S14 sr built bottom end boost

[cubbies1031]

have a notchtop s14 sr. it has a built bottom end, not sure whats do to it i was told just pistons and rods but not positive on that bought it that way. its running stock boost and i bought a boost controller for it. i know it wont hurt it with more boost since its running a bit rich anyways and it has the bottom end. it does have the stock t28 on it though and i was wondering how high i should cut the boost up. i dont want crazy amounts of boost or anything just wondered what psi i should be at with my set up.

[didderson]

Most people say keep stock sr turbos below 14psi. That's pushing it though. Stay 13psi for safety on 93 octane if you have stock tune and stock injectors. If you have a journal bearing turbo or have ceramic comp/turbine blades, you don't wanna spin them to death lol. (faster rpm's come with higher boost levels)
This is in a nutshell speak. Search search search will yield muuch more extensive discussions.

Just because you have a built bottom end doesn't mean it can take more engine knock if you don't have upgraded injectors/tune/pump/fuel system in general. That's your limiting factor. Maybe s14 injectors can stomach more increase and have more cc of flow from the factory than s13 sr20det's, but I am not familiar w/ that... search sayss

http://www.drift-connection.com/sr20det-specs.php

If this is a reliable source, and you check your ECU number to verify what car your SR20 came from, and have at it!

Specifications for the S14 Black Top SR20DET with VTC
(Found on the 95-98 Silvia)


Horsepower: 220hp @ 6000rpm
Torque: 203 ft/lbs @ 4800rpm
Turbo Specs:
Compressor: T-28, 60 trim 60mm BCI-1 compressor in T-04B housing
Turbine: T-25, 62 trim 53.8mm 0.64 A/R turbine housing.
Center Section: Ball Bearing
S14 SR20DET's use a different ECU and harness, these are extremely expensive and hard to find.
Variable valve timing system and a different turbo are the significant changes from the S13 SR20DET engines.
The S13 uses a "low port" intake design vs. the S14 "high port" design.
Performance:
The stock turbo will be safe to 13-15 psi. After that, the turbo is past its efficiency range, and power increases will fall off and are not worth the risk of turbo damage. The stock engine should produce 250-260 RWHP at safe boost using stock turbo. Upgrading turbo, fuel and rest of need parts will yield 300-375.

[cubbies1031]

Alright I may just put a gt28 on it bump the to 15 pounds and call it quits. I have the walbro 255 with stock injectors but I think that would be a good setup

[chituntang]

I have no idea of why you have a built engine with a stock turbo... Maybe the last owner ran out of money and just put things back together and sell it to you?

But in terms of stock SR turbos, they do not make enough boost/pressure to kill the engine itself. However, if you are going the GT28 route, you will need to upgrade injectors and get a tune. Stock injectors cannot handle the extra boost.

[cubbies1031]

You're saying stock injectors can't handle a gt28?