300 WHP Goal

[fahr_side]

So Fahrside, one can really get a 20whp bump just by swapping the exhaust headers? That's quite a nice bump in power.

Yep, and honestly I was skeptical. I had always thought you wouldn't see an increase in power until basically the restriction the header presented was more than the turbine and turbine housing. The stock header is more restrictive than I thought, and even on a small turbo like a 16G or VF-52 it does indeed make it worthwhile going to an ELH.

 

A few years back I did some tests on my own car with several turbos for a builder planning a brand play, so I got to test some different combinations. This is while I had the stock manifolds.

 

My own BNR 16G in the VF-40 housings.

A TD05H-16G with a 7cm2 housing and billet compressor.

Same turbo swapped into an '8cm2' housing that measured out around 8.4cm2.

 

In 7cm2 the 16G was faster to spool than my BNR but fell down much earlier. In 8.4cm2 it did slightly better on the top end than the BNR but had much later spool and poorer response. Peak power on all three was right around 280~290whp so the biggest difference was in delivery. The 7cm2 16G felt most like my stock TD04 (very similiar in size and potential vs. your VF-40) with very early abrupt spool and very fast response, only to fall down well short of redline. The biggest housing had more of that 'big turbo' feel about it with spool coming much later and very smoothly, and power holding up the best toward redline.

 

I did some other tests with various billet 16G compressors, different blade counts and aero design but nothing was as obvious in the results as the different exhaust housings.

 

The builder would have given me any of these turbos for my trouble tuning for them and providing test results but I instead opted to keep my BNR. I think that 7.5cm2 P18 housing is perfect for this application and the little extra power from the 8cm2 housing didn't make up for the hit either in spool or response.

 

A few months later I added the ELH and kept my spool, adding torque over the whole rev range, and 20whp at peak. I don't remember the bump in torque exactly but it was more than the bump in power. At no point in the rev range did I lose anything.

[The 2Fiver]

Are you modding for power or ricer points?

 

Ricer points and round numbers, we want the best of both worlds.

[xtea]

Another turbo people should consider is the boosted performance x500. Its 300 cheaper then the dom 1.5, same top end or little better and 200 rpms faster spool.

 

https://forums.nasioc.com/forums/showthread.php?p=45116107

[Rhitter]

Another turbo people should consider is the boosted performance x500. Its 300 cheaper then the dom 1.5, same top end or little better and 200 rpms faster spool.

 

https://forums.nasioc.com/forums/showthread.php?p=45116107

 

Looks like a really good option. Will strongly consider this as my next turbo: http://bcpdirect.com/Forced-Induction/Turbochargers/bcp-x500-turbo-sti-wrx

http://bcpdirect.com/image/cache/data/products/X500-vs-stock-turbo-500x500.jpg

 

I love these two quotes from Unabomber

 

8/7/2016

ASSEMBLED in Michigan. You need to read more. And you are playing Russian Roulette by going with an unknown turbo maker and odds are your have no idea what 54lb/min means. Have you read the post titled Turbo FAQ and have you had a conversation about turbo selection with your tuner? Methinks the answer to both is no and that's not how this works.

 

5/16/2017

These guys are wearing me down....I have a feeling I'll be getting one soon.

[boxkita]

Agree with Max, the VF-52 is much smoother than the VF40/46. Significantly less of a torque wall.

 

But, I made the mistake of driving a Porsche turbo and a new M4. My car feels so slow now. Sure it's "fast", but it's not "holy, shit I can't accelerate because this car is too fast fast."

 

 

 

Everything I read about them seems like they are great (although, a couple tuners on Nasioc say they are too small for the 2.5 block). However, Fahr-side's experience with their customer service makes me not like them. Maybe they just don't "do" email.

 

swap your wheels for light weight wheels. Then swap tires for something lighter. It doesn't make your car Porch fast but it does make a difference on acceleration.

[Rhitter]

swap your wheels for light weight wheels. Then swap tires for something lighter. It doesn't make your car Porch fast but it does make a difference on acceleration.

 

Yep, heavy stockers with heavy winter tires...is not appropriate. Probably going to get PF01s soon.

[boxkita]

Yep, heavy stockers with heavy winter tires...is not appropriate. Probably going to get PF01s soon.

 

I'm a big fan of the PF01. It was my race wheel of choice. A tad heavier than the RPF1, but stronger and had the bead locker pattern to keep it from slipping.

[The 2Fiver]

I did put an SPT catback on the car for primarily ricer reasons, but I love the way this car sounds.

 

Fully aware it's illogical, but I have less of a specific power goal in mind other than "more than I have now" and am more interested in the powerband I end up with (keep most of my current low-midrange, but actually keep pulling out through to redline)

 

I'll advise against the 3" catback with the VF-52. I was seeing boost spikes on the few tuning pulls I ran that were signifigant enough to get a fuel cut. Stock catback is back on, cut is gone. Magnawoah with 1k miles will be for sale

[shralp]

I have a 3" catback on my VF-52 set up and when my new forged motor went in I had Cobb/Surgeline re-do my dyno tune. They saw boost creep and recommended I pull my Cobb CAI off and put the stock airbox back on. Had to chuckle because they recommended pulling a Cobb product off the car and putting the OEM one back on. Apparently pretty much all VF series turbos tend to experience boost creep with aftermarket CAI's as the wastegate on these turbos just isn't big enough. The problem was the car was breathing too well. Guess that shows that unless you're going for huge power a CAI is just added expense and bling. Wonder if a aftermarket CAI with a smaller exhaust or stock airbox with a 3" exhaust is a equal comparison to keep things safe? hmmm...

[The 2Fiver]

I found a post that stated a 3" Tbe will result in some creep on most wrx/sti's and applied that logic to my car. I don't want to port the turbo or run an EWG so I guess it's a quick fix for me. Fwiw, I have a Perrin inlet and afta-maf hose mated to a stock airbox and panel filter.

[Mike07LGT]

Kinda getting off topic from the original post. Dom Turbos are alittle overkill for a 300whp daily driven setup, which is what the original poster wants. Not saying it cant be done, but cost wise its a bit much imo. Have you decided what route you want to go OP?

[Rhitter]

I think it's because the answer to OP is VF52 or 16g will pretty much get him where he wants.

 

Then everyone enjoyed the off-topic discussion.

[xtea]

Because everyone wants moar eventually.

[oODanKNesSOo]

I've long been against elh, as I LOVE my boxer rumble... Reading this thread has me second guessing though.

 

I guess one has to ask is 20hp worth losing the sexy purr of nameless 5" mufflers??

 

 

Fwiw, vf52 and e85 tune underway should have me at or above my 300+ power goals so meh...

Do uelh yield anything besides under car bling? What about port and polishing the stock em?

[fahr_side]

You may see a little gain on a big-tube UELH with a larger turbo. Like I said, the stock manifold is quite restrictive. I've tuned customer cars with the stock manifold and 18G-range turbos and then later had the customer install an UELH (against my advice) and ask me to check it over again. Spool got worse, power and torque peaks got no higher but moved up the rev range. So yeah, pretty pointless mod if you ask me.

[oODanKNesSOo]

Port and polish stocker? I was talking to a Scooby mechanic and he recommended keep the stockers and get the little Grimmspeed mid section thingy that connects each side of exhaust manifold.

 

Maybe when I'm over the 400hp mark I'll give up my rumble... Right now it doesn't seem worth it

[fahr_side]

Port and polish stocker? I was talking to a Scooby mechanic and he recommended keep the stockers and get the little Grimmspeed mid section thingy that connects each side of exhaust manifold.

 

Maybe when I'm over the 400hp mark I'll give up my rumble... Right now it doesn't seem worth it

Porting and the GS crossover have never been proven to show any gains. They stopped offering that. Waste of time and money. Either keep the stock manifolds as they are, or get an ELH.

[skibum0203]

So you think this test they ran on the crosspipe was not good proof of the gain?

 

http://legacygt.com/forums/showthread.php/hiflow-crosspipe-vs-oem-crosspipe-dynos-90418.html?t=90418

[fahr_side]

Independent testing did not support that result. Go ahead and spend the money if you really want to know.

[1-3-2-4]

I have a 3" catback on my VF-52 set up and when my new forged motor went in I had Cobb/Surgeline re-do my dyno tune. They saw boost creep and recommended I pull my Cobb CAI off and put the stock airbox back on. Had to chuckle because they recommended pulling a Cobb product off the car and putting the OEM one back on. Apparently pretty much all VF series turbos tend to experience boost creep with aftermarket CAI's as the wastegate on these turbos just isn't big enough. The problem was the car was breathing too well. Guess that shows that unless you're going for huge power a CAI is just added expense and bling. Wonder if a aftermarket CAI with a smaller exhaust or stock airbox with a 3" exhaust is a equal comparison to keep things safe? hmmm...

 

I found a post that stated a 3" Tbe will result in some creep on most wrx/sti's and applied that logic to my car. I don't want to port the turbo or run an EWG so I guess it's a quick fix for me. Fwiw, I have a Perrin inlet and afta-maf hose mated to a stock airbox and panel filter.

 

I had boost creep on I think it was a 18G that the last owner had.. the car had a catless DP and no tune.. but besides that I thought boost creep was just right for having a catless DP... I just ordered a hi-flow cat DP but i will be going for a VF52 for the time being it should put me in a decent spot.