Establishing a redline? - Subaru Enthusiasts Car Club of the Sierras

ShawnS · 2003-04-29, 12:08 PM

I am about to get my 2.4 Turbo engine build up underway soon and needed to know something. How do you establish a redline when using upgraded internals, new cams, new valve train, etc...? When using new parts, I would assume you could push the engine further than stock. Just curious on how one would determine redline after these mods.

sperry · 2003-05-09, 08:12 AM

I'd hope the person/shop doing the work would know. If you're doing it yourself, I'd suggest getting some books or something on the topic, and then finding someone that knows what they're doing.

If you're buying a kit, there are prolly some recomendations you can get from other people that have installed that kit.

dayofpain · 2003-05-09, 04:25 PM

Quote:

Originally Posted by The Lude

I am about to get my 2.4 Turbo engine build up underway soon and needed to know something. How do you establish a redline when using upgraded internals, new cams, new valve train, etc...? When using new parts, I would assume you could push the engine further than stock. Just curious on how one would determine redline after these mods.

the camshafts determine the redline. cams will be good from (a)rpm to (b)rpm. after that they will stop making power. youll want to set the spark cut off a little after "redline".

AtomicLabMonkey · 2003-05-10, 10:21 PM

Well the primary purpose of the redline isn't to just put an RPM limit after the point at which the engine makes its max. power... it's so you don't literally blow up the engine. Push the engine beyond a certain speed and a piston will bang into a valve, resulting in lots of little pieces everywhere in what's left of the motor. So, you want to establish a redline RPM at least slightly under that. As for how to calculate it, you got me.

.. Like Scott said, talk to reputable engine builders and see if they have a common way of figuring it out (that they'd be willing to share).

2003-04-29, 12:08 PM	#1
ShawnS EJ251 Join Date: Feb 2003 Location: Seattle Posts: 540 Car: 1995 S14 Zenki	Establishing a redline? I am about to get my 2.4 Turbo engine build up underway soon and needed to know something. How do you establish a redline when using upgraded internals, new cams, new valve train, etc...? When using new parts, I would assume you could push the engine further than stock. Just curious on how one would determine redline after these mods. __________________ Either this boy has a light bulb up his ass, or his colon has a bright idea.

2003-05-09, 08:12 AM	#2
sperry The Doink Real Name: Scott Join Date: Nov 2002 Location: Portland, OR Posts: 20,335 Car: '09 OBXT, '02 WRX, '96 Miata Class: PDX/TT-6 The way out is through	I'd hope the person/shop doing the work would know. If you're doing it yourself, I'd suggest getting some books or something on the topic, and then finding someone that knows what they're doing. If you're buying a kit, there are prolly some recomendations you can get from other people that have installed that kit. __________________ Is you is, or is you ain't, my con-stit-u-ints?

2003-05-10, 10:21 PM	#4
AtomicLabMonkey Nightwalker Real Name: Austin Join Date: Dec 2002 Location: Oshkosh, WI Posts: 4,063 Car: '13 WRX YGBSM	Well the primary purpose of the redline isn't to just put an RPM limit after the point at which the engine makes its max. power... it's so you don't literally blow up the engine. Push the engine beyond a certain speed and a piston will bang into a valve, resulting in lots of little pieces everywhere in what's left of the motor. So, you want to establish a redline RPM at least slightly under that. As for how to calculate it, you got me. .. Like Scott said, talk to reputable engine builders and see if they have a common way of figuring it out (that they'd be willing to share). __________________ "None of you seem to understand. I'm not locked in here with you.. you're locked in here with me."