Raj, I circled them in Red for you.

 

whatever you do don't mention this to nascar.....you'll destroy their whole engine program.they count on it in cam lift restricted racing (everywhere)

 

OK, Go-fast is a renowned engine builder. I accept that. But why does he not care about the valve overlap or cam lobe separation angle on the cams that he uses?

 

Be that as it may be, most all of us would have a tendency to believe folks like Jim Wolf, and are better off for doing so, so can't fault Terry there.

If everyone shared insights and understandings (right or wrong) and put as much effort into these kinds of topic as Terry did, we'd be able to start our own EFI college here in my350z. Even if this crowd can be a little harsh, your thoughts are appreciated Terry.

 

They have the beneifit of only needing their motors to hold up for a race or two. Completely different situation than our cars.

Now, if you have the big bucks to get your heads and cams refurbished every couple thousand miles, great. Use the launch off of the lobes to your advantage. But you, of all people, should know that the it will not be very long before something will break.

 

Yes, I know it says that Terry - lol. I asked Clark about it for S2 and he said I could use JWT springs if I wanted to. JWT is obviously not going to promote BC springs for their camshafts. They are also not going to recommend spinning the motor past 7500 rpms.

 

Thank you, Raj!

 

i do care....very much so,but it can only be used as a loose guide to the behaviour of the cam.ramp rate,intake lenght ect. have far more to do with actual performance than......again......advertised specs.

back on the original topic,jw's special springs are a bunch of hooey and any comparable spring from any quality manufaturer will work just fine....regardless of what jw says.


it makes me question the sales tactics and ethics of jw (yet again)

 

Thank you! That pretty much is what I have been saying.

Now, where is this information for the BC cams? Do they even publish it?

FYI, there is another thread where we hammered intake length to death.

 

Awesome. go-fast is still an OG and renowned expert in this industry who has chosen to remain anonymous on this forum. But a few of us know who he is and therefore will respect his professional opinion over anything you say or Jim Wolf tells you. I will take go-fast's word over Jim Wolf's any day of the week.

 

That's fine. That is completely your perogative.

 

Thanks for calling out Jim's BS and the bad info that was regurgitated.

 

I know Terry means well, but he has a tendency to make things unnecessarily complicated for those interested in a moderate power build. It's not rocket science! LOL I think he has muddied up threads in the FI section with theoretical speculations and JWT sales garble.

 

Go-fast, I'm assuming that you use BC cams, and you indicated that you use overlap and lobe separation angle as a loose guide to the behaviour of the cam.

Please share with the forum what the lobe separation angle and overlap are for the BC cams. Right now we do not have that information, which makes it difficult to evaluate those cams.

 

Unfortunately, in this forum, all too often statements are made without any rational basis, and they are taken for gospel. What I bring is the ability and a willingness to analyze the information, which helps to make the decision process more clear for those building motors. Now, you are correct, for people doing moderate builds, it does not always make a difference. But, for those doing large builds, it does matter. Based on previous questions, there were those who thought the T25 exhaust flanges would create a bottleneck that would hurt the performance of large turbo builds. No one came on the forum and said that there was nothing to worry about. So, I did the analysis, shared it with the forum, and now everyone who followed that thread knows. You may not appreciate that, but a number of other people do.

Rather than specifically mention cams, I would love to post a thread with cam profiles for cams from the various vendors. However, I have found only 2 vendors who make cams for our motors that specify lobe separation angle and/or valve overlap. Look at BC's website. The amount of information they provide about their cams is pathetic. If we as a community keep going along and ignoring that, why should they change???

 

LOL You're regurgitating what Jim Wolf (a man with **** poor integrity) tells you and posting up JWT pdf links as gospel! Pot meet kettle!

 

i have used jwt,gtm and bc cams.i should have bc cam cards somewhere.....let me get back to you on that.


btwy i only mentioned lift restricted cams as an example of how numbers lie.in no way did i suggest you use them on a vq,although several already employ this strategy and you would be suprised how prevelant it really is....can you say "high energy","magnum" or "voodoo" (hint hint)

 

JWT is the only company that has posted significant information about cams for our cars. If I had links or cam information from BC, or any other cam manufacturer, I would post them too. Then, everyone could read it and evaluate it. If someone feels so inclined to do a technical analysis on the information, they could do that too! But try to find any such infomration from any other manufacturers who make cams for our cars, If you find it, post it.

On that note, you obviously disagree with what the JWT pdf says. Please review it and post an analysis of it to clarify the problems with it.

 

Go-fast, that information would be great to have. Thank you!!!

I'll put together cam charts for every vendor's cams who we have the data for, and start a new thread with this information. That way, forum members will be able to compare various cams when making their cam selections.

 

Hey, if it gets go-fast to share some knowledge with us, let him be!

I would love to know what go-fast thinks about the various cams out today and which he'd recommend and why. I'll agree that there's often not a single right or wrong answer (i.e. "best" cam), but selecting the best cam for a particular application based on published specs is true voodoo and any insight (from Terry or go-fast) might be helpful in understanding it. I've read about concepts like jerk, splines, continuous snap, etc. but not of that stuff is published. The marketing data that is published doesn't help me evaluate the cams other than in generalities that Terry speaks to (about duration, lift, separation angle). How quickly the valve opens/closes would be another, but you can't really tell that from the specs. Or can you?

So, go-fast, how does anyone figure out what cam to buy? (other than trial and error from those who have tried it). Any insights on the thought process you go through would be appreciated.