As the subject implies, ET and MPH with the stock long tubes. Some guy called Torquemonster was claiming 12.98, but I don't know his MPH. Also, what ET/MPH change when switching from stock to aftermarket LTR's

 

12's on the stock intake with a 350 TPI and no power adders is tough, but doable. I went 13.25 @ 107.18 with the stock ported TPI intake, ZZ4 cam, and ported Corvette heads with SLP 1 5/8" headers. That was a 2.1 60' too. A little better traction and I would have hit 12's. A siamesed runner intake would be a lot better. Its the length of the runners that is bad, not the size of them.


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1991 Camaro Z28
5.7L 5-Speed (originally 305)
317 RWHP, 418 RWTQ
13.23 @ 107.62 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Member: SoCal F-Bodies
-=ICON Motorsports=-

 

12.98 might be possible with the right suspension setup, stall converter etc. My best so far is a 13.40 @ 104 with stock programming, converter, suspension and radials. I'm headed to the track on Friday to see if I can better that with custom programming and some sticky tires.

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Black 88 GTA L98
261 RWHP, 345 RWTQ
13.406 @ 103.72 MPH
ZZ4 bottom end, Edelbrock 6085 heads, LT4 HOT cam, GMPP 1.6 RR's, ported stock TPI, SLP 1 3/4" headers, no cat, Dynomax cat-back, Stock PROM
E.T.F.A Treasurer

 

108.78 mph with my stock, unported runners and done in 103 degree temperature.

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1991 Camaro RS/Z28,polished TPI, 355ci. Sportsman 11 heads, LT-4 Hot cam,Pete Jackson gear drive, on,and on, and on... best E.T.>13.4 new best MPH> 108.7, no traction, no tuning, The car is pictured in Chevy High Performance magazine, June 2000 issue.
http://www.geocities.com/jasonsz28us/INDEX.htm

1997 GMC Yukon, 4 wheel drive, leather, loaded, Gibson exhaust, K&N intake, Boston pro series speakers..... That's it so far.

1969 Camaro,12 point cage, total project right now, I am planning an LS1 - T56 - and a Vette independent rear. Pro Touring crowd, look out! 8^)

 

Kevin: I do not believe the statement you made about runner size versus length is correct. The length of the runner determines the frequency of resonance, or stated in another way, the RPM where you get the most torque boost. The size of the runner in terms of its cross sectional area has a small effect in the peak torque region, but a very LARGE effect at peak horsepower. If you look at a text on Fluid dynamics, and look at the equation which describes pressure drop for air traveling through a length of tubing, you will see that the pressure drop is directly proportional to pipe length, and INVERSLY proportional to the square of pipe diameter. In order to make horsepower or generate a high trap speed, you MUST reduce the pressure drop through the runners. BOTH reducing the length, AND increasing the diameter will reduce the pressure drop. As an example, The AZS&M large tube runners are 1.66" dia versus the stock 1.48". The length on the other hand is the same or slightly longer than stock. The flow numbers for a stock runner is 200cfm and the AS&M runners are 266cfm. From these numbers you can clearly see the very significant improvement is due solely to cross sectional area...... not length

 

If you think that cross section is more important than length, then please tell me why the fastest cars are using shorter runners (ie: miniram, superam).

 

Madmax... how long are runners on a carb setup?

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1984 z28 w/ a 357 cu in. monster engine which is looking like the posterchild for Edelbrock with the exception of the Holley 750vac... all the suspension stuff... 9-bolt posi disk is in...

-=ICON Motorsports=-

 

I didnt mean to say length was not important. I did say that pressure drop is proportional to length, so everytime you cut your length in half, you would reduce your pressure drop in half. The LT1 is an excellent example of this, the runners are so short, the pressure drop is tiny. The original post was with regard to the long tube TPI. The LT1 runner is not a "tuned" runner like the TPI. Actually it is referred to as an "anti" tuned intake design since no resonance effects come into play over the rpm range of the motor. Sorry if my post was not clear on this. A LT1 or miniram will ALWAYS have higher horsepower, and yes it is very short, but its not a tuned runner. I guess I should have said that if you are gonna stay with the long tube design, you will get more bang for your buck if you increase cross sectional area versus the small amount you can change the runner length using a siamezed type runner.

 

Fastest STOCK runner/plenum/manifold car I know of is a guy named Jerry Hogan and his Vortech blown ZZ3 1988 GTA.

Runs 10.00@12X.XX

 

I run 12.9 now with my gear change from 2.73 to 3.73. My previous best was 13.3 before the gear change. All tpi plumbing is stock. And this is on a drag radial, easing into it from an 1850 stall. It's still got more in it!

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1989 IROC-Z Camaro
12.90 in the 1/4
4.4 0-60
Specs/mods: V8, flowmaster, racing stripes and a few other things (Dr. Pepper Addict)

 

I went from stock runners and ported base to TPIS runners and TPIS base. I gained only 200 RPMs at peak horsepower. Its been dyno proven that shorter runners make more horsepower at a higher RPM, than larger runners. But at the expense of lower RPM torque. However, you gain upper RPM torque instead.

I think typical carb intakes have 10-12" runner lengths from carb to valve.

 

Find someone with a siamesed stock base on a 383, sounds(well looks at least) like a sleeper to me. "Sure it's all stock, just some old headers i threw on." Anyone have this combo? Sounds like a mid 12 sec combo to me.(Or at least I could hope so) Looking for a possible way to make some $$ street racing LT1's in the future. ...I'm gonna get the mostly stock ones with my 305 with stock runners this summer. aaaahhh