To Boss Manifold or Not??

devildog1679

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I’m planning some mods over the winter. I want to stay NA at least for the foreseeable future. I do about 4 track days a year and 6 Auto-x as well. The Auto x is just for fun so I don’t care about getting bumped into higher class due to mods. I currently have Steeda CAI, Letha H pipe with weld in high flow CAT and AED tune. I’m planning on getting a baseline dyno next week since I don't have one after I put the CAI, H pipe and tune. My stock dyno numbers were 352 HP & 342 TQ on a Mustang Dyno which is why the #’s are lower than what people see on Dyno Jet.

I guess my only options at this point are to go E85 and Boss manifolds. I realize that the verdict on the Boss is that I will lose low end TQ but gain high end HP. Great for the track but not so much for the street. Do you guys think that the addition of the E85 will negate the low end TQ lose? Would throwing in a TB help as well?

Would also like to add that I see in stock form the 5.0 drops off after 6500 RPM. Even if I decide to keep the 7000 redline I see thatt he BOSS will pull all the way to 7000 instead of dropping off. Maybe I'll up it to 7,200 but no further. Worried about engine life.
 
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blackbeast12

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Cobra jet intake stage 3 cams and a tune...no low end loss big power mid to high rpm? Cost more but you will be pleased!
 

devildog1679

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I can't cover the additional $600 needed for the CJ. I just wonder of the addition of E85 would make up for the initial loss of TQ.
 

IGO 202

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What I like about the Boss intake is how long the peak power will carry. I can shift over 7k rpm and when the revs fall they are still in the peak power.

With the oem manifold the power would peak and immediately fall off.

Don't be skeered! :)

Dan
 

devildog1679

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If you're not willing to shift at 7600 rpm minimum then the Boss Intake is not for you.

Why? All the dyno graphs I've seen show the stock manifold drop off at 6500 while the Boss still climbs. That an extra 500 RPM on the road course that I'll be accelerating vs maintaining speed if I shift at 7000. From the graphs I've seen that's anywhere between 20-40 HP.
 

by9468840

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no.. stick to the stock manny. the huge mid range torque loss cant be justified for a few additional hp at 7500 rpm.
 

scotmach

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Why? All the dyno graphs I've seen show the stock manifold drop off at 6500 while the Boss still climbs. That an extra 500 RPM on the road course that I'll be accelerating vs maintaining speed if I shift at 7000. From the graphs I've seen that's anywhere between 20-40 HP.

It's not always about where it shifts but rather where the shift drop off is.
 

zinc03svt

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You may want to reach out to Voltwings. He does the road course stuff and actually sold his Cobra Jet setup and went back to stock manifold. From what he said he did not like the idea of spinning motor 7600 plus rpms for long periods of time. Fyi
 

devildog1679

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You may want to reach out to Voltwings. He does the road course stuff and actually sold his Cobra Jet setup and went back to stock manifold. From what he said he did not like the idea of spinning motor 7600 plus rpms for long periods of time. Fyi

That's why I would stick to shifting at 7000 as I do now on the track. The stock manifold just falls off after 6500. I've seen graphs where the Boss pulls all the way past 7000. Between 6500 and 7000 there is some HP gain. I will reach out to him though. Thanks
 

devildog1679

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[video=youtube_share;JbNgjFqdtOs]http://youtu.be/JbNgjFqdtOs[/video]

Now that was funny. I'm torn because I do track the car a lot and I'm getting into a situation that I'm topping out 5th gear at RA on 2 of the 3 straights. Once I hit 6500 RPM the car stops accelerating. I'm then just coasting for a good 3-5 seconds. This is hurting my lap times and no sense in shifting into 6th. With Boss Mani I can make it all the way to my braking zone under acceleration.
 

manolith

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I shifter my motor at 7800 for quite a while when it was n/a. 7500 with blower. The motors can take a beating. 7600rpm n/a is on the safe side imo.
 

Angry50

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Do it. i loved it with my manual 3.73. i think it complimented it well and the extra rpm does allow you to hang on to a gear a good bit longer
 

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