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Old 04-26-2011, 05:45 PM   #1
Peruwrx
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Default Want more torque and better spool, which mods now?

Ok I have a 04 WRX 2.0L and I want more low-end torque and a quicker spool need help on which road to take next?

This are my mods:
VF34
STI 550cc injectors
Walbro FP
Big top mount Intercooler
Samco turbo inlet hose
BOV Turbo Smart dual port
full catless
2.5" Turbo back
drop in oem kind K&N air filter
STI IC scoop
2.25" STI OEM axle back/ 3" HKS axle-back (depending on my mood for noise)
MBC
Protuned

This are my numbers on a mustang dyno @ 16.5psi:

max whp: 240 @ 6450rpm
max wtq: 226 @ 3980rpm

I have increased it to 17.5psi since my tuner said the AFR was conservative yet to do so. For this I think my numbers go 10whp more an little lbs more of torque.

It is hitting almost full boost @ 4000rpm

This are my 21 questions:

1. I have an AEM CAI laying arround will this help me? my tuner says from experience (and he has a lot and is respected) AEM messes up the MAF sensor. or just get an elbow delete?
2. TGV deletes will help torque and faster spool?
3. Will getting a 3" turbo-back help?
4. Heat wrap the turbo?
5. get a STI TMIC? mine is bigger like an APS
6. any more ideas????

Sorry for the long post and thanks.
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Last edited by Peruwrx; 04-26-2011 at 05:59 PM. Reason: more info
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Old 04-26-2011, 06:00 PM   #2
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do the small things. porting will help a ton. port the exh side of the turbo to match the up pipe. u will see when u seperate them the up pipe is most likely larger than the inlet on the turbine side.

heatwrap everything in the engine bay that has exhaust flowing through it. i.e. turbine housing, up pipe, and downpipe. wrapping the up pipe will allow for hotter egt's for faster spool. wrapping the turbo and dp will reduce underhood heat and result will be less heat soak. so the tuner can prob put a little extra timing in side the intercooler was prob heat soaked on the dyno a bit.

tgv deletes. i can do them for you or u can do them if you have tools. pm for a price.

port the leading edge of the throttle body and taper inward. just dont remove material from around where the butterfly sits. a knife like edge will give better air flow.

port the exh manifolds where the x pipe meets each collector. they can be bored out a bit and gasket matched to give better flow.

get a CAI. since ur running a tmic u r going to have some underhood heat soak. getting cooler initial air will yield better temps overall entering the engine and can run more timing. whatever happens to the maf can easily be changed and ur tuner should be able to make those changes in no time at all.

the turbo can be pushed much further. 20psi with a little taper shouldnt be out of the question. a vf34 can make 300whp so lets see what ur tuner can do. my td04 makes alot more than ur making now and its stg 2.

a sti tmic and the one u have is up for debate. u would have to do a pressre test and efficeincy test to see what will work better for you. i have seen sti tmic used with 35r's but its not the best idea. it should have plenty of cooling power for your setup though. get a shroud made or make ur own that fits the whole tmic surface. the stock one only covers like 75% of it so 25% isnt getting any forced air flow.
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Old 04-26-2011, 06:06 PM   #3
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Quote:
Originally Posted by Peruwrx View Post
1. I have an AEM CAI laying arround will this help me? my tuner says from experience (and he has a lot and is respected) AEM messes up the MAF sensor. or just get an elbow delete?
2. TGV deletes will help torque and faster spool?
3. Will getting a 3" turbo-back help?
4. Heat wrap the turbo?
5. get a STI TMIC? mine is bigger like an APS
6. any more ideas????
1. no, your stock airbox is good for >400hp, leave it alone

2. yes, it will improve over-all Volumetric efficiency, but dont expect a massive change

3. yes! 3" turbo to tail, going from a larger turbo-back to smaller axle back is the oposite of what you want, it builds backpressure which is bad.

4. no, heat wrap is dangerous, do some research on this.

5. bigger normally = better. but you can find the efficiency rating on both of them, if yours is less efficient than the STI, then change it.

6. water/meth injection to help the low end.
twinscroll to help spool
change headers/UP to improve exhaust gas velocity to the turbo to help spool.

consider a different turbo that is designed to spool faster and provide more low end torque if that's what you want, but from the charts i've seen the VF34 spools up by 3.5k and has a very nice torquie power band and delivers power all the way to redline without dropping off.

check http://www.efilogics.com/dyno/#graphanchor
search WRX vf34 look at the EJ205's for reference.
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Old 04-26-2011, 06:29 PM   #4
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IHI VF-30 ------------- 435 CFM at 14.7 PSI
IHI VF-30 ----------- 460 CFM at 18.0 PSI

from cobb:
Boost Targets: ~16.5psi +/- 0.7psi

more boost theoretically helps, but all the data i've seen so far says 18psi is as high as you want to go. you should get the compressor map, and compare it to your engines VE and talk it over with your tuner before you consider upping the boost any more. if you get out of the compressor's efficiency range temps will go up very quickly and things will explode.

looking back over your mods with the turbo's info infront of me, i really think its the exhaust that's holding you back. 2.5" is good for ~250hp but restrictive if you want to push past that.

Last edited by Locky1138; 04-26-2011 at 06:35 PM.
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Old 04-26-2011, 07:56 PM   #5
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totally forgot about this but the idea of VE of your turbo is a big thing with raising the boost. I dont have any charts but i would assume that 20 psi would still be safe.

a note on backpressure. one must find the correct ratio for backpressure and power output. 3" seems to be the a common used exhaust and you shoudl expect good gains from this.

As for wrapping i guess getting a quality turbo blanket would be the first choice. ceramic coating is the best for the downpipe and up pipe but i didnt mention it because most people dont have access to this. I have a local guy that does it for private aerospace companies. he does our stuff on the side and has good prices so if that would interest you let me know.

going with different headers will cause a loss of heat retention because steel disipates heat much faster than cast so expect a slower spool with headers. UEL will see top end gains and loss of low end. EL will see increase in power over the entire band more most headers. This is just a general statement and going with headers one must do alot of research to find out what they want.
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Old 04-26-2011, 09:28 PM   #6
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1.) Dump the mbc and get a 3 port boost controller. This will help spool by a couple of hundred (200ish) rpm - this is a no brainer..

2.) EL headers.. this will be a trade off.. +20tq but will lose some spool.. then there is sound as well..

Everything else is a waste of money... IMO
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Old 04-26-2011, 09:36 PM   #7
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Heat wrap is dangerous?
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Old 04-26-2011, 09:40 PM   #8
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Quote:
Originally Posted by jamesw95 View Post
Heat wrap is dangerous?
you would have to look up some pics but some wraps hold in the heat and cause increased rusting rate on the stainless and eat through the metal pretty fast. i have personally never had any problems so maybe its just cheap wrap or something.

on the plus side its cheap as hell and can be done in no time at all. ceramic coating your car will be down for prob two days minimum if the place is in town and you schedule the coating ahead of time so they r ready for ya.
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Old 04-27-2011, 01:27 AM   #9
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Thanks All for your inputs. I dont think ill be going over 18psi, I dont want to risk the engine nor the gearbox.

So this is my route till now (depending on my wallet):

1. Airbox elbow delete
2. shroud that fits the whole tmic surface
3. TGVs delte
4. Turbo, UP and DP heat wrap
5. 3" turboback
6. Port & coating (I have to do moren research on this)

Dont like headers and have my reserves on Meth/water injection.

by the way this is a DD car with autox twice a month and any other time attack.

More inputs are welcome.

THANKS to ALL again!
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Old 04-27-2011, 02:45 AM   #10
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sounds like yer tune sucks...bad...and you need bigger injectors 20psi to make any real power outa all that

I ran a 16g on my 2.0 to 22-23psi and it ROCKED...and it made way more than what you are making and I had 20psi by 3300-3400
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Old 04-27-2011, 02:58 AM   #11
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Quote:
Originally Posted by Uncle Scotty View Post
sounds like yer tune sucks...bad...and you need bigger injectors 20psi to make any real power outa all that

I ran a 16g on my 2.0 to 22-23psi and it ROCKED...and it made way more than what you are making and I had 20psi by 3300-3400
I dont know if my tune sucks cause my chart (trq, hp, boost and AFR) are smooth and perfect. I dont want to go higher than 18psi for now and bigger injectors? I have the STI ones and I know STIs can do 300whp with theese injectors so I dont think for now I need them but thanks for the input Ill consider it definitely.
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Old 04-27-2011, 05:30 AM   #12
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Quote:
Originally Posted by Peruwrx View Post
I dont know if my tune sucks cause my chart (trq, hp, boost and AFR) are smooth and perfect. I dont want to go higher than 18psi for now and bigger injectors? I have the STI ones and I know STIs can do 300whp with theese injectors so I dont think for now I need them but thanks for the input Ill consider it definitely.
d0000000000d...with those numbers....


I could beat your numbers with a td04.....you have a vf34 and all the rest of that, which should be able to get you 270-280whp EASY

EASY

yer tune sucks....and you wont get what you are looking for with a wimpy tune....no way
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Old 04-27-2011, 05:50 AM   #13
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Quote:
Originally Posted by Uncle Scotty View Post
d0000000000d...with those numbers....


I could beat your numbers with a td04.....you have a vf34 and all the rest of that, which should be able to get you 270-280whp EASY

EASY

yer tune sucks....and you wont get what you are looking for with a wimpy tune....no way
Ok thanks for your input, ill talk to my tuner and try to get the map.

Still looking for more opinions.
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Old 04-27-2011, 06:00 AM   #14
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what kind of gas you using in peru? how is the quality?

an intake, exhaust manifold, tgvs, 3 inch turboback will help spool and torque. add a EBCS to your system?
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Old 04-27-2011, 07:12 AM   #15
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larger tmic
3" tbe catless
equal length header

and retune
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Old 04-27-2011, 08:35 AM   #16
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OMFG so much misinformation in this thread it makes my head hurt.

Quote:
Originally Posted by WhiteBgeye02 View Post
do the small things. porting will help a ton.
define your definition of "a ton."

ime if he picks up 1-200rpm from porting he's done well. not a ton in my book, but every little bit helps.

Quote:
tgv deletes. i can do them for you or u can do them if you have tools. pm for a price.
while tgv deletes remove a potential restriction to airflow, that restriction is not an issue in the spoolup range of rpms.

Quote:
get a CAI. since ur running a tmic u r going to have some underhood heat soak. getting cooler initial air will yield better temps overall entering the engine and can run more timing. whatever happens to the maf can easily be changed and ur tuner should be able to make those changes in no time at all.
i haven't seen a CAI yet that is worth the trouble.

Quote:
the turbo can be pushed much further. 20psi with a little taper shouldnt be out of the question. a vf34 can make 300whp so lets see what ur tuner can do. my td04 makes alot more than ur making now and its stg 2.
why do people on this board persist in comparing dyno numbers as an absolute reference?

Quote:
get a shroud made or make ur own that fits the whole tmic surface. the stock one only covers like 75% of it so 25% isnt getting any forced air flow.
again, while proper shrouding is important, that helps low end torqe/spool in what way?

Quote:
Originally Posted by Locky1138 View Post
6. water/meth injection to help the low end.
ummm... how does ADI improve low end torque? most "dumb" on/off systems do not even kick on until past wastegate boost pressure.

Quote:
Originally Posted by WhiteBgeye02 View Post
a note on backpressure. one must find the correct ratio for backpressure and power output.
the correct backpressure is ZERO.

however, the effect of exhaust VELOCITY on low end scavenging (and thus VE, and thus torque) is important and often overlooked.

there is an inherent tradeoff to be made wrt torque below and above the boost threshold.

Quote:
going with different headers will cause a loss of heat retention because steel disipates heat much faster than cast so expect a slower spool with headers.
an issue very handily remedied by adequate wrapping and/or coating.

Quote:
Originally Posted by SHARP_DAL View Post
1.) Dump the mbc and get a 3 port boost controller. This will help spool by a couple of hundred (200ish) rpm - this is a no brainer..
probably one of the most wrong statements in the thread.

NOTHING beats an MBC for spoolup. NOTHING.

Quote:
Originally Posted by WhiteBgeye02 View Post
you would have to look up some pics but some wraps hold in the heat and cause increased rusting rate on the stainless and eat through the metal pretty fast. i have personally never had any problems so maybe its just cheap wrap or something.
ALL wraps hold in the heat. that's what they do. that's why you use it.

what causes rust is WATER. keep the water off and/or hot enough to vaporize and you won't get rust.

people should AT LEAST seal the wrap with high temperature paint. better yet is a membrane barrier such as foil.

Quote:
Originally Posted by fastwrx25 View Post
add a EBCS to your system?
again, WHY ADD AN EBC system?? his question was about SPOOL!

peru: if you want to get more detailed advice, you're going to need to post some ecu logs. eyeballing when the boost hits is notoriously inaccurate. at this point i tend to agree with what scotty mentioned (in his own special way ) about the quality of the tune, based only on the fact that your PEAK torque occurs below 4k rpms. that should definitely NOT be the case.
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Old 04-27-2011, 10:21 AM   #17
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the reason i warn against heat wraps on a DD:
they are fibrous cloth, designed to hold in heat and wrapped around the hottest parts of your exhaust.
IF you get oil on them, they can act as a wick, ignite, and potentially turn your car into a smoldering heap.

so, if you want to use them, do a very thorough check for oil leaks before hand, and inspect them often and thoroughly to be safe. personally, i would also keep a fire extinguisher in any car i was running with heat wraps.
imho, ceramic coating is the way to go.
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Old 04-27-2011, 10:24 AM   #18
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"ummm... how does ADI improve low end torque? most "dumb" on/off systems do not even kick on until past wastegate boost pressure."

if low end torque is your issue, i would assume you would set up a "smart"? system to deliver H2O/Meth where it is needed, and tune accordingly. not the best solution listed by any means.
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Old 04-27-2011, 11:22 AM   #19
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Quote:
Originally Posted by Locky1138 View Post
the reason i warn against heat wraps on a DD:
they are fibrous cloth, designed to hold in heat and wrapped around the hottest parts of your exhaust.
IF you get oil on them, they can act as a wick, ignite, and potentially turn your car into a smoldering heap.

so, if you want to use them, do a very thorough check for oil leaks before hand, and inspect them often and thoroughly to be safe. personally, i would also keep a fire extinguisher in any car i was running with heat wraps.
imho, ceramic coating is the way to go.
personally i think the oil leak = DIAF scenario is vastly overblown.

first, you start dripping that much oil you've got much bigger problems;
second, a foil overwrap almost completely eliminates the possibility;
third, i have not seen a ceramic coat yet that came close to the performance of a wrap+foil combo.
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Old 04-27-2011, 12:26 PM   #20
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nitrous in the lower rpm will get u more low end grunt, and spool you up faster. then you can put the noz sticker in your window.

But I know my auto-x course doesnt allow nitrus (saftey i guess?) so may not help you.
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Old 04-27-2011, 01:03 PM   #21
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Quote:
Originally Posted by jayman4312 View Post
nitrous in the lower rpm will get u more low end grunt, and spool you up faster.
Not allowed in autox

Quote:
Originally Posted by ride5000 View Post
while tgv deletes remove a potential restriction to airflow, that restriction is not an issue in the spoolup range of rpms.
but will help with torque right?

Quote:
Originally Posted by ride5000 View Post
the correct backpressure is ZERO.

there is an inherent tradeoff to be made wrt torque below and above the boost threshold.
Didnt understand. Should I put a 3" or stay with the 2.5"? what is the tradeoff?

Quote:
Originally Posted by ride5000 View Post
NOTHING beats an MBC for spoolup. NOTHING.
Thanks, you saved me some $$ there.

Quote:
Originally Posted by ride5000 View Post
peru: if you want to get more detailed advice, you're going to need to post some ecu logs. eyeballing when the boost hits is notoriously inaccurate. at this point i tend to agree with what scotty mentioned (in his own special way ) about the quality of the tune, based only on the fact that your PEAK torque occurs below 4k rpms. that should definitely NOT be the case.
How can I get the ecu logs? should I buy a tactrix cable? when should my peak torque occur?

Quote:
Originally Posted by fastwrx25 View Post
what kind of gas you using in peru? how is the quality?
Im using 94 here and it is normal quality for autox i put some meth direct on the gas tank.

Thanks for your replies!
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Old 04-27-2011, 01:08 PM   #22
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Quote:
I want more low-end torque and a quicker spool
Quote:
VF34
STI 550cc injectors
Walbro FP
Big top mount Intercooler
Samco turbo inlet hose
BOV Turbo Smart dual port
full catless
2.5" Turbo back
drop in oem kind K&N air filter
STI IC scoop
2.25" STI OEM axle back/ 3" HKS axle-back (depending on my mood for noise)
MBC
Protuned

This are my numbers on a mustang dyno @ 16.5psi:
16.5psi on a vf34 is a waste of time

the ONLY way to realistically improve your low end power is MORE boost, sooner.....THAT is all in the tune and in keeping the exhaust hot

depending on available fuel quality......you should be able to move the curve to the left and increase the ramp of the curve by a good bit

leaner and less timing or a bit richer and more timing below ~2500rpm

I think a bit leaner and less timing is better for hotter egt, sooner...IF...IF you can keep the heat in the exhaust
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Old 04-27-2011, 01:55 PM   #23
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Any chance you could run e85? Nothing i have done has given me the improvement of TQ and spool up that e85 can offer.

Mike
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Old 04-27-2011, 01:56 PM   #24
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Quote:
Originally Posted by Peruwrx View Post
but will help with torque right?
it will buy you a couple of footlbs. the effect will be most pronounced when mass air flow is highest. which is to say, peak power. at idle, torque will be the same.

Quote:
Didnt understand. Should I put a 3" or stay with the 2.5"? what is the tradeoff?
this is an age old question, and one that i didn't really answer.

something often overlooked when talking about spoolup is the definition of the term. most use it when envisioning a graph of boost vs. rpm.

however, it is my belief that a more important metric is boost vs. time.

if you had a choice between a steep boost vs. rpm, OR a steep boost vs. time, which would you pick.

i'd pick the latter EVERY time.

keep in mind this is from the guy who had a LOGGED 1 bar @ 2200 rpms on a td04 6+ years ago.. http://forums.nasioc.com/forums/show...82#post8438482

the point is that below the turbo cooking up, the engine is a NA engine. at that operating condition, exhaust gas scavenging is a tremendous benefit in providing more torque. more torque means the rpms go up faster. more rpms, sooner, means your turbo will be waking up sooner too. not necessarily seen on boost vs rpm, but DEFINITELY seen on boost vs time.

a while back, there was a lot of debate on tuning for spool up. ie, let's retard the timing, get the combustion occurring in the exhaust manifold. people debated on whether lean or rich was the way to go: lean was hotter, but rich had more combustion.

i threw out the idea that we should be tuning for max torque, "boost" be damned. in other words, get the car moving, get the rpms up, and the boost would follow.

ultimately a tuner i greatly respect agreed that this was the best approach, or at the very least the approach he himself used when he tuned. he has a LOT of experience, and did so back then too.

exhaust diameter becomes an issue at peak mass airflow. that's at peak power. if your issue is in the spoolup range, that's by definition not peak power. the design goals for mechanically tuning an engine are the same no matter what: get air in and exhaust out. however the methods to achieve these goals differ depending on the operating point.

people who like to generalize and oversimplify do not like to hear things like this. they prefer to throw out statements like "3" is better," failing to see the subtleties in the argument. if 3" is better, why isn't 3.5"? 4"? why not 6"?

the fundamental questions which must be asked are: at which point does the exhaust diameter become a non issue wrt peak power mass flow rates? at which point does the exhaust diameter become an issue wrt keeping velocity UP and scavenging UP? to throw out a diameter like it's x hp = y inches may be a useful STARTING point, but it's not the END.

i suggest you start by running with what you have now. if that is 2.5", then use that. do not spend money by throwing "bigger, larger" parts on the car in an attempt to get what you want. it rarely if ever works.

Quote:
How can I get the ecu logs? should I buy a tactrix cable?
imo every scoob owner who has an OEM ECU should have a tactrix cable. even if a reflash is never done, the benefit of datalogging cannot be denied.

Quote:
when should my peak torque occur?
peak torque in a turbo car is a combination of two factors:
the engines natural volumetric efficiency
the turbo's response
peak torque occurs when the product of the two is highest.

with MOST street (ie, smaller) turbos, they overlap quite nicely. this happens in the 4500-5500 rpm range. this is where a few things occur.. the engine is most prone to detonation, and the maf-based engine load (a log parameter) is highest.

drag/high power turbos are too large to spool up fully by that range, so they "miss" the natural VE peak of the engine. of course they give back by providing tremendous amounts of cool charge air and a minimum amount of exhaust gas backpressure up into very high rpms, allowing them to move lots of air mass and unlocking silly power. typical mods to re-align them include short runner intake manifolds, and top end work, particular cam profiles and timing. when THAT happens watch out... now you've got a monster. but it'll suffer in streetability, which is to say, lower rpm torque, and you will have to spend more time rowing gears to stay in the powerband. not only that but the loss of scavenging, and the long intake cam duration necessary for high rpm VE, will lead to a lot of reversion of charge. intake manifold vacuum starts getting unstable, idle suffers, power brakes don't work as well, etc.

the fact that your torque peak is so low leads me to believe that something else is going on. it SHOULD be in the high 4000s. a chart/graph of the dyno pull may help shed light if you have it. it may be that the peak occurs right there because of a little boost spike when it ramps up. however, rpm of the peak power figure tells me that you're holding reasonably good boost up into the higher rpms.

logs would reveal a lot of information about how the car is running.

on a side note, along the lines of getting the car moving, have you considered lightening the rotating mass? ie, lightweight flywheel, light crank pulley? how about light(er) rims/tires? you can also do what i (and countless others) have done and that is to purposely undersize the tire diameter to net a lower effective final drive ratio. all of these tricks, while not increasing "steady state" torque, nontheless increase EFFECTIVE torque, which is to say, the ability of the engine to accelerate the car's velocity.
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Old 04-27-2011, 01:57 PM   #25
Peruwrx
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Join Date: Jul 2010
Location: Lima, Peru
Vehicle:
2005 wrx
silver

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Originally Posted by GrimmSpeed View Post
Any chance you could run e85? Nothing i have done has given me the improvement of TQ and spool up that e85 can offer.

Mike
What is E85? I dont think they sell it here
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