HP difference in the 'real world'
 

I'm looking at tuning packs for the WRX (just looking unfortunately, skint and bored at the moment) and it has got me wondering. Is there a point where an increase in BHP stops making a noticeable difference and it's more about bragging rights than enjoyment?

My car, for example, is a standard 04 WRX. PPP (via SIDC) would cost 1k and bump the HP up to 265 ish with Prodrive 0-62 estimates at 4.8. Greenwood developments do a kit that's £625 more and offers an extra 20hp, or one for £2,000 more that takes it up to 300hp.

How noticeable is an extra 35hp and is it worth an extra £2000? I imagine an increase of that amount to get less noticeable when added to a higher performing engine to begin with (Eg. add 100hp to a 100hp car and it will make more difference than adding it to a 500hp car).

How much have you lot spent and was it worth it? Honest answers appreciated.

mine was 279.6 bhp
after fitting a miltek de-cat downpipe im now at 300.
The downpipe was around 200 if i remember rightly.
fitted it myself so for 200 i got 20bhp.

I've also got:
Apexi power fc and commander
Apexi AVCR
Injectors
Fuel pressure regulator
Walbro fuel pump
Oil cooler
and its going to be mapped to 350 bhp until i get forger internals. The fitment and mapping has been quoted at 600-700 and the parts were alot but dont know how much. prob around the 1000 mark.

I'd rather do things my self than getting packs made by tuning companies. makes me feel like a had more input lol

How much difference in drivability did the 20hp make?

Have a look on scoobyclinic they do a package for about 2k that will take you to the 300bhp or they do one for 1k that will give you about 275bhp.

ScoobyClinic

have a look about though first before you buy.

:lol1:
Perhaps I didn't make my original post clear enough. I'm not looking for which is the best deal (i'm skint anyway so can't afford any!). I'm wanting to know how noticeable an increase of say 20hp would be in the real world. Does it honestly make a difference in how the car feels when you've already got 265hp or is it not that noticeable really and only good for bragging rights?

sorry mate, you won't really notice that much drive wise imo, i mean unless your going to be hitting top end speeds then maybe having that little extra will help.

I have 51 bugeye with a small exhaust mod, and its running 217.9bhp
had it on the rr at scoobyclinc and tbh i didn't notice the difference
and for the fact i gained just short of 15bhp from this mod.

it felt quicker but it could have been my ego telling me lol

It sounded so much better to get rid of the cat though.Im hoping for a nice difference when all the other work has been completed

you are correct in pointing out the small increases (in %age terms) that you gain but......

as this would incorporate a custom remap then drivability should increase noticably across the rev range. If you can try to get to one of your local meets and ask if you can drive/get driven in one that has similar mods to those you are considering and see if you can feel the difference yourself before deciding

Rather than top-end, getting the turbo in quicker and hitting a higher torque quicker will make the car feel much faster. Couple that with a lightened flywheel and it should really pull in the lower gears.

J.

I always get confused by the expression ' makes your car feel faster'? Surely, if your car 'feels' faster, it must actually be faster?:wonder:
Oh I've got myself even more confused now - can someone help me out?:confused:

Don't be hoodwinked by just headline figures mate.

It's the area under the power/torque curves that is more important! You want as much power under the broadest RPM range.

Ns04

"HP difference in the 'real world' " I thought we were going to have a discussion about the merits of a certain brand of sauce.

Ever driven an Evo 6 tommi mak? it does 0-60 in just over 4 secs but when you floor it nothing happens for the first couple of seconds then all hell breaks loose, 20-60 comes in one huge lump. The acceleration feels absolutely neck breakingly quick but if you get in a N/A car that accelerates as quick to 60 it will feel totally different / slower because of the power delivery. So the Evo feels faster than it is (which is bloody fast anyway)

tsl
 

i went the tsl route triple three (had a PPP on me classic before a drunk driver wrote it off) took the car from 276 to 333 approx cost about 2k definately worth it transformed the car, smooth delivery, rather than that delayed hit u have with the standard car, feels alot quicker and even more so with uprated susp package, fell in love all over again.

In a car that's used for ordinary, everyday duties, there is a lot of truth in the above.
I had my STi PPP re-mapped by Richard Bulmer via TSL and the result was quite impressive, however I don't really drive it any faster than before!
I have before and after rolling road power curves, and they show that below 3500rpm there is no gain at all (not a big surprise) beyond that, the curves seperate and there's over 40 bhp gain in places!
I'm glad I had it done, it's a better and smoother and of course I've thought of 370 - 380 but hey, is there really any point? From now on it would mean hardware changes - turbo, exhaust etc. so I would be looking at the wrong side of 3 grand? It's a case of "diminishing returns"
JohnD

Thanks mate - yes I do understand more now.:)

Love the EVO VI - best of the lot? But have you driven the EVO IX? My son has the FQ320 and the power delivery is so linear, you would think it was n/a albeit with about 6 litres! Stonking motor car, not as well built as the Scoob but I'd still have one!
JohnD

Thanks for the replies :luxhello:

So if 15hp makes no realistic difference in day to day driving. What amount would?

What would be a sensible power limit for a day to day road car and when would adding extra hp (not sauce badger ;) ) stop making a difference to one used daily?

It's not cheap to tune an Impreza and i'd want to weigh up extra smile factor over cost before spending my hard earned.

Assuming everything is standard at the mo. I reckon a budget of around £1750 would see you with a nice set-up of exhaust (with sport cat.) uprated fuel pump? free flow panel filter and re-map. Add to this the need to use SUL fuel and admitting to your insurance, at least about the exhaust (an obvious mod.) This would give you a noticable increase in power - more importantly, torque.
JohnD

I'd say the difference by some well judged mods getting a WRX to ~280bhp with a wide torque and power spread is massive (even compared to the PPP). It's not down to peak power figures, it's down to having the turbo in and big torque from ~2500rpm and keeping onto the power until 7000rpm that makes the car much faster in many "real world" situations and much nicer to drive.

Going another 20bhp, or 40bhp or so after ~280 would make for a different drive. It will use a different turbo, which will come in at higher revs, but hold on to the power better at the top end. So the performance at say 50mph in 4th will be worse - i.e. when you're not trying very much it won't be as fast. However, get the revs a little higher (say over 3200 rpm for a car with a TD05 turbo), you'll have a large slug of torque that keeps going much harder to the redline, so the car will be/feel much faster when you work it. I believe a few people with the big power cars (600bhp+ or whatever, but needs lots of revs) have commented in the past that for road use, they don't really get the benefit of much over 400-450bhp. On a track/drag strip you can use all the power and that's a different matter.

If you take two extremes with a like for like set-up (say full exhaust and remap on a WRX), the difference between say a 270bhp and a 290bhp will be noticable but not very big on the road. In other words, IMHO the tuning is much more about how the car delivers the power than the actual peak figure.

The only way to really tell what would suit you is to go drive.

When I remapped my MY00 last year, made a massive difference.

Gained 43bhp, but as mentioned already in this thread, the difference is not just in headline figures, but in torque and driveability.

Have a look:

before

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after

<IMG style="WIDTH: 480px; ; WIDTH: expression(this.width > 640 ? 480 : true)" alt="" src="http://www.bridgendkarate.co.uk/images/PICT0047.JPG" border=0>

Thread here (post 106):

https://www.scoobynet.com/group-buys...station-4.html