Goal is less than 350WHP and fastest possible spool was the ultimate goal so I will be running a VF48, IWG...
I considered running a EWG but for the horsepower goal, could not justify it. As a compromise, I will run a Turbosmart IWG75 wastegate actuator with a 3 port controller (not sure which brand still waiting on a deal)
Was planning on sending the turbo to six star for simple porting and but I think i'll take it a step further and get the full rebuild with billet compressor wheel. With the porting should be good for about a 400-900 rpm spool improvement over the stock unit and a good 20-30 hp across the board.
They have a ball bearing upgrade in the works, and so I am considering holding off until closer to my delivery date.
Complete setup will be pushed with a ceramic coated Perrin ELH and first gen Cobb (cast) catless uppipe.
IMHO this will be pretty much the best VF48 setup money can buy.
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I had a Saabaru 2.0 and it was an auto. I wanted the faster spooling turbo. I did a lot of research and went with a VF35 from a STI V5 RA. They were in Aussieland and South Africa. Has the housing for quickest spool. Had it ported and polished and coated. It was faster, but still not fast enough. I went 3 port boost solenoid and a 38 EWG a couple years later. Better response, but still not quick enough response for me. It was too laggy. Crazy fast and would hold 24 PSI, but the engine would last if I drove like that every day. If I were to do it over I would go twinscroll all the way. I don't think the Newer Legacy design would fit with the layout, but with such a short path that would be the best for lag. My kit will be 5 years away. I've thought about it and I will probably be just NA, even though a supercharger would really be fun, but a lot of work.
I would just get a gtx or efr for the funds you are looking at spending on upgrading a vf48. Besides a gtx and efr will spool even better and be way wayy more reliable.
Also not sure what sort of crazy spool you are expecting out of an ej20.. They really just weren't designed with low end torque and low speed spool in mind but sustained thrashing at 6500-8500rpm (thus why the prodrive rocket antilag came into being).
How quick a spool are you looking for, it is not just a turbo that creates quick spool, the cam profile, intake, exhaust, and head port sizes, and the way the tune brings /holds boost are all key. In general a smaller turbo will spool up faster, but some turbos just have the best of both. If you just want sub 350 and fast spool, the twinsroll vf37 is a great setup for a head ported, camed 2.0 Usdm wrx. Or the Vf 43 or 48 etc on the wrx stock works well. If you were building the engine the gt52 spools fast and makes about 450whp on 23 psi.
I know Marty, your building one with 700 or more,crazy, but wicked cool.
Last edited by metalmaker12; 04-18-2013 at 08:00 PM.
How quick a spool are you looking for, it is not just a turbo that creates quick spool, the cam profile, intake, exhaust, and head port sizes, and the way the tune brings /holds boost are all key. In general a smaller turbo will spool up faster, but some turbos just have the best of both. If you just want sub 350 and fast spool, the twinsroll vf37 is a great setup for a head ported, camed 2.0 Usdm wrx. Or the Vf 43 or 48 etc on the wrx stock works well. If you were building the engine the gt52 spools fast and makes about 450whp on 23 psi.
I know Marty, your building one with 700 or more,crazy, but wicked cool.
<-This.
Also have to deal with exhaust gas temps (and what the headers, up/down pipe and turbine can handle). How much exhaust back pressure. if you are using avcs. compression ratio. etc. etc. lots of stuff to consider. Also a turbo may spool super quick but depending on where in the RPM band you want to run it it can run out of "breath" and effectively you've got a quick spooling engine that dies right when you are wanting to push. Turbo choice shouldn't be done based upon just (this turbo makes 350hp i.e. ~35lb) but on the compressor map matching with driving style, intended use and where in the RPM band you'll be running. The reason for compressor and turbine shape uniqueness along with their associated housings, is to create a turbo that fits varying unique needs. If you don't know how to read a compressor map and plot it out against rpm, load and various other parameters essentially you are swinging at a pinata in the dark. Turbo has to match engine both of which have to match what you want out of your power band. Having the best vf48 setup doesn't mean much if everything isn't matched up. What are you doing about engine management? is this 350whp from an awd point of view or a 2 wheel drive point of view, because those are very different numbers.
Also what will you be using for fuel? 91, 93, E85, E90, E98, something crazier?
Should add be careful with what headers you use when looking at wraps and coatings. Those can cause heat retention that the alloy in the header isn't capable of taking without becoming brittle and cracking.
Also not sure what sort of crazy spool you are expecting out of an ej20..
Not Looking for "crazy" spool, more like factory TD04 spool with much more power, I've driven a stock vf48 and on a EJ20, and it's not bad... if it can be improved by 500 rpm why not.
Originally Posted by Evan78
What does a VF48 typically make with just a turboback and tune? What years/models does/did it come on?
VF48 came on the 2008-2011 STI are you thinking about a 2.0 or a 2.5?
Originally Posted by Matty_STi
Also have to deal with exhaust gas temps (and what the headers, up/down pipe and turbine can handle). How much exhaust back pressure. if you are using avcs. compression ratio. etc. etc. lots of stuff to consider. Also a turbo may spool super quick but depending on where in the RPM band you want to run it it can run out of "breath" and effectively you've got a quick spooling engine that dies right when you are wanting to push. Turbo choice shouldn't be done based upon just (this turbo makes 350hp i.e. ~35lb) but on the compressor map matching with driving style, intended use and where in the RPM band you'll be running. The reason for compressor and turbine shape uniqueness along with their associated housings, is to create a turbo that fits varying unique needs. If you don't know how to read a compressor map and plot it out against rpm, load and various other parameters essentially you are swinging at a pinata in the dark. Turbo has to match engine both of which have to match what you want out of your power band. Having the best vf48 setup doesn't mean much if everything isn't matched up. What are you doing about engine management? is this 350whp from an awd point of view or a 2 wheel drive point of view, because those are very different numbers.
Also what will you be using for fuel? 91, 93, E85, E90, E98, something crazier?
Should add be careful with what headers you use when looking at wraps and coatings. Those can cause heat retention that the alloy in the header isn't capable of taking without becoming brittle and cracking.
-Matt
obviously all of these are good points, and I have seen vf48 plots as well as seen the way actual cars with similar setups perform, pretty confident in the choice. Although there are always some unknowns in dealing with translating all these figures to a lighter RWD vehicle. As far as the GTX mentioned before, thinking it may be overkill, but i'll look at the numbers again. Tune will be initially on 93 with an E85+ map coming later. (protuned accessport)
Not ready to spend the money on the killer b so 304 SS will have to do for now. I don't plan on wrapping the header.
A well stocked beverage fridge is the key to any successful project.
How quick a spool are you looking for, it is not just a turbo that creates quick spool, the cam profile, intake, exhaust, and head port sizes, and the way the tune brings /holds boost are all key. In general a smaller turbo will spool up faster, but some turbos just have the best of both. If you just want sub 350 and fast spool, the twinsroll vf37 is a great setup for a head ported, camed 2.0 Usdm wrx. Or the Vf 43 or 48 etc on the wrx stock works well.
Fastest spool possible was a poor choice of words. I should have just said improved spool time.
Twin scroll would be nice but replacing headers, uppipe and turbo is just not something i'm ready for. If I did come across a low mileage twinscroll setup I might jump on it.
The heads on the motor just have a mild port cleanup and stock cams. Cams might be down the road but would have to be a cam with good midrange, maybe a 256 rather than a 264 but I don't know if i'll need it.
I have these parts now, when the car is put together, if I hate it... hey we'll make changes.
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Basic breakdown of OEM Subaru turbo's used as well as aftermarket turbos in following posts, basic characteristics, RPM spool and cfm. This is what I used when I went with the 35. more have been added to the list since I needed it.
You were talking about replacing the headers with EL in your first post. I think the twin scroll would be totally worth it with having to swap out the exhaust manifold and UP.
You were talking about replacing the headers with EL in your first post. I think the twin scroll would be totally worth it with having to swap out the exhaust manifold and UP.
That is a real nice reference.
I already have the header and the uppipe, otherwise I may have considered twinscroll or EWG.
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missed this one... I wouldn't expect a Blouch 16G to spool before 3400 rpms... I am HOPING to spool under 3000... but we shall see. A ported one might get me closer but then the price is up to $1000+
Correct me if I'm wrong though. My buddy had an 18g on his 2.0, great top end but the spool wasn't there. Never driven the 16g but I imagine it would be better.
Six Star has a deal right now on the rebuild, for $579 and I picked up the actuator for $160 so including the value of the turbo if I do the billet wheel I'll have about $1200 into this guy.
foolish? maybe... but keep the ideas coming.
thanks.
A well stocked beverage fridge is the key to any successful project.
VF48 came on the 2008-2011 STI are you thinking about a 2.0 or a 2.5?
Got it, thanks. I was just asking because I didn't know any OEM turbo was capable of much over 300whp, although I haven't kept up on stuff for the last several years. I am using a 2.5 for my build and possibly an APS SR-40 that I have lying around, unless my build partner has something better or gets us hooked up with something newer.
Came across a great deal on a VF36 today, complete with headers, up-pipe, and downpipe. From what I'm reading, it's just about the fastest spooling factory setup you can get. With a twin scroll setup, ball bearing, and titanium compressor wheel it achieves full boost by about 2800rpm. That site listed above showed it would hit 325whp which makes my 300whp goal easily attainable. Should be fun.
Jason, those are the numbers i'm hoping for. nice find... the titanium part is shrouded in mystery... that was Subaru PR... either way that turbo setup will be slick.
if you are ready for twin scroll overload read this thread
Thanks for posting that thread. Lots of good reading.
I'm a Nissan and Mitsubishi guy as far as Japanese imports, Porsche guy at heart and that's where my roots are. But learning all this new stuff about Subaru parts has been an experience to say the least, so many little differences depending on year, month, time of day, LOL.
From what I've seen so far, at 15psi the VF36 will make 300-320whp (depending on dyno of course) on an AWD setup, so theoretically 300-325whp on a AWD Subaru should be roughly 325-350whp in a FWD setup. So for me it's absolutely perfect, because it will reach the full 15psi at less than 3000rpm.
But doing a complete twin scroll conversion might not be what you are looking for. I originally wasn't going to do it, but fell into a good deal so I went for it. It sounds like the turbo you are looking at is going to be great, especially if you do the ball bearing upgrade.
Last edited by bnr32jason; 04-23-2013 at 06:51 AM.
Came across a great deal on a VF36 today, complete with headers, up-pipe, and downpipe. From what I'm reading, it's just about the fastest spooling factory setup you can get. With a twin scroll setup, ball bearing, and titanium compressor wheel it achieves full boost by about 2800rpm. That site listed above showed it would hit 325whp which makes my 300whp goal easily attainable. Should be fun.
This is amazing. Congrats dude! I can't wait to follow your build thread.
My build isn't going to be anything special. The main differences from mine is the use of Japanese market parts and that I've "junkyardyed" my way to a donor, instead of using a single donor. But if you want to follow, here it is: http://thefactoryfiveforum.com/showt...ry-April-2014) I need to update it with pictures of the parts I've gathered together but I'm still cleaning them. I'll try to update some today.
I'm now wondering what the VF36 or VF37 would be like on a 2006 2.5 with AVCS.
The VF36 supposedly reaches full boost at 2800-3000rpm on a 2.0 STI with AVCS, and I would think that an extra half liter would bring that down at least 400-500rpm. So full boost at potentially 2300-2500rpm sounds pretty nice. It should feel almost like a V8 powerband. Hopefully the AVCS would work to help it breathe at the top of the RPM range, but I don't rev much over 6500rpm anyways (for longevity/reliability reasons.)
Anyone think there would be something fundamentally wrong with running such a "small" turbo on a 2.5?
If the VF36/37 will make over 300whp, I wouldn't call it small turbo. Not big by any means, but it doesn't sound like a bad match. Subaru has sold the 2.5L with the TD04 that will only make 230whp. I know there's plenty of 2.5 owners that have run them, but don't recall what the dyno charts look like.
Exactly. this is not a map of a VF36 on a 2.5 ... those dynos should not be hard to find.
And I don't think I'd call that a small turbo either. I'm just saying this is what happens when someone says "I want a super fast spooling turbo, I'll put a td04 or (similar small turbo) on my 2.5"
Look at the hp though. Lowest line on this graph is 50hp.. each line is 50hp so at 2500rpm its making about 195fhp and at 6000rpm 240fhp
they stop the dyno at 6k because power drops off after that. That gain over the entire powerband just wont feel that sporty.
In comparison a wrx will gain about 100fhp in the same rpm range.
Last edited by longislandwrx; 05-03-2013 at 11:58 AM.
Reason: put*
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I read a post by Clark Turner on nasioc about a car he tuned running a 2.5L with TD04 and external wastegate (ewg) vented to atmosphere. He said it was one of the funnest cars he's ever driven because spool was so fast and the EWG (along with not being plumbed back into the exhaust) helped with top end power. Obviously there are downsides to that setup (noise, pollution), but I'd love to take a test drive.
Craig (mechie3) ran the stock TD04 on his 2.5 2006 WRX. He has done a lot of other things, but all ESP legal for autox. I forget his whp and wtq, but it's listed in one of his threads and if he sees this I'm sure he'll chime in with what it was/is.
243whp and 351wtq on a dynapak dyno
Stock block
Stock turbo (td04) @ 21psi.
Torque peaked @ 3100 rpms and dropped steadily to redline.
HP peaked at 3500rpms (?) and was flat until 5500 rpms at which point it dropped.
Awesome for autocross
Really good for a DD (no downshifting to pass, instant power, etc)
Kind of boring for drag racing (though I find that boring anyways) as you could feel the top end being anemic.
Found a pic. It says flywheel, but it's wheel measurements (flywheel of the dyno).
So comparing Mechie's plot to dscoobydoo's STi w/ vf36, the TD04 comes on about 500 rpm earlier but at 6500 rpm is making about 145 ft/lb torque vs 245 for the vf36.
I've attached a very quick overlay of the two charts.
Since vf36/vf37 only came on Japanese cars, they're not very common here, but should be available from a number of sources if you're willing to pay market rate. I seem to remember a complete setup (turbo, header, uppipe, downpipe or downpipe flange) running around $1500 or maybe a bit more retail price for a used setup from an importer.
Thanks for all the information. I already got the complete VF36 setup from a low mileage STI Spec-C, and after some further research, it may be one of the only parts I can actually use out of all the stuff I've bought here. (Spoke to a WA state inspections person and they want receipts and documentation for damn near everything). That's why I'm asking about the 2.5 setup, as I may go with that from 818Donors and just sell off all the stuff I bought here to fund that purchase.
So from looking at the dyno charts, it seems like it will meet exactly what I want from my 818. I don't want to have to rev it to the moon to get the power, I want to be lazy (and safe) with it and change gears around 6000rpm. It's not going to be a race car, it's going to be a fun street car and occasional fun trackday car.
In the one thread they were talking about an upgraded internal wastegate. Which would be a good one to go with?
You can get a cheap donor, use that title and all you need is a recipe for the jdm sti intercooler and and intake manifold, the engines have no vin on them, they will not be looking for the if you have a title. They just want your money, they don't know what to look for when it come to usdm or jdm. You can say the rest of the parts came from the donor, how can they prove otherwise, you could also get some recipes made up for those parts etc,,, use the jdm stuff, it is awesome and more unique.
You can get a cheap donor, use that title and all you need is a recipe for the jdm sti intercooler and and intake manifold, the engines have no vin on them, they will not be looking for the if you have a title. They just want your money, they don't know what to look for when it come to usdm or jdm. You can say the rest of the parts came from the donor, how can they prove otherwise, you could also get some recipes made up for those parts etc,,, use the jdm stuff, it is awesome and more unique.
That's not the impression I got from the WA state inspector people. They are saying I need to have receipts for every major component used on the car and that many of the components need to have numbers on them that can be searched in their database. I asked him about Japanese parts and he said if they can't verify the part wasn't stolen, they won't approve my registration.
I've read on other kit car forums that the registration process in Washington is one of the worst in the country, so maybe this is evidence of that.
Have you already read the Washington laws? This page from the Washington State Legislature says the following (emphasis mine):
(c) Proof of ownership for all major parts used in the construction of the vehicle. Major parts include the frame, engine, axles, transmission, and any other parts that carry vehicle identification numbers;
(d) Bills of sale or invoices for all major components used in the construction of the vehicle. The bills of sale must be notarized unless the vendor is registered with the department of revenue for the collection of retail sales or use tax and must include:
(i) The names and addresses of the seller and purchaser;
(ii) A description of the vehicle or part being sold, including the make, model, and identification or serial number or the yard number if from a wrecking yard;
(iii) The date of sale; and
(iv) The purchase price of the vehicle or part;
There is nothing that says it can't be from a private party.
I've read over everything on the WA site it's just that I don't have receipts because most of the parts I've acquired have been through small junkyards and friends. Things work a little differently in Japan, when you buy a part from a small junkyard they normally don't even give you a receipt or anything. Theft isn't a big deal here and junkyards are loaded with cars since they have a different mindset over here about vehicles. It's common to see perfect condition running cars that are only 6 or 7 years old sitting in a junkyard pile. Then deals from private parties say they must be notarized, that's not gonna happen, LOL.
I'll tackle this issue when I get there, but for now I'm just researching if I do need to get new components if a 2.5L block is worth it over the 2.0L. Right now, from looking at the dyno sheets it seems that the VF36 + 2.5L with AVCS is pretty much ideal for what I want ("lazy" power which is accessible throughout the rpm range).
When you are ready to register, whatever parts you don't have receipts for, just "sell" them to me first and I will "sell" them back to you 10 minutes later with a notarized receipt.
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Originally Posted by metalmaker12
