Stock Cam Profile?
12-02-2004, 01:43 PM
#4
Originally Posted by mean8t
202 int/206 exh @.050 .403"/.415" lift 115 LSA
hope this helps, not sure exactly what year this is but I think they are all really close.
hope this helps, not sure exactly what year this is but I think they are all really close.
no wonder why the CHP isnt up there....
12-02-2004, 02:36 PM
#5
Perhaps, but you've got to remember that if you throw a really aggressive cam in there it'll just be choked by the intake. The cam is small and geared towards low RPM torque because it compliments the intake. If you put in a more radical cam that sacrifices low end torque but is then choked by the intake you've just decreased HP and Torque, which certainly isn't a good thing. It's always about the total package.
12-02-2004, 03:29 PM
#6
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For '88 with 1.5:1 rockers:
Lift=.410/.423 (int./exh.),
Dur=211/219@.050” (int./exh.),
LSA=117,
3/8” studs with 7/16" base,
~80lbs on the seat with stock springs
With 1.6:1 rockers you can get a little help:
Lift=.437/.452 (int/exh),
Dur=213/222@.050” (int./exh.)
Actually our stock TPI intake will outflow (199cfm) even the stock #113 heads (190cfm @.045"). Isn't this why going with 1.6RRs works.
If you install the Accel base with AS&M LT runners (232cfm) it would be the stock heads holding back the engine. Ported & worked #113s would be the match to such an improved intake. Then the cam could be selected to match.
And yes if you go with a big cam and big head runner volume then you also need to change the intake from TPI.
Indeed it is the "system" that needs to be considered.
Lift=.410/.423 (int./exh.),
Dur=211/219@.050” (int./exh.),
LSA=117,
3/8” studs with 7/16" base,
~80lbs on the seat with stock springs
With 1.6:1 rockers you can get a little help:
Lift=.437/.452 (int/exh),
Dur=213/222@.050” (int./exh.)
Actually our stock TPI intake will outflow (199cfm) even the stock #113 heads (190cfm @.045"). Isn't this why going with 1.6RRs works.
If you install the Accel base with AS&M LT runners (232cfm) it would be the stock heads holding back the engine. Ported & worked #113s would be the match to such an improved intake. Then the cam could be selected to match.
And yes if you go with a big cam and big head runner volume then you also need to change the intake from TPI.
Indeed it is the "system" that needs to be considered.
Last edited by 65Z01; 12-02-2004 at 03:44 PM.
12-02-2004, 03:45 PM
#7
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The 202/206 number up there is correct for the 85-86 cams.
12-02-2004, 03:52 PM
#8
Originally Posted by 65Z01
Actually our stock TPI intake will outflow (199cfm) even the stock #113 heads (190cfm @.045"). Isn't this why going with 1.6RRs works.
12-02-2004, 04:17 PM
#9
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Beach Bum has tested this for us...
http://forums.corvetteforum.com/showthread.php?t=850274
Originally Posted by Beach Bum
I had to give back my borrowed Miniram..... so in order to make a Points event, I slapped on a stock untouched TPI manifold, runners and plenum.
I ran 1.58 - 12.02 @ 110.7 Track elevation was 900 feet, DA was just about 3000 ft.
It could have easily run into the 11's, but, my transmission was shifting at literally 6000-6200 rpm..... I couldn't get it to shift any earlier.... and trust me, this thing needed to be shifted down around 4500 rpm or so.... thus the motor for the shifts was just making a ton of noise with no pull at all.... this hurt et, but hurt mph just as much. I think if I was able to get it to shift below 5000 rpm, 11.8 @ 113 mph could have been realized in this bad air.
Not bad for a stock TPI ?? I was a bit surprised.... I take back everything negative I have ever said about long tube runners !!
I ran 1.58 - 12.02 @ 110.7 Track elevation was 900 feet, DA was just about 3000 ft.
It could have easily run into the 11's, but, my transmission was shifting at literally 6000-6200 rpm..... I couldn't get it to shift any earlier.... and trust me, this thing needed to be shifted down around 4500 rpm or so.... thus the motor for the shifts was just making a ton of noise with no pull at all.... this hurt et, but hurt mph just as much. I think if I was able to get it to shift below 5000 rpm, 11.8 @ 113 mph could have been realized in this bad air.
Not bad for a stock TPI ?? I was a bit surprised.... I take back everything negative I have ever said about long tube runners !!
Originally Posted by Beach Bum
My set-up is a 383, lpe 74219 cam, 1 3/4" headers, AFR 190 cylinder heads, 3000 rpm vig conveter, 3.45 gears, stock 700R4 tranny.
As a comparison against other intakes, within the last month on this same track, and in similar weather, the Superram ran a 1.54 60 ft - 11.47 @ 117.8 mph and the Miniram ran 1.61 60 ft - 11.66 @ 116.6 (untuned).
As a comparison against other intakes, within the last month on this same track, and in similar weather, the Superram ran a 1.54 60 ft - 11.47 @ 117.8 mph and the Miniram ran 1.61 60 ft - 11.66 @ 116.6 (untuned).
http://forums.corvetteforum.com/showthread.php?t=850274
12-02-2004, 04:35 PM
#10
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I have a spare base manifold i'm siamesing. I'm thinking of going with something that is around 218I/222E and .440/.450 that range should still be good for 1500-5500. do you think this cam will work? i can't (and I don't want to) go too aggressive (at least on the lift) since it has to work with a flat tappet setup.
12-03-2004, 02:30 AM
#11
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Hi.
I have an 85 and has changed the cam. When I investigated about different cams I think I remember that the 86 had a less progressive cam than the 202/206 and that the 87 came back with the 202/206 duration but with a roller cam. On 88 and up I don't know.
I have an 85 and has changed the cam. When I investigated about different cams I think I remember that the 86 had a less progressive cam than the 202/206 and that the 87 came back with the 202/206 duration but with a roller cam. On 88 and up I don't know.
12-03-2004, 08:58 AM
#12
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85 and 86 have the same cam specs.
12-04-2004, 11:53 AM
#13
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Originally Posted by vader86
The 202/206 number up there is correct for the 85-86 cams.
