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Cam only LS7 dissapointing dyno numbers

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Old May 27, 2015 | 09:51 PM
  #21  
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Originally Posted by Goosecaddy05
i picked up 30hp and 23 lbft going from a 3.5 intake with 85mm maf to a 4" tube with no maf
What size TB?
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Old May 27, 2015 | 09:53 PM
  #22  
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You have alot goin wrong wrong here. But even with all the wrong it should've made more power than that. We made a little over 450whp with that cam back in 03 or 04 with just a 346 and a ls6 intake. Car had shitty mac 1 3/4 mid length headers to.
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Old May 27, 2015 | 10:55 PM
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That 3.5" intake tube is doing you no favors. You need to upgrade to a 4" and use as big a radius bend(s) as possible. As asked, what size throttle body?

I would try to have only one 90 degree bend. Maybe angled up so the air filter will clear the rear bar or even straight up.
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Old May 27, 2015 | 11:03 PM
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Originally Posted by 1989GTA
That 3.5" intake tube is doing you no favors. You need to upgrade to a 4" and use as big a radius bend(s) as possible. As asked, what size throttle body?

I would try to have only one 90 degree bend. Maybe angled up so the air filter will clear the rear bar or even straight up.
90mm TB
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Old May 27, 2015 | 11:51 PM
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Originally Posted by fmyth
I pulled it apart and verified that the cam was installed dot to dot. I do not have a degree wheel. I suppose the cam grind could be off from the manufacture. The valve springs are the originals. Not sure how many hours are on them. Sand cars have no odometers so there is really no way to tell.
Stock valve springs? I know the stock LS7 springs are pretty good, but I'd think about upgrading them.
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Old May 28, 2015 | 12:56 AM
  #26  
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Originally Posted by 1970camaroRS
Stock valve springs? I know the stock LS7 springs are pretty good, but I'd think about upgrading them.

This. It's your problem.
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Old May 28, 2015 | 09:11 AM
  #27  
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Originally Posted by fmyth
What size TB?
I'm still using the stock OEM 90mm LS2 TB. No porting. Before i did the new intake tube I was dropping down to 91 kpa on the map during wot.
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Old May 28, 2015 | 10:13 AM
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Originally Posted by Goosecaddy05
I'm still using the stock OEM 90mm LS2 TB. No porting. Before i did the new intake tube I was dropping down to 91 kpa on the map during wot.
Thank you for the insight. I wish I would have thought of asking for the map readings. Next time I get it on the dyno I will. Going to pull the heads and get them inspected/freshened up. Might get a cam designed specifically for the LS7 from one of the vendors here. I will build a new 4" intake tube before I do anything else.
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Old May 28, 2015 | 10:42 AM
  #29  
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Put a BTR spring in it.
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Old May 28, 2015 | 04:19 PM
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Originally Posted by fmyth
Thank you for the insight. I wish I would have thought of asking for the map readings. Next time I get it on the dyno I will. Going to pull the heads and get them inspected/freshened up. Might get a cam designed specifically for the LS7 from one of the vendors here. I will build a new 4" intake tube before I do anything else.
Put a better spring on it before you do anything else.
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Old May 28, 2015 | 09:42 PM
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how much are you asking?
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Old May 28, 2015 | 10:26 PM
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I don't think your intake is the problem my 90/90 made the numbers below just fine.
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Old May 29, 2015 | 08:42 AM
  #33  
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Its the Cam! It couldnt be more wrong for the application!!!
Seriously! There is nothing wrong with any other part of your engine! At least nothing that will hold it back real bad,
Id get a grind like this 244in 254ex .640 lift 114 LSA
You would gain a Ton everywhere!
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Old May 29, 2015 | 08:42 AM
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Yea, springs won't hold it back.. Especially not the cam you recommended.

LOL
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Old May 31, 2015 | 07:04 PM
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Peaking @ 5500rpm and making more torque than hp makes me think you have an issue with the top end of the rpm band as mentioned... Interested to see if a spring swap solves it. What is coil bind on LS7's?
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Old Jun 2, 2015 | 01:45 AM
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Ls2 90mm TBs have a large step cast into them that disrupts airflow. That 90* bend is also killing power. Run a straight shot style intake that gets the coolest air possible. I'd also get that TB ported before changing cams. A FAST102 is definitely worth power over the stock ls7 intake... But will be $1k once you change the fuel rails out to make it work. The headers are also rather small.... But try the ported TB/straight shot 4" intake first! K&N ls7 air filter on my last setup. I made a disappointing 520rwhp/472rwtq on my LS7.. But it did go 111mph 1/8 best and 138mph with mods similar to yours. 1 7/8" primaries and 243/256 cam though.
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Old Jun 2, 2015 | 08:22 AM
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Originally Posted by gnx7
Ls2 90mm TBs have a large step cast into them that disrupts airflow. That 90* bend is also killing power. Run a straight shot style intake that gets the coolest air possible. I'd also get that TB ported before changing cams. A FAST102 is definitely worth power over the stock ls7 intake... But will be $1k once you change the fuel rails out to make it work. The headers are also rather small.... But try the ported TB/straight shot 4" intake first! K&N ls7 air filter on my last setup. I made a disappointing 520rwhp/472rwtq on my LS7.. But it did go 111mph 1/8 best and 138mph with mods similar to yours. 1 7/8" primaries and 243/256 cam though.
Did you miss the part where he's running stock ls7 valve springs?
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Old Jun 2, 2015 | 05:30 PM
  #38  
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Change your valve springs.. I bet it's floating the valves..
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Old Jun 3, 2015 | 02:42 PM
  #39  
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I am pulling the heads and sending them out for cnc porting, valves/guide upgrade. I will also have new springs/keepers installed for the Kartech Torquer 110 cam I just picked up. When I get it back together my son will fab a 4" intake tube and then I will get it back on the dyno.
I will post up the results this fall when it's done.
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Old Jun 3, 2015 | 03:09 PM
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That should help a ton. I know people are saying the cam is wrong and undersized, and I agree. But that cam should still be making more power at a higher rpm than what's shown.
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