Chike's official n/a upgrade thread... - Page 7

SVXRide · #91 11-28-2005, 07:36 AM

Quote:

Originally Posted by TomsSVX

yes... these cams are actually allowing the peak power to be moved up in the rpms (Which allows for more power) and also to allow the engine to breath in deeper (Which allows for more power)... I am pondering about getting a little more aggressive

Tom

aren't you aggressive enough as it is?

-Bill
p.s. I'm wondering if a little less retard on the timing + little more duration might bring some bottom end back in and punch the top end up a bit more...

TomsSVX · #92 11-28-2005, 10:23 AM

yeah... I was thinking something around there... More about the duration than anything... I am not sure yet but I am liking the odds

Tom

Chiketkd · #93 11-28-2005, 11:12 AM

Quote:

Originally Posted by TomsSVX

yeah... I was thinking something around there... More about the duration than anything... I am not sure yet but I am liking the odds

Tom

The longer the duration, the higher up in the rpm band that peak power is made (correct me if I'm wrong). What we need to do is to find out on a dyno the rpms at which peak power is reached in our current set-up.

If peak power is being made at 6,100rpms, then we'll have some room to work with. But if peak power is made at a lofty 6,800rpms, then we shouldn't raise it any higher as we may run into issues such as 'valve float' in those higher rev ranges (due to the increase in intake valve lift).

Depending on Harvey's input, maybe the 5/6MT guys can try the same specs (8.0mm lift, 247 degrees of duration) but without retarding the profile by 7 degrees??? I know Harvey came up with those final specs in the way he did, to keep the IRIS system functional.

-Chike

SVXRide · #94 11-28-2005, 12:05 PM

Guess we'll either have to get your car or Tom's 5spd down to the dyno to see were the peak is!

That, or wait until I have the cams installed...
-Bill

Chiketkd · #95 11-28-2005, 12:38 PM

Quote:

Originally Posted by SVXRide

Guess we'll either have to get your car or Tom's 5spd down to the dyno to see were the peak is!

That, or wait until I have the cams installed...
-Bill

If you wait till January, I should at least have my new 4.44 4EAT installed by then. It also would give me *hope* that the OBDII stage 2v5 chip might be out!

-Chike

Chiketkd · #96 11-28-2005, 12:52 PM

Quote:

Originally Posted by Chiketkd

my city/highway gas mileage has gone down to roughly 20.5mpg (21.5mpg before), while my highway mileage is around 25mpg (26-27mpg before).

One thing which I wasn't taking into account before was that temps are cooler now and I've been running my heater constantly when I drive. When I compare my current fuel consumption to what it was over the summer when I used the a/c alot, it's virtually identical (20.5mpg now, 20.2mpg during summer in mixed city/highway)...

So there's no noticeable change in fuel consumption with these cams.

-Chike

oab_au · #97 11-29-2005, 08:02 PM

Quote:

Originally Posted by Chiketkd

The longer the duration, the higher up in the rpm band that peak power is made (correct me if I'm wrong). What we need to do is to find out on a dyno the rpms at which peak power is reached in our current set-up.

If peak power is being made at 6,100rpms, then we'll have some room to work with. But if peak power is made at a lofty 6,800rpms, then we shouldn't raise it any higher as we may run into issues such as 'valve float' in those higher rev ranges (due to the increase in intake valve lift).

Depending on Harvey's input, maybe the 5/6MT guys can try the same specs (8.0mm lift, 247 degrees of duration) but without retarding the profile by 7 degrees??? I know Harvey came up with those final specs in the way he did, to keep the IRIS system functional.

-Chike

The set up that Chike used, was to suit the 4.44 auto that he uses to run the quarter, as there was going to be some low rev power loss from the IRIS, it would only be below 3500, on the run up in first gear, and as the power drops after 5700, it was better to move the lobe center higher to fully use the top end, between 5500/6500. With this end of the range pulling harder, there is more power over the rev range that he uses on the strip, 3500 to auto change 6800.

I don't reconmend others use this lobe center setting. If the car has a 3.55 auto, it should use the standard 116*. If it has a 4.11 auto/ 3.9, 4.11 manual, then you could go to 118*. The duration and lift remains the same, you just need to tell Scott what lobe setting you want, when he does them.

Harvey.

shotgunslade · #98 11-29-2005, 08:23 PM

Harvey:

So, if I have a 5MT with a 3.9 ratio and I am looking for maximum performance on a road track (not AutoX), with top speeds of maybe 110-120 mph, but only getting down to 2nd gear, what lobe center setting should I ask for? Thanks.

TomsSVX · #99 11-29-2005, 08:25 PM

Here are a couple pics of my cam install without taking the engine out

wtf why can I not add images to the post???

eh here is a link to Mike621's locker where the pics are

Linky link linker

Tom

intellibomb · #**100** 11-29-2005, 09:41 PM

Quote:

o, if I have a 5MT with a 3.9 ratio and I am looking for maximum performance on a road track (not AutoX), with top speeds of maybe 110-120 mph, but only getting down to 2nd gear, what lobe center setting should I ask for? Thanks.

is the 5mt with 3.9 refer to the WRX 5spd?
isnt 3.9 the stock final drive? thats why i ask

thanks

shotgunslade · #**101** 11-30-2005, 07:15 AM

Yes. The 3.9 would be a WRX 5MT, which is what I am planning to have by next summer. As I understand it, the rear drive shaft from the WRX transmission is underdriven, so that it can be used with the stock SVX rear differential, and be consistent with the 3.9 ratio on the WRX front differential.

Earthworm · #**102** 11-30-2005, 12:20 PM

Quote:

Originally Posted by oab_au

If it has a 3.9 manual, then you could go to 118°. The duration and lift remains the same

Pseudo-quote

shotgunslade · #**103** 11-30-2005, 01:14 PM

Earthworm:

thanks

OBI · #**104** 11-30-2005, 01:14 PM

would porting the heads net some more power with these cams? Is it possible that the ports flow good enough already and the bottle neck is at the valve opening making a port job useless. Does this make any sense? Anyone?

SilverSpear · #**105** 11-30-2005, 02:14 PM

Of course OBI, the secret of performance begins by flow. either air flow, or fuel flow or water (cooling) flow, they all contribute to the increase in power.
I have been told by many tuners that plated valves (we call it chrome plated, I dunno if it is actually chrome) ease up the flow of fuel and do not form sludge on them. There wouldn't be loss of fuel which leads to higher compression caused by the combustion of a greater amount of fuel injected (remember no loss).

What I am really interested in is rather can we shorten the ports leading to an even faster flow through the valves? I am asking this question because I read like 6 years ago about the superiority of Mercedes Benz's 99' E320 engine, having direct injection in the combustion chamber... or directly above the valve... sorry I do not recall...