Turbo or Clutch issue?

[05gtripper]

Hello,

So i've had this gt for 2.5k miles & its near 163k miles.      First manual vehicle & first trubo. 

My vehicle is hitting boost waay too early & producing low power..  gets worse the higher i go in gears.   1st & 2nd dont rlly have the prob as much as higher.   But 4th i was limping at 40mph, cuz if i go faster, my engine revs- boosts & i hardly gain speed..        may not be explaining the best..    feels like wheelspin-- but i never had power/revs so easily at these rpms & gears.  

   Few days ago i noticed in 4th (didnt need 5th) while driving up a mtn highway that my boost was VERY quick to engage.  I'd be rocking 40mph, 2.3k rpm or so, like just enough gas pedal to keep going good-- & once i gave it any xtra fuel, it'd spool up quickly/asap.    Was cool at first & i thought it was the incline of the road giving engine more load..    now 3 days later & its worse, smells like a burning clutch (as i've drug it few times learning & pushing in 2nd or 3rd from a 'stop').        Spooky tbh.     I feel like a had a very similiar issue ONCE FOR 2 DAYS- 1.5k miles ago--(was newer vehicle to me & on the highway in 5th it was making lowww power.  Yet somehow fixed itself.. which is wack & isnt the first time this vehicle ran bad then parked then ran good.    Concerning as idk why.     1st post here, been learning to tune-the vehicle currently has a decent lil tune from somebody else but nothing too wild from stock as I've been learning.  

So idk what my issue is.   Is my clutch slipping?? Prev owner claimed a "stage 2 clutch" (but he kinda snakeoiled me anyhow)    Or is my tubro fkd somehow & getting boosted super easily??        Any & all helped appreciated,

 

Thank you,

Mick

[Pleides]

Does the car have mods and has it been tuned to account for those? Unless you have a spare shortblock lying around, I'd recommend you have someone watch you like a hawk when attempting to tune the car. Do a proper vacuum leak test before messing with the ECU as well. You likely have at least one vacuum leak if the hoses haven't been touched under the engine bay after 18 years. When checking under there, look for a Cobb or Grimmspeed boost control solenoid, if you don't mind reporting back if you see one.

Going 40 MPH in fourth gear and sending it is lugging the engine - you should be in second or third. It is possible that your clutch is letting go if the car is revving higher but not going. If you're on the original clutch then it's absolutely time to change that thing. Never seen a member here get more than 120K or so out of the factory clutch and dual mass flywheel these cars come with. I'm on my third clutch at 250K. 

Edited December 11, 2023 by Pleides

[05gtripper]

1 hour ago, Pleides said:

Does the car have mods and has it been tuned to account for those? Unless you have a spare shortblock lying around, I'd recommend you have someone watch you like a hawk when attempting to tune the car. Do a proper vacuum leak test before messing with the ECU as well. You likely have at least one vacuum leak if the hoses haven't been touched under the engine bay after 18 years. When checking under there, look for a Cobb or Grimmspeed boost control solenoid, if you don't mind reporting back if you see one.

Going 40 MPH in fourth gear and sending it is lugging the engine - you should be in second or third. It is possible that your clutch is letting go if the car is revving higher but not going. If you're on the original clutch then it's absolutely time to change that thing. Never seen a member here get more than 120K or so out of the factory clutch and dual mass flywheel these cars come with. I'm on my third clutch at 250K. 

The boost control solenoid is a Densco- aka OEM.     How can I check my clutch minus fluid & massive unbolting+lifting? 

[Max Capacity]

I'm thinking your clutch is gone.

When you give it gas going up a hill in a higher gear, the rpm's will increase faster than the normal, and not gain speed. At your mileage, that's common.

When it comes to a replacement clutch set-up. I have had great performance from my Spec 2+ clutches. Call them directly and order from them, cut out the middle man. 

You'll need to have the DMFW changed for a single mass flywheel. Again, their LWFW with the replaceable friction surface works great. 

[Pleides]

18 hours ago, 05gtripper said:

The boost control solenoid is a Densco- aka OEM.     How can I check my clutch minus fluid & massive unbolting+lifting? 

Put the car in 5th at 40 MPH and floor it. If the car gets rev happy and doesn't go anywhere then there's your sign.

Someone who's DIY'd the job will have to chime in on where the inspection cover for the clutch is, but I'm pretty sure you can inspect the guts of the clutch assembly without dropping the transmission. 

[05gtripper]

Thanks everyone & I'm wrapping this up as a failing clutch.    As mention above from Maxcapacity, i'm going to get a Spec stage 2+ clutch & their single alum flywheel.    Read a few older posts about these clutches & model, seems a good choice.   Did speak with one of the guys at Spec today, says the stage2+ is direct drop in. The addon bolts for 79$ were not needed & "way down the road" he said.. idk what that means lol, guess im reusing stock. They are in AL & the guy I spoke to was helpful, might've been his lunch hour tho   

Now to decide to order parts, and decide if I do it myself or not.     I'd like to but know that it'd increase the time frame.  & at this point, might be 50/50 vs a mechanic.   (The risk of a sloppy job vs me fking it up) 

 

 

****also, what FLUID does the 05 lgt clutch use?  Dot3 or not?  Im confused.  The dipstick is like dot 3 but I read of lightweight gear oil often..   I dont even have the darn owners manual!    The clutch resivor is behind the TMIC closer to center than the brake fill- yeah?    

But perhaps the dot3 is in a closed system for the hydralic clutch & then the actual gears & plates are in oil?? Where is that fill & check at tho, if the case? 

 

Thanks again 

Edited December 12, 2023 by 05gtripper

[KZJonny]

38 minutes ago, 05gtripper said:

 

But perhaps the dot3 is in a closed system for the hydralic clutch & then the actual gears & plates are in oil?? Where is that fill & check at tho, if the case?

This. The hydraulics use DOT 3 brake fluid, for the master/slave.

 

The actual transmission gearbox takes 75w90 gear oil. Any good synthetic is probably just fine for you.

Nothing wrong with Redline or Motul or what have you, but it’s a lot of $$$ if this is just for a street driven car. You’ve got to be pretty in tune with the car to notice the difference.

I also chatted with someone at Spec, and for me, sticking with my modified VF40 and supporting mods they recommended the Stage 1 clutch. So it probably depends on your wants and needs.

Fill and dipstick are on the passenger side below the intercooler for the gearbox, inboard of the turbo.

Edited December 12, 2023 by KZJonny

[05gtripper]

26 minutes ago, KZJonny said:

This. The hydraulics use DOT 3 brake fluid, for the master/slave.

 

The actual transmission gearbox takes 75w90 gear oil. Any good synthetic is probably just fine for you.

Nothing wrong with Redline or Motul or what have you, but it’s a lot of $$$ if this is just for a street driven car. You’ve got to be pretty in tune with the car to notice the difference.

I also chatted with someone at Spec, and for me, sticking with my modified VF40 and supporting mods they recommended the Stage 1 clutch. So it probably depends on your wants and needs.

Fill and dipstick are on the passenger side below the intercooler for the gearbox, inboard of the turbo.

Ok, thank you very much!   I'm going stage2+ because it can't be worse than a stock & it can also go hard.  Idk what turbo i got, likely stock.    Downpipe & a tune basically, cold air.       

   How is the stage1? & the break in?

[KZJonny]

I’ll tell you when I install it, hah!

The stock clutch has been stubbornly refusing to give up with an upgraded turbo, headers, full exhaust and Stg 2 tune…

So, maybe 260-270 awhp? Nothing crazy, but I’ve got year of some ‘spirited’ driving on it since doing the upgrades, no problems yet, and it is 160k kms old.

Guess I figured if Spec told me I’d be fine with a Stage 1, and have room for a little more power even, then I’d do it.

No reason at all not to get the 2+. The fella from Spec told me to either get a Stage 1 or 2+. Something about the friction material used in the stage 2 that is less street friendly.
 

The car is my summer daily, and I sometimes get caught in traffic where I live, so I elected for the Stg 1, to keep the pedal as light as possible. Ymmv.

Edited December 12, 2023 by KZJonny

[Max Capacity]

My Spec 2 only lasted 50,000 miles. The 2+ gives more than 90,000 miles. I have not had a Spec 1.

My Spec Aluminum smfw used the stock T50+ bolts. You can see the set up in my click here link.

I used Motul Gear 75w-90 Not cheap but its one of the best out there.

Danny Smith was an old drag racing buddy that worked/works at Spec, Jeremy was a contact there years ago.

Look through the stickys, here, https://www.legacygt.com/forum/61-transmissions/

[Max Capacity]

Found some pictures for you.

 

 

[05gtripper]

**UPDATE** 1/2/2024-- got 110miles on my Spec stage 2+ clutch. *Thank you to everyone above!!*  holds well & i'm happy.   havnt hit more than 4psi of boost yet, getting as many 'perfect' shifts as possible (while learning revmatch downshift) before 500/750 miles.  Then i will lay on the boost.  street dyno it with romraider is the goal- then proceed.   got a decent tune- yet idk HOW good.  looking for 303whp. likely be 263 lol.         Vehicle need new tires, control arms, driveline(ujoints) & also has the 'quiet' legacy fuel pump housing issue where a 3/4 tank fkn leaks & stinks the cab to where you'd be scared to smoke a cig/joint.  It's safe tho        So my new budgeting( I love my vehicle- pickups are too slow & bulky, rolled the baja model, diesel vehicle sure ok I'd rather)    but this 05 legacy is the closest I've gotten to dirtbike acceleration & maneuvering.        I'll buy a new fuel pump housing & then put a better pump in- prep for injectors- yet my engine is @163kmi.  ( i got the NA 2003 BAJA engine in the barn-- think it's 2.5l but no way it bolts up to turbo easily..?)       I posted my current ROM (some unknown WA tuner) on Romraider forums a few months ago(under name 05lgt--- "05lgt judging current tune vs stock")-  it's beefed up vs the stock 05 5mt ecu image.   cam advance, boost targets,--   im learning of the open looping & Turbo Dynamics Comp tables.  Gonna look there as the boost Target tables hit 18 yet I max 8psi.    I dont recall the comp tables let alone in accordance with Wastgate duty, RPM target & all that.  Total noob but i love to read & learn shit I can do!         So my plan of attack is: break in clutch while obtaining new control arms & tires & obtain a driveline.. Perhaps do some MAF plotting.  Street DYNO car when clutch happy.  Adjust map/ROM image based on results.        

Thanks again to great people & community here.

--MICK