40 replies to this topic

[Subaru_Bloke]

I need some info on mods and tune for my car, it's a 98 WRX STI 2.0 with a IHI VF24, other mods are full 3 inch from turbo back and pod filter.

 

-Is the stock TMIC going to flow enough for more power (just upping boost 2psi ( to16psi) for the time being via a profec B EBC

-Can I chip the ECU for tuning or can it be tuned? (I don't like the idea of buying an aftermarket ECU due to $ and it's a daily)

-At what point will I need to change the injectors? (parallel fuel rail is on the cards before any other mods)

-At what point is a rising reg required?

-Can anyone tell me the efficiency range for the VF24? I read it is not good to boost it over 17psi?

 

Thanks.

 

Brad.

[aekOne]

if you're only planning on 2psi increase i couldn't worry about any of that stuff.
 
my v4 sti powered legacy was running standard injectors, standard tmic, standard tune, cai, VF24, 3" tbe exhaust and ran 21psi all day every day and loved it

[Subaru_Bloke]

2psi increase is just for the time being, so thanks for letting me know I can do that without an issue.

 

However not too far down the track, I want to increase boost further than 2 psi, but I also want to tune it for the mods I have. Not much point in only tuning it just for the current mods, so if I install a rising rate, increase injector size and parallel the fuel rail, I can make more power, more efficiently right? What I am wondering is what the next weakest link is in the process?

[sbv]

Contact Emmanuel from Eculabs - I understand he can modify this ecu so you can tune it. Very reasonable price and you can get some great options (launch control, flat foot shifting, multi maps, flex fuel, live tuning etc). He's based in Paris, but I've have a very good experience with him so far and great ongoing support.

 

Not sure about capability of the VF24, but if you have the yellow 440cc injectors, they should be ok to around 190kw. You can have them hi flowed easy enough too. Mine are flowed to nearly 800cc and retain the standard 4 hole spray pattern, so should be fine for E85 and well into the 200+kw range.

 

Intercooler should also be ok around the 200 mark - but what are your objectives?

[Subaru_Bloke]

I will look into the ECU modding further then. With my S13, it was a simple matter of modding a chip on the ECU and it could then be tuned on the fly. This mod could be carried out by anyone with a soldering iron and a simple understanding of electronics.

 

I believe the VF24 is good for around 300-350hp (I believe the STI tune is around 260-280?) Which at maximum is 260kw.

 

E85 isn't on the cards as it's not highly available in bendigo.

 

My objectives are good power on a conservative tune. More fuel efficiency than power. I know that then it would make sense to stay stock, but with the VF24 being bigger than standard and it's ability to flow more, if I am making less power than it's efficiency range and it's not tuned for the mods I currently have, then I am most likely using more fuel than I need to be.

 

So I guess my objective power atw is around 210-220kw. I would guess that this would be a good spot for a daily driver?

[Josh.]

You will need at least a bigger turbo, injectors and fuel pump or a very happy dyno for 210-220.

I believe the VF24 is pretty happy with 18-20 psi.

[Subaru_Bloke]

My maths might be a little bit off, but if the VF24 flows 410cfm @14.7 psi, my conversion gets 210kw. I realise that's not atw, but it's not too far? My initial quote of 300-350hp was wrong, that was the VF23.

[Ben_20EJT]

if you're only planning on 2psi increase i couldn't worry about any of that stuff.
 
my v4 sti powered legacy was running standard injectors, standard tmic, standard tune, cai, VF24, 3" tbe exhaust and ran 21psi all day every day and loved it

agree with aek, my v3 sti gear was running 20psi daily and now 24psi on the built motor, stock jdm v3 computer and injectors but with a twist mount vf30 sti turbo.

[aekOne]

exactly. i honestly wouldn't worry. 15psi will probably see around 160kw atw which the stock everything will be able to handle.

 

if you've got your heart set on all that stuff, and it sounds like you do, by all means go for it but it really isn't required as your car will handle it fine as is.

 

save the money and spend it on something else fun like rims or beer

[CodeBurn3r]

I have a V3 with the VF23 and i run 17 - 21 depends how i feel..

ok i have a PowerFC but its all stock other than that and a 3in TBE its not even tuned at the moment and i ran around the 160KW at the last dyno and it was only running 15psi then.

 

if i had my time again.. i would talk to ESL http://www.enduringsolutions.com/ they mod the factory ECU and add in some awesome features at a really good price.

 

Dont forget to get a new Fuel Pump.. often forgotten but its a cheap mod for safety.

[Subaru_Bloke]

exactly. i honestly wouldn't worry. 15psi will probably see around 160kw atw which the stock everything will be able to handle.

 

if you've got your heart set on all that stuff, and it sounds like you do, by all means go for it but it really isn't required as your car will handle it fine as is.

 

save the money and spend it on something else fun like rims or beer

It's all just getting to understand what I need, and what I don't - but with regards to rims and beer... I want both! 

 

I have a V3 with the VF23 and i run 17 - 21 depends how i feel..

ok i have a PowerFC but its all stock other than that and a 3in TBE its not even tuned at the moment and i ran around the 160KW at the last dyno and it was only running 15psi then.

 

if i had my time again.. i would talk to ESL http://www.enduringsolutions.com/ they mod the factory ECU and add in some awesome features at a really good price.

 

Dont forget to get a new Fuel Pump.. often forgotten but its a cheap mod for safety.

So is it not possible to head to Melbourne and put my car on a dyno where a guy plugs in his computer and does a tune for my car specifically??

The reason I ask is because my S13 was able to do that.

 

I have a Walbro 255 Installed

 

The car pulls from boost to redline, and stays on boost, which I read something about the factory ones cutting at 5k??

 

I don't know if my ECU has been played with either, so that's something else I need to find out.

[Grant]

Can't tune a 1998 ecu unless you get someone to mod it, or you get an aftermarket ecu. It'll automatically adjust to the mods, but you won't get the maximum gains from the modifications you do.

Factory ecu's cutting at 5k rpm? Don't know where you heard that one lol.

[CodeBurn3r]

Haha yeah no

Ecu won't cut boost until well and truly over boosting. . Even then it's just fuel cut.
VIOLENTLY I might add.

The early wrx ecus were locked. They are able to adjust to some lean /rich conditions such as intake mods and exhaust etc but that's just more so the ecu adjusting timing a tad and the amount of fuel to compensate for the afr change but it's limited. . Think of it more of a.. "I'll adjust to keep from going bang" rather than. .
"Ooohh I can breath. . Better up the boost and make more power" kind of adjustment.

Really you have 3 ecu options. . Mod current ecu (ESL or eculabs)
Aftermarket replacement ecu.. PowerFC
And Piggyback (these usually just take your afr reading and "adjust"/lies to fool the ecu so it leans out) there is a tad more some of them do but most of the time is the cheap and nasty way to get a figure on the dyno.

Some do a bit more but most are pretty basic like that.

[Subaru_Bloke]

Thanks very much for all the info guys, this is all quite new to me, as when I got my S13 tuned (this is the only experience I've had) I went to dr. drift, put it on the dyno, pulled out my ecu, he said 'here, put this in, it's already modded'. I put the new ecu in, he plugged in his computer and made the new ecu parameters all while doing power runs, after an hour and $300, I had a car with far more power. It was a very simple and inexpensive trip for us.

 

Now, from what I understand, I need to send my ECU off for it to be modded, and be without my car for a while as both the businesses listed in this thread are over seas?

 

Then, when I get my ECU back, I can then take it to be dynoed, but only by someone that supports the reflash I get?

 

Does someone do it here, or are these guys just much better at what they do?

[CodeBurn3r]

I'm not sure about the other I've but esl sends you a board you install yourself. .
Car is still driveable bit not tuned any different.

Then you find someone who tunes 99> subarus.. Take your pick. .

Once the ecu is "chipped" its just like a later model ecu in the way it can be tuned. But contact esl to be 100%
They have really good support pre and after sales

[Subaru_Bloke]

I'm not sure about the other I've but esl sends you a board you install yourself. .
Car is still driveable bit not tuned any different.

Then you find someone who tunes 99> subarus.. Take your pick. .

Once the ecu is "chipped" its just like a later model ecu in the way it can be tuned. But contact esl to be 100%
They have really good support pre and after sales

I understand. It's quite expensive to buy one off ebay compared to the $100 for a chipped ECU for my S13 haha.

 

I bought a Profec B EBC. I wouldn't need this with a chipped ECU or?

 

I found this link to avoid confusion for others without a clue like me http://www.autospeed...ctronics&A=0895

[Adam]

I'm not sure about the other I've but esl sends you a board you install yourself. .
Car is still driveable bit not tuned any different.

Then you find someone who tunes 99> subarus.. Take your pick. .

Once the ecu is "chipped" its just like a later model ecu in the way it can be tuned. But contact esl to be 100%
They have really good support pre and after sales

 

That's cool.

[Subaru_Bloke]

I installed my profec ebc today, and although I didn't play around with the settings all that much, I was only getting to 12.5psi at redline...? I need to do some more checking, but it seems odd that I can't get full boost at 2900rpm. I have a IHI VF24, so as far as I know the initial boost setting can't be changed. Tomorrow I will turn off the EBC and see what I get stock, to make sure the boost controller is working (it is brand new)

[aekOne]

what did you have the target boost value set at? how steady has it holding 12.5? you might not have "full boost" under 3k but you should obviously be reaching it by redline

[Subaru_Bloke]

Had Target boost set to 14.5. Even so it starts boost at about 2000 and it doesn't build boost up high till near redline and only about 11psi. I don't have a bov fitted at the moment, and will fit it this week. Could that possibly be retarding boost from flutter? The only other thing I can think of (the guy before me removed the bov because he liked the flutter sound) is the fins could be damaged if it was running high boost without a bov. Is that a possibility?