T28 GUYS .... How much boost on pump gas?

[hottboost]

Just as the title says, Im curious as to how much boost everyone is running on pump gas?

 

[kspharris]

I would also like to know this. Let us know please.

 

[kenamond]

Just as the title says, Im curious as to how much boost everyone is running on pump gas?

15psi with a bit of knock

 

[zippyshoe]

I am also running at 15 psi on 93 octane pump. I am still limited by the stock sidemount intercooler. With a front-mount, I could probably run higher boost - I should have plenty of fuel available with 660cc injectors.

 

[hottboost]

I am running 20psi with a good timing curve.........for 4-5 pulls befor the smic heatsoaks!

 

[1g_tsi_awd]

15 maybe 16 on 93 octane is effiecient.

 

[kspharris]

Hottboost: Have you had any knock issues or any issues for that matter?

 

[Dasamary]

What kind of powerare you gusy seeing on T28 running 15 psi?

 

[2gGSX]

28 lbs/min

 

[JayRolla]

20 psi on the stock sidemount thats pretty good. Couldnt get more than 17psi on my bros car on 91 without any knock and thats with a large 4"inch thick FMIC. The guy that did the tuning with us added way to much timing I think and thats why he gets knock at any higher boost. On a cold night he can run 20 but it has to be pretty cool out.

 

[hottboost]

Hottboost: Have you had any knock issues or any issues for that matter?

No, Ive been lucky so far I am right on the edge though I have a good timing curve and max at 21* timing advance at 6700RPM range. I may be getting a few counts
(1-2) of knock because I have no way to monitor it. But not enough to effect timing.

 

[pnishr]

Are we talking JUST a T28, or a Big28, or a T28Killer (allT28 variants)?

I'm gonna have to disagree with the 15-16 being the end of efficiency comment. It's a more efficient wheel than a T25 and that's good to 16. I also don't know why so few have run it to 19-21psi on 93. My T25 runs at 18 (for the tiny time it'll hold it, spikes to 21) and I rarely get knock from it.

Also, I was looking at logs last night so I can do a comparison after the T28 (FPBig 28) is on. I'm getting 21.4 lb./min at 11psi on the T25.

I'll look at some more recent logs of hard runs (if I have any - I delete a lot) and check my airflow at higher boost. 28lb/min just doesn't gel with me for being the max efficiency for that turbo. Isn't it supposed to be 36ish?

 

[hottboost]

Are we talking JUST a T28, or a Big28, or a T28Killer (allT28 variants)?

I'm gonna have to disagree with the 15-16 being the end of efficiency comment. It's a more efficient wheel than a T25 and that's good to 16. I also don't know why so few have run it to 19-21psi on 93. My T25 runs at 18 (for the tiny time it'll hold it, spikes to 21) and I rarely get knock from it.

Also, I was looking at logs last night so I can do a comparison after the T28 (FPBig 28) is on. I'm getting 21.4 lb./min at 11psi on the T25.

I'll look at some more recent logs of hard runs (if I have any - I delete a lot) and check my airflow at higher boost. 28lb/min just doesn't gel with me for being the max efficiency for that turbo. Isn't it supposed to be 36ish?

I was curious on all 28's! I am running a SBR Big T28 ported. From my understanding the Big 28 doesnt really come alive untill about 18-19psi.

 

[pnishr]

I was curious on all 28's! I am running a SBR Big T28 ported. From my understanding the Big 28 doesnt really come alive untill about 18-19psi.

That's the impression I've always gotten. I was looking at more like 19-21. I'll probably shoot for 20. If they're only getting 28lb/min at 15psi, it's gotta be good for a bit higher.

 

[talonTSIDriver]

I push 17 psi on 93 octane with no knock with a Greddy 24r I/C. 21psi on 110 race fuel.

 

[siceclipse]

im at 20psi right now with 18*timing at 6000-6500RPM

93octane with a FMIC that kills airflow to my radiator, so timing may be knocked down due to high coolant temps.

still a kick in the pants at 20 psi tho.

 

[hottboost]

Yeah I love mine for what it is. If I can ever find time I want to get it on the dyno. Im in the car business so I work all the time.

 

[pnishr]

I actually had emailed FP about this issue this morning. This is the reply I got about 30 minutes ago:

Jeff,

Anywhere between 18-22 PSI should be efficient on that turbo, now if you're still on the stock sidemount, you're going to heat soak that pretty quickly. Do you have the upgraded 17psi wastegate actuator or are you still on the stock actuator for the big 28? Going with the higher pressure actuator will help you regulate the boost a little better as well, especially if you're wanting to run close to the 20-22psi mark.

As far as us slowing down, last year about late September to December were are few slower months that we had. If you were to bring your turbo in for porting at that time, we could probably get it turned around within a week. Just give me a call whenever you think you might want to bring it in and I can check with my port guy and see what he says.

Thanks,
Amber

Nanson,Jeffrey L. wrote:

>
>Amber,
>
>Thanks again for the info and help yesterday. There was another
>question that I forgot to ask yesterday; what (obviously this is an
>approximation) max boost would be safe to run that Big28 on 93octane.
>I'm on the stock sidemount, and just curious of a good starting point
>to keep the turbo in a good efficiency range. I've read on tuners that
>most run up to about 21psi (I'm spiking my T25 to 20.3psi with almost
>NO knock). Any and all input is appreciated. Also, around when do
>things start to slow down around there, so maybe I could get the 28 off
>and ported?
>
>Thanks,
>
>Jeff

 

[hottboost]

I actually had emailed FP about this issue this morning. This is the reply I got about 30 minutes ago:

Yeah I got the 17psi actuator when I got the turbo from sbr. And like I said a few post ago I soak the smic with about 4 hard pulls. I need a fmic bad!! Just havent had the time or money to piece it together!

Carl

 

[zippyshoe]

Yeah I got the 17psi actuator when I got the turbo from sbr. And like I said a few post ago I soak the smic with about 4 hard pulls. I need a fmic bad!! Just havent had the time or money to piece it together!

Carl

I am also anxious to upgrade from my stock sidemount. I would like to run my FP Big28 at around 20 psi instead of my current 15 psi - I think this would bring the turbo more into its peak efficiency range and allow me to take better advantage of my fuel mods.

 

[pnishr]

OK, well, I found one hard run. I'm running over 27lb/min on the T25. Spiking to 23!!! WTF That's the first time I've seen that! (that was on a DSMLink 5000rpm launch) still no knock. boost ran down to 11psi at 6499rpm. 2nd gear spikes at 19psi at 4000, falls to 15 at 5372, again making 27lb/min. That Big28 better knock my socks off. I better see at least 35lb/min. We'll see in 2 weeks.

 

[bushy]

What are you guys running for fuel upgrades?

 

[zippyshoe]

What are you guys running for fuel upgrades?

I am currently running with a Walbro 190lph fuel pump and Denso 660cc injectors (may be slightly overkill for this turbo - a set of 550's would probably be adequate for this turbo). I'm using DSMLink for tuning and logging. I decided to go with the 660's because with DSMLink, it is easy to tune-in larger injectors (even 1000cc and larger), the larger injectors keep your injector duty cycles low, and there was not a big price difference between 550's and 660's.

 

[diablos991]

I am installing a big t-28 tomorrow, and all my mods are in my profile. Fuel mods are walbro 190. I also have a hahn big SMIC. What boost should I start out at? I won't be able to log it for a couple of days, because I have to wait to use my buddies logger.

 

[pnishr]

What are you guys running for fuel upgrades?

a 255lph, FIC 750s, and DSMLink for tuning. the 750s are WAY overkill, but I plan on WAY more turbo than a T28... in time.

When I install my 28, I'll probably just start at 17psi (with the actuator) and work my way up. I'll make it nice and rich to start out, and figure out how far I can go, though I'll probably stop at 20-21. You might be able to go to 22 since your IC will be a little better. Let us know how it goes.