How much boost is ok? 6bolt with FP T28

[saturnshadow]

my 97 Talon has a 6 bolt swap, FP T28 ported, 750cc injectors, 190 with rewire, dsmchips stage 3, Greddy fmic.
I am running 18psi at about 11.3 AFR, what do you guys think is "safe" on pump gas?

 

[LiquidX]

Well we personally don't know what you will be fine at as each car is different. The turbo does have a range of efficency (I don't know what it is personally) and you don't want to go outside of that. But to answer your question more properly, you need to log to see when you start knocking and that's as much as you'll be able to run with the tune you have and the parts being used. It will change depending on if you are using pump or ethanol(have to have a tune for it).

 

[saturnshadow]

1 i hate you because you have the fog lights....
i have never seen any knock, i will hook up my pocket logger this weekend and make sure. also there is a safc2 for fine tuning and i have a avcr to control boost.
I do have a methanol kit i just have not put it on yet.

 

[LiquidX]

I don't have foglights on now since I have a FMIC. The avatar picture is from the day I saw it at the dealership all stock.

With everything you have you should be fine to run the turbo hard. Keep an eye on your knock and the IDC which should be fine. The meth kit will allow you to lower your knock but I don't know if that would upset your tune or not. Easier to account for if you can burn your own chips or alter your tune on the fly. That's about as much as I can help you out with as I don't know tuning yet. If you are on stock head studs then don't go higher than I believe it's 28psi on the 12mm studs.

 

[SFrymyah]

FP says that 19-22 PSI is right on the edge of its efficiency range. Someone already said every car is different, so whether or not you can get there without knocking is the big question. If you can get 93 where you live, then you should be able to make into the 20's without an issue.

 

[saturnshadow]

i can burn my own chips but i can't alter my tune on the fly.
It is a 100% stock 91 6bolt with new Timing Belt, Tensioner, Balance Shaft Belts, Idler Pulleys, Water Pump, Valve Cover Gasket, Throttle body,External oil cooler. it had 75k miles on when swapped, but less then 10k since the swap. Compression tested 185psi across.
also it has:
Ported 2g Exhaust Manifold
Ported O2 Housing
3" Downpipe
3" Apexi N1 exhaust
Injen Air intake with K&N air filter REAL Greddy Type S BOV

 

[SFrymyah]

With your mods, you should be able to get a few more psi out of her. do you have an AFPR?

 

[saturnshadow]

I do not have a AFPR yet,
Also i have a new turbonetics 60-1 ball bearing i was thinking about putting on. anyone have experience with the BEP housing for garret/turbonetics?

 

[pboglio]

If you throw everything at the T28, I mean everything, then do not boost more than 25 psi. I ran 25 psi and the car pulled great, 27 psi the engine was hating the backpressure and power was dropping off bigtime. Both pulls the ignition timing was at 23* on race gas so no timing retard. I attribute the difference so the turbine section choking since the wastegate had to close more to spin the boost up higher. So, I'd say 25 psi is the limit regardless of what mods you have.

 

[Long Duk Dong]

If you throw everything at the T28, I mean everything, then do not boost more than 25 psi. I ran 25 psi and the car pulled great, 27 psi the engine was hating the backpressure and power was dropping off bigtime. Both pulls the ignition timing was at 23* on race gas so no timing retard. I attribute the difference so the turbine section choking since the wastegate had to close more to spin the boost up higher. So, I'd say 25 psi is the limit regardless of what mods you have.

Being that the OP stated that he had an alchy kit I wonder how the turbo nad backpressure would be with it installed.

 

[pboglio]

With a 3" downpipe, it might help a bit. I run a 2.5" downpipe so that backpressure gets multiplied up thru the exhaust manifold. I also ran the old old T28 with 10 blades on the exhaust wheel, the ones after 2002 or late 2001 were running the 9 bladed wheel which is higher flowing. Maybe 27 psi is possible, but for sure it is an upper limit anyways as the compressor can't even make much beyond 27 psi according the the compressor maps. I tell you, the car felt just horrible with nothing but 2 psi added.

I doubt the alcohol injection would make a difference other than preventing knock, but in this case I was running the same 23* timing either way with zero knock due to very high octane fuel.

I would have to say 23 psi is the sweet spot where the car just felt great. I made the most power with this setting, somewhere around 353 w.h.p. via DSMLink. What it took to hold that psi was speed density removing the restriction in front of the turbo and tighting the hose clamps JUST before I did my runs.

On pump gas, 19 psi is as high as I can run without knocking because of the cams. Without cams, maybe 21 psi if the timing is adjusted right. All depends on so many factors.

 

[mindset]

How many miles on your HG? What kind? And do you have ARP's?

I'd say anything more than what you're running will stretch your head bolts and blow the headgasket.

 

[saturnshadow]

100% stock 91 6 bolt. maybe 85k miles on it. never been apart.
also my downpipe is getting a cutout welded on it.

 

[donniekak]

How many miles on your HG? What kind? And do you have ARP's?

I'd say anything more than what you're running will stretch your head bolts and blow the headgasket.

I run 30+ psi on e85 with a 20g, stock 12mm headbolts and a felpro composite. The people with the headbolt problems are the 7 bolt guys with the junk tty 11mm bolts.

 

[saturnshadow]

E85 is way to far from me, but i am thinking about putting my methanol kit on for added safety.

 

[pboglio]

Agreed, the guys running 11mm studs need to go to ARP's above 300 w.h.p. I stretched mine without even trying, ARP's fixed it right up. Stocker headgasket can take you FAR, leave it alone if its already on there.

 

[UofACATS]

The people with the headbolt problems are the 7 bolt guys with the junk tty 11mm bolts.

IMO that would read more accurately if it said "those who detonate on the stock 7-bolt.." IMO that's much worse than running 25psi or 300+whp on a great tune.

Personally I ran my FP3065 at 24-25 psi on an e85 tune (Wingz tune pro tuner) aka 20º up top and a massive bump low and midrange timing. Car was unbelievable for what it was (the turbo really wakes up at 30+psi) but I'm confident it was well north of 300whp. There was *no* knock on the e85 tune. I did get 0.4 blips every now and then, which I ignored. This is on my stock 7-bolt. There was nothing stopping me from raising the boost except the inability to afford any down time or breakage, thus I remained conservative and left it alone.

As far as taking a *great* tuned stock 6-bolt (stock headstuds), read this:
http://www.dsmtuners.com/forums/tun...-e85-update-new-jmf-race-intake-manifold.html

OP: I ran the BigT28 at 24-25lbs (meth+91) and it was a huge wakeup from the usual 19-20psi. Extremely hard-hitting turbo, especially with the FP17psi actuator.

 

[SFrymyah]

IMO that would read more accurately if it said "those who detonate on the stock 7-bolt.." IMO that's much worse than running 25psi or 300+whp on a great tune.

Personally I ran my FP3065 at 24-25 psi on an e85 tune (Wingz tune pro tuner) aka 20º up top and a massive bump low and midrange timing. Car was unbelievable for what it was (the turbo really wakes up at 30+psi) but I'm confident it was well north of 300whp. There was *no* knock on the e85 tune. I did get 0.4 blips every now and then, which I ignored. This is on my stock 7-bolt. There was nothing stopping me from raising the boost except the inability to afford any down time or breakage, thus I remained conservative and left it alone.

As far as taking a *great* tuned stock 6-bolt (stock headstuds), read this:
http://www.dsmtuners.com/forums/tun...-e85-update-new-jmf-race-intake-manifold.html

OP: I ran the BigT28 at 24-25lbs (meth+91) and it was a huge wakeup from the usual 19-20psi. Extremely hard-hitting turbo, especially with the FP17psi actuator.

Good post, especially the bold.

I was always under the assumption that the T-28 just died after about 21 psi. i guess i do have room for a race gas tune!

 

[saturnshadow]

I guess its time to put my methanol injection kit on. have to find a place for the big ass pump and tank or maybe use the stock windshield sprayer tank. i hit 20 psi once when i was messing with the AVCR, it pulled hard, i didn't see any knock but i don't trust cali piss 91.

 

[UofACATS]

Good post, especially the bold.

I was always under the assumption that the T-28 just died after about 21 psi. i guess i do have room for a race gas tune!

It was the "newest" version of FPs T28. It's still T25 based, so it does die up top. The midrange is where it hits 25psi and MASHES you into your seat.

Search pboglio's old posts for good T28 information.

 

[saturnshadow]

So i added the apexi ATS to my exhaust and hate it. granted my neighbors love it because my car is quiet, but it sounds like crap at idle, takes a few hundred more rpm to spool and has a noticeable drop in power. And even when it opens up (take to long) is still sounds crappy.
now i am thinking about putting on my turbonetics 60-1 BB HiFi with my meth kit and putting in a electric cutout.