GT35R to GTX35R - Made Less Power w/ Better Turbo

 
Old 04-26-2019, 04:32 PM
  #1  
Honda-Tech Member
Thread Starter
 
Tootsie7944's Avatar
 
Join Date: Apr 2010
Location: Joined 2004, 6,000+ posts
Posts: 263
Likes: 0
Received 0 Likes on 0 Posts
Default GT35R to GTX35R - Made Less Power w/ Better Turbo

Good ole Honda-tech. It's been a while.

I have a 2000 Integra Type R w/ a full-race AC Turbo kit and originally had the GT35R turbo. The car made 550 whp on 93 octane pump gas (600 whp w/ Meth). That was about 8 years ago at this point. I recently "restored" the car and felt a bit of shaft play on my GT35R, so I ordered the GTX35R while the engine was out. I also removed my old Skunk 2 Pro 1 cams, with new Skunk 2 Pro 1 cams (same cams).

So, only thing touched on the engine was the turbo as far as a real change. Went to re-tune today with Jeff Evans and it seemed like the turbo just wasn't responding/building boost like it should have. Jeff had to keep cranking up the duty cycle more than he thought he should need to in order to raise the boost to just 18 PSI.

We side by sided today's tune with my tune 10 years ago and both tunes were around 18-19 PSI. Old tune my 550 whp all the way to 9,000 rpm. Tune today made 480 whp to only 8,700 rpm.

We checked boost solenoid - was working - we could hear it clicking, and we checked the vacuum lines to make sure were good.
Compression test was 180, 180 177, 177
9:1 compression in engine
Good spark

Any of you guys heard of issues like this before going to the GTX when not using race gas and going big #'s? Like I said, car made 550 whp on 18 PSI before with the GT, and only 480 who on 18 PSI with GTX and it didn't seem to react to the duty increases as sensitively as Jeff would have thought.I still have my old turbo as well, so if I can't figure it out, I'll swap the turbos and re-tune and see if anything changes.

I am going to fill the system with 30 PSI tomorrow to see if I hear any boost leaks, but the car is pretty flawless and I am meticulous. While I'm not ruling out there is another issue, I wanted to get the ball rolling with you guys as well. Just seems like a sluggish turbo. I called Full-Race to see what they say also. Pretending there isn't a boost leak, any other thoughts?

Dyno plot looked good, Jeff did a great tune, but I know my car and something sounded off. I haven't actually driven it yet b/c it's been raining all day, but I will take it out tomorrow to see if I can feel something off as well.

**Update** - Shoutout and thank you to Steve Belliveau (motoxxxman). I took my ECU to him to get looked at. I got a new S300 chip in case of any memory/battery issues as it was around the 10 year mark. So that could have been some/all of the issue. But, when looking at my OEM board, he also noticed that 2 of my capacitors were leaking and in 3 places, the actual copper runway from the capacitor to the next connection points were completely destroyed. All of that has been fixed now. I haven't put the ECU in the car yet, or retuned. But has anyone ever had something like this happen, where you had a significant power decrease, while the car technically tuned 'ok' and it was from a bad ECU?

I'm still not sold that the ECU is causing a 120 hp decrease, but I am definitely not a tuner or ECU expert. I still need to check flex section on downpipe, get injectors cleaned and check wastegate diaphragm & spring. Thanks guys.

Last edited by Tootsie7944; 06-25-2019 at 06:04 AM.
Tootsie7944 is offline  
Old 04-26-2019, 05:40 PM
  #2  
Honda-Tech Member
 
Chance EG's Avatar
 
Join Date: Jan 2013
Location: Austin, TX
Posts: 1,651
Likes: 0
Received 0 Likes on 0 Posts
Default Re: GT35R to GTX35R - Made Less Power w/ Better Turbo

That's definitely not the right output for 18PSI on a GTX35.

Sounds like something is off with the turbo, kneecapping it's efficiency. I definitely wouldn't second guess Jeff on his tuning...
Chance EG is offline  
Old 04-27-2019, 12:14 AM
  #3  
Honda-Tech Member
 
The sweed's Avatar
 
Join Date: Sep 2002
Location: IKEA Land
Posts: 510
Likes: 0
Received 0 Likes on 0 Posts
Default Re: GT35R to GTX35R - Made Less Power w/ Better Turbo

Did you degree the new cams.. There are rumors that they changed centerline position on the newer pro1 cams so if you have had old ones the new ones needs to be degreed.
The sweed is offline  
Old 04-27-2019, 03:59 AM
  #4  
Honda-Tech Member
Thread Starter
 
Tootsie7944's Avatar
 
Join Date: Apr 2010
Location: Joined 2004, 6,000+ posts
Posts: 263
Likes: 0
Received 0 Likes on 0 Posts
Default Re: GT35R to GTX35R - Made Less Power w/ Better Turbo

Jeff is my man. Been tuning my car for 15 years. He did a great tune, curves all look good. But we both know the car should make well over 500. So just trying to figure out what's going on, when all the obvious stuff seems fine.

These are new Pro 1's, but Jeff did degree the cams.
Tootsie7944 is offline  
Old 04-27-2019, 02:22 PM
  #5  
Honda-Tech Member
 
turbociv910's Avatar
 
Join Date: Oct 2005
Location: expensive land, usa
Posts: 2,471
Likes: 0
Received 0 Likes on 0 Posts
Default Re: GT35R to GTX35R - Made Less Power w/ Better Turbo

boost leaks, valve lash, plugs, blown up motor, leaky bov, exhaust crushed.. need to start working on it.. ht aint going to fix it
turbociv910 is offline  
Old 04-27-2019, 02:44 PM
  #6  
Honda-Tech Member
Thread Starter
 
Tootsie7944's Avatar
 
Join Date: Apr 2010
Location: Joined 2004, 6,000+ posts
Posts: 263
Likes: 0
Received 0 Likes on 0 Posts
Default Re: GT35R to GTX35R - Made Less Power w/ Better Turbo

Originally Posted by turbociv910 View Post
boost leaks, valve lash, plugs, blown up motor, leaky bov, exhaust crushed.. need to start working on it.. ht aint going to fix it
It won't? I honestly thought HT would magically fix it. Like I said, I was meticulous and my car is flawless. Whatever it is, is not an obvious issue. Was seeing if any of the guys on here had ever experienced some fantom issues that maybe we haven't thought of yet.
Tootsie7944 is offline  
Old 04-27-2019, 06:53 PM
  #7  
Honda-Tech Member
 
Txdragon's Avatar
 
Join Date: Mar 2016
Posts: 2,117
Likes: 0
Received 0 Likes on 0 Posts
Default Re: GT35R to GTX35R - Made Less Power w/ Better Turbo

Originally Posted by Tootsie7944 View Post
It won't? I honestly thought HT would magically fix it. Like I said, I was meticulous and my car is flawless. Whatever it is, is not an obvious issue. Was seeing if any of the guys on here had ever experienced some fantom issues that maybe we haven't thought of yet.
The way I see it, it's extremely obvious and, you have 2 options..
Option 1: put the old cams in with the new turbo and see what happens..
Option 2: put the old turbo on with the new cams and see what happens..

Edit.. I suggest looking into a possible boost solenoid problem.. You've already said that Evans had to crank it higher than he believed he should to get boost where it was at.. I think this may be an issue.. While it may "click" to indicate it works, it doesn't mean it's working properly.
Txdragon is offline  
Old 04-30-2019, 09:23 AM
  #8  
Honda-Tech Member
 
Join Date: Aug 2016
Posts: 405
Likes: 0
Received 0 Likes on 0 Posts
Default Re: GT35R to GTX35R - Made Less Power w/ Better Turbo

Swap turbos first, its easier. If that doesnt fix it, something is likely wrong with the engine.
k20z1ej1 is offline  
Old 05-11-2019, 05:12 AM
  #9  
Honda-Tech Member
Thread Starter
 
Tootsie7944's Avatar
 
Join Date: Apr 2010
Location: Joined 2004, 6,000+ posts
Posts: 263
Likes: 0
Received 0 Likes on 0 Posts
Default Re: GT35R to GTX35R - Made Less Power w/ Better Turbo

Found a small boost leak and repaired and went back for a re-tune. No better, and boost leak wasn't significant enough I expected it to fix the issue. Power was actually 5 less. The only thing I need to check still is if the flex section of my downpipe may be collapsed some after all these years. Will check tomorrow.

Compression test would say engine is ok. 180 180 177 177

I know my car, something even sounds off. It used to have a ton of torque/pickup even in 5th gear around 3500 rpms...now it's like a slow old lady until 6500 rpms. It's like something is holding the car back. Not sure if maybe the Vtec solenoid is starting to go bad or what. The car sounds more "gurgly".

At Jeff's yesterday, it seemed like the S300 ECU was starting to go bad. It would shut off, not re-start and he would have to re-upload the tune again. Then on my drive home, the car would shut off ever 10 miles and I had to let it sit. The fuel pressure would also just drop to 0. I swapped relays and that wasn't it. I have the Bosch 044 inline pump and I read they can die after years of use, and it did feel pretty hot. But the engine didn't even want to fire, so it doesn't seem likely the fuel pump alone is the issue (or at all). Really seems like the ECU isn't acting right.

As a note, yesterday we did 18-19 PSI again on the GTX3582R and it only produced 475 whp. Something is holding the car/engine back. 9 years ago with my GT35R it made 550 whp on 18 PSI at Jeff's. The power curve flattens out a lot after 5000-5500 rpms or so.

I think this is actually unrelated to the power loss issue, just ironic.

I am going to send S300 back to Hondata to get checked out and upgraded since it's V1 and I may have the memory loss issue going on. I will also check the flex section tomorrow. Then I'm going to rebuild wastegate, new fuel filter, new Bosch 044 and relay for it, clean injectors.

As a side note, when I used to track my R 3-5 years ago, sometimes I'd come out of a corner, floor it, and the car felt like it had no power. It felt and sounded JUST like it does now, slow to pick up RPMs and boost. Then I'd rev it in neutral or shift gears, and BAM power was back like an ape at 3500 RPM's. Could this be a software ECU issue I've had for years? Vtec solenoid going bad? Momentary collapse of flex section? Wastegate maybe going bad? Seems like this is all related.

Last edited by Tootsie7944; 05-11-2019 at 05:47 AM.
Tootsie7944 is offline  
Old 05-11-2019, 06:11 AM
  #10  
Honda-Tech Member
 
Chance EG's Avatar
 
Join Date: Jan 2013
Location: Austin, TX
Posts: 1,651
Likes: 0
Received 0 Likes on 0 Posts
Default Re: GT35R to GTX35R - Made Less Power w/ Better Turbo

^To me that does sound like an ECU issue. Revving the car in neutral to wake things back up is the red flag for me there.

But tuning and electronics have never been my strong suit, at all. Let us know what ends up happening, I'm curious. Hope it all turns out well.
Chance EG is offline  
Old 05-11-2019, 10:25 PM
  #11  
Honda-Tech Member
 
The sweed's Avatar
 
Join Date: Sep 2002
Location: IKEA Land
Posts: 510
Likes: 0
Received 0 Likes on 0 Posts
Default Re: GT35R to GTX35R - Made Less Power w/ Better Turbo

Originally Posted by Tootsie7944 View Post

As a side note, when I used to track my R 3-5 years ago, sometimes I'd come out of a corner, floor it, and the car felt like it had no power. It felt and sounded JUST like it does now, slow to pick up RPMs and boost. Then I'd rev it in neutral or shift gears, and BAM power was back like an ape at 3500 RPM's. Could this be a software ECU issue I've had for years? Vtec solenoid going bad? Momentary collapse of flex section? Wastegate maybe going bad? Seems like this is all related.
This sounds like fuel is not getting to your fuel pickup in hard turns.. If you have a wideband and do a datalog it will show lean when that happens. The fix is a fuel catch can.
If this happens above vtec point maybe it can be the same with the oil and you are loosing vtec because oil is getting away from the oil pickup and you loose pressure for a while. But if it is under the vtec point in the rpm´s it doesn´t seem likely that it would be a vtec solenoid issue.. Take off the vtec sloenoid and clean the filter might be a good idé..

Sounds like you have a good plan for finding the other issues.. Check the whole exhaust.. Silencers can also break and restrict.
The sweed is offline  
Old 05-12-2019, 09:30 PM
  #12  
Honda-Tech Member
 
Join Date: Mar 2018
Posts: 41
Likes: 0
Received 0 Likes on 0 Posts
Default Re: GT35R to GTX35R - Made Less Power w/ Better Turbo

Gtx turbo

s300... upgrade the ems.
Pepe14 is offline  
Old 05-13-2019, 04:40 AM
  #13  
Honda-Tech Member
 
motoxxxman's Avatar
 
Join Date: Mar 2005
Location: CT, US
Posts: 2,364
Likes: 0
Received 0 Likes on 0 Posts
Default Re: GT35R to GTX35R - Made Less Power w/ Better Turbo

Have you checked for exhaust leaks before the turbo? Everything you described can happen if there's an exhaust leak anywhere on the manifold.
Where did you buy the turbo from? How sure are you that the exhaust housing is correct? If the exhaust housing is wrong, it can do exactly what you're describing.
Record a datalog and check the battery voltage. What is voltage while cruising, and how far does voltage drop through a full pull? If voltage drops too far, it's possible to be causing weak spark
A coil going bad is also a possibility. Check and clean all engine grounds too.
motoxxxman is offline  
Old 05-14-2019, 09:04 AM
  #14  
Honda-Tech Member
Thread Starter
 
Tootsie7944's Avatar
 
Join Date: Apr 2010
Location: Joined 2004, 6,000+ posts
Posts: 263
Likes: 0
Received 0 Likes on 0 Posts
Default Re: GT35R to GTX35R - Made Less Power w/ Better Turbo

Originally Posted by motoxxxman View Post
Have you checked for exhaust leaks before the turbo? Everything you described can happen if there's an exhaust leak anywhere on the manifold.
Where did you buy the turbo from? How sure are you that the exhaust housing is correct? If the exhaust housing is wrong, it can do exactly what you're describing.
Record a datalog and check the battery voltage. What is voltage while cruising, and how far does voltage drop through a full pull? If voltage drops too far, it's possible to be causing weak spark
A coil going bad is also a possibility. Check and clean all engine grounds too.
After some more research on Hondata's forums, it definitely seems like almost all my issues (if not all) are ECU related. Even the momentary power loss, there are threads with the exact same issues. I still haven't had a chance to check my downpipe flex section, but hopefully Thursday.

It's a full-race ramhorn kit and there are no leaks before the turbo. Everything is in plain sight and if there was anything major you'd be able to see some blowby, which I have none of.

The distributor is brand new, but I may buy another one to have ready to go to swap on dyno and see if that's the culprit when I do next re-tune. Haven't checked battery voltage, but can do that next re-tune as well. Regarding the grounds, nothing has changed in years, but I checked them over and all look good.

Really think it's the ECU and perhaps either the wastegate or flex section causing issues, but will address everything that comes to mind and refresh everything before next re-tune.

Just a thought, but my car sat for like 3 years only running maybe 2 tanks of gas through it during that time. I have Injector Dynamics injectors. I will send them out to get cleaned, but any thoughts on if that could cause THAT much of a power loss? Like I said, it seems like the power loss/flat lining of the curve is around 5500 rpms or so.

Thanks for all the input guys. Will clean Vtec screen as well.
Tootsie7944 is offline  
Old 05-14-2019, 09:31 AM
  #15  
Honda-Tech Member
 
Txdragon's Avatar
 
Join Date: Mar 2016
Posts: 2,117
Likes: 0
Received 0 Likes on 0 Posts
Default Re: GT35R to GTX35R - Made Less Power w/ Better Turbo

Originally Posted by Tootsie7944 View Post
After some more research on Hondata's forums, it definitely seems like almost all my issues (if not all) are ECU related. Even the momentary power loss, there are threads with the exact same issues. I still haven't had a chance to check my downpipe flex section, but hopefully Thursday.

It's a full-race ramhorn kit and there are no leaks before the turbo. Everything is in plain sight and if there was anything major you'd be able to see some blowby, which I have none of.

The distributor is brand new, but I may buy another one to have ready to go to swap on dyno and see if that's the culprit when I do next re-tune. Haven't checked battery voltage, but can do that next re-tune as well. Regarding the grounds, nothing has changed in years, but I checked them over and all look good.

Really think it's the ECU and perhaps either the wastegate or flex section causing issues, but will address everything that comes to mind and refresh everything before next re-tune.

Just a thought, but my car sat for like 3 years only running maybe 2 tanks of gas through it during that time. I have Injector Dynamics injectors. I will send them out to get cleaned, but any thoughts on if that could cause THAT much of a power loss? Like I said, it seems like the power loss/flat lining of the curve is around 5500 rpms or so.

Thanks for all the input guys. Will clean Vtec screen as well.
Buggered injectors will cause problems across the board. With specific power loss/flatline at 5500, providing your VTEC is set to activate here, I'd certainly not rule out the solenoid given this info. Clogged screen, etc.. something maybe fishy here. Still maybe dizzy/ICM related. The B and their quirky ignition system.. **shrug**
Txdragon is offline  
Old 05-14-2019, 10:56 AM
  #16  
Honda-Tech Member
Thread Starter
 
Tootsie7944's Avatar
 
Join Date: Apr 2010
Location: Joined 2004, 6,000+ posts
Posts: 263
Likes: 0
Received 0 Likes on 0 Posts
Default Re: GT35R to GTX35R - Made Less Power w/ Better Turbo

It's not a power loss at that RPM, but the increase/slope in the power curve starts to flatten off, but it's really before Vtec, so I doubt it's the solenoid (though I will clean it anyway).

Going to send out my injectors to ID regardless to get cleaned. Just want it fixed haha so doing anything/everything that comes to mind.
Tootsie7944 is offline  
Old 05-16-2019, 01:41 AM
  #17  
Honda-Tech Member
iTrader: (1)
 
1HGEJ2's Avatar
 
Join Date: Jan 2009
Location: Germany
Posts: 581
Likes: 0
Received 0 Likes on 0 Posts
Default Re: GT35R to GTX35R - Made Less Power w/ Better Turbo

do u use a garrett gtx35 turbo or a china gtx35 turbo?
1HGEJ2 is offline  
Old 05-16-2019, 12:49 PM
  #18  
Honda-Tech Member
 
motoxxxman's Avatar
 
Join Date: Mar 2005
Location: CT, US
Posts: 2,364
Likes: 0
Received 0 Likes on 0 Posts
Default Re: GT35R to GTX35R - Made Less Power w/ Better Turbo

Tootsie I sent you a PM
motoxxxman is offline  
Old 06-25-2019, 06:05 AM
  #19  
Honda-Tech Member
Thread Starter
 
Tootsie7944's Avatar
 
Join Date: Apr 2010
Location: Joined 2004, 6,000+ posts
Posts: 263
Likes: 0
Received 0 Likes on 0 Posts
Default Re: GT35R to GTX35R - Made Less Power w/ Better Turbo

**Update** - Shoutout and thank you to Steve Belliveau (motoxxxman). I took my ECU to him to get looked at. I got a new S300 chip in case of any memory/battery issues as it was around the 10 year mark. So that could have been some/all of the issue. But, when looking at my OEM board, he also noticed that 2 of my capacitors were leaking and in 3 places, the actual copper runway from the capacitor to the next connection points were completely destroyed. All of that has been fixed now. I haven't put the ECU in the car yet, or retuned. But has anyone ever had something like this happen, where you had a significant power decrease, while the car technically tuned 'ok' and it was from a bad ECU?

I'm still not sold that the ECU is causing a 120 hp decrease, but I am definitely not a tuner or ECU expert. I still need to check flex section on downpipe, get injectors cleaned and check wastegate diaphragm & spring. Thanks guys.

Originally Posted by 1HGEJ2 View Post
do u use a garrett gtx35 turbo or a china gtx35 turbo?
I bought this from Full-Race, I don't cut corners on my car.

Tootsie7944 is offline  
Old 06-25-2019, 06:05 AM
  #20  
Honda-Tech Member
Thread Starter
 
Tootsie7944's Avatar
 
Join Date: Apr 2010
Location: Joined 2004, 6,000+ posts
Posts: 263
Likes: 0
Received 0 Likes on 0 Posts
Default Re: GT35R to GTX35R - Made Less Power w/ Better Turbo

**Update** - Shoutout and thank you to Steve Belliveau (motoxxxman). I took my ECU to him to get looked at. I got a new S300 chip in case of any memory/battery issues as it was around the 10 year mark. So that could have been some/all of the issue. But, when looking at my OEM board, he also noticed that 2 of my capacitors were leaking and in 3 places, the actual copper runway from the capacitor to the next connection points were completely destroyed. All of that has been fixed now. I haven't put the ECU in the car yet, or retuned. But has anyone ever had something like this happen, where you had a significant power decrease, while the car technically tuned 'ok' and it was from a bad ECU?

I'm still not sold that the ECU is causing a 120 hp decrease, but I am definitely not a tuner or ECU expert. I still need to check flex section on downpipe, get injectors cleaned and check wastegate diaphragm & spring. Thanks guys.

Originally Posted by 1HGEJ2 View Post
do u use a garrett gtx35 turbo or a china gtx35 turbo?
I bought this from Full-Race, I don't cut corners on my car.
Tootsie7944 is offline  
Old 06-25-2019, 09:34 AM
  #21  
Honda-Tech Member
 
Txdragon's Avatar
 
Join Date: Mar 2016
Posts: 2,117
Likes: 0
Received 0 Likes on 0 Posts
Default Re: GT35R to GTX35R - Made Less Power w/ Better Turbo

Originally Posted by Tootsie7944 View Post
**Update** - Shoutout and thank you to Steve Belliveau (motoxxxman). I took my ECU to him to get looked at. I got a new S300 chip in case of any memory/battery issues as it was around the 10 year mark. So that could have been some/all of the issue. But, when looking at my OEM board, he also noticed that 2 of my capacitors were leaking and in 3 places, the actual copper runway from the capacitor to the next connection points were completely destroyed. All of that has been fixed now. I haven't put the ECU in the car yet, or retuned. But has anyone ever had something like this happen, where you had a significant power decrease, while the car technically tuned 'ok' and it was from a bad ECU?

I'm still not sold that the ECU is causing a 120 hp decrease, but I am definitely not a tuner or ECU expert. I still need to check flex section on downpipe, get injectors cleaned and check wastegate diaphragm & spring. Thanks guys.
In my experience, it either works or doesn't. However, I may have a similar issue with failing capacitors.. I have a cold start issue that my fuel pump will not prime until my main relay warms up. I have to provide ground to pin 8 and try to start a couple times, eventually it will catch on its own and it'll be fine the rest of the day or til it cools down again.. **shrug** brand new relay, all fuses are good wiring has good continuity, and again, it will all work when relay gets warm. Failing capacitors is the best I've got so far. Lol..

So.. It may be possible. Best for you to replace them and see what happens when the smoke clears.
Txdragon is offline  
Old 06-25-2019, 09:43 AM
  #22  
Honda-Tech Member
Thread Starter
 
Tootsie7944's Avatar
 
Join Date: Apr 2010
Location: Joined 2004, 6,000+ posts
Posts: 263
Likes: 0
Received 0 Likes on 0 Posts
Default Re: GT35R to GTX35R - Made Less Power w/ Better Turbo

Originally Posted by Txdragon View Post
In my experience, it either works or doesn't. However, I may have a similar issue with failing capacitors.. I have a cold start issue that my fuel pump will not prime until my main relay warms up. I have to provide ground to pin 8 and try to start a couple times, eventually it will catch on its own and it'll be fine the rest of the day or til it cools down again.. **shrug** brand new relay, all fuses are good wiring has good continuity, and again, it will all work when relay gets warm. Failing capacitors is the best I've got so far. Lol..

So.. It may be possible. Best for you to replace them and see what happens when the smoke clears.
Thanks. Yea I replaced all of them. So the ECU is ready to go. Keep me posted on your issue. I will hopefully get some time next week to check the last few things on my car and then see when Jeff can get me back in for another tune.
Tootsie7944 is offline  
 


Thread Tools
Search this Thread

Contact Us - About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: