Notices
Engine Management and ECU Remapping This section is to discuss the various aspects of engine management modification for your Subaru.

More Power.....

Thread Tools
 
Search this Thread
 
Old 03 January 2015, 09:52 AM
  #31  
RS_Matt
Scooby Regular
 
RS_Matt's Avatar
 
Join Date: Sep 2008
Location: Wakefield
Posts: 5,303
Received 18 Likes on 17 Posts
Default

Originally Posted by fat-thomas
OK for a change I'll ask for a serious answers,firstly by trying to run low torque all you are doing is trying to make up for the weak wrx components, namely the bottom end and gearbox.
So how exactly do you map for high bhp and low torque as they go hand in hand upwards on tuned engines.
Say what you want but advising someone to run 400 bhp through wrx components which are commonly known to only be able to handle 350 bhp is very poor advice and furthermore unfounded as you haven't done it.
the red highlighted part tells you all you need to know about the post
I'm certainly not recommending 400bhp as yet, rather that it could well be possible in the right circumstances.

The gearbox is weak tom but great for speed and allowing more power to get to the wheels with less wheelspin. It's a no-brainer to try and work around it. For me to swap with a 6 speed at 330bhp+ would be like losing circa 50bhp and the use of 1st and 2nd gear.

They say use smaller Turbo's as they reduce lag and increase torque when running similar boost to a large one. I've seen countless dyno figures from people using 400bhp turbos at lower boost and getting very modest peak torque figures. A large Turbo operating near it's peak efficiency will provide good power from cooler air and low torque. Torque is the bitter enemy of Scooby owners who enjoy the take-off factor of the Impreza. I've fitted a larger turbo inlet and forsaken headers to keep my torque lower thus far.

I know what kills pistons and rings tom apart from how bhp itself kills them. Surely if you keep boost low on a big turbo, temps low and the map on the rich side you have window to go past the commonly quoted 350bhp limit?

Th
Old 03 January 2015, 02:53 PM
  #32  
bigdal
Scooby Regular
 
bigdal's Avatar
 
Join Date: Jul 2014
Location: London
Posts: 167
Likes: 0
Received 0 Likes on 0 Posts
Default

http://www.superstreetonline.com/how...s-engine-tech/

Another article I found. I've spoke to a few tuners about the engine handling 400bhp and and they said it will but have all mentioned the 5 speed box being the weak point
Old 03 January 2015, 03:17 PM
  #33  
RS_Matt
Scooby Regular
 
RS_Matt's Avatar
 
Join Date: Sep 2008
Location: Wakefield
Posts: 5,303
Received 18 Likes on 17 Posts
Default

Originally Posted by bigdal
http://www.superstreetonline.com/how...s-engine-tech/

Another article I found. I've spoke to a few tuners about the engine handling 400bhp and and they said it will but have all mentioned the 5 speed box being the weak point
I guess as long as you tune to keep torque under 350lbft then 400bhp is on the cards.

Will this rationale lead us to a possible 450/350 tune on a WRX? At 450bhp in a WRX an STI would have to be insanely powerful to match it.

I'm guessing a FMIC would help increase the power to torque ratio too?
Old 03 January 2015, 04:37 PM
  #34  
neil-h
Scooby Regular
 
neil-h's Avatar
 
Join Date: Apr 2013
Location: Berks
Posts: 4,224
Likes: 0
Received 0 Likes on 0 Posts
Default

You do realise bhp is proportional to torque don't you?

http://en.m.wikipedia.org/wiki/Horse...culating_power
Old 03 January 2015, 06:12 PM
  #35  
RS_Matt
Scooby Regular
 
RS_Matt's Avatar
 
Join Date: Sep 2008
Location: Wakefield
Posts: 5,303
Received 18 Likes on 17 Posts
Default

I believe my car would make circa 360/340 running a SC360 at 1.4bar. I also believe my car would make 400/330 running a SC42 at 1bar. Boost pressure is a big factor in torque.

I think if you run the same boost the BHP to LBFT difference widens as you increase turbo size. I.e a TD04 at 1 bar = 250/250, a TD05 at 1 bar = 280/260 and a SC60 at 1 bar 330/290

I see a lot of benefits v a sacrifice in spool time.
Old 03 January 2015, 06:21 PM
  #36  
bigdal
Scooby Regular
 
bigdal's Avatar
 
Join Date: Jul 2014
Location: London
Posts: 167
Likes: 0
Received 0 Likes on 0 Posts
Default

You've also got torque to the engine and torque to the wheels so then other factors like gearing come involved.
Old 03 January 2015, 06:24 PM
  #37  
bigdal
Scooby Regular
 
bigdal's Avatar
 
Join Date: Jul 2014
Location: London
Posts: 167
Likes: 0
Received 0 Likes on 0 Posts
Default

https://danielmiessler.com/study/horsepower/
Old 03 January 2015, 06:28 PM
  #38  
fat-thomas
BANNED
iTrader: (4)
 
fat-thomas's Avatar
 
Join Date: Apr 2014
Location: fawor's car wash
Posts: 4,258
Likes: 0
Received 2 Likes on 2 Posts
Default

Why not run 700bhp and 100ftlbs of torque....
Old 03 January 2015, 06:41 PM
  #39  
bustaMOVEs
Scooby Regular
iTrader: (31)
 
bustaMOVEs's Avatar
 
Join Date: Jan 2012
Location: The 2dr club
Posts: 12,979
Likes: 0
Received 30 Likes on 21 Posts
Default

Can I just say, you won't get nowhere in regards to shifting, torque is more important than bhp otherwise your car wouldn't move.
Making more bhp and same tourque as say td04, you havnt actually gained anything in times, infact lowered times.
Old 03 January 2015, 06:50 PM
  #40  
fat-thomas
BANNED
iTrader: (4)
 
fat-thomas's Avatar
 
Join Date: Apr 2014
Location: fawor's car wash
Posts: 4,258
Likes: 0
Received 2 Likes on 2 Posts
Default

Originally Posted by bustaMOVEs
Can I just say, you won't get nowhere in regards to shifting, torque is more important than bhp otherwise your car wouldn't move.
Making more bhp and same tourque as say td04, you havnt actually gained anything in times, infact lowered times.
Spot on
Old 03 January 2015, 07:13 PM
  #41  
RS_Matt
Scooby Regular
 
RS_Matt's Avatar
 
Join Date: Sep 2008
Location: Wakefield
Posts: 5,303
Received 18 Likes on 17 Posts
Default

Originally Posted by bustaMOVEs
Can I just say, you won't get nowhere in regards to shifting, torque is more important than bhp otherwise your car wouldn't move.
Making more bhp and same tourque as say td04, you havnt actually gained anything in times, infact lowered times.
I can post a quicker 0-60 than a lot of 700bhp Imprezas due to them having too much torque.

BHP is everything in regards to acceleration, though I wouldn't fancy 700/100. Maybe 500/300 if poss. I believe the WRX WRC made circa 300/500 from mainly the Turbo 'nipped hosepipe effect' inlet restrictor? so if 500/300 is possible then It's something I'd like to try out.
Old 03 January 2015, 07:14 PM
  #42  
fat-thomas
BANNED
iTrader: (4)
 
fat-thomas's Avatar
 
Join Date: Apr 2014
Location: fawor's car wash
Posts: 4,258
Likes: 0
Received 2 Likes on 2 Posts
Default

Originally Posted by RS_Matt
I can post a quicker 0-60 than a lot of 700bhp Imprezas due to them having too much torque.

BHP is everything in regards to acceleration, though I wouldn't fancy 700/100. Maybe 500/300 if poss. I believe the WRX WRC made circa 300/500 from mainly the Turbo 'nipped hosepipe effect' inlet restrictor? so if 500/300 is possible then It's something I'd like to try out.
Just need a car that can handle it then lol
Old 03 January 2015, 07:27 PM
  #43  
RS_Matt
Scooby Regular
 
RS_Matt's Avatar
 
Join Date: Sep 2008
Location: Wakefield
Posts: 5,303
Received 18 Likes on 17 Posts
Default

Originally Posted by fat-thomas
Just need a car that can handle it then lol
Well my clutch, rods and box was happy on the strip with 307lbft so 300lbft should be a walk in the park.
Old 03 January 2015, 07:29 PM
  #44  
bustaMOVEs
Scooby Regular
iTrader: (31)
 
bustaMOVEs's Avatar
 
Join Date: Jan 2012
Location: The 2dr club
Posts: 12,979
Likes: 0
Received 30 Likes on 21 Posts
Default

Originally Posted by RS_Matt
I can post a quicker 0-60 than a lot of 700bhp Imprezas due to them having too much torque.

BHP is everything in regards to acceleration, though I wouldn't fancy 700/100. Maybe 500/300 if poss. I believe the WRX WRC made circa 300/500 from mainly the Turbo 'nipped hosepipe effect' inlet restrictor? so if 500/300 is possible then It's something I'd like to try out.
I'm not getting into a speech on here, as you can't get blood out of a stone.

A 700hp with simlar torque will be in the 9-10s so no you can't, even if you're jesus.

Torque is actually acceleration bhp is just the top end curve.

Wrc makes 300hp 500lbs like you say, go figure.

Sheeet, my audi is only about 270hp but 340lbs and I'd show you up.

Last edited by bustaMOVEs; 03 January 2015 at 07:31 PM.
Old 03 January 2015, 07:44 PM
  #45  
RS_Matt
Scooby Regular
 
RS_Matt's Avatar
 
Join Date: Sep 2008
Location: Wakefield
Posts: 5,303
Received 18 Likes on 17 Posts
Default

Originally Posted by bustaMOVEs
I'm not getting into a speech on here, as you can't get blood out of a stone.

A 700hp with simlar torque will be in the 9-10s so no you can't, even if you're jesus.

Torque is actually acceleration bhp is just the top end curve.

Wrc makes 300hp 500lbs like you say, go figure.

Sheeet, my audi is only about 270hp but 340lbs and I'd show you up.
Look forward to you hitting 12.5 secs in the spring then! Nobody is talking 700/700 btw.

Am I right in thinking a car with 400/300 will hold torque better at high revs better than a car with 300/300? On the strip I launch at 6k and barely drop below 5k.
Old 03 January 2015, 07:52 PM
  #46  
fat-thomas
BANNED
iTrader: (4)
 
fat-thomas's Avatar
 
Join Date: Apr 2014
Location: fawor's car wash
Posts: 4,258
Likes: 0
Received 2 Likes on 2 Posts
Default

Old arsematt just gets better,now the wrx is faster than a 700 bhp impreza
Old 03 January 2015, 08:00 PM
  #47  
mickywrx
Unmapped 12.4s @ 105
iTrader: (29)
 
mickywrx's Avatar
 
Join Date: Apr 2005
Location: Newcastle. 330bhp-289lb/ft @ 1bar boost - 12.4s @ 105mph
Posts: 11,776
Likes: 0
Received 4 Likes on 4 Posts
Post

Originally Posted by fat-thomas
Old arsematt just gets better,now the wrx is faster than a 700 bhp impreza
Matt's is currently faster than SteveBT's, that's only about 650bhp though, so I guess it doesn't count, and IIRC Steve's still has a broken gearbox.

I could well be wrong on the box though.
Old 03 January 2015, 08:05 PM
  #48  
RS_Matt
Scooby Regular
 
RS_Matt's Avatar
 
Join Date: Sep 2008
Location: Wakefield
Posts: 5,303
Received 18 Likes on 17 Posts
Default

Originally Posted by fat-thomas
Old arsematt just gets better,now the wrx is faster than a 700 bhp impreza
I suspect my 333/307 WRX could push a 700/100 WRX to 60mph...

You trolls are favouring torque are you not?
Old 03 January 2015, 08:10 PM
  #49  
RS_Matt
Scooby Regular
 
RS_Matt's Avatar
 
Join Date: Sep 2008
Location: Wakefield
Posts: 5,303
Received 18 Likes on 17 Posts
Default

Originally Posted by mickywrx
Matt's is currently faster than SteveBT's, that's only about 650bhp though, so I guess it doesn't count, and IIRC Steve's still has a broken gearbox.

I could well be wrong on the box though.
You and I are running 307lbft and 289lbft and are posting far better times than Newage STI's with over 350lbft.

Torque is good for overtaking and standing starts without launching. On the strip where you are keeping a car between 5,000-7,500rpm HP is crucial.
Old 03 January 2015, 11:04 PM
  #50  
bigdal
Scooby Regular
 
bigdal's Avatar
 
Join Date: Jul 2014
Location: London
Posts: 167
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by RS_Matt
Look forward to you hitting 12.5 secs in the spring then! Nobody is talking 700/700 btw.

Am I right in thinking a car with 400/300 will hold torque better at high revs better than a car with 300/300? On the strip I launch at 6k and barely drop below 5k.
Torque decreases at higher rpm
Old 04 January 2015, 01:21 PM
  #51  
neil-h
Scooby Regular
 
neil-h's Avatar
 
Join Date: Apr 2013
Location: Berks
Posts: 4,224
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by bigdal
That's actually a very good article. Well worth a read (hint hint).

Originally Posted by RS_Matt
I can post a quicker 0-60 than a lot of 700bhp Imprezas due to them having too much torque.

BHP is everything in regards to acceleration, though I wouldn't fancy 700/100. Maybe 500/300 if poss. I believe the WRX WRC made circa 300/500 from mainly the Turbo 'nipped hosepipe effect' inlet restrictor? so if 500/300 is possible then It's something I'd like to try out.
Any particular reason you've gone from 300/500 to 500/300?
Old 04 January 2015, 01:57 PM
  #52  
Shaun
Scooby Regular
Support Scoobynet!
 
Shaun's Avatar
 
Join Date: Mar 2000
Location: 5 beats 4 - RS3 Rulez!!!
Posts: 8,617
Received 22 Likes on 18 Posts
Default

RS_Matt,
Two people have already stated that HP is a calculation based on torque * revs / 5252. You can't just pick a HP and Torque curve and say about achieving it. It has to be based on the formulae.

BHP has nothing to do with acceleration.... if you think that, than you seriously don't understand the basics. BHP is derived from torque.... the torque is the rotational force. That's what gives you acceleration.

Think of it as HP enables you to achieve a speed.... the torque get's you there (i.e. acceleration).

High HP engines on the drag strip means that torque available is higher up the rev range, which with a big blower can mean that when you shift, you're still within the torque power band.
Old 04 January 2015, 02:00 PM
  #53  
Blue by You
Scooby Regular
iTrader: (23)
 
Blue by You's Avatar
 
Join Date: Jul 2008
Location: In the fast lane
Posts: 3,458
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Shaun
RS_Matt,
you seriously don't understand the basics.
This is the root of his problem.
Old 04 January 2015, 02:01 PM
  #54  
Shaun
Scooby Regular
Support Scoobynet!
 
Shaun's Avatar
 
Join Date: Mar 2000
Location: 5 beats 4 - RS3 Rulez!!!
Posts: 8,617
Received 22 Likes on 18 Posts
Default

Also....

You MUST consider the area UNDER THE CURVE. Peak figures on their own mean very little. You quote peak figures as the be all and end all...... surprisingly enough they are not. If you want a quick car, it needs an appropriate torque curve for the job intended.
Old 04 January 2015, 02:03 PM
  #55  
fat-thomas
BANNED
iTrader: (4)
 
fat-thomas's Avatar
 
Join Date: Apr 2014
Location: fawor's car wash
Posts: 4,258
Likes: 0
Received 2 Likes on 2 Posts
Default

Originally Posted by Blue by You
This is the root of his problem.
One of many 😉
His biggest problem is he has weak components I.e. wrx gearbox and bottom end which as we all know can't take a lot of torque,unlike the sti version.
Old 04 January 2015, 02:14 PM
  #56  
bustaMOVEs
Scooby Regular
iTrader: (31)
 
bustaMOVEs's Avatar
 
Join Date: Jan 2012
Location: The 2dr club
Posts: 12,979
Likes: 0
Received 30 Likes on 21 Posts
Default

Originally Posted by Shaun
RS_Matt,
Two people have already stated that HP is a calculation based on torque * revs / 5252. You can't just pick a HP and Torque curve and say about achieving it. It has to be based on the formulae.

BHP has nothing to do with acceleration.... if you think that, than you seriously don't understand the basics. BHP is derived from torque.... the torque is the rotational force. That's what gives you acceleration.

Think of it as HP enables you to achieve a speed.... the torque get's you there (i.e. acceleration).

High HP engines on the drag strip means that torque available is higher up the rev range, which with a big blower can mean that when you shift, you're still within the torque power band.


I wasn't as thick as I thought I was, listening to matt I was beginning to think that.
I feel for the newbs reading and digesting it though.
Old 04 January 2015, 02:24 PM
  #57  
fat-thomas
BANNED
iTrader: (4)
 
fat-thomas's Avatar
 
Join Date: Apr 2014
Location: fawor's car wash
Posts: 4,258
Likes: 0
Received 2 Likes on 2 Posts
Default

Originally Posted by bustaMOVEs


I wasn't as thick as I thought I was, listening to matt I was beginning to think that.
I feel for the newbs reading and digesting it though.
its the same crap you read on any of those facebook pages or sioc, idiots with no ******* clue.
Old 04 January 2015, 02:35 PM
  #58  
Reef
Scooby Regular
iTrader: (2)
 
Reef's Avatar
 
Join Date: Dec 2007
Location: Horsham, Sussex
Posts: 784
Likes: 0
Received 0 Likes on 0 Posts
Default

I'm still reading this although I'm not sure what your on about
Old 04 January 2015, 04:04 PM
  #59  
bustaMOVEs
Scooby Regular
iTrader: (31)
 
bustaMOVEs's Avatar
 
Join Date: Jan 2012
Location: The 2dr club
Posts: 12,979
Likes: 0
Received 30 Likes on 21 Posts
Default

Originally Posted by Reef
I'm still reading this although I'm not sure what your on about
Notice:
Please dont read
Old 04 January 2015, 05:20 PM
  #60  
RS_Matt
Scooby Regular
 
RS_Matt's Avatar
 
Join Date: Sep 2008
Location: Wakefield
Posts: 5,303
Received 18 Likes on 17 Posts
Default

Originally Posted by Shaun
RS_Matt,
Two people have already stated that HP is a calculation based on torque * revs / 5252. You can't just pick a HP and Torque curve and say about achieving it. It has to be based on the formulae.

BHP has nothing to do with acceleration.... if you think that, than you seriously don't understand the basics. BHP is derived from torque.... the torque is the rotational force. That's what gives you acceleration.

Think of it as HP enables you to achieve a speed.... the torque get's you there (i.e. acceleration).

High HP engines on the drag strip means that torque available is higher up the rev range, which with a big blower can mean that when you shift, you're still within the torque power band.
We have a winner.


Quick Reply: More Power.....



All times are GMT +1. The time now is 02:11 PM.