Why less lag on Evo than WRX when Evo turbo is bigger?

lotarg · 10-12-2009, 01:22 PM

My brother has an Evo VIII stock (16g) with a tune and I noticed the car has barely any turbo lag, while I have a smaller turbo (TD04 and boost solenoid/exhaust/18 psi tune) and have substantially more lag. Is it the design of the turbo not the size? Or the way the 2.0L engines are designed?

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69subaru360 · 10-12-2009, 01:25 PM

It's all in the tuning. You could retune yours to spool up the turbo quicker.

BryanR · 10-12-2009, 01:31 PM

I think it's a combination of quite a few factors.

1) The EVO has a much shorter pre-turbo exhaust path
2) Unless you've swapped it you still have a cat pre-turbo
3) The 4G63 has an 88mm stroke and 85mm bore so it has better low end, thus you don't notice lag as much.

As an aside, if you want to feel no lag you should see my Stroked 4G63 with a TD04HL on it. 10psi by 1200 RPM.

DiscoGsus · 10-12-2009, 01:36 PM

Inline 4 vs Boxer.
Done.
Look at an evo "header", and then look at a subaru.

Its not in the tuning.
The pre-turbo cat also won't matter in this case.
And the bore/stroke doesn't matter.

The exhaust goes 4in to the turbo in an evo and 4ft in a subaru

dauss · 10-12-2009, 03:00 PM

Are the Evo turbos twin scroll?

happs subi · 10-12-2009, 03:07 PM

Yeah, all the tuning in the world could not change the physical length of subaru headers vs evo headers

SomeoneWhoIsntMe · 10-12-2009, 03:14 PM

Quote:

Originally Posted by happs subi

Yeah, all the tuning in the world could not change the physical length of subaru headers vs evo headers

front mount turbo with a chopped up EL header

lotarg · 10-12-2009, 03:16 PM

This makes sense thanks

GT35RHybrid · 10-12-2009, 03:18 PM

Simple answer is VE of the 4g63 vs the EJ.

aaronmsadler · 10-12-2009, 03:18 PM

Better VE, turbo manifold is 1' long, twin scroll, bore/stroke and about 50 other reasons.

904scooby · 10-12-2009, 03:49 PM

Quote:

Originally Posted by DiscoGsus

Inline 4 vs Boxer.
Done.
Look at an evo "header", and then look at a subaru.

Its not in the tuning.
The pre-turbo cat also won't matter in this case.
And the bore/stroke doesn't matter.

The exhaust goes 4in to the turbo in an evo and 4ft in a subaru

+1, you can try to tune the car to bring on boost quicker but all the tuning in the world cannot completely overcome design constrictions.

bugeye4life · 10-12-2009, 03:59 PM

i've always been told the twin scroll has a lot to do with it, and a bunch of other reasons

Not-EWRX · 10-12-2009, 04:05 PM

Insert pic of the new legacy turbo piping here.

Mechie3 · 10-12-2009, 04:17 PM

Quote:

Originally Posted by Not-EWRX

Insert pic of the new legacy turbo piping here.

Beat me to it. Not only does it take time for exhaust gases to travel to the turbo, but we lose kinetic energy along the way.

SomeoneWhoIsntMe · 10-12-2009, 05:25 PM

Quote:

Originally Posted by Not-EWRX

Insert pic of the new legacy turbo piping here.

and you just need a front mount with an inlet right there for this to be one badass setup

CynicX · 10-12-2009, 06:59 PM

Quote:

Originally Posted by Not-EWRX

Insert pic of the new legacy turbo piping here.

So, I bet the price of turbo inlets is going to increase some huh?

Chi_San · 10-12-2009, 10:39 PM

Now, if only the new Legacy turbo manifold was available in twinscroll form...

andrew3776 · 10-12-2009, 10:46 PM

So, to work on these turbo's now your going to have to jack up the car or something? That setup makes it look much easier to do a turbo swap for sure.

chazly413 · 10-12-2009, 11:36 PM

Quote:

Originally Posted by andrew3776

So, to work on these turbo's now your going to have to jack up the car or something? That setup makes it look much easier to do a turbo swap for sure.

Most definitely.

woodys77 · 10-12-2009, 11:42 PM

Quote:

Originally Posted by CynicX

So, I bet the price of turbo inlets is going to increase some huh?

i never thought of that! 8ft of inlet anyone

vinxH · 10-13-2009, 04:29 AM

Quote:

Originally Posted by andrew3776

So, to work on these turbo's now your going to have to jack up the car or something? That setup makes it look much easier to do a turbo swap for sure.

not like it's that hard on these previous gens to begin with.

OP, if you want to see virtually no turbo lag, get in a 2.5L WRX TD04 and get a protune with a catless TBE and a nice intake + turbo inlet.

10-12-2009, 01:22 PM	#1
lotarg Scooby Specialist Member#: 90940 Join Date: Jul 2005 Chapter/Region: Tri-State Location: Westchester, NY Vehicle: 2002 WRX Silver	Why less lag on Evo than WRX when Evo turbo is bigger? My brother has an Evo VIII stock (16g) with a tune and I noticed the car has barely any turbo lag, while I have a smaller turbo (TD04 and boost solenoid/exhaust/18 psi tune) and have substantially more lag. Is it the design of the turbo not the size? Or the way the 2.0L engines are designed? * Registered users of the site do not see these ads.

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10-12-2009, 01:25 PM	#2
69subaru360 Scooby Specialist Member#: 159682 Join Date: Sep 2007 Chapter/Region: Tri-State Location: Fleetwood, PA Vehicle: 1995 Impreza coupe 1969 360	It's all in the tuning. You could retune yours to spool up the turbo quicker.

10-12-2009, 01:31 PM	#3
BryanR Scooby Newbie Member#: 64450 Join Date: Jun 2004 Chapter/Region: MWSOC Location: Tecumseh, MI Vehicle: 2002 WRX Blue	I think it's a combination of quite a few factors. 1) The EVO has a much shorter pre-turbo exhaust path 2) Unless you've swapped it you still have a cat pre-turbo 3) The 4G63 has an 88mm stroke and 85mm bore so it has better low end, thus you don't notice lag as much. As an aside, if you want to feel no lag you should see my Stroked 4G63 with a TD04HL on it. 10psi by 1200 RPM.

10-12-2009, 01:36 PM	#4
DiscoGsus Scooby Specialist Member#: 47646 Join Date: Nov 2003 Chapter/Region: MAIC Location: NoVa Vehicle: 0200 JDM Wagon Rally coupe	Inline 4 vs Boxer. Done. Look at an evo "header", and then look at a subaru. Its not in the tuning. The pre-turbo cat also won't matter in this case. And the bore/stroke doesn't matter. The exhaust goes 4in to the turbo in an evo and 4ft in a subaru

10-12-2009, 03:00 PM	#5
dauss Scooby Specialist Member#: 108369 Join Date: Feb 2006 Chapter/Region: RMIC Location: Colorado Vehicle: 2005 CGM WRX Wagon 68HTA	Are the Evo turbos twin scroll?

10-12-2009, 03:07 PM	#6
happs subi Scooby Specialist Member#: 200288 Join Date: Jan 2009 Chapter/Region: BAIC Location: East Bay Area, CA Vehicle: 2002 Impreza WRX World Rally Blue	Yeah, all the tuning in the world could not change the physical length of subaru headers vs evo headers

10-12-2009, 03:16 PM	#8
lotarg Scooby Specialist Member#: 90940 Join Date: Jul 2005 Chapter/Region: Tri-State Location: Westchester, NY Vehicle: 2002 WRX Silver	This makes sense thanks

10-12-2009, 03:18 PM	#9
GT35RHybrid Scooby Newbie Member#: 223237 Join Date: Sep 2009 Chapter/Region: South East Location: Boonies	Simple answer is VE of the 4g63 vs the EJ.

10-12-2009, 03:18 PM	#10
aaronmsadler NASIOC Supporter Member#: 133597 Join Date: Nov 2006 Chapter/Region: SCIC Location: On the links Vehicle: 2006 STiStageCatless Clubs baby seals too!	Better VE, turbo manifold is 1' long, twin scroll, bore/stroke and about 50 other reasons.

10-12-2009, 03:59 PM	#12
bugeye4life Scooby Newbie Member#: 146328 Join Date: Apr 2007 Chapter/Region: Tri-State Location: allentown PA Vehicle: 05 sti 02 wrx	i've always been told the twin scroll has a lot to do with it, and a bunch of other reasons

10-12-2009, 04:05 PM	#13
Not-EWRX Scooby Specialist Member#: 158043 Join Date: Aug 2007 Chapter/Region: RMIC Location: SLC Vehicle: old 97 GC stage 9.5 Will sale $75k Pm offers	Insert pic of the new legacy turbo piping here.

10-12-2009, 10:39 PM	#17
Chi_San Scooby Guru Member#: 53558 Join Date: Jan 2004 Chapter/Region: NWIC Location: Deadford, OR Vehicle: 2002 WRX Wagon Silver	Now, if only the new Legacy turbo manifold was available in twinscroll form...

10-12-2009, 10:46 PM	#18
andrew3776 Scooby Specialist Member#: 172133 Join Date: Feb 2008 Chapter/Region: NESIC Location: Holyoke Mass Vehicle: 2003 Stage 2 Wrx rotten banana	So, to work on these turbo's now your going to have to jack up the car or something? That setup makes it look much easier to do a turbo swap for sure.