TR 224 Sound Clip

[misterp]

wow, thanks for the info!!!  So on a heavy N/A truck with stock converter, a larger LSA would be best for us guys(street and track)?  do they make a 116?  When does the LSA get to big?  For a low LSA you have to have a higher stall to really use the cam then right?  The duration also gets lower with a low LSA then right?  On a low LSA you could have the cam profile real steep to avoid over lap on a S/C motor and still keep cylinder pressure up, right?  What cam do you feel works well in our N/A stock converter trucks, and why?

 

Thanks again

Brad

Whew lots of the right questions there.

 

CAM NOTES:

Factory cams usually have 116-degree LSA, in practical terms I have not heard of many performance cams going more than 114-degrees in LSA. Most performance cams have LSA between 108 and 114 degrees.

 

To maintain good idle with a narrow LSA yes you usually sacrifice gross duration, but in turn sacrifice power. Example is the good old Crane EconoPower cam (tow truck cam) which as I recall a 112 LSA and relatively mild duration, the low duration shifted the powerband down about 750-RPM and the 112LSA brought up the torque quick; as a result, the idle was really good (sounded like a tow truck) and was responsive and a stump puller plus got really decent mileage but would not breathe worth a crap above 5K-RPM. A better strategy (the one seen in today's camming) is to up the duration *and* LSA, good example being the FMS cams on 114-degree LSA.

 

CONVERTER NOTES:

For whatever reason (increased duration or increased overlap) you want to select a converter that is achieving 100% lockup -just- above the point where the cam is starting it's powerband. So, if after installing your bumpstick of choice you observe that it is really into the power at 2200rpm then you'll want a 2200-2400 rpm converter; any higher stall speed then you are not taking advantage of the lower end of the cam, and too low the vehicle will be a dog because you are lugging it and the cam has not reached it's 'sweet spot' yet. You have to know where the cam 'comes in' and when you talk to the cam manufacturer they should be able to tell you point-blank what stall speed converter is required.

 

Because our trucks have lock-up clutches highway mileage is not as affected by stall speed changes as is city driving mileage. Stall speeds above 2500 will really start to eat into your around-town mileage; I've got a TCS-2800 in my SS and my annual average MPG fell almost 1.5mpg because I drive almost entirely in town (no chance for lockup). I still get acceptable highway mileage though.

 

Converter stall speeds above 2800-rpm are not recommended in our trucks unless you know *exactly* what you are doing and it is for a max-effort strip truck.

 

MY CAM FOR STOCK CONVERTER SS

Well, the stock converter in the SS is a huge performance hindrance - I'll just get that out of the way right now. If you are leaving in the stock converter then I say leave the stock cam and try to gain power through FI, putting $1K into a cam/spring/exhaust swap is wasted effort with a stock converter and the factory cam is actually a pretty good compromise given the situation. Again that's my opinion.

 

If you really want to cam a truck with stock converter, then the power has to be there probably in the 1500-rpm area, so I'd start shopping for a cam on a 114-LSA with no more than 220-duration, and there are a ton of cams available in this 'market' to choose from. Or, you could go old school and install a stouter version of one of the venerable 'tow truck grinds'. Again, from experience usually if you go this route you will spend a few hundred dollars (if you ignore changing the stock springs, bad idea btw) plus a whole weekend (if you DIY) just to gain 10-20 ponies - been there, done that once, got the t-shirt.

 

If it were my truck, I'd install the GM Trailblazer Converter (< $200, or if you've got the money a premium $800 piece) and try something on a 114-LSA with duration between 224 (safe) to 230, even as high as 235 if you can really get a good custom tune to make it idle. Now we're talking a $1200-1400 project (cam, springs, GOOD custom tune) and you've got a truck that is still very driveable with the A/C on and showing anywhere from a true 30 to 50 hp gain. With CAI + Catback + tuning I would expect 400+hp at the flywheel an achievable goal, even more with properly tuned headers.

 

As for me, I'm going SuperSized next year.

 

Mr. P.

[shadowsniper3006]

wow, thanks for the info!!!  So on a heavy N/A truck with stock converter, a larger LSA would be best for us guys(street and track)?  do they make a 116?  When does the LSA get to big?  For a low LSA you have to have a higher stall to really use the cam then right?  The duration also gets lower with a low LSA then right?  On a low LSA you could have the cam profile real steep to avoid over lap on a S/C motor and still keep cylinder pressure up, right?  What cam do you feel works well in our N/A stock converter trucks, and why?

 

Thanks again

Brad

Whew lots of the right questions there.

 

CAM NOTES:

Factory cams usually have 116-degree LSA, in practical terms I have not heard of many performance cams going more than 114-degrees in LSA. Most performance cams have LSA between 108 and 114 degrees.

 

To maintain good idle with a narrow LSA yes you usually sacrifice gross duration, but in turn sacrifice power. Example is the good old Crane EconoPower cam (tow truck cam) which as I recall a 112 LSA and relatively mild duration, the low duration shifted the powerband down about 750-RPM and the 112LSA brought up the torque quick; as a result, the idle was really good (sounded like a tow truck) and was responsive and a stump puller plus got really decent mileage but would not breathe worth a crap above 5K-RPM. A better strategy (the one seen in today's camming) is to up the duration *and* LSA, good example being the FMS cams on 114-degree LSA.

 

MY CAM FOR STOCK CONVERTER SS

Well, the stock converter in the SS is a huge performance hindrance - I'll just get that out of the way right now. If you are leaving in the stock converter then I say leave the stock cam and try to gain power through FI, putting $1K into a cam/spring/exhaust swap is wasted effort with a stock converter and the factory cam is actually a pretty good compromise given the situation. Again that's my opinion.

 

If you really want to cam a truck with stock converter, then the power has to be there probably in the 1500-rpm area, so I'd start shopping for a cam on a 114-LSA with no more than 220-duration, and there are a ton of cams available in this 'market' to choose from. Or, you could go old school and install a stouter version of one of the venerable 'tow truck grinds'. Again, from experience usually if you go this route you will spend a few hundred dollars (if you ignore changing the stock springs, bad idea btw) plus a whole weekend (if you DIY) just to gain 10-20 ponies - been there, done that once, got the t-shirt.

 

If it were my truck, I'd install the GM Trailblazer Converter (

 

 

Mr. P.

 

so the cam from Allen(the 90 hp gain post) is real close to the cam you would go with, on a higher stall truck? 224/228 on a 114LSA. or what about the comp cam 228/230 on a 112(2200-7200 rpm range). With what you have learned me so far, the 112lsa will help a stock converter truck(untill it has a 2800 stall in it) pass through the "dead spot" of the cams rpm range(i can brake stall to 2000) faster then a 114 and the 112 still has a longer duration of 228 230 so you are not going to fall flat in the upper rpm range. And a general rule, the longer the duration the higher rpm range of the cam? But now i have to ask....what about the higher duration, or is it the lower lsa, that hurts the idle?

 

also, i did some digging to find you posted the stock cam at 196/207 .479 lift 116 lsa. SO with the comp cam, i would expect my power band to be much higher because of the higher duration? And the lower LSA would make the motor have much more of a sweet spot, then a broad torque curve, but the peak would still be higher in the rpm's? but because of the amount of hp/torque increase with the cam, it would still dyno higher numbers at every point(hp and torque) so you would not be "losing" any bottom end? is that right, or at like 2000 rpm would the truck have actual less torque?

 

Thanks again for all the time your spending on this!!! I really am learning a lot.

 

Brad

[SCIV]

WOW. And all of this from an exhaust clip

 

Good knowledge getting tossed around, and that is what everyone needs when looking for a cam. I wanted the 112 because 95% of my driving is around town, I just go to the strip for giggles.

 

I agree on the stall, and that will be my next move. TB stall most likely. On Saturday night I ran a 14.5 @ 95. I wasn't impressed. Nelson was there, and figured out the shifts were @ 5,900. Moved those to 6,300 & ran 14.1 @98. I only got one chance at that run & the strip closed. I think some more tinkering could get a 14.0, maybe better.

[shadowsniper3006]

WOW.  And all of this from an exhaust clip 

 

Good knowledge getting tossed around, and that is what everyone needs when looking for a cam.  I wanted the 112 because 95% of my driving is around town, I just go to the strip for giggles.

 

I agree on the stall, and that will be my next move.  TB stall most likely.  On Saturday night I ran a 14.5 @ 95.  I wasn't impressed. Nelson was there, and figured out the shifts were @ 5,900.  Moved those to 6,300 & ran 14.1 @98.  I only got one chance at that run & the strip closed.  I think some more tinkering could get a 14.0, maybe better.

 

 

yeah....sorry for hijacking your thread!

 

if you do all your driving around town why did you choose the 112, i thought the peaky nature of the cam was more of a strip cam then a street cam? But nice times. My truck shifts at 5800, is that good for the stock cam. Also with a 112, did it move your hp and torque up higher, and thats why you had to raise your shift points? I thought the 114 or 116 would hold the curve longer with out dropping off as much, so it could hold a higher RPM shift point, rather then a peaky hp curve that drops off fast in the higher rpms?

 

Brad

[SCIV]

yeah....sorry for hijacking your thread!

 

 

<{POST_SNAPBACK}>

 

 

hijack away. I like the peaky nature, because this is a truck, not an F-body. I don't plan on seeing too many WOT blasts to redline on my way to work. For gods sake, my truck has 15k miles, and the average speed in the data center is only about 35 mph!! It is all about personal preference, and I also factored in getting the cam, springs & TI retainers as a package for $380 bucks. Maybe that is part of it too

 

My knowledge is limited, so listening to these other guys will help out better. The best thing to do is ride in some trucks w/various cams to get a real idea of how it drives. Next year I will probably go with a bigger cam & stall.

[misterp]

so the cam from Allen(the 90 hp gain post) is real close to the cam you would go with, on a higher stall truck?  224/228 on a 114LSA.  or what about the comp cam 228/230 on a 112(2200-7200 rpm range).  With what you have learned me so far, the 112lsa will help a stock converter truck(untill it has a 2800 stall in it) pass through the "dead spot" of the cams rpm range(i can brake stall to 2000) faster then a 114 and the 112 still has a longer duration of 228 230 so you are not going to fall flat in the upper rpm range.  And a general rule, the longer the duration the higher rpm range of the cam?  But now i have to ask....what about the higher duration, or is it the lower lsa, that hurts the idle?

 

also, i did some digging to find you posted the stock cam at 196/207 .479 lift 116 lsa.  SO with the comp cam, i would expect my power band to be much higher because of the higher duration?  And the lower LSA would make the motor have much more of a sweet spot, then a broad torque curve, but the peak would still be higher in the rpm's?  but because of the amount of hp/torque increase with the cam, it would still dyno higher numbers at every point(hp and torque) so you would not be "losing" any bottom end?  is that right, or at like 2000 rpm would the truck have actual less torque?

 

Thanks again for all the time your spending on this!!!  I really am learning a lot.

 

Brad

Some pretty serious bench racing here! Again, short and sweet - changing lobe separation angle will change the torque curve between 'peaky' and 'broad'; changing gross duration will either raise or lower the RPM band. Generally. The actual answer is where the valve events are timed in relation to crank (piston) position...

 

Your question on idle quality - LSA definitely makes more impact on driveability than changes in gross duration. Change the LSA 4 degrees and it makes a hell of a difference in the idle whereas 4 degrees increase/decrease in duration will probably go unnoticed to the uninitiated.

 

A 224/228-114 cam would probably be about the largest I would run in front of a stock converter provided the engine still had factory manifolds and exhaust ports (on an LQ9 with trick heads + headers you will want a single-pattern cam or you will be over-exhausting).

 

The 228/230-112 cam will not be optimum with stock converter, because it is not really in its sweet spot until 2200-rpm - before that point it is down on the power a bit due to it's 'peakier' torque curve; let me qualify this, I'm not saying the truck won't run at all, just that it will not be optimum. However put a 2200 converter in the truck and it'll run very well. Or, change to a 114-degree LSA to broaded the torque curve and it'll do a lot better.

 

Also, since the intake duration on this cam is nearly the same as the exhaust duration (only 2 degrees difference) this cam will expect and need improved breathing on the exhast-side (headers at least). And don't be misled by the 7200-rpm upper RPM number, that cam probably does not make effective power that high up, the cam company is probably just saying that it won't go into valve float if you've used the correct spring package.

 

Comp 228/230-112 vs stock LQ9 cam - yes, higher gross duration will move the power band up the RPM chart a bit. Yes, the Comp grind will definitely exhibit a distinct sweet spot in it's power band due to lower LSA. And yes the Comp grind will make more power 'all over'. Does the Comp cam still make similar amount of torque as LQ9 cam off idle, I dunno but the cam grinder should be able to tell you this exactly, my guess would be yes the two will be nearly the same BUT you will get far more performance and fun if you use the recommended converter.

 

Mr. P.

[SCIV]

Word.

[2006LS2TB]

DAMN!!! I wish my truck sounded like that.

[shadowsniper3006]

so the cam from Allen(the 90 hp gain post) is real close to the cam you would go with, on a higher stall truck?  224/228 on a 114LSA.  or what about the comp cam 228/230 on a 112(2200-7200 rpm range).  With what you have learned me so far, the 112lsa will help a stock converter truck(untill it has a 2800 stall in it) pass through the "dead spot" of the cams rpm range(i can brake stall to 2000) faster then a 114 and the 112 still has a longer duration of 228 230 so you are not going to fall flat in the upper rpm range.  And a general rule, the longer the duration the higher rpm range of the cam?  But now i have to ask....what about the higher duration, or is it the lower lsa, that hurts the idle?

 

also, i did some digging to find you posted the stock cam at 196/207 .479 lift 116 lsa.  SO with the comp cam, i would expect my power band to be much higher because of the higher duration?  And the lower LSA would make the motor have much more of a sweet spot, then a broad torque curve, but the peak would still be higher in the rpm's?  but because of the amount of hp/torque increase with the cam, it would still dyno higher numbers at every point(hp and torque) so you would not be "losing" any bottom end?  is that right, or at like 2000 rpm would the truck have actual less torque?

 

Thanks again for all the time your spending on this!!!  I really am learning a lot.

 

Brad

Some pretty serious bench racing here! Again, short and sweet - changing lobe separation angle will change the torque curve between 'peaky' and 'broad'; changing gross duration will either raise or lower the RPM band. Generally. The actual answer is where the valve events are timed in relation to crank (piston) position...

 

Your question on idle quality - LSA definitely makes more impact on driveability than changes in gross duration. Change the LSA 4 degrees and it makes a hell of a difference in the idle whereas 4 degrees increase/decrease in duration will probably go unnoticed to the uninitiated.

 

A 224/228-114 cam would probably be about the largest I would run in front of a stock converter provided the engine still had factory manifolds and exhaust ports (on an LQ9 with trick heads + headers you will want a single-pattern cam or you will be over-exhausting).

 

The 228/230-112 cam will not be optimum with stock converter, because it is not really in its sweet spot until 2200-rpm - before that point it is down on the power a bit due to it's 'peakier' torque curve; let me qualify this, I'm not saying the truck won't run at all, just that it will not be optimum. However put a 2200 converter in the truck and it'll run very well. Or, change to a 114-degree LSA to broaded the torque curve and it'll do a lot better.

 

Also, since the intake duration on this cam is nearly the same as the exhaust duration (only 2 degrees difference) this cam will expect and need improved breathing on the exhast-side (headers at least). And don't be misled by the 7200-rpm upper RPM number, that cam probably does not make effective power that high up, the cam company is probably just saying that it won't go into valve float if you've used the correct spring package.

 

Comp 228/230-112 vs stock LQ9 cam - yes, higher gross duration will move the power band up the RPM chart a bit. Yes, the Comp grind will definitely exhibit a distinct sweet spot in it's power band due to lower LSA. And yes the Comp grind will make more power 'all over'. Does the Comp cam still make similar amount of torque as LQ9 cam off idle, I dunno but the cam grinder should be able to tell you this exactly, my guess would be yes the two will be nearly the same BUT you will get far more performance and fun if you use the recommended converter.

 

Mr. P.

 

 

 

thank you, once more for all the time you put into this!

 

Brad

[shadowsniper3006]

sounds great! what else is done to the truck?  How does it run, any drivability issues?  alot of prople said to go with the 224 on a 114, yours is a 112, where does the power come on at?  new springs, lifters, rockers??    thanks

 

Well, quite a list actually... '05 fans, Nelson harness, 160* stat, '05 K&N intake, Thorley headers, Magnaflow cats, Flo-Pro HD muffler. As far as the cam, I did change to Comp 918's. Stock rockers. Tranny mods probably next week.

 

Driveability is fine, except for the idle. It is too low, & stalls without notice when idling in gear. That will get fixed tomorrow. After the retune I will post my opions on true drivability. Oh, stock converter too (and it isn't bad).

 

 

so how did everything turn out???? Did you get the truck to idle right? did you ever get back to the track?

 

Brad

[SCIV]

so how did everything turn out????  Did you get the truck to idle right?  did you ever get back to the track?

 

Brad

<{POST_SNAPBACK}>

 

 

Tune is great. No more driveability issues. Idles just like normal (other than a little lope ). I can still get good gas mileage too!! (about 18-20 on the highway)

 

Got to only make one pass, ran 14.1 @ 98. About 1/2 a second better than w/o the cam. Now I wish I went bigger. Oh well, live & learn. TB stall soon to come, and hopefully mid 13's.

[misterp]

so how did everything turn out????  Did you get the truck to idle right?  did you ever get back to the track?

 

Brad

<{POST_SNAPBACK}>

 

 

Tune is great. No more driveability issues. Idles just like normal (other than a little lope ). I can still get good gas mileage too!! (about 18-20 on the highway)

 

Got to only make one pass, ran 14.1 @ 98. About 1/2 a second better than w/o the cam. Now I wish I went bigger. Oh well, live & learn. TB stall soon to come, and hopefully mid 13's.

<{POST_SNAPBACK}>

That will put you in the 13s for sure. Lemme know if you want a hand hefting your tranny...

 

Mr. P.

[shadowsniper3006]

so how did everything turn out????  Did you get the truck to idle right?  did you ever get back to the track?

 

Brad

 

 

Tune is great. No more driveability issues. Idles just like normal (other than a little lope ). I can still get good gas mileage too!! (about 18-20 on the highway)

 

Got to only make one pass, ran 14.1 @ 98. About 1/2 a second better than w/o the cam. Now I wish I went bigger. Oh well, live & learn. TB stall soon to come, and hopefully mid 13's.

 

 

great to hear that! You have a nelson tune right? Did he just keep updating it for you untill the truck felt right or did you take it some where to have it tuned in person?

 

has any one had pcmforless tune their truck when it had a "hard to tune" cam, or torque converter. Just wondering how the 2 guys compare when it comes to tuning a modded truck.

 

 

i know bryan is on this web site from time to time, is nelson(it's Allen right) ever on here.

 

 

Brad

[tblrk1980]

SCIV....do have the flo pro 2504, 2505, or 2506?

[SCIV]

SCIV....do have the flo pro 2504, 2505, or 2506?

<{POST_SNAPBACK}>

 

2503 dual in, single offset out. Been a great muffler, but I am going to be taking it off in the next month or so for a custom setup.