T25 to S16g = slower? whats wrong?

[93_tsi_fwd]

I just swapped out my T25 to a small 16g with a big 16g turbine housing, ebay atmospheric o2 housing, and SSAC FMIC.

I got everything in with no problems. I figured out the oil feed line problem. I let the car Idle for 10+mins before taking it out for a test drive.

My stock T25 has a lot of shaft play and the 16g has a small shaft play. Not as much as the t25. My MBC is set to 13 14 psi.

When I took it out for a drive, (not boosting it yet) its all good. but then I did a 3rd gear pull, I can barely feel the boost hitting. The t25 with more shaft play pulled way more stronger than this 16g.

I will try to do a boost leak test tomorow and go through the whole thing

Any suggestion on what to check or do?


Here's my mod list.
rc 550 cc injectors,
ebay intake pipe w/ KnN FIPK,
manual boost controller,
RC 550 cc injectors
SAFC2
SSAC fmic
small 16g
greddy sp2 cat back 2.5''
ebay dump o2 housing

 

[90laserRSfwd]

no fuel pump or fpr? logger? wideband?

 

[93_tsi_fwd]

I have a wablro 255 hp waiting to be put in but Im still looking for an AFPR. no logger or wideband

 

[TommyDSM]

I didn't see anything for you to tune your car with... If thats the case I suggest you not drive your car until you get something to tune. And some kind of Logger... For one your running alot richer if you just put the 550's in. And if you put in your 255 pump, your probably going to overrun your Stock FPR...

Also do you have a boost gauge? Are you even making boost? If you didn't do a boost leak test after the install I suggest you also try that... Try connecting the nipple on the turbo/jpipe directy to the wastegate... Also check to make sure bolts on the turbo to manifold are tight... maybe exhaust leak between turbo and manifold or manifold to head....

 

[Boosted98gsx]

Here's my mod list.
rc 550 cc injectors,
ebay intake pipe w/ KnN FIPK,
manual boost controller,
RC 550 cc injectors
SAFC2
SSAC fmic
small 16g
greddy sp2 cat back 2.5''
ebay dump o2 housing

I would recommend DSMlink over an SAFC, but at least you have something. You are going to gain more with timing than a/f ratios torque wise.

Also, get an AFPR kit from Fuel Injector Clinic or the like, and a new in line fuel filter kit as well.

Do a boost leak test first off. If you're not seeing boost, you're not making power.

 

[93_tsi_fwd]

I didn't see anything for you to tune your car with... If thats the case I suggest you not drive your car until you get something to tune. And some kind of Logger... For one your running alot richer if you just put the 550's in. And if you put in your 255 pump, your probably going to overrun your Stock FPR...

Also do you have a boost gauge? Are you even making boost? If you didn't do a boost leak test after the install I suggest you also try that... Try connecting the nipple on the turbo/jpipe directy to the wastegate... Also check to make sure bolts on the turbo to manifold are tight... maybe exhaust leak between turbo and manifold or manifold to head....

I have apexi SAFC 2 to controll the fuel. I know im going to over run my stock fpr if I put in my 255 fuel pump so i still looking for an AFPR before i put it in.

I do have a bost gauge, and it is making boost.


Most of the suggestion I tried are in here. including a boost leak test.
T25 to s16g = slower - DSMtalk Forums

 

[Stapl3]

No wonder it feels slow. 13# on a 16g might as well be 13# on a stock turbo. Put the boost up higher.

I've been running 18psi on a small 16g and stock fuel system for half a year now. Going from 13 to 15 was noticeable, going from 15 to 18 was awesome.

Get a logger and see how much boost you can safely run. There's no point in doing all these upgrades if you can't use them to their full potential. You can have a logging setup for literally the cost of a old palm pilot on eBay. It's the best mod you can do for yourself at this point.

 

[Bud92gsx]

You need more boost than 13-14 lbs. Your t25 is insta boost and cannot hold as much boost as your s16g. I was running 14psi on my 14b, then i got a s16g. I thought the same thing, no more power right. So what I did was turn my boost up. The spool time is slow but as soon as you bump up the boost you will notice a big difference, once you hit boost. Good luck, and keep us posted on results please...

 

[93_tsi_fwd]

I turned the mbc all the way to its maximum and it did show a whole lot more power. It hits way harder now.


(copied from talk)
I just got back from testing it again. I took it around 2 times.

1st. time, MBC untouched, but changed the oil. It pulled a little bit harder.

2nd time around, turned the MBC all the way to maximum, it definately made a huge different. Way faster and hits harder now, but it is like the t25 now. I was boosting 18, 19 psi and spikes up to 22, 23 psi.

The boost starts to build around 2k rpm and hits full boost at 4500 or so(when the waste gate opens up)

I still have to do a second boost leak test and get them all fixed up.

 

[RedTurboEclipse]

I just put in an mHI big16g in my daily. I did not have an MBC so it was running the wastegate boost which was like 8-9lbs. Passengers did comment how it did feel faster already than my t25 at 15lbs. At 8-9 lbs I could start to feel the big torque hit that the 16gs are known for, but because of such low boost its like coming up short. I finally got my MBC and turned it up to 15 and yuppp, its definitely a monster that the t25 cannot touch at all.

I have dsmlink, denso660s, stock fp and fpr, full upper and lower ic pipes with real greddy type s and injen knockoff intake pipe with filter, stock turboback. I hit full boost in this mhi ported big16g around 3300~ give or take some. no creep or spike, but we'll see after I get a full 3" tb.

I got some logs of cruising on dsmlink if you need data. The MBC i'm using is the $15 NXS one I got on ebay. Don't want to turn it up anymore until i put in a fuel pump.

 

[dsm-onster]

Something is wrong. My 60lb/min 60-1 turbo hit full earlier than that. My holset now does. And my small 16g hit full boost with laggy 272 style cams at 3400rpms.

Do you mean creep or spike? Does it hit a certain boost number then "creep" to a higher number?

 

[RedTurboEclipse]

Yea something is up, my 50trim on my other GSX hits full boost (22psi) sooner than his s16g. How are the wastegates on those s16gs, maybe its going bad or needs adjusting (if applicable) thus why its boosting slow?

 

[93_tsi_fwd]

Do you mean creep or spike? Does it hit a certain boost number then "creep" to a higher number?

Well, it goes up to 22, 23 psi's at the biggining then goes back down to 18 psi at higher rpm.

 

[dsm-onster]

With a WOT stab, in 3rd gear, at what rpm does it spike?

 

[93_tsi_fwd]

Didnt really look at the gauge as much, but ill post back later on with more details

 

[93_tsi_fwd]

Yea something is up, my 50trim on my other GSX hits full boost (22psi) sooner than his s16g. How are the wastegates on those s16gs, maybe its going bad or needs adjusting (if applicable) thus why its boosting slow?

the waste gate on it came off of a evo3 16g. I not sure how much pressure those hold.

 

[Bud92gsx]

Well our small 16G's flow more air than the T25. Add an Evo 3 or ported 2G manifold, and you should notice a big difference. I have an unported 1G manifold at the moment. Although I am building a tubular manifold to help spool the 16G sooner. With the turbo in the factory location I might add. By the beginning of October, the build should be complete, and I might start producing a few for special interests. The only drawback is that there being built out of mild steel, and are going to need to be ceramic coated before instalation.

 

[93_tsi_fwd]

I just bought an MHI evo3 16g, and ill fill you guys in with an update in a couple of days.

 

[Stapl3]

Please get a logger and play with that safc a bit. Just tuning for knock would be fine and you wouldn't be doing things so blindly.

 

[dsm-onster]

I just bought an MHI evo3 16g, and ill fill you guys in with an update in a couple of days.

Did you ever find out why your small 16g was spooling so slow?

 

[93_tsi_fwd]

Not yet. Im still waiting for it to come in the mail. I did check my timing and its off by alot. Ill be redoing it on saturday and see if that'll fix the problem.

 

[PieEyedPiper]

Just wondering how do you know how to set your SAFC since you don't have a logger?

 

[93_tsi_fwd]

I followed the RRE set up tips.

RRE's Super AFC Setting and Adjustment Tips

 

[93_tsi_fwd]

I seem to have fixed the problem. Changed the timing belt, got everything on time, and and took it for a 4 hour drive,(kind of like breaking it in(baby shower)) when we got there, i let her rest for 1 day. the next morning, i check everything, all looks to be good. took it around for an hour of so and it seems to be way stronger now. 3rd gear WOT pulls crazy. full boost hits somewhere around 3k rpm.

Now, on the way home. the oil light started flashing. Checked everything but nothing. oil is full. has oil pressure. etc. the whole way home the oil light was on, even now. cant seem to figure it out.

 

[propeine]

Disconnected one of the sending units by accident while you were doing the timing belt perhaps? Maybe just knocked it a bit loose and after driving for a while it came off the rest the way?