14b Turbo Lag

[gorf]

I have done a lot of reading here and everyone says that a ported 14b with ported exhaust manifold responds like a t25 with a lot more pull.

Not the case with my car.

I just installed a ported 14b with ported exhaust manifold, ported o2 housing, mbc and built a hard LICP. Had some boost leaks that I think I have fixed.

My boost starts coming on about 4k and is fully spooled at 5k. I am holding 18 lbs boost up to redline and the car is still pulling like crazy. My problem is the amount of lag, any ideas what would cause 1500 rpm lag over a t25?

 

[goalieman24]

I know you said you fixed the leaks, but maybe double check to see if there are any more.
I'm breaking in my new motor and shifting about 3k, but still can build about 7lbs then. Boost not coming until 4k sounds a little off

 

[NOMIEZVR4]

ported 14b and manifold I get 15lbs by 2700 rpms

 

[daren_p]

Ya something is defently up, while a 14b won't spool quite as fast as a t25 you still should be looking at high 2000's/low 3000's to see full boost. Things to check are boost leaks, exhaust leaks, defective wastegate actuator or the turbo itself can be crapping out, know of a couple guys that had the same thing happen when their 14b was on its last legs.

 

[tstkl]

yeah, I see 26 lbs by 3200, and I see 15 by 2800, on my completely stock 1g exhaust mani, untouched 14b, and my choke hold of a 1g o2 housing. You got an exhaust leak or something...


and for those of you who don't think the 14b can handle that kind of pressure, I accidently whipped my car up to 28 lbs at 4.5ish k at partical throttle. As much as boost creep sucks, the 14b is a damn good turbo.

 

[compression]

Sounds like an exhaust leak to me maybe you are leaking at the manifold - turbo flange, did you use a gasket? was it the stock gasket? got a logger? check your o2 voltage and see if its lower then usual , exhaust leaks tend to make you run richer then usual also. Not to mention spool time will be hurt pretty bad.

 

[ChvyKc]

Sounds like an exhaust leak to me...

That's what I was thinking or it could still be a boost leak. I was at full boost by 3200 at 19 pounds on my 14b and I believe that I get 24 pounds on my 16G by 3600. It's been so long since I drove it last that I can't remember, but I know for sure that it is below 3800.

I would definately check everything one more time and make sure that you don't have any boost/exhaust leaks. Let us know how it comes out.

 

[gorf]

Sounds like an exhaust leak to me maybe you are leaking at the manifold - turbo flange, did you use a gasket? was it the stock gasket? got a logger? check your o2 voltage and see if its lower then usual , exhaust leaks tend to make you run richer then usual also. Not to mention spool time will be hurt pretty bad.

I will check more closely for an exhaust leak, but do not smell exhaust or hear any leak under the hood.

Used a new 7cm stainless gasket http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=8066887907&category=42610. It is thick as a shim.

I have a A/F gauge and it does seem to be running rich. How do you check the voltage?

Do not have a logger, looking for one. Are these any good for a 2g?
http://www.obdloggers.com

 

[ChvyKc]

You need some type of logger to check your O2 voltage. You can also use a O2 voltage gauge or any type of gauge that read between 0 and 1.00v. My turbo timer has O2 voltage on it.

If you have an autometer air/fuel gauge then it is not accurate at all. The very last green light become lite when the O2 voltage is between .9 and 1.0 which is either right where you want to be or extremely rich. If you have any of the lights on below that then the car is running lean. I wouldn't trust one of those gauges.

Here is a link to what RRE says about O2 voltage:

http://www.dsmtuners.com/forums/showthread.php?p=1698317#post1698317

And here is a good read on those gauges from the tech section:

http://www.dsmtuners.com/forums/showthread.php?t=161136

 

[Killa_dsm]

Have you checked if your flapper door is closing all the way? Have you checked if you had any cracks by the flapper door? You should check the preload on the actuator. When I had my 14b I had to put a couple washer where the actuator bolts up to the turbo in order to keep the flapper door closed. Once I did that the turbo lag on the 14b was gone. Give that a try.

 

[ChvyKc]

Have you checked if you had any cracks by the flapper door?

I think that is what is hurting my spool on the 16G. Mitsubishi turbine housings are known for doing that. I have the typical crack running from the manifold flange down to the flapper but it doesn't go to the outside of the turbo. I would probably spool my turbo by 3400 if that crack wasn't there.

 

[gorf]

Have you checked if your flapper door is closing all the way? Have you checked if you had any cracks by the flapper door? You should check the preload on the actuator. When I had my 14b I had to put a couple washer where the actuator bolts up to the turbo in order to keep the flapper door closed. Once I did that the turbo lag on the 14b was gone. Give that a try.

Thanks after all the other comments, this was my exact thought. This is the only thing that I did not check before installing the turbo, I didn't want to separate the o2 housing. Guess now I have to pull the turbo again.......

If there are cracks, is there anything that can be done to fix them?

 

[ChvyKc]

Thanks after all the other comments, this was my exact thought. This is the only thing that I did not check before installing the turbo, I didn't want to separate the o2 housing. Guess now I have to pull the turbo again.......

If there are cracks, is there anything that can be done to fix them?

There is nothing that you can really do to permenantly fix the problem. If the crack does go to the outside of the turbo then I would just run it unless you just want to buy a new turbine housing.

 

[gorf]

When I had my 14b I had to put a couple washer where the actuator bolts up to the turbo in order to keep the flapper door closed. Once I did that the turbo lag on the 14b was gone. Give that a try.

You Da MAN! If you get to North Carolina - I owe you a beer.

I loosened up the two mounting screws for actuator and kinda tugged and pulled on it. It looked like I needed about the thickness of one washer to keep it closed so I put two under the bracket at each bolt. Blew some air into the actuator too make sure it worked and did not hang. I knew that if my leak was that bad, it would change my boost setting so took it easy. Second gear I jumped on the gas, at 3200 it started boosting, at 3800 My wheels broke loose and boost spiked to about 21, so backed off and adjusted my MBC.

Absolutely correct man - lag gone!

 

[UMR98GSX]

3200 still seems a little late for that turbo to START spooling. I would continue to check for pre turbo exhasut leaks like cracks in your manifold or a bad mani to head gasket.

Did you mash on the gas to WOT or did you kinda gradually press it down?

 

[Killa_dsm]

You Da MAN! If you get to North Carolina - I owe you a beer.

I loosened up the two mounting screws for actuator and kinda tugged and pulled on it. It looked like I needed about the thickness of one washer to keep it closed so I put two under the bracket at each bolt. Blew some air into the actuator too make sure it worked and did not hang. I knew that if my leak was that bad, it would change my boost setting so took it easy. Second gear I jumped on the gas, at 3200 it started boosting, at 3800 My wheels broke loose and boost spiked to about 21, so backed off and adjusted my MBC.

Absolutely correct man - lag gone!

Haha no problem man. Hey instead of the beer you could give me rep points!

But yeah, I have about 4 washers each bolt on my actuator to keep the damn thing closed. But I'm glad I could help.

 

[gorf]

3200 still seems a little late for that turbo to START spooling. I would continue to check for pre turbo exhasut leaks like cracks in your manifold or a bad mani to head gasket.

Did you mash on the gas to WOT or did you kinda gradually press it down?

It MIGHT be a little lower than that like maybe 3k, but certainly not into the 2800 range.
Generally what I do is, mash the gas at about 2k and try to watch when it kicks in. Obviously the higher the gear, the easier to watch the boost.

Is there a better way to check?
No I do not have a logger yet, not sure what kind I should be looking for.

 

[gorf]

3200 still seems a little late for that turbo to START spooling. I would continue to check for pre turbo exhasut leaks like cracks in your manifold or a bad mani to head gasket.

Did you mash on the gas to WOT or did you kinda gradually press it down?

UGH sorry man - I have been doing my testing during the day so could not read the gauges all that well. Last night went out, it was pitch black, so I could see the gauges real well.

1st gear hard to tell but about 2800k boost is coming on full boost by 3600
2nd - close to the same but a little lower.
3rd - boost is coming on by 2500 10 psi by 3K, full boost about 3200
4th - starts about 2400, full boost by 3K (possibly 2800)
5th - about the same as 4th

 

[ChvyKc]

UGH sorry man - I have been doing my testing during the day so could not read the gauges all that well. Last night went out, it was pitch black, so I could see the gauges real well.

1st gear hard to tell but about 2800k boost is coming on full boost by 3600
2nd - close to the same but a little lower.
3rd - boost is coming on by 2500 10 psi by 3K, full boost about 3200
4th - starts about 2400, full boost by 3K (possibly 2800)
5th - about the same as 4th

If your getting full boost by 3200 in the upper gears then I wouldn't worry about it. I don't even see full boost in first gear because it is so short (especially after a hard launch).

It sounds to me like you fixed the problem before. You might be able to see a little faster spool if you do some more digging but you probably won't see that big of a difference for all the work that you are going to have to do to find the other problem (if there is one). I would stay with it, 3600 in first and second and 3200 in the upper gears sounds good to me.