Blow Dog

Hello fellows
I have an enquiry, not so much a problem, but a mystery. I own a MY97 Impreza with SS Downpipe, backbox and air filter. I know this adds a few BHP onto the total, but mainly benefits torque. Now for some strange reason, my car is fast. I dont mean Impreza turbo fast, I mean, faster-than-STI's-and-heavily modded-Imprezas fast. I have encountered this mystery on a number of occassions and have always written off the idea and told myself it is my imagination. These occassions where I find myself pulling away from these 'faster' models have also been when I have been at a weight disadvantage, (2 people in car).

I have heard rumours of Impreza engines all being unique and varying in BHP upto 10BHP, but is it this noticeable?
Also, is it possible that my motor was chipped in anyway without me noticing? Although I really doubt this as the previous owner I bought the car off was a mother of 2 and the car had 2 child seats in the back. The car was completely original when I bought it.

Apart from spending £50 on a rolling road, is there a way of finding out if my chip has been worked on? Would the Subaru dealers have figured it out during their servicing?

Mysteriously myteriousized,
Cem

jasontaylor

Cem

How many miles has it done? My 95 car is noticably quicker than newer cars, but I've put this down to the engine being very loose.

Perhaps you just got lucky like Stef.

TFG

chuckster

I agree with Jason, I have a my97 with 30,000 miles on it and whilst test driving a my99 prodrived one they seemed about par - where I expected the newer one to be much quicker. Could it be the smaller turbo's on the older cars just give this feeling because of the smaller amount of time taken to get spinning?

Lee

The "feeling" of quickness has a lot to do with lag/boost. I test drove a MY98 which felt a lot more agressive than a MY99 - mainly due to a bit of lag and aggressive boost rush.

that said, my MY99 has some 33K on it and is far quicker than when it was almost-new.

spence

You may well just have a 'good one' as you suspect. If you think about it all engines are going to be made within a set of acceptable tolerances... some further out than others... some better than others, a 'luck of the draw' element is in there on that. Also the previous owner may well have done a very good job on the running in, that will affect the engine a great deal.

How it makes the power will also change your perception when comparing it with faster or different models, there was allot of talk some months ago about the UK car being as quick as the more powerful imports just because of how they made their power...

DJB

Have a look this site:

Suresh

Mine always seems a lot quicker when freshly washed and polished. I put it down to wax vapour entering the intercooler and thereby increasing the calorific value of the charge.

Then again, maybe it's just the increased grin factor!

Suresh

DavidG

Suresh - it's an aerodynamic thing. Zymol is by far the quickest. <I>(Or is it? I just don't know what to think anymore...)</I> Little known fact: F1 cars are regularly waxed with pure carnuba .

Blow Dog

Hmmm...
Bloody strange,
Thing is, it isnt a case of 'feeling' quicker, it genuinely 'IS' quicker than all those cars I mentioned.
229-248 bhp is a HUGE difference if you ask me. It seems as though I may be one of those lucky ones...

I think I should get mine rolling roaded.
Cem

DavidRB

From the SIDC FAQ (2.4.1.1 The Fabled ECU Reset):

"The above also explains how a well sorted UK specification 1998 turbo (running on Super unleaded with reset ECU, RAMair filter and free flow rear silencer) managed to repeatedly beat a WRX in sprints."

It's not unheard of for a "good" UK car to be quicker than a "bad" WRX.

As for "feel", if you look at the dyno curves, a UK turbo torque curve starts to rise around 2500 and typically rises by about 25% to 3500. The torque curve on a WRX/STi doesn't start rising until nearer 3500 rpm, but when it does, it goes up more steeply, typically a 33% increase (based on a highly scientific 30 second study )

Torque relates to acceleration, so an increase in torque gives an increase in the rate of change of acceleration (how much your acceleration is accelerating ) and this "feels faster" than a constant rate of change of acceleration. The steep climb in the torque curve is one of the reasons why the WRX/STi's have that "whoosh" factor. (the other is the higher torque & power output! )

In simple terms, a car with a wide, flat torque curve might accelerate constantly from 50-70 whereas one with a narrow, peaky one might accelerate slowly from 50-60 then rapidly from 60-70. The two cars could take exactly the same amount of time to reach 70, but the latter would feel quicker than the former.

[This message has been edited by DavidRB (edited 22-02-2000).]

Akira

Cem,

Gimme my car back!

My car is also a MY97 model with SS Downpipe, Backbox and K&N Induction Kit. On route to Santa Pod with the Midlands Convoy I was following Paul WALKER who was leading in his MY00 with PPP & Blitz exhaust.

When we got to Northampton to meet up with Stef etc. Paul questioned my ability to keep up when he had booted it on a couple of occassions. It was only then that I found out that his car had the PPP, and not standard with just a Blitz exhaust as I had first thought. In fact when we flew out of a layby I had to back off in 3rd as I was right on him. I was obviously chuffed as to how my car was running .
Sorry Paul lol.

I think that a good loose engine (28K) as opposed to WALKER'S car which must still be tight explains most of it.

Or could it be something with MY97/98 UK cars ehh Cem, Stef.

Cheers
Chris

p.s. all the power in the world can't help with crap navigation coming back from the Pod. Apologies to Jase,IanG and his brother. Good laugh though! lol



[This message has been edited by Akira (edited 22-02-2000).]

Stef

Cem.
I've found that the changes I've made to my car (similar to yours) have actually increased the bhp a lot more than the torque.
An average MY98 has 230bhp/228lbft as standard (on the dyno-site).
Mine now has 267bhp/235lbft.
My exhaust and induction kit have given an increase of approx 37bhp but only 7lb/ft of torque, although this does appear earlier on now.
It's possible that my car had more than 230bhp, but I don't think it's that likely really. Only post 98 cars seem to show much more than this.
I've asked Paul to put my graphs up against his standard MY98, to see exactly where the gains have been made.
To be honest though, I'd swap all my bhp gains for a bit more torque.

Stef.

DavidLewis

Stef,

With the number of posts to your name(s) I think you've got plenty of talk

MorayMackenzie

AlexM,

Would it be unreasonable to assume that you have a UK (small turbo, low reving, lazy driving) car?

WALKER

Chris
Having a downpipe fitted soon, so we will see if that makes any differance. Your probably right though, my car only having 4500 miles on it, probably, hopefully still tight engine. Much more likely though is that we were carrying a much larger load than you due to all the bloody sandwiches, pork pies, scotch eggs, crisps, pop and sweets the missus packed.LOL
See you at Donno

Paul

Marcos

OK - I'm glad somebody has questioned this:

I have a 5 door 95 WRX with Magnex Back Box, Blitz air induction (noisy as hell sounds like mating whales), only 32K miles on it and it goes like hell. Honestly.

How do I know?

The garage where I service it, the manager has an Sti Type R with all the mods and commented it was much faster than some older STis? Also a friend has an RX7 and can't believe how quick the turbo cuts in.


I was in Cyprus in November and test drove a demo 5 door STi Vi - very nice, but really did not feel as neck wrenching as my old WRX - maybe 'cos it was so new?

This made me think of just test driving a UK model - until I found one that 'feels' fast - and modify it with all the classic stuff exhaust, chip, air etc etc

Or maybe it just the perception of smoother acceleration...STI VI - 300BHP, mine possibly 250-80Bhp?

Mmmmm

marcus

MorayMackenzie

Watch out for STI version 3s, they may well alter your "faster than an sti" ideas.

AlexM

The formula for calculating HP is

Torque x RPM / 5252

If the UK car could rev (and maintain it's torque output) for an extra 1000 rpm then the ultimate power would be pretty much the same. The trade off in turbo size gives you better response at low engine speeds, but limits peak power to somewhere around 6200rpm on a UK car, whereas the WRX and STi are biased towards the higher rev ranges.

If you don't drive around using mega high revs then a UK car with a boost increase would come pretty close in day to day driving by virtue of it's superior torque output at low revs.

Cars with larger amounts of turbo lag often feel quicker than those with more linear acceleration - thats why I generally don't like small high revving NA engines.

Cheers,

Alex

JON HUGHES

Moray
I agree sti3's rule(as seen at the pod )
JON

AlexM

Moray,

Thats exactly right - low revving lazy car for a low revving lazy driver

Anyway as the Clio ad would have it 'less is now officially more' which pleases me on somany levels LOL

Cheers,

Alex

MorayMackenzie

Missing Details

wierd answer for you: beeeeeeeooooooby offel stounden switch on your overhead torsion beam stoppers.