kane.s2k

There's more air flowing in and more air flowing out. It keeps the valve open a little more since the air is rushing out/in.

That's the simplified understanding of it. It's hard to close a door when the wind is blowing one way or it closes too easy when the door has wind blowing the other way and vice versa.

That being said - no you probably dont need to upgrade. Just check all clearances and look for any cracks and wear. If you're going to replace, OEM is the most hassle free and longest lasting.

kane.s2k

Don't even think about with stock valvetrain

AusS2000

What is the story with Titanium retainers? From what I've heard they are 'harder' than stock and hence 'fatigue' quicker. Is that right?

If so, I guess they are a good race part but not ideal for long term reliability. In fact they may actually be a step backwards. Are there any 'stronger' retainers?

NB. The quoted words are used in their Materials Properties sense.

Silver S2k4

I don't want to highjack this thread but how realistic is it to rev the f22 to say 8,500 using the EMS? I really want to try this because I just don't have enough RPMs and they go so quick with the SC.

kane.s2k

There was a post about this a while back and was pretty through. Titanium is actually softer than the stainless steel in the stock retainers. So what happens is that they deform. The benefit to Ti is that they're significantly lighter.

hukares

Titanium is softer than the hardened steel they use in retainers. They can deform but otherwise will wear from contact with the harder spring material. This is especially true if using spring dampers which looks like and basically is a flat spring for those that don't know, as the dampers tend to slowly cut through the retainer. As for the valve being harder to close under boost, I doubt there is a noteworthy difference. The pressure already filling the cylinder would also be pushing up on the valve at the same time. The only time you would need higher rate springs and a lighter valvetrain is when you increase rpms, put in a higher lift cam, and most important, when you put in a cam with increased ramp rates.

JeremyM

skip, have you mentioned your inquery with to dave yet. i know he was looking into different boost/pulley options in the near future if he keeps the car and im sure he has found some good information. you could always save up a little more, go ahead and do the full headwork and run an even smaller pulley. then you could achieve your hp goals w/out the spray. and since you will already be utilizing the EMS, tuning shouldnt be such an issue.

jeremy

FF2Skip

Thank you all for the responses. I'll proceed in accordance with staying at the stock rev limit... for now. I'll have to research all that needs to be done before bumping up to 9500 rpm. If someone knows of a post that I can be directed to or use specific words for the search function, lay it on me!

Sideways

I went to a 9500 rpm redline one year ago. http://forums.s2ki.com/forums/index.php?showtopic=215021
The car is running fine with probably a thousand forays into the 9300-9500 rpm range.

Due to the HP peak at 9250 rpm, I lowered the redline to 9350 soft, 9400 hard this year. I plan to go lower with added boost.

The retainers are Titanium, the springs are all Honda intakes (yellows.) The valves are Manley stainless steel (larger and lighter than stock.)
The head was ported, polished and blueprinted by Joe Alaniz.

The best thing about 9500 rpm is the sound. I'm currently running an Amuse and it gets everybodys attention with the sweet sound.

bigworm

Hey silvers2k4, have you lowered the vtec change over below 6k. If so how much? I also have an ap2, and I am thinking about FI. I could only imagine how fast 1st gear goes by with the different gears and lower redline and the blower. How do you like the ap2 w/ the charger. Was it worth it?

Plus, it is easier to drop the car out of vtec in the 1>2 shift, so lowering the engagement would help with that also.

sorry to jack the thread guys.