ATTN: Cam owners

[twilightprotege]

i dont know which is which, but i think from the pm i sent to him, he just replaced the stock pistons with 10.4's (first one) and 10.7's (2nd one)...not sure

i'm going to get macs to do a senario on what my car might be pushing out after the exhaust is done

 

[thewrench]

Ahhhh, damn, I really don't want to tear apart the bottom end. I'm about ready just to get some custom cams, but I'm not sure about what #s to specify for the straight-up overlap. And I really don't want to be a guinea pig.

 

[twilightprotege]

i'm going to get him to run a few scenarios with just my cams and exhaust, but with the 9.1:1 compression ratio. that'll give everyone an idea on what my setup will do to your car.

then i'll get him to do the same with 9.7:1 comp (mine), then 10.4, 10.7, 10.8 and 10.9....just to give me some more food for thought...

i'll also see how willing he is to play around with adjustable cam gears (if the program can allow it) and see what that has to say

 

[thewrench]

That'd be cool. I'm trying to wait and see what perf is coming out with, but I REALLY don't like it that he's not giving out specs. I would never buy cams for my V8s without knowing the specs, P5 shouldn't be different. I may do some more research, and come up with some #s and run them by you. Bear in mind, I'm looking for more midrange torque than you. That has also depended on being able to majorly advance the timing with the EMS, but pricing on that has me discouraged. Damn you and your ECU

 

[twilightprotege]

yep, feel free to run numbers by me.

 

[akhilleus]

hey wrench. I am about to send an exhaust cam to get reground. If it works well maybe i can help u out. Also about perf's cams he just didnt want to release his specs before they have been installed and dyno and ready for sale. I would believe. And at the least u could get raw duration and lift #. U might want to get his if u will do them all at once since they will be made to work with each other while mine will be made for the jdm cam.

 

[thewrench]

Thanks man. Maybe I misunderstood what perf said. I thought he said he was going to sell them by stages, ie stage 1, stage 2, etc. And then back up performance with dyno #s. Problem with that is, if you don't have the exact same mods as his dyno mule, then dyno results can't be guaranteed, and may not even be close. Things such as headwork and intake mani work will vary from car to car. It seems silly to me though, one person buys them and has them measured, everybody has the numbers anyway. I'll wait to see what happens when he releases them, but I'm more and more leaning towards doing my own. Or just going your route and forgetting about it.

 

[iluvmacs]

Just got back from vacation. About specs, I didn't know if twilight wanted his specs posted, since I think I got them from a PM.

I'll be happy to run any numbers through the computer. I prefer to get a PM because they're easier to get numbers from.

I can do cam timing adjustments. The only problem is that I don't know what the STOCK numbers are. It won't be worth much at all if I don't have a base set of numbers to compare cam timing adjustments too. Any help would be appreciated.

 

[akhilleus]

Have u gotten any data on my mods yet?

 

[iluvmacs]

Just woke up, turned on computer. Give me a few hours to get some breakfast and run the program.

 

[akhilleus]

thanks

 

[aftershock63]

I have both the J-spec and Mazdaspeed cams form www.srmotorsports.com and I think they are worth it. When I inspected the new cams against stock the ones I put in the car did not seem to change the lift at all but rather it had a much longer duration. I think that after my turbo goes on this could end up being a real performance advatage, being able to have just that much longer to squeeze more air into the camber. I will have to buy the cam gears and get it dyno tuned for sure though. Someone should post a list of places where you can buy the cams and gears. I'll start

www.srmotorsports.com

 

[iluvmacs]

ATTN akhilleus

Here's what I get for your mods. Check for a PM explaining what I did.

 

[iluvmacs]

With your torque peak at around 4500 you could make some really nice gains with other mods, like exhaust headers, intake/head porting, and maybe some exhaust cams.

I don't know about emissions, but when you shift the torque peak, you should try to match the airflow through the engine to get max power. You might need to increase your fuel flow for any more mods.

 

[akhilleus]

Thats what i figured actually.. although power seems to drop off a little sooner or at least plateau after 5.5k+ in reality.. nice torque though

 

[iluvmacs]

ATTN akhilleus

Here's with the exhaust cam. The problem is that I don't know the valve overlap, so I did the best I could to figure out what the power should be with 0 overlap or at 2 overlap. You need to consider that error when you look at the graph.

 

[akhilleus]

so power goes up but torque goes down... although in comparison it seems that i wouldnt gain much in perf.... and it seems like this graph isnt much different from twilights

 

[iluvmacs]

I don't like the exhaust cam numbers, mainly because I can't time the cams right. I'm sure that if the cams were timed right in the program that you would see better numbers. I just don't know where to start and I can't figure out what the best timing is.

That graph is with no overlap, so basically the intake cam opens at TDC, and the exhaust cam closes at TDC. All the duration additions did was start the exhaust cam 10 degrees earlier, and keep the intake cam open 10 degrees later.

If anyone has a better idea of when the cams actually open and close the valves, I can run better numbers. Does the intake open before, after, or at TDC?

 

[iluvmacs]

so power goes up but torque goes down... although in comparison it seems that i wouldnt gain much in perf.... and it seems like this graph isnt much different from twilights

Actually, your torque went UP. The scale is on the right for torque, and left for horsepower. It looks lower but it's about 3 ft*lbs higher if you look to the scale on the right.

 

[iluvmacs]

Here's that same graph, this time with exhaust headers...