Prowler217

iTrader: (5)

hey guys need some insight. I have been building my lexus sc300 for a while, and now it is on the DYNO. first it made 250 hp on 7lbs , i got a new wastegate and now its at 350hp on 13lbs. I want 425-450 hp.. thinking of having them increase it to 16lbs. I have read where people have pressed more boost and had no problem. I am running a 2jzge:
2mm head gasket Cosmic
Arp head bolts
FFM intake manifold with 90mm throttle body
RC750 injectors,
255lb fuel pump with upgraded lines and fuel rail.
Magnacore 10mm wires ( have set up for distribute less though also )
Turbonetics t3 57mm trim turbo
front mount greddy intercoller
synapse BOV
38mm turbo smart wastegate
stock internals
engine approximately 70k on it


w58 tranny with 6 sprung clutch with a supra LSD also.

imDementeD

iTrader: (7)

really whatever your tuner feels comfortable with...exactly what turbo do you have?? t04e 57 trim?..ur block can handle whatever and u having the thick headgasket u can easily run a lot more boost but the bottom line is what can ur tuner extract on pump gas if u want this for ur daily driver..you shouldnt have a problem boosting ~20psi

99SC42

iTrader: (44)

20-22 is the max I would do on pump gas 93 octane.You don't wanna blow that trans trying to get the maximum hp.
Nice numbers.
What are you using to control timing? what ecu are you running?

good2go

iTrader: (6)

THIS (and its tune) ^^ are the most important factors

Ali SC3

iTrader: (10)

since you have the 2mm headgasket you will have to push more boost to hit those numbers. you should at least be running 16 lbs and you may want to look into a bigger turbo since a 57mm isn't the best option to push high amounts of boost on a low compression setup, but should work ok for now.
the problem with more boost is you need better engine management, so I hope you have a nice EMS or some kind of timing/fuel controller.

you could also just go back down the a TT headgaket and you would just break 400 around your current boost level.

Rising_Sun

iTrader: (2)

+1

This is good advice!

Prowler217

iTrader: (5)

hey hydra nemesis ecu.

Prowler217

iTrader: (5)

hey so you saying back down from the 2mm . I thought the better or thicker head gasket was safer.

99SC42

iTrader: (44)

You can keep the way it is right now it's not worth it take the head off again.
You need bigger Turbo and about 18-20psi you will hit that goal no problem.

The TT HD would have been you best bet but you will be fine with the 2mm HG.

Prowler217

iTrader: (5)

oh ok. thanks. so you think I cant hit it with that turbo. I want something as close to natural through the powerband as I can. no big top hit. That's why i chose the turbo. The turbo came from a turbonetics kit for a scion ball bearing and rated at 600hp. I want 425 -450. i think at 18lbs of boost I can hit 425 if 13lbs has me at 350. you think the block its self can handle that boost pressure?

imDementeD

iTrader: (7)

the block can most definitely..easily handle 700+whp as long as it was maintained
just use the turbo u have tune it at ~20psi see what ur hitting..if you arent pleased..then upgrade.

99SC42

iTrader: (44)

Remember you have a 3.0 what size AR are you running?
You have a T3 footprint.
The high compression will help you spool that turbo really fast, don't worry about lag because you won't have any!
Ali is running a 60-1 and his car turbo spools like the gte stock twins.

I understand that you are not looking for a hwy monster which is cool, I still think the 61mm will do just fine.
or you can try the current turbo and see what happen.

Prowler217

iTrader: (5)

Thanks for the knowledge and ideas. Yeah think I am going to dial up 18 maybe 20. By next week. After holiday on duno.

lexforlife

iTrader: (7)

agreed on what ali and quickgs are saying

i have gone thru 2 boostlogic 2.5mm hg in the space of 1 yr.. thicker is not better ... they dont seal correctly and they destroy the intended quench area of the combustion chamber where it actually increases flame travel and increases the chances for detonation...

i finally listened to my tuners advice after he showed me the tech data and went to a tt headgasket and could not be happier in fact when its time for a fresh motor , 10:0:1 compression or damm close to it is what i want

tune for tune compared to when i was 2.5mm hg i picked up 35 more rwhp on 3 psi less boost ...off boost driving is sweet as hell as i can do drive around and accelerate without hitting pos pressure at all. during the tuning process , we saw zero knock at 19psi on straight 93 pump gas , zero knock via the aem

in the na-t world , going standalone is critical as the stock ecu has zero lookup maps for safe timing and fueling curves in positive pressure

good2go

iTrader: (6)

Yep, that generally happens because most people don't have the head and block surfaced to the required RA spec for an MLS gasket to seal properly.

You are spot on about the destroyed quench issue. As far as quench is concerned, if you need to go lower compression than the TT HG provides, it's better to go with the TT pistons instead; at which point you're rebuilding the short block anyway and most will just go GTE. Well, for that matter, having the block deck surfaced to necessary RA spec means your basically rebuilding the sb too.

I have come to the simple conclusion that a good standalone and a professional tune are ultimately the most significant factors and can make or break the success of the build, even if you've followed everyone's "cookie-cutter" specifications for what your setup SHOULD be.

$.02