I want somethign that gives me max power. I have a auto. I'm not worried about idle. I'll be getting ls1edit. I have a b1 in there now and that cant be doing any good.

<small>[ June 06, 2002, 02:15 PM: Message edited by: Pro Stock John ]</small>

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Cool28:
<strong>I want somethign that gives me max power. I have a auto. I'm not worried about idle. I'll be getting ls1edit. I have a b1 in there now and that cant be doing any good.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I would email one of the sponsors bro.I know that a 116lsa will hold boost longer.

 

cams with less overlap are better for turbo apps.

 

TR 230/224 xxx/xxx 111

<small>[ June 04, 2002, 12:50 AM: Message edited by: Ryan ]</small>

 

Harlan,

What do you think of the following:

218/218 .519/.519 114 LSA

Dave Inall seemed to think that it would work really well with the twins...Terry Norris at Cam Motion actually picked out this cam for me.

Thanks,

Scott

 

People named Terry usually know what they are talking about. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> RE Turbo cams, I found myself it doesn't really matter much. Just match the cam to the heads, with a little more bias towards the intake side and a 113-114ls. The B1 you have is probably fine actually.

 

I'm looking for some damn near on the edge of insane kind of cam but for a turbo stock engine car. Does lift matter with turbo cars or is it more duration?

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Ryan:
<strong>TR 230/224 xxx/xxx 111</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">111 LSA is not good for a turbo. I would recommend that cam on a 114.

 

Todd,

Give cam motion a call and talk to Terry...they helped me pick out a mild cam for my stage 2 heads and m6.

He seems to know what he is doing. I don't have their number handy, but someone might...or you can try an internet search.

Scott

 

Are we speaking from experience?

If i can ever get my motor back in the car i'll tell you just how well mine does

228/224 .540 112 LSA

 

Typically you don't want a large overlap on a Turbo motor. However.....there are some interesting byproducts if your going radical.

 

a bit of overlap can be a saving grace when talking mid-range cylinder pressures versus top end flow.

nothing quite like a lopey turbo motor <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Scott 98Z M6:
<strong>Harlan,

What do you think of the following:

218/218 .519/.519 114 LSA

Dave Inall seemed to think that it would work really well with the twins...Terry Norris at Cam Motion actually picked out this cam for me.

Thanks,

Scott</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I talked to dave on the phone almost a year ago about the cam/heads/intake setup.

a very similar cam was discussed, same duration, bit more lift, and a 112 LSA. The relief of mid range cylinder pressure was again the key to the equation.

It was agreed to have a head/intake combo that would flow near 290 CFM as a unit to compliment the cam.

I've got the heads there, the cam is a tad bigger than discussed, and the intake is under the knife right now.

I personally would say duration will benifit you more than lift. You are after all shoving it in <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by y2khawk:
<strong>Are we speaking from experience?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Yes.

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by y2khawk:
<strong>228/224 .540 112 LSA</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Matt:
If you're pressurizing the intake, why crutch it? There's NO way that the LS1 intake port is so incredibly poor that compensation is required for a pressurized application. That doesn't seem engineering wise, engineering-wise, that is. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

SC

<small>[ June 05, 2002, 05:34 PM: Message edited by: SS00Blue ]</small>

 

The FI cams you are recommending with the 114 LSA... you sure your thinking turbo and not supercharger? The funny thing is that in a lot of turbo cars, cams don't seem to make a whole hell of a lot of difference as to how much power you make... just where you see the power. (as opposed to NA or supercharger where a powerband higher in the RPM range typically <being very general here> means more power. Regardless, I've seen theories that run the gamut, but reverse splits with tight LSA's definately are one school of thought on turbo cams. The thought is that with how much backpressure you get from the turbo you want to keep the exhaust duration short to keep a short but powerful burst of exhaust gas, you increase the intake duration to allow as much air in as possible... the tight LSA... well, not totally certain on that... I'm thinking it's a cyl. pressure issue, but that's just a guess... This really is something I wish I understood better... but that's what I've gathered so far :-)

PS- reference popular DSM turbo cams (web cams), buick turbo cams and other common turbo cars... you'll see this trend.

 

opps wrong tread

<small>[ June 05, 2002, 06:41 PM: Message edited by: Cool28 ]</small>

 

That's exactly the reasoning. A general guestimate for backpressure generated from the turbos themselves is on the order of 2X manifold pressure. so at 15 psig manifold, that's approaching 30 psig in the exhaust, preturbo. That's HUGE backpressure in the exhaust.

Indeed, there is a school of thought that says get as much in as you can, and keep as much pressure in the exhaust event to get it past the backpressure. That's what i'm going after.

Steve, i've already hit the limits of the manifold/intake system. datalogs and dyno data to show it quite well. I am going with the engineering route, give the air as much time as possible to get in the cylinder <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Ever see a choked flow turbo dyno graph? There's a point where increasing boost will not get you anymore top end power, but you'll end up with a lower and lower over-exagerated torque peak. I began to hit that mark at 10 psig.

back to back to back runs going from 10 psig to 13 psig netted me an increase of a massive 15 rwhp at like 5400 RPM, but my torque peak moved from 4800 to 3500 RPM and jumped nearly 80 RWTQ. Something's not right with that picture.

The intake (not the heads) is a restriction, presurized or not. You can't argue with fluid dynamics. But don't get me started on compressable flow. That **** is wack <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

I'm attacking the manifold issue with a holley modified to increase high RPM flow. Short runners make good HP, and turbos make good TQ. Hope it all works out in the end <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

<small>[ June 06, 2002, 01:10 AM: Message edited by: y2khawk ]</small>

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by y2khawk:
<strong>A general guestimate for backpressure generated from the turbos themselves is on the order of 2X manifold pressure. so at 15 psig manifold, that's approaching 30 psig in the exhaust, preturbo. That's HUGE backpressure in the exhaust.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">With a T04E/T-50 and T3HF turbine, ported (more like hogged) I measured 1.5x to 1.8x on my Talon. However, the intake ports and plenum were massive (at least for a 2.0L). That amounted to 33 to 40PSI in the ex-man. I'm surprised, though, that the twins represent substantially more.

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by y2khawk:
<strong>Ever see a choked flow turbo dyno graph? There's a point where increasing boost will not get you anymore top end power, but you'll end up with a lower and lower over-exagerated torque peak. I began to hit that mark at 10 psig.
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Very sound reasoning. But I'm still a little torporous where you are suggesting a crutched intake duration will improve the intake manifold restriction. The previous reply does make some sense, though, as short positive bursts of exhaust flow would tend to spool the turbo quicker. That's a good thing!

Thanks for the education. I've worked with many Ford and GM graduates of Cornell. If you (collectively) are any indication of the quality of that school, then it is definitely a fine institution!

SC

<small>[ June 06, 2002, 09:18 AM: Message edited by: SS00Blue ]</small>

 

Wow alot of good info. I almost know what a cam does <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> .

 

Umm, more overlap due to duration is going to reduce cylinder pressure, but tightening the LSA is going to increase it. Lets not confuse the 2.

J.