would the GT intake work better on a BOSS engine? lets find out!

[pufferfish]

Bottom line is this... when i shift at 8k... I come back into the next gear making the same power I did when i left the previous gear. Between that, the MT82 gearing, and 3.90s... I could careless about that low end tq number.

that is a very good point. if all we did was flat foot, it would be beneficial to be at or near the same horsepower you left off with before shifting. with steep enough gearing, you can get from a standstill to that rpm range quickly, so it may be a better drag race manifold.

I still, however, don't buy that it is a better road race strategy. to hold that range, you need to shift ALOT. that's fine for "flappy paddle" dual clutch cars, but rowing the gears constantly takes time and you are inevitably going to end up out of your range, since its not advisable to shift in a turn.

I do enjoy this debate though! its good stuff!

 

[pufferfish]

I made a speed/ratio calculator years ago when deciding which trans to put in my 95 gt for an all around car (street, track and drag). I imputed the MT-82 ratios, adjusted the tire sizes (I run 26" tall on the track and 27" on the street).

the RPM shift drops are interesting.
1-2: 7k shift=2352 rpm drop, 8k shift=2689 rpm drop
2-3: 7k=2132, 8k=2436
3-4: 7k=1533, 8k=1751
4-5: 7k=1697, 8k=1939

so, it seems you can never stay in the "sweet spot" of the boss intake?

 

[86Fbody]

That is what the numbers look like. Then it just looks like the Boss intake is for sustaining power at higher RPM's which does seem a little silly.

 

[isrboss]

I agree staying in the sweet spot always is not doable. However we all realize how important a driver is. Setting driver aside, let's just look at how important a good motor is with good delivery that can rev. The S197 platform is unchanged, Ford puts a good revy motor in the S197, and it's competitive. That applies to the GT/GT500/Boss. I thought we all learned having a higher rev range was a good thing when we butted up against the ls6 and ls1 GM motors.

 

[pufferfish]

its a good motor because it revs...pushrod 302's in SCCA AS routinely turn 8400. its a GREAT motor because it has more torque per liter than the chevys and can bring it in the same rpm range as the big boys.

by the way, anyone super annoyed that the graphs I posted earlier make the thread uber-wide? its driving me nuts! if there are any mods checking in, can you shrink them?

 

[Serpent]

If you shrank the picture it would help. I have 2 24'' monitors at work an I have to almost use both just to view this page.
Change the pic size: TinyPic - Free Image Hosting, Photo Sharing & Video Hosting and resize to 17'', should still be readable.

I agree with losing 2hp/11hp to gain 25tq/19tq in 4th and 5th gear, although it is top end gears I would take the tq any day.

 

[isrboss]

annoying the hell out of me, lol!

 

[isrboss]

If you shrank the picture it would help. I have 2 24'' monitors at work an I have to almost use both just to view this page.
Change the pic size: TinyPic - Free Image Hosting, Photo Sharing & Video Hosting and resize to 17'', should still be readable.

I agree with losing 2hp/11hp to gain 25tq/19tq in 4th and 5th gear, although it is top end gears I would take the tq any day.

Daily driver I agree tq. I road course and as long as you keep momentum hp will trump tq.

 

[specizripn]

Damn I've always heard the Boss intakes fall flat after 7800 or so but it looks like that holds the power really well past 8k, must have been Boss intakes on GT cars. Nice test :beer:

 

[EJR]

mehh

 

[pufferfish]

since we are on the second page now, its all fixed up

I have some work to do to join my gear calculator with the dyno info to come up with what intake looks better on paper. I intend to run TT3 next year and want to be competitive. its kind of a dicey game on the power/weight ratio I need to stay within. since NASA mandates a DynoJet, I am good there. power must be read in 1:1 gear, which I have with the 5th gear pull. since 5th gear is all "fuzzy" above 7500, the numbers work, but the indicator is that if there was more rpm capability in the dyno, the boss intake might go over max.

 

[pufferfish]

mehh

glad you changed that EJR. I will leave it at that:beer:

 

[pufferfish]

Damn I've always heard the Boss intakes fall flat after 7800 or so but it looks like that holds the power really well past 8k, must have been Boss intakes on GT cars. Nice test :beer:

I think you are exactly right, but to add to that, I think the boss heads and cams helped BOTH intakes hold more power past their respective peaks. definitely more so for the boss, of course.

 

[pufferfish]

anyone know how to determine a good shift recovery strategy? I got the raw numbers of tq and hp at the shift rpm and what they are at the rpm after the shift, but not sure what to do with the info? I believe torque is what is important right after the shift, to keep the momentum going and then hp carries it from there? right? wrong?

 

[darreng505]

The shop I use said a lot of boss owners swap over to the GT intake for the torque which can be more valuable than HP on the track. A taboo but worthy subject to bring up. lol

 

[pufferfish]

The shop I use said a lot of boss owners swap over to the GT intake for the torque which can be more valuable than HP on the track. A taboo but worthy subject to bring up. lol

Man, you ain't kiddin' on the taboo thing!

That interesting to hear some have done it for the reason I thought. Surprised nobody has EVER posted about such a swap before me!

 

[isrboss]

The shop I use said a lot of boss owners swap over to the GT intake for the torque which can be more valuable than HP on the track. A taboo but worthy subject to bring up. lol

Where are all of these Boss owners? The tq lost with the Boss intake is not significant enough to swap it imho. The only way a Boss owner would swap to a GT intake would be if they were rpm limited to 7000-7200rpm. Maybe a track where there are no long straights and low speed corners.

If you're doing things right out on track, you are mostly staying past the tq peak, in the high end of the hp. So tq becomes less significant when your driving fast and revs are high. I know the tq still needs to be high to help push the front end through the air, but tq is already dropping off for both intakes.

 

[pufferfish]

Don't mean to sound disrespectful, but have you ever been in a wheel to wheel race? You don't get to keep it above 5000rpm half the time. When jockeying for position, mid range torque is where you are able to make the push to pass. I guarantee, 20ft/lbs means a great deal to those guys!

Top 6 NASA midatlantic American iron cars run gt intakes for a reason.

 

[isrboss]

Don't mean to sound disrespectful, but have you ever been in a wheel to wheel race? You don't get to keep it above 5000rpm half the time. When jockeying for position, mid range torque is where you are able to make the push to pass. I guarantee, 20ft/lbs means a great deal to those guys!

Top 6 NASA midatlantic American iron cars run gt intakes for a reason.

No disrespect taken, and no I have not. That doesn't have any impact on being able to understand that extending the rev range is a positive thing. I'm not sure the difference is quite 20ft/lbs of tq lost with the boss intake. Point well taken though, I do understand you can't always stay in the sweet spot, which I already agreed with you on earlier. Tq is a great savior on track when revs go down, but other manufactures have been very successful in competition with low tq and high rev range.

 

[darreng505]

No disrespect taken, and no I have not. That doesn't have any impact on being able to understand that extending the rev range is a positive thing. I'm not sure the difference is quite 20ft/lbs of tq lost with the boss intake. Point well taken though, I do understand you can't always stay in the sweet spot, which I already agreed with you on earlier. Tq is a great savior on track when revs go down, but other manufactures have been very successful in competition with low tq and high rev range.

With some spec classes (like NASA American Iron) they mandate a hp/weight and hp/torque ratio - maximum. So it becomes a racers dilemma if they want to trade high end speed (say < 10mph on at most two long straights but typically just one) for mid range torque (acceleration they can use throughout the track) and many do. I suppose for other applications like drag or autocross the calculus for which intake to run may change.

And of course most dyno addicts only care about HP numbers...so there's them. ;-)

Also, its important to understand (not you but in general) that putting the GT intake on does not "add power" but rather releases it. It's already there. Kinda the same thing with the CJ intake, but I won't go there. There's a flame thread about that elsewhere. :burn: