Whats the max boost for 91oct?
Dec 16, 2020, 09:35 AM
#2
EvoM Guru
iTrader: (1)
It varies car to car, but if you want to be safe, it's usually going to have a 25psi spike on the hit, and taper off to around 15 or so. Typical 91 octane results with bolt ons (full exhaust, intercooler, intake, boost control solenoid) will vary from 330-350whp on a dyno jet.
Dec 16, 2020, 01:23 PM
#3
It varies car to car, but if you want to be safe, it's usually going to have a 25psi spike on the hit, and taper off to around 15 or so. Typical 91 octane results with bolt ons (full exhaust, intercooler, intake, boost control solenoid) will vary from 330-350whp on a dyno jet.
In evoscan using mode23 to log boost thats the value i get.
Feb 25, 2021, 12:57 AM
#4
That sounds about right, of course, you gotta factor timing, backpressure, intake size and afr. the limit on the oem turbo is going to be turbine flow. at some point its going to be choked so much, back pressure will stop it from making anymore boost.
i have a 5" intake, fp red bb turbo, sakura manifold, ams dp, 3.5 exhaust, and 1000cc injectors with a 450lph pump. i run 24psi on a stock engine, with 9-10deg of timing, 11.6 afr, on 93, and it made 498awhp on a dynojet. its been like that for a year now, and so far the engine is healthy.
with the stock turbo, the fuel octane isnt really the issue, its turbine flow and exhaust back pressure that is the limiting factor. plus i think the oem intake becomes a flow restriction at 350-390whp.
just be careful when maxing out the oem turbo. with high boost levels, the thrust loading on the shaft will begin weakening the journal bearings and it can start to have oil blow by. the last thing you want is to have too much shaft rpm, causing either a compressor wheel failure or turbine wheel failure. if the compressor wheel were to explode, its gonna sent debris through the ic piping, ic, and into the engine.
29psi seems a bit dangerous, even with the taper down to 17psi. i guess if it hits 29psi for a really brief amount of time, itll be ok, but its def going to shorten the life of the turbo.
i have a 5" intake, fp red bb turbo, sakura manifold, ams dp, 3.5 exhaust, and 1000cc injectors with a 450lph pump. i run 24psi on a stock engine, with 9-10deg of timing, 11.6 afr, on 93, and it made 498awhp on a dynojet. its been like that for a year now, and so far the engine is healthy.
with the stock turbo, the fuel octane isnt really the issue, its turbine flow and exhaust back pressure that is the limiting factor. plus i think the oem intake becomes a flow restriction at 350-390whp.
just be careful when maxing out the oem turbo. with high boost levels, the thrust loading on the shaft will begin weakening the journal bearings and it can start to have oil blow by. the last thing you want is to have too much shaft rpm, causing either a compressor wheel failure or turbine wheel failure. if the compressor wheel were to explode, its gonna sent debris through the ic piping, ic, and into the engine.
29psi seems a bit dangerous, even with the taper down to 17psi. i guess if it hits 29psi for a really brief amount of time, itll be ok, but its def going to shorten the life of the turbo.
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jrsimon27 (Feb 28, 2021)
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