is that the conditions on the road are far better in terms of optimum conditions for best performance, than the conditions on the dyno. What I mean by this is that conditions on a dyno are very unvafourable to cars, especially with forced induction. This can be clearly seen when cars produce much less boost on the dyno than they do on the road, which means that a car will be performing to spec on the road far more consistently than on the dyno.

The problem is that if anyone wants to verify power claims, it needs to be done on very good dyno, and more importantly one with a very large fan. Otherwise the power readings will be down. You can never recreate the airflow you get on the road with a small dyno fan. Simple as that. This applies to anyone wanting to verify claims for any tuners software, be it TME, BSR, RICA etc.

One more thing, even a high torque figure doesn't translate to fastest car. You can have a big peak torque figure at low rpm and nothing mid range or top end, resulting in diesel-like performance. The best indication of real world performance is the area under the torque curve, and over what rpm range it covers. The wider the range and the larger the area, the faster the car.

Adam.

[TheJoyOfSix]

As we all know, a good driver in a 2CV can beat a bad driver in a WRX out on the road (only just, and given the conditions are favourable but you get the picture.......)

However, a good driver in a WRX...........

[Ross9]

Personally, mine is a quest for speed, not power, though in essence power is a large contributing factor obviously.

The best measure is that of a car on the road, or to get a fair comparison, a car round a track. 1/4 miling can test one aspect of a fast car, but not them all.

It is a case of always wanting that bit more though, and it's all to do with tolerance, after a while your car just doesnt feel as fast as it used too, purely because you have become accustomed to it, recently I was out in a friends Skyline after a new triple plate clutch was fitted, power would be estimated at about 670-700BHP at the time, in a rwd road car, as you can imagine, it was a bit much for the road, yet he still had to ask me if it really did "feel" that fast, obviously you can feel yourself being forced back, but the fact is he was much more used to it than I was, so it felt much faster to me.

To get back to Iains post a bit, how does horsepower relate to the road, well, again it has a big part in how a car performs on the road I feel, as is an indication of how quickly it will accelerate and make speed, however, how it actually performs on the road always makes the final impression for me, and when it comes down to it, how quickly a car will go from a-b, or round a track, is the best indicator, followed by a straight line drag and your interpretation of it after accounting for drivetrain type, and finally, a RR figure, they are better used for tuning, however, if you can, set a car up on the road as opposed the rollers, the car looks a bit mad with wires going over the roof to widebands up the exhaust etc, but then its set up in the same conditions it will be used in, not in a box with a fan in front of it.

Ross

Wires to a wideband LSU4 in the exhaust is precisely how we check the fueling on the road and on the dyno!!! It doesn't look very nice but it's a superb way of measuring it.

Adam.

[Ross9]

Yeah I totally agree, my point was, as you said yourself, that doing it on road gives you more realistic conditions, obviously rollers are more convenient in that you dont have to keep stopping, opening the bonnet and adjusting things etc.

Yes! And you can simulate rolling road constant speed loading with left foot braking (and hope you don't get brake fade), but it needs 2 people really - one to drive, and the other to actually take the measurements or make real-time adjustments.

In theory, you could also measure engine power on the road by eliminating all absorbing engine mounts except one which would be replaced with a strain gauge to measure the torque, and in-car software to display the power and torque!!!

Adam.

[KeatV70D5SE]

Sorry to intrude on what appears to be a petrol thread but I drive a V70D5, my quest would be for torque. My car will apparently do 130mph, which is plenty fast enough for anyone I would imagine. This is a result of the horsepower. How fast it gets there is more a result of the torque. I like to feel the push between 40 and 80 or wind it out a bit from walking pace in second gear. This is where performance matters on the road (in my opinion). Diesel car performance is nothing to be sneezed at in every day driving conditions.

With this in mind has anyone chipped a D5, I had read that I can get about 435lb/ft of torque which would be nice! This is approaching (or overtaking) T5 standards. It would be nice to out drag the kids in their "performance" cars whilst towing my 1400kg caravan!

Incidently if Adam from Volvo tuning is suscribed to this topic can I ask if you received my email, I sent it a couple of weeks ago and have yet to receive a reply.

Sorry I probably didn't receive it. We had a lot of email trouble recently and the only email address that now works reliably is info@chiptuninguk.com. I will check my records.

By the way, my dad has a V70 D5 auto, with RICA and he loves outdragging loads of cars, including ones like BMW 330 ci on the motorway!! The BMW will edge away only after about 120 mph. With the manual D5, it's even faster on the motorway, and will even out-drag a modified T5 mid range.

Adam.

[Andy Mcl]

I can vouch for diesel power,
My V70 Tdi is superchipped and a reasonable panel filter and it surprises alot of cars. It is as quick as a 2.5T and as a T5 running on ordinary fuel.
I would love to get more out of it but funds don't allow at the moment.BTW does anybody know if the 2.5 tdi can be taken up to 200bhp.
I like T5 performance but couldn't live with stopping at every garage.I am used to a minimum of 40mpg.
I'd love a D5 (chipped of course) but the torque you get, 4WD is really beginning to become necessary just to put the power down!
Cheers
Andy