The following is a detailed chronology of my efforts to get the Indy Modman intake to work efficiently on my Gen 3 HEMI.

While I have never had any complaints about the finish or workmanship of this intake …the following experiences should serve as a caution anyone planning on using this intake for qtr mile racing.

All tuning changes were validated both on the same dyno and at the track in similar DA.

I have been tuning Carter and Edelbrock carbs for thirty years and am fully aware of the processes required in re-calibration and enhancements.


1st tune – Single 800CFM AVS Thunder carb
333 RWHP – 110.8 MPH – 12.4 sec qtr - 1.94 60ft
Comment - Lean bog very apparent on launch

2nd tune - Drilled pump shooter to .040th – 1.91 60ft
Comment – No bog if I rolled on the throttle, but sluggish response

3rd tune – Pro Systems 830 cfm – 50cc Primary pump shot, 30cc secondary
No dyno – 109.8 mph – 12.4 sec – 1.84 60ft
Comment – No bog but sluggish 60 ft

4th tune – Twin Edlebrock 500cfm Performer carbs – drilled shooters to .040th
No dyno – 111.1 mph – 12.39 sec - 1.91 60ft
Comment– Slight bog unless I rolled in the throttle...improved top end.

5th tune – Twin Edelbrocks with twin Brodix turtles inserted in plenum
Comment - No change

6th tune – Twin Edelbrocks with full height divider along length of plenum – increased initial timing from 15 to 21 deg .
348.7 RWHP – 114.3 MPH – 11.9 sec - 1.82 60ft

This has been the best result achieved. The 60 ft is still woeful for the mph and HP but the MPH jumped significantly.

NOTES

– Traction not a factor in any testing...simply not making enough initial torque to be a concern!

- No modification of air bleeds with Holley, just jetting.

- The Modman plenum volume results in a significant loss of signal and requires a MAMMOTH pump shot to overcome the overall plenum volume requirements.

- The full height divider I ran was also ½” wide, serving to occupy some plenum space as well as improve the signal.

- The car 60 footed better when I rolled on the throttle than when I rugged it in every scenario.

- Stalling up had a negative effect – often resulting in a bigger bog. I have determined this was because stalling uses up some of the ‘tip in’ travel hence a smaller pump shot.

- The cam I ran was a HR with [Email]219@.50[/Email] – It does not require a big converter , nor really high gears, so this was not contributing to the issue .

Summary

On the street, no one would ever guess that these issues were to arise at the track..until I did some street tuning on drag radials. It was only then I noticed the car struggled to turn the tyres on the street until tune #6.

This problem manifested even worse at the track.

I hope to be able to provide a comparative using the Edelbrock dual plane dual quad in a couple of months time – but I'm already certain the 60 fts will be largely better…even if top end MPH stays appx the same.

Conclusion

The Modman is a show/supercharger intake – pure and simple.

It may function better with a large cube motor – but as it runs a plenum that is 5x the volume of a normal single plane M1, I would still recommend experimenting with a divider.