solution

[dayofpain]

word

[MikeK]

I would wait until an actual dyno chart of that setup shows up somewhere.

[sperry]

I'm having a hard time seeing what that turbo is good for. It's an awful lot of monkeying around with crazy plumbing for what looks like what you get with a GT35R + meth injection.

But I will agree with going rotated... that's the way I'm leaning right now for my car. But I'm thinking GT3076R on 100 octane. Looking for 375-400 whp with a flat powerband from 3800-7200 rpm.

[dayofpain]

well there are actually alot of differences from a rotated 35 to the twr 70.

first and the absolutely biggest difference would be the fact that its twin scroll. it has anti-surge points in the intake. its also one of the very few kits that would bolt right into my current setup. all i would need is an aps turbo back. almost every other rotated kit has to use a standalone. and THAT is the biggest hurdle for me. it turns it from a 3500 dollar endeavor to a 5200 dollar huge deal.

[sperry]

Originally Posted by dayofpain

well there are actually alot of differences from a rotated 35 to the twr 70.

first and the absolutely biggest difference would be the fact that its twin scroll. it has anti-surge points in the intake. its also one of the very few kits that would bolt right into my current setup. all i would need is an aps turbo back. almost every other rotated kit has to use a standalone. and THAT is the biggest hurdle for me. it turns it from a 3500 dollar endeavor to a 5200 dollar huge deal.

Really, I thought the Perrin rotated kits have a blow-thru MAF pipe which you can tune for with any of the normal reflash setups like AP or EcuTek?

http://www.perrinperformance.com/pro...Kit?category=5

Is blow-thru hard or impossible to tune for with a stock ECU?

[dayofpain]

the perrin stuff is just using the big maf. its blow through but not made for the purpose its being used for.

and yeah i heard tuning blow through is really tough.

[knucklesplitter]

- Don't forget to add the cost of a crack-prone APS header in there - +$700.

-Don't forget to add the cost of that overpriced intake too - +$480!?!?!

-There are plenty of rotated set-ups running around without standalones.

- The APS rotated intake is a problematic design with an almost-90deg. bend just before the MAF sensor. People have been having trouble tuning idle and part trottle with it.

- Surge ports? So what - you can get surge porting on any of the GT30/35R's.

- Look at that extreme downpipe bend coming out of the turbo.

- This set-up has been available to the public for about a year and there are very few if any people putting down relatively impressive numbers (that they will show anybody anyway).

- If you wanna go big and go twin-scroll go for the Full Race manifold set-up (but it is BIG$$$)

[knucklesplitter]

Originally Posted by dayofpain

the perrin stuff is just using the big maf. its blow through but not made for the purpose its being used for.

and yeah i heard tuning blow through is really tough.

The stock intake for the Perrin rotated kit is a Big MAF (and it sucks). They also offer a replacement IC pipe that has a blow-thru set-up incorporated.

Mike at GST has tuned many blow thrus using the Perrin blow-thru tube and using weld-on MAF flanges that he bought from me. But yeah, it is tough to tune BTM for driveability.

[sperry]

Originally Posted by knucklesplitter

The stock intake for the Perrin rotated kit is a Big MAF (and it sucks). They also offer a replacement IC pipe that has a blow-thru set-up incorporated.

Mike at GST has tuned many blow thrus using the Perrin blow-thru tube and using weld-on MAF flanges that he bought from me. But yeah, it is tough to tune BTM for driveability.

Perrin took the hint from you and Mike apparently, and now sell their GT30R kits w/ a new blow-thru housing. Read the link I posted.

[knucklesplitter]

Originally Posted by sperry

Perrin took the hint from you and Mike apparently, and now sell their GT30R kits w/ a new blow-thru housing. Read the link I posted.

Oops, sorry... That's a nice improvement to the Perrin kit. Really nice - BTM and a CAI.

[WRX06TR]

somethingsomethingsurgeholessomethingsomething...

[badrover]

These turbos make me happy in the pants...

[knucklesplitter]

Ya know... those fancy surge "ports" don't even go all the way thru the housing. They are just basically deep dimples there to create intentional turbulence at the inlet and move the surge line a little on the compressor plot. BFD...

[renosubby]

I like your current setup but if you went bigger... I'd say a 35r with the the blow trough maf... Ed tunes the Blow through all the time and loves it!

[WRX06TR]

Here...

http://forums.nasioc.com/forums/show...ht=twin+scroll

you could do some Garrett Twin Scroll Setup, but I personally really like the APS.

[cody]

I know it worked earlier today, but the link in the first post give me, "Product not found!"

[EQ Tuning]

As for some useful info, I do prefer blow-through MAF housings with just about any FMIC setup. Here are some of the main advantages:

-- Air metering dellay
When using a FMIC with a standard pull-through type setup, you're adding a lot of volume between the MAF sensor and the throttle body that cannot be accounted for in the ECU. This added volume introduces an inherent delay in the air metering and fueling system. In simpler terms, the air gets metered by the MAF sensor, then travels through the turbo, through the long FMIC piping, and the big fmic core, before finally getting to the throttle body. Since the ECU isn't set up for this much volume between the MAF and throttle body, it ends up reacting to the metered air before that air actually gets into the engine. This causes inconsistent fueling and the common rich spike during quick boost transitions generally associated with FMIC's.

Using a blow-through setup moves the MAF sensor much closer to the throttle body and eliminates this delay. The end result of this is more accurate fueling, no more rich spike on quick boost transitions, and much crisper throttle response. Drivability in general is vastly improved if tuned correctly.

-- Intake temp measurement
In most Subaru's the intake temp sensor is integrated into the MAF sensor. When the MAF sensor is used in a pull-through arrangement, the measured temperatures are heavily influenced by underhood temps rather than intercooler efficiency. This means that the ECU has no idea how hot or cold the intercooler is. The FMIC may be completely cool and the air that's actually going into the engine may be near ambient while at the same time the underhood temps can be very hot. With a pull-through setup the ECU can only see the underhood temps which makes the built in IAT trim tables somewhat useless.

With a blow-through setup, however, the intake temps as measured at the MAF sensor will actually correspond to the temperature of the air going into the throttle body. So if the FMIC is nice and cool , the ECU knows about it and doesn't pull timing. If the FMIC gets heatsoaked, the ECU knows about this as well and the ignition maps can be adjusted accordingly to pull timing before knock occurs.

-- Intake/BOV setup
Finally, using a blow-through MAF allows you to run whatever you want on the intake side... you could even just run a screen on the turbo if that's your style . Since the MAF sensor is no longer there, there is absolutely no limit to what you can do with the intake. This is great for a lot of the rotated setups because you can now run a nice free-flowing 4" intake without any sort of restrictions.

This also means that you can run a fully atmospheric BOV without any of the associated side effects. Since the BOV is positioned before the MAF in a blow-through setup, the air that the BOV is venting has not yet been metered by the MAF sensor and won't have any impact on the resulting a/f ratio and drivability.



All of that being said, remember that the final results will really depend on the tuning. Blow-through MAF Setups take a slightly different approach to tune properly. I've seen some very poorly running cars with blow-through simply because the tune wasn't right. If done correctly, however, a blow-through setup will provide significantly better overall drivability, response, and performance than any FMIC setup with a pull-through setup.

BTW, Perrin developed their blow-through MAF based on some discussions and data I gave them after putting together a custom setup for a customer with a GT30R. We used the standard Perrin Big MAF intake housing as a starting point for this setup:



Thanks
-- Ed

[knucklesplitter]

....

[sybir]

Split to allow Phil's thread to continue.