CovertRussian's 05 LGT Build Thread

Funny cause about 3 months ago, literally both of my cars had the same failure occur at the same time (upper plastic tank leaking at the seams). I just went with the TYC13091 radiator. ~70$. Also replaced the radiator and turbo tank caps with OEM, including hoses and thermostat.

Funny cause about 3 months ago, literally both of my cars had the same failure occur at the same time (upper plastic tank leaking at the seams). I just went with the TYC13091 radiator. ~70$. Also replaced the radiator and turbo tank caps with OEM, including hoses and thermostat.

 

I did the same thing with my LGT at the time. The cheap TYC tank work just fine and had no issues.

Yeah I just replaced my radiator as precautionary with the Denso one. I tried the CSF but it is modeled after the wrx/sti stile turbo return so I had the same issue as you but I didn't feel like making adapters. So I returned it for the Denso which had the proper sized port. For the price and DD of the car, can't beat it.

 

Anyway, I'm not convinced that going to thicker radiator would help, there are a few threads that discuss the pitfalls of thicker cores (takes much longer to cool them down).

 

That's a good point.

 

On same topic and per mwiener2's post you quoted, I recall watching a tear down of B58 engine out of 2020 Supra on Youtube, where one of the features is lack of traditional thermostat that is replaced by a valve controlled by ECU. ECU decides how much it needs to open based on temperature and operating mode. Much more flexibility than a traditional thermo-mechanical thermostat.

Edited October 29, 2019 by SubOperator

I know that a lot of times TYC actually ships Koyo's, but in this case I simply didn't wanna risk it. Plus the Denso STI was only $80, so not worth the hassle. Now if I knew that WRX one would actually have the bigger port, I would have spent the extra $10 to get Denso WRX one instead.

 

That's a good point.

 

On same topic and per mwiener2's post you quoted, I recall watching a tear down of B58 engine out of 2020 Supra on Youtube, where one of the features is lack of traditional thermostat that is replaced by a valve controlled by ECU. ECU decides how much it needs to open based on temperature and operating mode. Much more flexibility than a traditional thermo-mechanical thermostat.

 

I'm a little surprised we are only now seeing it in production cars. Some of our SR20 guys have been running electric water pumps since late 2000's. With those electric pumps, they double as thermostats since they can stay off until the car is warmed up.

 

I heavily considered one myself, reduces rotational weight and water pump replacements are a pita on the FWD SR20's (about the same amount of room as GDs have for spark plugs)

I changed into a WRX cooler 3 year ago, worked great

Tommy, I moved your post into its own thread at covertrussian's request, his thought (which I agree with) is that you'll get more views that way and have a better chance at finding a solution. Good luck!

 

New thread location: https://legacygt.com/forums/showthread.php/spring-identification-question-280869.html

 

I've been sitting on this mod far too long because I was getting conflicting data. Turns out my culprit was trying to apply barometric pressure to a turbo car. I was going retest everything, do MPG tests, etc, but at this point it's been almost 2 years and I don't feel like digging in again, so here's the pictures and data...

 

This all started with the Intake Depression (Vacuum) Testing, as part of that testing I noticed that my first gen Perrin inlet had pretty high inlet depression at the turbo. Plus after installing the Custom 3" Cold Air Intake, I wasn't thrilled about going from 3" to 2.75" and wanted it all to be 3".

 

 

Parts:

3" Aluminum Elbow

2.4" to 3" Offset Silicon adapter (I used Agency Power AP-GDA-174-225, but I don't love it)

1.25" Alumium Pipe (for BOV)

PCV/Breather Ports

Aluminum Brazing Rods

 

I got the idea for doing a custom 3" inlet back in 2014ish when I had to fix the stock broken inlet. The aluminum 3" L that I had fit so well under the manifold:

 

I didn't get a chance to really put the plan in motion until I did the TGV deletes in 2018. At this point I cut the pipe to fit and made modifications to the manifold/TGV for smoother flow.

 

The TGV housing was digging into the AP coupler quite a bit, I think the coupler could be better molded to avoid this:

 

Here is a before and after grinding the TGV's and manifold:

 

Test fitting a 3" pipe, you can still see the TGV dimple inside the coupler

 

Next issue is with 2005/2006 bypass valve hose butting into the coupler, it needs to be stretched way forward.

 

First I marked off how far inlet pipe went into the silicon coupler, then I drilled a blow off valve hole as close to that line as possible, to reduce BPV hose stretching. Now I don't have the equipment to weld Aluminum, but I did have good success with using Alumiweld like brazing rods.

 

After brazing was done I used a die grinder to expand the BPV hole, this way the brazing rods wouldn't drip inside, plus better flow from BPV.

 

For breathers I quickly drilled and tapped 1/8NPT ports for breathers and pressure drop testing. The sharpie mark up front shows about where I should cut it if I want to use stockish intakes, but since I'm all custom now I left it full length

 

I had to unbolt the BPV hose dragged it out to the front of the manifold and then put it back in place, lets just say it's quite a stretch. I should either do a custom hose or get a 2007+ pipe.

 

All installed, don't mind my "temporary" breather hoses, which have been on there for almost two years now...

 

I hooked up my manometer to the port closest to the turbo (roughly the PCV port location), went for a drive and my jaw draw dropped with how little total pressure drop there was compared to the Perrin inlet (Perrin first, Custom Inlet second).

 

Now I was interested to see what the stock inlet would do like! I dug it out, but since it was partially ripped I had to get creative on attaching it.

 

 

As you can see above, the inside corner is a sharp 90* instead of a smooth radius bend, this is horrible for airflow along with the accordion style section.

The stock inlet HAD to flow worse then the Perrin inlet right? Not according to the manometer, here are all the inlets and the depression measurements plotted:

 

Onto the run data...

Here is Engine Load, MAF Voltage, and Mass Airflow graphed. Did anyone ever tell you that you don't need to tune for inlets because they are post MAF? Well they are wrong if you get a good inlet...

 

Finally the street dynos after tuning: like I said in the beginning, at this point I was still trying to apply barometric pressure to my dynos and was also over smoothing the runs, this made the differences be negligible. Since it's a turbo car, no barometric pressure should be applied and smoothing should be left at 1 for most accurate data. Thus for this graph, I only applied the temperature based corrections and weight corrections:

 

First, the Stock Inlet (red line) spikes up at 6k RPM, this is wrong and happens a lot with my logs, which is another reason it can be hard to get good logs. I would say stock inlet is probably 280whp worth. Interestingly enough the stock inlet was knocking Perrin's level of timing, I don't recall reducing timing helping power either.

 

Perrin Inlet (blue line) did VERY good for such high inlet depression, especially compared to stock which has less depression but probably flows worse.

 

Finally the Custom 3in Inlet (green line) saw slightly faster spool but it also wanted around 2* less timing across the whole map. Now while I would love to think that the inlet alone gained 25whp peak, I would say it's probably being optimistic (remember dynos can have up to 5% variation, which is 15whp at my power levels!)

 

Overall the new inlet seems to be a success for not much money!

I'm inspired....honestly though, I am surprised a similar solution hasn't already been commercially available.

Can you build me one?

It's like an hour or two or work total and $15 elbow . I will say that getting the stock airbox and S bend to fit on this would probably be pretty hard, the bigger radius-ed inside puts it a little forward of the stock inlet. This is why I just stuck to running my 3" CAI.

 

Also the woosh BPV sounds are pretty awesome with this setup

So I don't really quite understand all the tuning graphs yet. Would you say the perrin inlet is still an improvement over the stock inlet even with the pressure differences? Or would you say it appears to be a negligible difference? What do you think causes such a severe drop on the perrin inlet?

So I don't really quite understand all the tuning graphs yet. Would you say the perrin inlet is still an improvement over the stock inlet even with the pressure differences? Or would you say it appears to be a negligible difference? What do you think causes such a severe drop on the perrin inlet?

 

Keep in mind that I have a gen 1 Perrin inlet, which I think could be collapsing under my turbo's vacuum. Newer versions seem to have a better metal ribcage to prevent it form collapsing. Now, I'm not fully sure if mine is collapsing, thus increasing the pressure drop, or it's increasing the velocity, which according to the Bernoulli Principle would lower pressure (and in turn increases vacuum & pressure drop).

 

Power wise, it does seem like the Perrin has a slight edge over stock, but since my stock was starting to rip beyond fixing I couldn't really test more. In my opinion, the possible 5-10whp gains are not worth the $250-$300 premium! Now if you need a replacement, since our stock one rips by you looking at it, I would do a hard inlet any day, since it's so easy to install on our plastic manifold EJ's.

Edited November 10, 2019 by covertrussian

I'm inspired....honestly though, I am surprised a similar solution hasn't already been commercially available.

 

APS 3in hard inlet. It’s about $240.

APS 3in hard inlet. It’s about $240.

 

Still way too much money for something as simple as the inlet, $ per HP is just not worth it . Inlet & intake should be sold together for $300 ...

always interesting stuff in here!

i m interested in developing something similar . the first for me is to make a box where your filter plunge in the fender , to really cut the heat around , cause is to close from the collector .

I thought about doing that when I first built the intake, but after two years of mostly city driving, I'm not sure it matters. Hot air rises and the intake sits relatively low, so IAT's don't really increase by that much.

 

On the flip side, as soon as you start moving IAT's drop real quickly (compared to stock). Which, now that I think about, is because stock intake is gobbing up air from higher in the engine bay.

Yea my stock inlet tore, mostly because I'm a brute who doesn't know what they're doing. I got a used gimmick motor sports inlet and maf hose. I'm not super stoked on the fitment and would like to use the engine cover so was thinking of a smaller inlet.

 

How do you think a smaller diameter inlet would fair with the stock intake? The stock inlet seems about the same size all the way through so a smaller but smoother bend hard inlet should still be an improvement I'd think. Not sure what size it would need to be for the engine cover though. Would likely still use the silicone maf and stock airbox.

 

 

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Can you modify the engine cover to fit the bigger inlets by any chance?

 

As for smaller inlet, I may test 2.5" vs 3.0" on my turbo SR20 in the future. Mostly because I don't need to add BOV ports to that one, so would be easier to do.

I thought about doing that when I first built the intake, but after two years of mostly city driving, I'm not sure it matters. Hot air rises and the intake sits relatively low, so IAT's don't really increase by that much.

 

On the flip side, as soon as you start moving IAT's drop real quickly (compared to stock). Which, now that I think about, is because stock intake is gobbing up air from higher in the engine bay.

 

i agree with you . when car is moving a lot of thing change .

but just for the pleasure of fabricating

i agree with you . when car is moving a lot of thing change .

but just for the pleasure of fabricating

 

Fair enough and typically I would happy to do another mod, but lately (basically all of 2019) has been occupied with house projects. I've been hand digging a new driveway, so the cars have been getting the bare minimum love .

Fair enough and typically I would happy to do another mod, but lately (basically all of 2019) has been occupied with house projects. I've been hand digging a new driveway, so the cars have been getting the bare minimum love .

 

 

 

Wow that sounds difficult and tedious and probably rewarding if it comes out well. My attempts at house projects so far have been sub par.

 

I'm not sure about modifying to fit. The gimmick is shaped like the cobb, where the maf tube is bigger at the air box side, tapers slightly to the inlet, gets huge at the inlet, and tapers into the turbo. I never took fluid dynamics, but that seems silly. No flow walls though, I guess that's good?

 

I'm actually hoping to look at the engine cover but I'm leaving it off during break in for ease of access. But after I'm going to look at if it will fit or what I can do to it.

 

 

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I'm not sure about modifying to fit. The gimmick is shaped like the cobb, where the maf tube is bigger at the air box side, tapers slightly to the inlet, gets huge at the inlet, and tapers into the turbo. I never took fluid dynamics, but that seems silly. No flow walls though, I guess that's good?

 

It reduces pressure drop across that sharp 90* bend without having to fit flow directors into the pipe. Then the taper helps to smoothly accelerate the air before it goes into the turbo. Or at least that would be the theory without modeling it. I think they also designed them to take 3in I takes without the drop down to 2.5in at the coupler, but I’ve never seen someone hook it up like that.

 

The large smooth bend that covertRussian has on his is obviously superior though. I just wonder about the sharp flow transition from 3in to 2.4 with that offset coupler. Not that one has much of a choice on a stock location turbo due to the way Subaru laid it out. Well, unless we can convince Covertrussian to try and build a rotated turbo setup and buy a 3in turbo compressor cover to test. Which I would totally toss some money in the pot for.

 

Edit: I’d actually love to see a 3in stock location turbo cover test. Which they make one for our cars. Which I’d also be willing to toss some cash in for.

Edited November 12, 2019 by utc_pyro

lol, i was about to suggest that we fund the money for a contractor to do the house work so he can get back to car stuff. but new turbo bits works too.

 

Here's what I've been up to, silly me underestimated how much digging needed to be done, because from my standing perspective it doesn't look all that much! Unfortunately cars are more sensitive to big elevation changes, so lots of extra digging to smooth it out.

 

 

Needless to say I've gained a lot of core strength, which means I'm not going to the chiropractor monthly anymore . I've also been busy with taking down big dying oak trees around the house. Maybe I should start a house build thread in Off Topic.

 

The large smooth bend that covertRussian has on his is obviously superior though. I just wonder about the sharp flow transition from 3in to 2.4 with that offset coupler. Not that one has much of a choice on a stock location turbo due to the way Subaru laid it out. Well, unless we can convince Covertrussian to try and build a rotated turbo setup and buy a 3in turbo compressor cover to test. Which I would totally toss some money in the pot for.

 

Edit: I’d actually love to see a 3in stock location turbo cover test. Which they make one for our cars. Which I’d also be willing to toss some cash in for.

 

100% agreed with you, I really don't like that reducer/coupler, but it's mostly Subaru's fault. Now I've seen someone take the 3" coupler and modify it to fit with 2.4", but I'm not sure it helped with flow that much.

 

Now that I'm TGV less, perhaps I could try a 3" housing. Going rotated is too much money for probably minimal gains and I'm starting to max out the stock injectors and/or fuel pump on cold days.

 

I'm also starting to wonder if it's time for a newer car... But don't worry, I first need to afford a new family hauler before I can consider a new toy for myself.