OEM Sidefeed to Topfeed TGV Conversion (05/06 to 07+ Conversion)

[gkstar]

Just now, Tehnation said:

I think that might be when the sti came out with the 2.5 liter thats why things get squirrely. 

I will take more photos. The stud aligns with one of the attachment points on the intake manifold. 

[gkstar]

41 minutes ago, gkstar said:

I will take more photos. The stud aligns with one of the attachment points on the intake manifold. 

So the 92-X had the EJ20 like any WRX from 03-06 but were topfeed. Where the STI in 04-06 are sidefeed like the LGT. Here are some more photos including intake manifold set on one TGV. If there are more angle requests lmk I can take them later 

 

[Tehnation]

Now I wonder if the electronics are the same and send the same signals as ours. You try connecting your harness to it? Number of pins may be the same but the connectors may be different. 

[m sprank]

Did not read everything recently posted.  But the pix are sidefeed TGV's.  Also, it is well known that you can use a TGV from a plastic manifold with a metal manifold (you oblong the TGV mount holes to line up with the metal manifold studs).  But it does not work the other way around. 

 

EcuTek is the easy answer. 

[Tehnation]

You are right those are sidefeed! 

Isn't it easier to just use a tgv from a 02-05 wrx? Apparently those are plug and play I thought. 

I gotta track down a set from a junkyard, but its gonna be a pita cause carpart can't search for tgvs so I gotta do it locally which means..... it will take a while. 

I still have my old sidefeed tgvs, I wonder if the electronics would fit in the top feed tgvs? 

[m sprank]

They are not plug and play to my knowledge.  They might be to an STi manifold, but not an LGT plastic manifold.  I never tried to swap from my Bugeye to my LGT's.   Electronics are different iIrc. 

Edited February 5, 2023 by m sprank

[gkstar]

2 hours ago, m sprank said:

Did not read everything recently posted.  But the pix are sidefeed TGV's.  Also, it is well known that you can use a TGV from a plastic manifold with a metal manifold (you oblong the TGV mount holes to line up with the metal manifold studs).  But it does not work the other way around. 

 

EcuTek is the easy answer. 

So I will hold the L on TGV’s. Should have been more careful with purchase.

But why will the tgv from a metal manifold not work on a plastic manifold. After market tgv’s do not make that distinction. 

[gkstar]

2 hours ago, Tehnation said:

You are right those are sidefeed! 

Isn't it easier to just use a tgv from a 02-05 wrx? Apparently those are plug and play I thought. 

I gotta track down a set from a junkyard, but its gonna be a pita cause carpart can't search for tgvs so I gotta do it locally which means..... it will take a while. 

I still have my old sidefeed tgvs, I wonder if the electronics would fit in the top feed tgvs? 

Search intake manifold. They are sometimes listed as intake manifold lower. 

[m sprank]

I have pix, but it will take some time to dig them up. Last time I remember performing the mod (plastic manifold tgv to sti manifold) was 2010, lol. 

I think I had it backwards before as well. You oblong the inner manifold bolt holes to align with the threaded tgv holes. 

I only recall buying one set of tgvs. That was GS way back in 2008 or so.  I dealt with a bunch of different "plastic" tgvs that all either warped or melted down. I refused to sell them due to my bad experiences. I personally ported and deleted literally hundreds of sets of tgvs.  I even used to sell a block off plate kit I made in house. But I dont recall the distinguishing nomenclature for aftermarket tgvs.  You only gain 1-2 whp from a delete with porting. The desire to replace sidedeed with topfeed but not delete is a new EPA game. 

Its late.  I will try to answer your question in entirety with pix asap.

 

[Tehnation]

Yea i'm about done with these plastic tgvs, I went through 2 sets. The plastic warps and bends, especially in my case where I'm pulling the intake manifold like every other month. The bolt holes start to sink in cause if you don't torque them down enough they leak but the torque requirement is extremely low.... it was good thought but seems it was not practical which is why I only see ones made from aluminum or some kind of metal now. The only good thing was you got what you wanted, top feeds and delete, for a cheap price. I paid like 150 or 175 for a set, had enough leftover to get a spacer as well. 

[m sprank]

Just now, Tehnation said:

Yea i'm about done with these plastic tgvs, I went through 2 sets. The plastic warps and bends, especially in my case where I'm pulling the intake manifold like every other month. The bolt holes start to sink in cause if you don't torque them down enough they leak but the torque requirement is extremely low.... it was good thought but seems it was not practical which is why I only see ones made from aluminum or some kind of metal now. The only good thing was you got what you wanted, top feeds and delete, for a cheap price. I paid like 150 or 175 for a set, had enough to get a spacer as well. 

Amazing how even phenolic spacers failed to stop the warp and melt down. I went up to 12mm with no luck. 

Daughters at sleepover. Time for me time. Bye for tonight.

[Tehnation]

On 1/3/2023 at 2:50 PM, Underdog said:

I clicked through the iWire page and found the following parts that could be used:

2-pin TGV actuator receptacle pigtail

3-pin TGV sensor receptacle pigtail

5-pin combined TGV assembly plug pigtail

 

On 1/12/2023 at 8:22 AM, Underdog said:

I looked up the TGV I/O info in the manual and confirmed that the sensor polarity is flipped between the 05-06 and 07-09 setups.

05-06: 3.8-4.9V (Closed), 0.2-0.9V (Open)

07-09: 0.4-1.2V (Closed), 2.8-4.6V (Open)

The good news is that it looks like the actuators operate simply by toggling 12V and ground between the terminals to open/cose.

 

On 1/4/2023 at 1:31 PM, shralp said:

I had a similar issue this fall when I had a compression check done on my track car as it was potentially showing signs of getting tired and in need of a new short block, (the shop I took it to totally phoned in my comp check, gave me low readings and so I took it to Cobb Surgeline for a new motor.  They did their own compression check and the motor is FINE.  But that's a whole 'nother story).

Anyway, new motor was going to mean a new tune which meant my Top Feed IAG TGV deletes were going to have to get tossed.  Since the newly released IAG TGV's had not been released yet, I looked at OEM options to gut.  The '06-'08 Forester XT TGV's are 3 pin Top Feed and will drop right in.  I pulled the butterflys out and did a light porting job to smooth out and remove material that the butterfly rests on when its closed.  Kept the rod and chose not to remove the partition wall as it wasn't really necessary at my power levels.  For those not wanting to pay for the new EPA compliant IAG TGV's this is a good low(er) cost option.

...and in the end I didn't even need to get them, now they are just sitting in a box  

 

hmmm, so the easiest and simplest route is just getting a tgv from an 06-08 forester XT? These have to be like unicorns used, car-part cant find any intake manifold parts for the XT. 

And so far the next best option is to get a tgv from an 07+ lgt or sti, I am assuming all these have the 5 pin which is the issue? Cause the 5 pin we gotta take our 3 and 2 pin connectors, depin them and then just stick them into a 5 pin connector. But the problem here is the polarity is different for 3 pin sensors? I hate electrical engineering.... probably cause I suck at it, its why I went mechanical lol, but couldn't we just swap the power and ground to get the right voltage or would that blow up the sensor? Can you adjust that variable with a tune? Seems like something you should be able to do with the cobb or opensource. 

[m sprank]

Meaning the fix is the same as it has always been. Tune.  But now that Cobb no longer supports the tuning function go EcuTeK.  Sorry, cant recommend opensource, had too many issues. 

[m sprank]

As soon as you offer a retail product the EPA will crush your balls in a vice.  Ask Cobb.  Why do I not have a shop anymore?  4 seperate EPA licenses, CARB regulations and FINES. 

 

[subisubisu]

12 minutes ago, Underdog said:

Agreed, so if you’re locked in to the AP, which has vastly superior capabilities for tuning the car compared to OS, then using sidefeed TGVs with a top feed adapter rail may be your best bet to avoid a CEL. Otherwise you’re stuck in the muck with the rest of us until a workaround is developed - which frankly would be doable with $10 in relays and resistors, but I’m not going to spend the time prototyping it unless someone can help take it to the next level, and so far we’ve had no takers. 

 

8 minutes ago, m sprank said:

As soon as you offer a retail product the EPA will crush your balls in a vice.  Ask Cobb.  Why do I not have a shop anymore?  4 seperate EPA licenses, CARB regulations and FINES. 

 

As I read Underdog's post, the "workaround" would be to allow proper TGV operation with the newer units on older ECUs, which expect a different "polarity", which is the word being used but is causing some confusion.

Why would the EPA break out the ball crusher for something that enables the emissions equipment to work properly?

[m sprank]

1 hour ago, subisubisu said:

 

As I read Underdog's post, the "workaround" would be to allow proper TGV operation with the newer units on older ECUs, which expect a different "polarity", which is the word being used but is causing some confusion.

Why would the EPA break out the ball crusher for something that enables the emissions equipment to work properly?

Because it has not been tested and approved.  Cost of said testing and approval will cost far more than any possible profit.  You are modifying an emissions control device from its factory installed and approved design, you must get govt authorization.  You must have thought America was FREE.  LOL. 

[shralp]

Kinda wished I had been forced into trying these ‘06 FXT TGV’s a few months back when my motor was supposedly going bad. But hey, grateful that it actually wasn’t so that saved me thousands for a new motor   Guess I’ll just hold onto these until I need them in the future. Got mine from Subie Recycler in Colorado. 
 

still don’t see why the new IAG deletes are not an option? Looks to me like everything in this package is pure hardware and you swap all your motors, plugs, etc off your OEM TGV onto the IAG unit. If it’s all the electrical guts from your existing TGV plugged right back in to your existing plug then why wouldn’t it work? What am I missing here?  

[gkstar]

1 hour ago, Underdog said:

One of the potential workarounds is a module that emulates proper tgv operation, rather than making the 07+ style functional, so Mike may be referencing that. However it’s likely that any device that touches emissions equipment at all would be a potential liability for the developer, so I stand by my comment about not offering a retail product. That does not preclude a workable and accessible solution, just means we need to be deliberate about what that looks like. 

the APS adapters(or similar) would have been first choice and most elegant, but alas I fumbled through an attempt to make the older top feed tgv's work with our manifold. Ordered a real set of 02 wrx ones to look at how much off the bolt holes are that @m sprankfor my curiosity. Will keep the thread updated once they arrive

[shralp]

14 minutes ago, Underdog said:

I think you are assuming there are adapters to mechanically mount the older style sensors and actuators, which doesn’t seem to be the case. 
 

ahhh I see.  What that sucks!

[seanyb505]

Epa is concerned with your car having the equipment it was sold as new. Since most people go backwards when they mod, it's easier to make a blanket law "no tampering with emissions equipment." 

As for carb, I could be saying something pretty ignorant but I don't think they have jurisdiction in about 49 states, right? 

[KZJonny]

I think I'm following along reasonably with the conversation here, and what will and won't work for various reasons.

Just for clarity tho, if you're not chasing big power, where every possible restriction in the path is a real problem for air/fuel flow...

- what is the downside to just using aftermarket top feed fuel rails that adapt to the side feed TGVs? It is mainly just cost, or is the adaptor rail a less than ideal configuration. I ask this because there is the obvious selection in top feed injectors, and the are less expensive to service... But, I also have a spare set (or potentially 2 spare sets) of 550cc yellow tops which could be de-capped etc.... for more fuel if needed.

- Is a TGV delete kit really so much more flow than removeing the shaft and butterflies from the stock bodies and leaving the motors and sensors on the car, which (I thought) kept the DTC codes from occurring. Yeah, I'd love to be able to have another input to the stock ECU for oil pressure or whatever, but it's not that critical to me, and my analogue oil gauge is good enough...

My interest was mainly becaue I could get a set of rails/injectors/tgvs for next to nothing, but as discussed they won't work. And while I understand what's being discussed in terms of an elec eng solution to the problem, my understanding of electronics ends at what you need to know to have an Amateur Radio license, so grade school stuff by comparison to a university education on it...

We have no emissions testing or follow up on passenger cars in Ontario, so I can do whatever I please as far as that goes, and don't need to answer to anyone about it. That said, I still want to have a clean running car, and have a catted DP etc....

[m sprank]

17 minutes ago, seanyb505 said:

Epa is concerned with your car having the equipment it was sold as new. Since most people go backwards when they mod, it's easier to make a blanket law "no tampering with emissions equipment." 

As for carb, I could be saying something pretty ignorant but I don't think they have jurisdiction in about 49 states, right? 

14 other CARB states plus the District of Columbia, currently.

[Tehnation]

23 minutes ago, KZJonny said:

I think I'm following along reasonably with the conversation here, and what will and won't work for various reasons.

Just for clarity tho, if you're not chasing big power, where every possible restriction in the path is a real problem for air/fuel flow...

- what is the downside to just using aftermarket top feed fuel rails that adapt to the side feed TGVs? It is mainly just cost, or is the adaptor rail a less than ideal configuration. I ask this because there is the obvious selection in top feed injectors, and the are less expensive to service... But, I also have a spare set (or potentially 2 spare sets) of 550cc yellow tops which could be de-capped etc.... for more fuel if needed.

- Is a TGV delete kit really so much more flow than removeing the shaft and butterflies from the stock bodies and leaving the motors and sensors on the car, which (I thought) kept the DTC codes from occurring. Yeah, I'd love to be able to have another input to the stock ECU for oil pressure or whatever, but it's not that critical to me, and my analogue oil gauge is good enough...

My interest was mainly becaue I could get a set of rails/injectors/tgvs for next to nothing, but as discussed they won't work. And while I understand what's being discussed in terms of an elec eng solution to the problem, my understanding of electronics ends at what you need to know to have an Amateur Radio license, so grade school stuff by comparison to a university education on it...

We have no emissions testing or follow up on passenger cars in Ontario, so I can do whatever I please as far as that goes, and don't need to answer to anyone about it. That said, I still want to have a clean running car, and have a catted DP etc....

Years ago 05-06 people like me who wanted to go top feed but didn't want to spend 1000 bucks or so on a fuel rail kit figured why bother when you can go to the junk yard grab some top feed fuel rails for like 50 bucks, then buy a topfeed tgv delete kit for like 200-400 bucks wtih enough change to get a phenolic spacers. The tgv delete wasn't really the main purpose it was more a byproduct, like if i'm going topfeed why not just buy aftermarket deletes its basically free horsepower at that point(compared to buying a 1000 dollar kit), not much if any but like I said it's free so why not.  So for less than 500 bucks basically you could go topfeed and get the tgv deletes and spacers, saving you 500 bucks towards better injectors. It was just purely more efficient economically to go that route. Now fast forward and it may come back to bite us in the ass lol. Back then the tgv was out of site and out of mind so the electronics never came into the picture, cause you just turn it off! 

[Tehnation]

21 minutes ago, m sprank said:

14 other CARB states plus the District of Columbia, currently.

 

40 minutes ago, seanyb505 said:

Epa is concerned with your car having the equipment it was sold as new. Since most people go backwards when they mod, it's easier to make a blanket law "no tampering with emissions equipment." 

As for carb, I could be saying something pretty ignorant but I don't think they have jurisdiction in about 49 states, right? 

How do the carb laws work? Seems every damn state is jumping on the bandwagon, including mine. I thought it didn't apply to our 4th gens cause they are before 2010 or 2011 or something. 

Anyone know how exactly it affects people in those states for 4th gens? 

[m sprank]

I am not familiar as WV does not participate. In Cali the old grandfather clauses had run out long ago, like 1972.  

Modified cars are no longer registerable. Smog testing can now determine if ecm has been modified from stock.  Visual and computer.  Its a shit show. Shops are working as "speak easys" trying to stay in business.