shift to 5th
Jun 18, 2008, 06:21 AM
#18
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I would like to add that if you are going 176 fps, and you depress your clutch pedal to make a shift, you do not hold steady at 176 fps. You would actually drop speed VERY quickly. An un-aerodynamic EVO @ ~ 115 mph is going to slow down REALLY fast if it is not under power.
Jun 18, 2008, 09:07 PM
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I would like to add that if you are going 176 fps, and you depress your clutch pedal to make a shift, you do not hold steady at 176 fps. You would actually drop speed VERY quickly. An un-aerodynamic EVO @ ~ 115 mph is going to slow down REALLY fast if it is not under power.
The added time under the tq curve more than make-up for the .4 tenths to shift to fifth.
You will get to the line quicker.
Aug 6, 2008, 08:09 AM
#20
I would like to add that if you are going 176 fps, and you depress your clutch pedal to make a shift, you do not hold steady at 176 fps. You would actually drop speed VERY quickly. An un-aerodynamic EVO @ ~ 115 mph is going to slow down REALLY fast if it is not under power.
Aug 6, 2008, 08:17 AM
#21
Wow, super old thread revival!
Hah, I didn't comment on it when I saw it over a year ago, but now I will.
Your math and logic is right on Jerry, I just don't understand why I've gone my fastest times bouncing fourth like 10 times as opposed to hitting fifth? I've tried it like 10 times either way and its always quicker staying in fourth upto 7800 with the stock turbo to boot!
I thought at first this may be because I am shifting into 5th right before the traps so I shifted earlier 7300-7400 ( which wasn't an optimal shift point in my car, even with the stock turbo and thats a fact) and the car still went slower. Maybe the difference with the sub-optimal shift point negated the benefit from continued acceleration, but I still trapped higher staying in 4th.
This may be and exception to the rule?
Just trying to add good discussion....
Boltz
Hah, I didn't comment on it when I saw it over a year ago, but now I will.
Your math and logic is right on Jerry, I just don't understand why I've gone my fastest times bouncing fourth like 10 times as opposed to hitting fifth? I've tried it like 10 times either way and its always quicker staying in fourth upto 7800 with the stock turbo to boot!
I thought at first this may be because I am shifting into 5th right before the traps so I shifted earlier 7300-7400 ( which wasn't an optimal shift point in my car, even with the stock turbo and thats a fact) and the car still went slower. Maybe the difference with the sub-optimal shift point negated the benefit from continued acceleration, but I still trapped higher staying in 4th.
This may be and exception to the rule?
Just trying to add good discussion....
Boltz
Your back to back run times would need to look like this. If you cars times look this consistent then you could use your observations as data. I am gonna guess your times were no were near this consistent. you only have to look at drag times of cars that post 3 or 4 back to back runs.
10.031 at 130
10.030 at 129.9
10.033 at 129.5
Aug 7, 2008, 11:22 AM
#22
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My best run was 11.85 @ 116.39 60-foot of 1.721
Thing thats sucks is this was bouncing off the rev limiter in 4th. I even raised the limiter to 8200 and it still did not give me enough room.
I know with a slightly longer 4th or higher revs the car would be good for 11.7 or 11.6
I got a nice 60 foot of 1.687 one run but I tried shifting to fifth and it did not really work. Wound up running 11.9 @ 109
Maybe I can put a taller tire on it and then I will get some 11.7's or 11.6's for sure.
?????????????????????????????????????????????????? ????????????????????????????????????
No disrespect for the poster of this quote. There are hundreds of quotes like this all over this board. I am just using this as an example.
I am really tired of these type statements. It is really without knowledge to say your car will improve .1-.2 in the quarter by not having to shift to 5th. So here are some facts for you. At 120mph you are moving at 176ft per second. During a shift you loose acceration but not speed. What this means is instead of being able to accelerate to 177ft per second you stay at 176fps during your shift. So what does that do to your ET? Not much. Not worth crying about. But worth discussing just this once. In a drag race I have noticed how much distance my car looses during a shift. In a really close race where you are door to door it is really easy to tell how much distance your car looses during a shift. For me it is about 2 feet on a good shift and 6 feet on a really bad shift. Perfect example is I was racing a mustang and our cars were really close in performance. Door to door in fact. He couldn't pull on me and I couldn't pull on him. When it came time to shift to 5th I look at his car and see how much distance I loose. Since this is a mustang and his gears are spaced different during my whole shift the mustang is still accelerating. I loose 2ft during my shift to 5th. Are you with me so far? Shifting to 5th costs me 2ft. but at a time when the car is moving 176fps. That means my ET will suffer by having to drive an additional 2 ft at 176fps. or .011 seconds. So in reality your ET will plummet by .01 on a good shift and only .03 on a real granny shift . Is this really worth crying about? What really erks me about this is all the threads that people are considering dropping their rear end ratio to the 4.11 down from factory 4.53. What this does is make your car excellerate SLOWER in every gear. Your ET will suffer 1-2 tenths from doing this. Be smart people and do some basic math. Relax and shift to 5th.
Thing thats sucks is this was bouncing off the rev limiter in 4th. I even raised the limiter to 8200 and it still did not give me enough room.
I know with a slightly longer 4th or higher revs the car would be good for 11.7 or 11.6
I got a nice 60 foot of 1.687 one run but I tried shifting to fifth and it did not really work. Wound up running 11.9 @ 109
Maybe I can put a taller tire on it and then I will get some 11.7's or 11.6's for sure.
?????????????????????????????????????????????????? ????????????????????????????????????
No disrespect for the poster of this quote. There are hundreds of quotes like this all over this board. I am just using this as an example.
I am really tired of these type statements. It is really without knowledge to say your car will improve .1-.2 in the quarter by not having to shift to 5th. So here are some facts for you. At 120mph you are moving at 176ft per second. During a shift you loose acceration but not speed. What this means is instead of being able to accelerate to 177ft per second you stay at 176fps during your shift. So what does that do to your ET? Not much. Not worth crying about. But worth discussing just this once. In a drag race I have noticed how much distance my car looses during a shift. In a really close race where you are door to door it is really easy to tell how much distance your car looses during a shift. For me it is about 2 feet on a good shift and 6 feet on a really bad shift. Perfect example is I was racing a mustang and our cars were really close in performance. Door to door in fact. He couldn't pull on me and I couldn't pull on him. When it came time to shift to 5th I look at his car and see how much distance I loose. Since this is a mustang and his gears are spaced different during my whole shift the mustang is still accelerating. I loose 2ft during my shift to 5th. Are you with me so far? Shifting to 5th costs me 2ft. but at a time when the car is moving 176fps. That means my ET will suffer by having to drive an additional 2 ft at 176fps. or .011 seconds. So in reality your ET will plummet by .01 on a good shift and only .03 on a real granny shift . Is this really worth crying about? What really erks me about this is all the threads that people are considering dropping their rear end ratio to the 4.11 down from factory 4.53. What this does is make your car excellerate SLOWER in every gear. Your ET will suffer 1-2 tenths from doing this. Be smart people and do some basic math. Relax and shift to 5th.
Anyway one thing worth considering is that I was crossing the traps in fourth banging against the rev limiter....so not accelerating for a good distance before crossing the traps.
If I shifted to fifth I was having lockout problems and had to shift VERY slowly, lifting off complelty and really taking my time. During this time the car is not only lacking acceleration but it is slowing down. Based on the charts posted from MLR, I would guess that my slow shift was loosing about 3mph as it was very slow and was also at high speed with lots of aero resistance.
Perhaps my claims of improving by .1 or .2 were exaggerated but I don't think so. I wound up chaing my 4th gear to an evo 8 gear....went back to the track and ran 11.70 ---- or .15 faster than last time--- exactly what I predicted.
Aug 7, 2008, 02:55 PM
#23
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It is now common knowledge.
I hope you guys can take this as food for thought.
Congrats Brian on reaching your goal of 10's, however you got there.
So the full list of changes done to the car to take it from 11.01@125mph with the TTP-Engineering stock ecu/maf reflash, to 10.77 @ 123mph with CFT tuning was the following?
AEM standalone EMS
AEM Meth Kit
Custom ram air intake, no MAF sensor, no intake filter
24" slicks swapped for street tires
New OEM 0 mile Evo IX turbo
C16 w/ Methanol injection
RaceMan Oscar Robles, pro driver (140lbs) NLTS
We heard about most of the changes, but the use of meth injection is a surprise.
So the full list of changes done to the car to take it from 11.01@125mph with the TTP-Engineering stock ecu/maf reflash, to 10.77 @ 123mph with CFT tuning was the following?
AEM standalone EMS AEM Meth Kit Custom ram air intake, no MAF sensor, no intake filter 24" slicks swapped for street tires New OEM 0 mile Evo IX turbo C16 w/ Methanol injection RaceMan Oscar Robles, pro driver (140lbs) NLTSWe heard about most of the changes, but the use of meth injection is a surprise.
I hope you guys can take this as food for thought.
Sep 9, 2008, 07:36 PM
#24
Obiously it will be better for gearing in certain situations, but a taller sidewall will tend to flex more then a shorter one giving more straight line traction with similar tires..Theres really no info to go by in this post though other then huge slicks to street tires..I don't see anything going by what you are referring to as "data" but rather just a generality where almost all variables are left out..No disrespect meant whatsoever.
Last edited by PeteyTurbo; Sep 9, 2008 at 07:38 PM.
Sep 9, 2008, 09:25 PM
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Obiously it will be better for gearing in certain situations, but a taller sidewall will tend to flex more then a shorter one giving more straight line traction with similar tires..Theres really no info to go by in this post though other then huge slicks to street tires..I don't see anything going by what you are referring to as "data" but rather just a generality where almost all variables are left out..No disrespect meant whatsoever.
If you are concerned about the height of the sidewall, move to a smaller rim.
I've been drag racing for a long time. Making changes to the gearing, wheather it be tranny oriented, final drive, ring/pinion, or tire diameter can have positive OR negative effects.
The point is, there are many ways to skin the cat. Personally, I would have gone with TRE final drive if I had a 6 speed. Turbo cars LOVE numerically low gearing. It helps to keep the motor in the powerband through the pass. In the case of the op's thread, the shift to fifth is inevitable. Either invest in tranny mods, or swap tires to finish the quarter in the powerband. The shift to 5th can be damaging, but not more damaging than bouncing of the limiter imho.
The cheaper fix is to take advantage that the short gearing, short powerband, stock turbo car offers. Getting into 5th gear sooner means the car is running through its powerband sooner, and therefore saving et.
Here's an example that most of the mustang guys will attest to. A stock foxbody car (1987-2002) runs the 1/4mile at 14.0 at 98 or so mph. Stock configuration puts the rear-end ratio from 2.73-3.08 to 1 ratio. Swapping out the ring and pinion to a 3.73-4.10 to 1 ratio (along with a sticky tire) drops the car down to mid 13's @ 95 or so mph. The mph is lower because the car gets to the line quicker, not based on any drop in power. Keep in mind that the stock gearing allows you to complete the 1/4mile in 3rd gear. Moving up in gearing forces you to use 4th gear to complete the run. An additional shift still yielding a lower et.
I hope I've explained this clearly enough, I'm a little tired tonight.
Sep 9, 2008, 09:34 PM
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You yielded a better result due to the fact that the motor was left in it's powerband for a greater period during the run. Adjusting your shiftpoints may have gotten you 2 mph as well.
Again, there are different roads to obtain the same goals. The traction and gearing from the shorter FULL SLICK would have improved your 60ft's and ultimately your 1/4 mile passes. Your 1/8th mile et might have been lower by as much as 3 tenths.
Sep 9, 2008, 09:51 PM
#27
I totally agree there 100% and I am sure I have been racing as long as you, I'm old lol..The 6 speed absolutely makes the the boost/power curve even WORSE for the 1/4 then it already is, let alone comparing it to a 5 speed..
If you are concerned about the height of the sidewall, move to a smaller rim.
I've been drag racing for a long time. Making changes to the gearing, wheather it be tranny oriented, final drive, ring/pinion, or tire diameter can have positive OR negative effects.
The point is, there are many ways to skin the cat. Personally, I would have gone with TRE final drive if I had a 6 speed. Turbo cars LOVE numerically low gearing. It helps to keep the motor in the powerband through the pass. In the case of the op's thread, the shift to fifth is inevitable. Either invest in tranny mods, or swap tires to finish the quarter in the powerband. The shift to 5th can be damaging, but not more damaging than bouncing of the limiter imho.
The cheaper fix is to take advantage that the short gearing, short powerband, stock turbo car offers. Getting into 5th gear sooner means the car is running through its powerband sooner, and therefore saving et.
Here's an example that most of the mustang guys will attest to. A stock foxbody car (1987-2002) runs the 1/4mile at 14.0 at 98 or so mph. Stock configuration puts the rear-end ratio from 2.73-3.08 to 1 ratio. Swapping out the ring and pinion to a 3.73-4.10 to 1 ratio (along with a sticky tire) drops the car down to mid 13's @ 95 or so mph. The mph is lower because the car gets to the line quicker, not based on any drop in power. Keep in mind that the stock gearing allows you to complete the 1/4mile in 3rd gear. Moving up in gearing forces you to use 4th gear to complete the run. An additional shift still yielding a lower et.
I hope I've explained this clearly enough, I'm a little tired tonight.
I've been drag racing for a long time. Making changes to the gearing, wheather it be tranny oriented, final drive, ring/pinion, or tire diameter can have positive OR negative effects.
The point is, there are many ways to skin the cat. Personally, I would have gone with TRE final drive if I had a 6 speed. Turbo cars LOVE numerically low gearing. It helps to keep the motor in the powerband through the pass. In the case of the op's thread, the shift to fifth is inevitable. Either invest in tranny mods, or swap tires to finish the quarter in the powerband. The shift to 5th can be damaging, but not more damaging than bouncing of the limiter imho.
The cheaper fix is to take advantage that the short gearing, short powerband, stock turbo car offers. Getting into 5th gear sooner means the car is running through its powerband sooner, and therefore saving et.
Here's an example that most of the mustang guys will attest to. A stock foxbody car (1987-2002) runs the 1/4mile at 14.0 at 98 or so mph. Stock configuration puts the rear-end ratio from 2.73-3.08 to 1 ratio. Swapping out the ring and pinion to a 3.73-4.10 to 1 ratio (along with a sticky tire) drops the car down to mid 13's @ 95 or so mph. The mph is lower because the car gets to the line quicker, not based on any drop in power. Keep in mind that the stock gearing allows you to complete the 1/4mile in 3rd gear. Moving up in gearing forces you to use 4th gear to complete the run. An additional shift still yielding a lower et.
I hope I've explained this clearly enough, I'm a little tired tonight.
Sep 10, 2008, 04:00 PM
#28
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Agreed. My main concern with the 6speed (besides its weaknesses) is that it isn't a proper match for the evo in the 1/4 given the car's weight and powerband with the stock motor. It would be so mucj better in a car 500-6--lbs lighter combined with turbo/valvetrain that lived life from 6500-9000rpms. THEN you would love this tranny.
Too bad we don't have a bridgeport 13b with dual webbers under the hood!!!,,,,hehehehe
Sep 10, 2008, 05:58 PM
#29
Well I DO have a 1st gen RX7 I can transplant it into lol..
Agreed. My main concern with the 6speed (besides its weaknesses) is that it isn't a proper match for the evo in the 1/4 given the car's weight and powerband with the stock motor. It would be so mucj better in a car 500-6--lbs lighter combined with turbo/valvetrain that lived life from 6500-9000rpms. THEN you would love this tranny.
Too bad we don't have a bridgeport 13b with dual webbers under the hood!!!,,,,hehehehe
Too bad we don't have a bridgeport 13b with dual webbers under the hood!!!,,,,hehehehe
Sep 10, 2008, 07:02 PM
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Ahhh... I had 3 of those cars in my day!!
Best transplants I've seen in that bodystyle is the 2.3 turbo ford motor from svo mustang/merkur xr4ti,,, and the vq twin-turbo motor from the 300zxtt. Man, that little car handles like mad!!!
We used to love those cars in the early 90's. I crossed over to dsm's around 1996 and some of my buddies just kept growing with the changing rx-7 stages..
http://www.youtube.com/watch?v=NTyKHqaWQb0&feature=user