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Discussion Starter · #1 ·
I know that we are not supposed to compare trap speeds across platforms and all, but I have a question... Just because my car can trap at 102mph in the quartermile, does that mean that I can take out cars that trap at slightly lower speeds on the highway?? (ex. 100mph)??? Please forgive this dumb question, but I am still trying to figure out where my car fits in the automotive pecking order with regard to the performance of my car with my current mods (TBXS Stage 2.5). Any ideas?

The other thing that I have heard is that a stage 2 WRX might be able to trap at even higher speeds if not for the AWD (the ability to hook up). If this is the case, does this mean that my car might be even quicker on the highway than the trap speed suggests (since there is no AWD launch to increase the distance the car needs to accelerate to a higher "trap" speed???
 

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Yes and no. Remember gearing? I've got a friend with a 99' Miata (SE w/6spd) T28 turbo kit. I have another friend who has the identical kit on a Miata that is several years older w/a 5spd. Both cars on the dyno generate nearly the same power with the newer one putting down more (about 280WHP).

The Miatas at the track ran nearly identical times (60' and all) but the 6spd trapped at 106 vs. the 5spd at 109. Why? It doesn't make since to me.

So It's a little deceptive to say if one car is faster vs. another when comparing traps within several mph of each other.
 

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Discussion Starter · #3 ·
So not to magazine race here on anything, but are you saying that if for some reason I decided to run against a Honda S2000 on the highway from a roll, I would still most likely lose? I am just a little confused to say the least....
 

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no it doesnt when measuring 1/4mi performance. what matters is elapsed time. whoever gets across the line first wins regardless of speed . as far as highway roll ons goes, it is an indicator but doesnt necessarily mean you'll win...you have to take gearing into account, from what speed you start to what speed you cut off at as well as spool times if forced induction ect..many variables. There is no hard and fast rule or easy answer to highway runs.

There are plenty of instances where a lighter less powerful car with shorter gearing can take a heavier more powerful car with taller gearing in a highway roll race..all depends upon those many variables above.
 

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Discussion Starter · #5 ·
hmm... I see... So now that I am at TurboXS's Stage2, any idea as to what cars I can play with, and what to run from especially on the highway at typical speeds (at about 70mph)???Honda S2000, Ford Mustang GT's, RSX-S, Maxima's, 350Z's, etc... I just don't want to make an ass of myself if I do run across one of those.. ya know!
 

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jigga said:
hmm... I see... So now that I am at TurboXS's Stage2, any idea as to what cars I can play with, and what to run from especially on the highway at typical speeds (at about 70mph)???Honda S2000, Ford Mustang GT's, RSX-S, Maxima's, 350Z's, etc... I just don't want to make an ass of myself if I do run across one of those.. ya know!
well, I have no problem dispensing with any of those cars easily on the highway but on top of stage 2 chip I have a few other mods that boost the hp and the power curve over the standard stage 2 setup. You wont be embarrassed by any of those cars, maybe the 350Z will pull on you above 80 or 90 but they will all be good races and may well come down to driver vs driver. just keep that boost at 16.5psi per TurboXS ;)
 

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jigga -

Let's say you're cruising down the road around 65 mph and a fart pipe Integra GSR rolls up behind and taunts you into a race from a roll. You've got a few choices:
a.) drop down into 3rd and wait for him to try and come out around you
b.) since you're already in 5th you decide to drop dpwn one gear and go from 4th, or
c.) you decide not to do anything because you think that the Rex doesn't have it on the highway (bad move)

You answered correctly if you chose answer a.)

Reason is, is that from a 65 mph roll, that's a the sweet spot for the WRX and hold it there up to about 95 mph before you even think about shifting into 4th. Gearing is way too important and must not be over looked.

Anyhow, IF you're comparing a WRX to another WRX (assuming that they've got the same gearbox/final drive then you definately CAN use trap speed to determine how fast your car is. If you're comparing to my friend's Miata, then it's not such a cut and dry answer.

One other thing too. Remember that some tracks read quicker than others, i.e. if you took your Rex to a track and trapped at 102 mph, and then to another and it reads only 100 mph. That's the sad reality of traps!

-boosted 4
 

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Discussion Starter · #8 ·
Hmm.. Thanks very much for your responses guys, they have given me a great deal to think about.

I guess I might be looking into a turbo upgrade in the near future! :D
 

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Gearing, weight, power, none of that matters if you know what both cars trap speeds are. Pretty much a trap speed is an indicator of who would win in a race from a roll. A car that runs 13.0's @ 104-mph will lose a highway race to a car that runs 15's @ 110-mph. Now this is exagerated, but I did that so you could see the difference.

In the other guys example the Miata that trapped 109-mph would beat the other Miata from a highway roll pretty well.

For instance a stock 911-turbo runs 11.9's @ around 115-mph. I would run 12.5's around 115-mph. From a stop he is going to kill me (it would be ugly) but from a roll (and I have tested this) we are about dead even. He has a better coefficient of drag and top speed than my car, so I would expect him to start pulling once we hit around 120-130 mph.

You should be able to hang with most any car that traps around 103-mph and less. That would be Mustang GT's, S2000, 3SI's...

I hope this helped.
 

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The WRX 4th Gearing is major drawback to top end runs and results in the low trap speed.

Compare the gearing of the USDM WRX to a JDM Evo 7 gearing and you'll realize it plays a major factor.
*Although the Evo7 does have the higher HP's advantage.

Evo7 Manual Gear ratio:
1st 2.928
2nd 1.950
3rd 1.407
4th 1.031 <-------------

5th 0.720

Reverse 3.416

Final reduction gear 4.529
***********************************
'02 USDM WRX Manual Gear Ratio:

1st - 3.454
2nd - 1.947
3rd - 1.366
4th - 0.972 <--------------

5th - 0.738
reverse - 3.333
final drive ratio - 3.90


Stock Evo7 at the drag strip **Video**
 

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dazz said:
The WRX 4th Gearing is major drawback to top end runs and results in the low trap speed.

Compare the gearing of the USDM WRX to a JDM Evo 7 gearing and you'll realize it plays a major factor.
Thank you! That's exactly what I was saying about my firend's Miatas. So much of it is gearing! Hence the reason my WRX usually traps in the mid-104mph range BUT on the street in 1st - 3rd gears it screams.

I've raced a few Camaro Z28's, a friend's E36 M3, etc and none of them can hang form a roll below 4th gear. Even if they do pull 104 traps my WRX will be quicker from a 2nd gear pull from what I've seen. Even my friend's 6spd Miata, 280whp and 106mph traps can't pull from me.

Moral to the story is it's not only the traps for the 1320 that count. Look at my 1/8th mile and the ol' WRX is moving at 85mph.
 

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Discussion Starter · #13 ·
Wow! That Evo7 is sick!

So is there any way of swapping out the 4th gear for something a little more agressive without replacing the whole gearbox???Would a JDM 4th gear fit right in on our gearboxes?? Would doing this not be cheaper than going for a turbo swap and all the little details that entails?

You tend to wander what Subaru was thinking when they speced our 4th gear:rolleyes:
 

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jigga said:
Wow! That Evo7 is sick!

So is there any way of swapping out the 4th gear for something a little more agressive without replacing the whole gearbox???Would a JDM 4th gear fit right in on our gearboxes?? Would doing this not be cheaper than going for a turbo swap and all the little details that entails?

You tend to wander what Subaru was thinking when they speced our 4th gear:rolleyes:

Probably MPG rating. 5th gear in the WRX will result in lower roms on the highway compared to the 6th gear in the STI IIRC.
 
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