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

[pufferfish]

Darren, I don't know why the ford guy was telling you to stay under 8000, but for the most efficient use of your power, you should be shifting 8-8500. all the tuners I talk to, say the CJ pulse ring is not required for this RPM range. I really just installed it because it was cheap and easy to do with the engine out.

Assuming you have similar mods (headers, no cats, cold air and tune), I entered your gear ratios and tire size into my spreadsheet with my dyno numbers. 1-2 shift=8300rpm, 2-3 shift=8200rpm, 3-4 shift=8100rpm, 4-5 shift=8100rpm.

 

[pufferfish]

Puffer, I have no doubt that on a given track better mid range tq is going to produce better lap times. Like what was said earlier, in traffic while racing the better mid tq is going to be a better choice. I just have a hard time seeing a large margin in lap times though with a consistent wheel man in the seat.

Are you planning to give each intake a couple of sessions each soon? I really think on an open track without traffic(leading) you will see better laps with the Boss intake with the 8000 rpm revs. It would be great to give each intake two 20-25 min sessions then avg. the times and post that with best lap with both.

I am actually headed to the track this Friday and plan to try both intakes. even then, it won't be a fair comparison though. it will be colder in the morning, which will make more power and offer less traction. but, I will do my best to be objective. its not a timed event, so I will have to use the video clock to determine lap times. if they are close, there may not be a clear winner.

but, in my statement earlier about the gt intake being underappreciated, I am not saying I think the gt intake will be faster on a qualifying type lap. on the contrary, in developing my shift point chart, its clear to me the boss would be faster. the shift point graph shows that if shifting optimally, the lesser mid-range torque of the boss is never seen. even if short shifting at 7500, there is virtually no wheel torque loss compared to the gt intake.

that said, if in a race, you don't get to wind out past 7500 very often and you find yourself consistently under 5000 exiting turns, the gt intake will smoke the boss.

 

[darreng505]

Darren, I don't know why the ford guy was telling you to stay under 8000, but for the most efficient use of your power, you should be shifting 8-8500. all the tuners I talk to, say the CJ pulse ring is not required for this RPM range. I really just installed it because it was cheap and easy to do with the engine out.

Assuming you have similar mods (headers, no cats, cold air and tune), I entered your gear ratios and tire size into my spreadsheet with my dyno numbers. 1-2 shift=8300rpm, 2-3 shift=8200rpm, 3-4 shift=8100rpm, 4-5 shift=8100rpm.

Interesting. Well, now that I think about it, it was a tech from Capaldi I talked to. They were running a prototype CJ intake on one of their 302s'. I think the engine can handle >8000 rpm from an integrity point of view but I think he was suggesting maybe the ECU cannot.

In terms of shift points, given a -2000 drop in RPMs from shift to shift (roughly speaking), wouldn't you want the shift point RPM's to center around the maximum torque where it intersects horsepower? Such that the shift drops the torque below maximum and you are constantly gaining torque and therefore acceleration as you shift? In my dyno chart, the peak power was around 6900 rpm, and of course torque falls off first and faster. If you shift too far beyond the torque fall off are you losing acceleration?

e.g. where is your torque at 8000 rpms? Probably far below its peak?

 

[TheVikingRL]

Sorry for the quick derail here.

Darren, nice meeting you this weekend. Sweet car, hope you have a good time at VIR.

 

[darreng505]

Thanks Ron! Nice meeting you too.

 

[isrboss]

I am actually headed to the track this Friday and plan to try both intakes. even then, it won't be a fair comparison though. it will be colder in the morning, which will make more power and offer less traction. but, I will do my best to be objective. its not a timed event, so I will have to use the video clock to determine lap times. if they are close, there may not be a clear winner.

but, in my statement earlier about the gt intake being underappreciated, I am not saying I think the gt intake will be faster on a qualifying type lap. on the contrary, in developing my shift point chart, its clear to me the boss would be faster. the shift point graph shows that if shifting optimally, the lesser mid-range torque of the boss is never seen. even if short shifting at 7500, there is virtually no wheel torque loss compared to the gt intake.

that said, if in a race, you don't get to wind out past 7500 very often and you find yourself consistently under 5000 exiting turns, the gt intake will smoke the boss.

You can always download the Racechrono app, and pickup a Qstarz BT-Q818XT. The Racechrono app even allows you to analyse your laps on your phone.

If you know being below 5000 is going to hurt your lap, and you are revving in the 8400 range, rpm is just a downshift away. I'm not suggesting this works at every turn out there, but maybe try to go down one gear on a few corners when in traffic, and see if you can get a good exit maybe you out drag someone lugging. This is all theoretical on my part because I don't race, but if I'm in a race to the finish, I'm always going to downshift to get me in my power range to race. I would elect to make 2 more shifts in the traffic than lug along out of my power range, if I could put the power down effectively.

 

[pufferfish]

Interesting. Well, now that I think about it, it was a tech from Capaldi I talked to. They were running a prototype CJ intake on one of their 302s'. I think the engine can handle >8000 rpm from an integrity point of view but I think he was suggesting maybe the ECU cannot.

In terms of shift points, given a -2000 drop in RPMs from shift to shift (roughly speaking), wouldn't you want the shift point RPM's to center around the maximum torque where it intersects horsepower? Such that the shift drops the torque below maximum and you are constantly gaining torque and therefore acceleration as you shift? In my dyno chart, the peak power was around 6900 rpm, and of course torque falls off first and faster. If you shift too far beyond the torque fall off are you losing acceleration?

e.g. where is your torque at 8000 rpms? Probably far below its peak?

that notion is widely accepted and mostly incorrect. the shift graph looks like a rounded off staircase. what you are suggesting will actually provide a vertical cliff of torque loss at each shift. that means you are instantly dropping torque with no additional MPH. Allowing the engine to rev past the power peak will smooth the transitions and allow more acceleration.

now, your optimized shifts may be different than mine. my max hp is around 7500. send me your dyno chart and I will plug the data into the spreadsheet.

 

[pufferfish]

You can always download the Racechrono app, and pickup a Qstarz BT-Q818XT. The Racechrono app even allows you to analyse your laps on your phone.

If you know being below 5000 is going to hurt your lap, and you are revving in the 8400 range, rpm is just a downshift away. I'm not suggesting this works at every turn out there, but maybe try to go down one gear on a few corners when in traffic, and see if you can get a good exit maybe you out drag someone lugging. This is all theoretical on my part because I don't race, but if I'm in a race to the finish, I'm always going to downshift to get me in my power range to race. I would elect to make 2 more shifts in the traffic than lug along out of my power range, if I could put the power down effectively.

I hear ya. the issue is you don't always get to shift when the engine needs it. example: summit main has a series of turns (5 through 9), that have no area where the car is without steering input. imagine a 5 turn area of the track with no reasonable place to shift! you have to rely on 1 gear for the slowest to the fastest turn. oh, and turn 9 has a nasty reputation of creating oversteer in just about any car, so max torque is actually NOT what you want. road course racing is just really dynamic.

 

[86Fbody]

I hear ya. the issue is you don't always get to shift when the engine needs it. example: summit main has a series of turns (5 through 9), that have no area where the car is without steering input. imagine a 5 turn area of the track with no reasonable place to shift! you have to rely on 1 gear for the slowest to the fastest turn. oh, and turn 9 has a nasty reputation of creating oversteer in just about any car, so max torque is actually NOT what you want. road course racing is just really dynamic.

3.27's and a blower seem to sort out that 5-9 combo.

 

[isrboss]

I hear ya. the issue is you don't always get to shift when the engine needs it. example: summit main has a series of turns (5 through 9), that have no area where the car is without steering input. imagine a 5 turn area of the track with no reasonable place to shift! you have to rely on 1 gear for the slowest to the fastest turn. oh, and turn 9 has a nasty reputation of creating oversteer in just about any car, so max torque is actually NOT what you want. road course racing is just really dynamic.

This looks perfect, but I imagine being out front helps. Shifting prior to 8 looks perfect. Sounds like he is keeping the revs up there, are you familiar with this intake setup?

PAS/Cobetto 2011 Saleen Mustang NASA AI racecar @ Summit Point 8/21/11 - YouTube

 

[86Fbody]

That's about the only place to shift and I could see wanting to hold off. You would be shifting and turning into 8 basically at the same time, possibly get a little lift oversteer when you do that.

 

[pufferfish]

This looks perfect, but I imagine being out front helps. Shifting prior to 8 looks perfect. Sounds like he is keeping the revs up there, are you familiar with this intake setup?

PAS/Cobetto 2011 Saleen Mustang NASA AI racecar @ Summit Point 8/21/11 - YouTube

Cobetto uses a gt intake (same as all the AI guys in this area). I don't know what rear gear he uses, but I never see 2nd gear and he uses it twice per lap. He is a premier driver, but the lap times in that video indicate he is leaving speed on the table, probably to defend his position. he was doing 1:22 lap times. I ran back to back 1:23.7 in the video below with the new engine for the first time and keeping the revs below 7000. I know my car isn't nearly as capable as his, nor am I as capable of a driver. so, I am going to guess that a typical 1:19-1:20 qualifying lap for him involves 3rd gear through the esses.

Summit Point FSP 2011 Mustang GT 3-10-2013 scca 1st place - YouTube

note that I do, in fact, shift to 4th between 8 and 9, but wouldn't if I wasn't trying to keep my revs down.

 

[isrboss]

Cobetto uses a gt intake (same as all the AI guys in this area). I don't know what rear gear he uses, but I never see 2nd gear and he uses it twice per lap. He is a premier driver, but the lap times in that video indicate he is leaving speed on the table, probably to defend his position. he was doing 1:22 lap times. I ran back to back 1:23.7 in the video below with the new engine for the first time and keeping the revs below 7000. I know my car isn't nearly as capable as his, nor am I as capable of a driver. so, I am going to guess that a typical 1:19-1:20 qualifying lap for him involves 3rd gear through the esses.

Summit Point FSP 2011 Mustang GT 3-10-2013 scca 1st place - YouTube

note that I do, in fact, shift to 4th between 8 and 9, but wouldn't if I wasn't trying to keep my revs down.

Thanks for sharing the video puffer, nice smooth inputs. I'm looking forward to what you find when you do real world testing between these intakes.

 

[darreng505]

Cobetto uses a gt intake (same as all the AI guys in this area). I don't know what rear gear he uses, but I never see 2nd gear and he uses it twice per lap. He is a premier driver, but the lap times in that video indicate he is leaving speed on the table, probably to defend his position. he was doing 1:22 lap times. I ran back to back 1:23.7 in the video below with the new engine for the first time and keeping the revs below 7000. I know my car isn't nearly as capable as his, nor am I as capable of a driver. so, I am going to guess that a typical 1:19-1:20 qualifying lap for him involves 3rd gear through the esses.

Summit Point FSP 2011 Mustang GT 3-10-2013 scca 1st place - YouTube

note that I do, in fact, shift to 4th between 8 and 9, but wouldn't if I wasn't trying to keep my revs down.

He's running 4.10's I was told.

But he shifts more than me with my 3.90's

 

[pufferfish]

He's running 4.10's I was told.

But he shifts more than me with my 3.90's

WOW! I didn't expect that. I expected 3.31's with all that 2nd gear action.

 

[86Fbody]

he's running 4.10's i was told.

But he shifts more than me with my 3.90's

t56?

 

[darreng505]

t56?

Yes. 2.66 magnum

 

[pufferfish]

Yes. 2.66 magnum

are you saying Cobetto is running the close ratio t56? I thought he was running the mt82?

 

[isrboss]

I just wanted to toss this in for an example of what a fast s2000 driver has the stomach for(I mentioned beating an S2000 to the end of it's life earlier in the thread). If your power is up top, there is no mercy, you have to step outside the box.

My Best Lap Around Summit Point - Short Version - YouTube

 

[86Fbody]

I just wanted to toss this in for an example of what a fast s2000 driver has the stomach for(I mentioned beating an S2000 to the end of it's life earlier in the thread). If your power is up top, there is no mercy, you have to step outside the box.

My Best Lap Around Summit Point - Short Version - YouTube

9k does tend to sound that way, if Spoon happened to make heads for the S2k like they did for the Civics you could have run it to 11k I think.