Hey guys looking at doing a custom project and was wondering if there maybe a stock turbo out there that will make around 400whp on a 2.5L?
You can get somewhat close on E85, but not gas. Straight up 400 wheel HP will be hard to reach but I believe I've seen as much as 380 with E85 on the stock turbo. You can only run so much boost before you get out of the efficiency range of the compressor wheel and it starts blowing hot air.
400whp is more 20G and up territory. Also goes without saying you need a lot of supporting mods to get there.
Um, please point me in the direction of the stock turbo STi making 380hp on e85.....difficulty: No P&L and No Crawford dynos.
I'm posting from Tapatalk so I can't see which particular car the OP has, I assumed we were talking about current generation WRX/STi with a VF52. Now I'm not an expert, I'm not speaking from experience, only what I've seen from browsing the forums. I believe with low 20's psi, supporting mods, E85 and an aggressive tune the upper 300 WHP range is not out of the question. Of course the dyno used will make a difference.
Thank you for the replies. I was wondering if the STI turbo would be able to push it, but it looks like I'm going to need a 50mm+ T3 turbo.
How so? I was merely curious as if a stock Subaru turbo would be capable of making the desired figures.
you said it looks like you will need a 50mm+ T3 turbo to get the desired power you were asking about. What Im saying is you will need alot more then just the turbo. Will need bigger injectors fuel pump catless down pipe things of that nature.
Thank you for the clarification but in my first post I stated it was for a custom project and am well aware of the parameters it takes to make the desired output. As space and the turbo would be the limiting factor in the equation I was looking for a small framed turbo with a high cfm volume.
There are quite a few turbos in the stock frame that can push 400+ Are you looking to achieve 400 on 91/93 octane or race fuel or ethanol?
I was looking to stay on 91 and will be adding a methanol injection system to be activated by pressure sensor over 6psi as the engine in this project has a fairly high compression ratio. I do plan on changing out the pistons in the future for something in the more boost friendly range of 9.0 to 1 so I would like at turbo that would be able to work well at 8 psi as well as 18psi efficiently. I was looking at a Garrett 60-1, as it looks like it would fit my needs, but have never seen one in person so I don't know how big the compressor housing is to see if it would fit..
You'd be better off just getting a stock location 8cm 20G. You can find them everywhere, and I've always felt that they were the best match for the stock 2.5L in terms of powerband and daily driveability. As far as the 2.5L stock engine, the compression ratio is already boost friendly. IIRC the stock CR sits somewhere around 8.5:1 which is a highly boost friendly setup. Or am I getting the impression that you are doing this to a 2.5L N/A block?
Here's a VF turbo making 400WHP and running in the 10's (in a stripped GC racecar): http://forums.nasioc.com/forums/showthread.php?t=2563127 I would agree that typically the VF39/VF48/VF52's are not going to make 400WHP, even on E85. On E85 it is more typically for VF setups to do the low to mid 300's WHP. I think a TD06 20G is a good option for meeting the 400WHP goal (on E85). A 60-1 is getting quite larger. Close to 35R size. It should make 400WHP easy, but will be laggy for that power level.
I get that impression too. Sounds like this is a N/A block with the meth injection and low psi. I think OP needs to give more info on the car/engine to get better advice for the project as a whole but I agree that a TD06 20G with 8cm hotside is a great size for the 2.5L with his power goal in mind.
Again, reliability comes into play. A VF turbo EJ257 is going to be pushed hard to get 400 out of it for more than just quartermile passes in a drag car. I've been down the 60-1 route, you're spending a little more for the GT35R but you're moving your power band to the left 500-1000rpms without losing the right side of the chart. Sounds like not alot, but in terms of drivability and usable power under the band, it's a huge difference. Really though, I think anyone that has driven, had a ride in, or owned a 20G STi would agree, while it wont make the biggest power out there, it is almost a perfect match for that motor. It almost feels like an OEM solution. Power band comes on strong and stays that way through the band, but the curve is smooth and manageable. It isn't some punch crazy large frame monster, and it isn't some piddly snail wheezing out at 5500 RPMs. It seems like the perfect turbo for a daily driven car.
It is in fact a NA engine that I plan on making forced induction, but it isn't a Subaru engine unfortunately. It is a 5L BMW engine that I was looking to add a pair of Subaru flanged turbos on as they are, in my opinion, easier to fabricate a manifold for. I understand that I'm comparing a boxer engine to a conventional v style engine but the bore and stroke are similar along with a similar head design and rpm range so these engines should give me a realistic model of what to expect by roughly -.5 when I drop the compression. This will be a fluids project for me at school.
You said a pair. Is this a sequential or twin bank setup? For twin bank setup, the VF's would likely work just fine.
Twin bank setup with log style manifolds, so pretty basic. Are any series of VF turbo that will be more reliable than the others?
VF39's have a sordid history of cracked housings, but they are going to be the most plentiful and least expensive of the bunch by a huge margin. Probably cheap enough that if you did crack a housing, you could easily find another used one to roll with, and still be out less than if you had spent that money on one pair of expensive turbos. Other than the 39, I'm not sure of what is readily available in the VF market, I haven't really shopped for a VF turbo for about a decade.
Like readymix said the VF39 will be the cheapest and most readily available but almost all have the wastegate crack issue. VF43 is the same as the 39 but they fixed the wastegate boost creep and might not crack as much but they are rare because only used in 2007 STI. I would look into used VF48's if you can't find good VF39's because they are plentiful (used in the 08+ STI) and will probably be in better shape than the VF39's kicking around the used market. Check Nasioc or IWSTI, I am sure lots of 08+ STI owners have swapped to bigger aftermarket turbos. Otherwise, the VF52 is plentiful (used in 09+ wrx) and is the same size as the VF48 but they have the Legacy GT style housing. If you don't care about what the flange for the intercooler looks like then the VF52's will probably be a little cheaper than the 48's and you should go that direction. The project sounds interesting! Please update with pictures as you progress.
Or just go with that! OP, if you go with an 18G I will recommend Kinugawa turbos to save some money but still keep the quality. Also, which BMW engine are you using? If it is a V8 the only 5L I know is the S62 from the old E39 M5 with an 11:1 CR! That is pretty high compression for FI but an awesome engine!
if twin turbo charging with that compression ratio, running lower boost should be able to obtain 400whp (assuming he'll be using meth injection to help)
The dynamics of reaching your goal change based on what you're starting out with. Are you trying to acheive 800HP with a 5.0 BMW engine or 400HP?
Someone knows their BMW power plants! It is a S62. As the engine sits in NA form it's only 41whp shy of 400 but with the end goal with a sleeved block and lower compression pistons is to achieve 800whp. I was just hoping to find a turbo that wouldn't give out on me before the drivetrain as it looks like the axles and prop. shaft wouldn't handle much more than that. This is for a class so the process will be highly documented and it will be one of a very small number of turbocharged S62's. For the short term I'm less concerned with power, mainly being restricted by the comp. ratio, as I am with a reliable and functional system.
I would just do twin VF's. They're dirt cheap. Two of them (used) are cheaper than one (new) 18G. You can swap in 18G's or 20G's later if you'd like.
Awesome! I love me some S engine. I wish I could have afforded an E90 M3. I want to see this when it's finished. It will be hard to limit your boost at such a low pressure with all that displacement and high revs, what are your wastegate/boost controller plans? Also I might be worried about the rod bearings while it is stock so I would keep the revs high when mashing the pedal. Low oil pressure and so much torque can kill. Another reason to go with bigger turbos (18g or 20g size) is the turbos won't spool as quickly and is likely nicer on your engine than a peaky turbo like the vf39.
Don't worry the new m3's price will drop like a rock once the new m3 & m4 are released. Boost control is going to going to be controlled by the piggy back I'm going to attempt to install on the car. The waste gate is going to be an issue, especially in naturally aspirated form. I calculated that I would need a 40mm waste gate for each turbo. I was thinking of removing the actuator and welding the internal gate closed on the turbo. I have been looking more closely at a set of 20g's as they would leave more room to play with. My rod bearings were changed last fall along with the timing chain guides as they are known to be issues on this engine.
To be honest I would suggest going with a t3 or t4 flanged turbo. There are way more turbo options and if you need to go larger or smaller in the future it is much easier to change. For what you're trying to do I would suggest looking into something like a Borg warner 251 or 256. You can get them brand new very cheap and they are very reliable and cheap to mod if you want to go to larger wheels. You can get s200 be new for 630. Also smaller frame turbonetics journal bearing turbos are great for the buck. Always Garrett to but you pay more.
Vband inlet turbos. Precision and Garrett has options. Borg is going to be working with tial for new vband housings also. Twin 5858?
[quband turnNuke, post: 745603, member: 337"]Vband inlet turbos. Precision and Garrett has options. Borg is going to be working with tial for new vband housings also. Twin 5858?[/quote] Ya vband turbines are really nice to. Easy to adjust and clock whatever direction needed. Precision turbos are very nice to just more expensive.
Thank you all for your input! I did make a decision this weekend and got a pair of BW 56mm T3 turbos. Hopefully these will do the job for my situation and for those that wish to see the project unfold, I will post a link to the M5 board where I will do the documentation when more of the parts arrive. Thank you again
