so tubes and filters alone were good for 2mph in the 1/4 *before & after slips*

[darkostoj]

so I went back to the track with nothing but ACR smooth tubes and S&B filters installed from roe compared to the last time I went to the track.

before:

60' - 1.969

1/8 - 8.101
mph - 96.64

1/4 - 12.221
mph - 118.49

after:

60' - 1.926

1/8 - 7.934
mph - 91.27 (5mph lower)

1/4 - 12.101
mph - 120.53


All my car has is a corsa 3" catback and the smooth tubes/filters....other than that its completely bone stock with 31k on the clock and 20psi in the stock tires.

next mods are removing the cats and adding a crossover pipe

 

[dave6666]

How many runs was that? Don't you need to back up those runs or have an average of several runs?

 

[darkostoj]

How many runs was that? Don't you need to back up those runs or have an average of several runs?

well i had 4 runs last night, and each run was progressively getting better. I posted my best 2 slips from each track outings(the one yesterday and the one from about a month ago).

pretty much ALL my slips from the track outing before the mods were at 118mph, and all the slips from yesterday after the mods were 120mph.

 

[Dom426h]

the Driver is a MUCH bigger variable than tubes/filters.

i'd pat yourself on the back before crediting the 5hp mod

Nice runs.

 

[darkostoj]

the Driver is a MUCH bigger variable than tubes/filters.

i'd pat yourself on the back before crediting the 5hp mod

Nice runs.

thanks

but no matter how i drove it the first time out i could only trap a 118, after the filters & tubes I was trapping 120

 

[Russ M]

I did multiple back to back dyno sessions testing the smooth tubes/K&N's and there was no measurable power gain.

Your 1/4 time improvement is due to several things:

1) Driving
2) Weather

You can tell by your 1/8 mile time that you have considerably improved your launch, shifting and traction.

 

[FE 065]

60' times were almost identical. Most people agree MPH shows HP differences, where ET is more driver and other variables. Don't forget Dodge rated the ACR 10hp higher with the same filters and tubes..

Nice runs Darko



Dyno runs only take a few seconds, drag strip runs take longer and would/could show HP gains/losses better

I'm waiting for the crossover pipe results

 

[darkostoj]

I did multiple back to back dyno sessions testing the smooth tubes/K&N's and there was no measurable power gain.

Your 1/4 time improvement is due to several things:

1) Driving
2) Weather

You can tell by your 1/8 mile time that you have considerably improved your launch, shifting and traction.

well i think the track is going to be a more accurate measure of power gained since its at a real world situation and you're taking advantage of the air velocity coming in through the airbox.

even though my e/t's on my runs were all different, my MPH on all runs were the exact same (except for the first run where i missed 3rd gear...ouch)

The time I went to the track without the tubes and filters every run was a 118mph trap speed and all the E/T's were different then also.

So next time don't tell me my gains were only due to weather and driving because thats simply not the case. I'll take track results over dyno results ANY DAY....i mean how often are you gonna race someone strapped down with a shop fan blowing at the front of your car

 

[darkostoj]

60' times were almost identical. Most people agree MPH shows HP differences, where ET is more driver and other variables. Don't forget Dodge rated the ACR 10hp higher with the same filters and tubes..

Nice runs Darko



Dyno runs only take a few seconds, drag strip runs take longer and would/could show HP gains/losses better

I'm waiting for the crossover pipe results

yea i havent had time to mess with the car at all. I want to throw on the shift light and the tubes to eliminate the cats...i havent got around to cleaning them up and rewelding all the stuff yet though.

I also dont plan on doing anything with the car until i install a set of woodhouse mounts. I was getting some wheel hop in 2nd gear and just picturing the mounts being bad was enough to keep me from doing anything with the car till i get them swapped out.

so next time i go to the track i'll go catless, then i'll do the crossover tube and see what kind of gains I get...you should try to make it out that day.

 

[Russ M]

Dodge rated the ACR at more power becuase it could, all gen 2 vipers were under rated from factory.

MPH will become higher if you get down the track faster, shift better, have better traction. Is a good way to compare if everything else is equal, it is obviously not unless you think even if he did pickup 10hp that he could gain 2mph from it in the 1/4 mile.

Every tenth you take of the 60' equates to roughly 3 tenths in the 1/4 mile, which means his .040 better 60' foot mark means a .120 better time. Now look at his time slips again.

 

[JonB]

the Driver is a MUCH bigger variable than tubes/filters.

i'd pat yourself on the back before crediting the ..... mod

E X A C T L Y ! And if the air temp was 15-degrees cooler, THAT mattered....

ps THE YEAR MATTERS..... 96-98 GTS get a bigger bump

 

[FE 065]

yea i havent had time to mess with the car at all. I want to throw on the shift light and the tubes to eliminate the cats...i havent got around to cleaning them up and rewelding all the stuff yet though.

I also dont plan on doing anything with the car until i install a set of woodhouse mounts. I was getting some wheel hop in 2nd gear and just picturing the mounts being bad was enough to keep me from doing anything with the car till i get them swapped out.

so next time i go to the track i'll go catless, then i'll do the crossover tube and see what kind of gains I get...you should try to make it out that day.

Give me a shout a few days in advance, I'll definitely try and be there one way or the other

 

[FE 065]

By the way, just to set the record straight, the idea that " a .1 sec reduction in 60' time = .3 sec quicker at the end of the strip is so far off it's not funny. At least on near stock Vipers

For example, PAULS had a 1.375 60' when he went 11.05 on slicks. That about a .6 quicker 60' than I was getting in my 11.80 '99GTS, but he was only .75 sec quicker than me in the 1/4, not 1.8 sec quicker.

I've strip tested Viper mods enough to know the gains that an experienced driver like Darko got don't just happen from some sudden improvement in driver technique, and it's just not worth debating with people who've never posted any evidence that they've spent time at the strip whittling down their ET by testing one mod at a time.

The rule of thumb that changes in MPH at the strip are mostly attributed to changes in HP is one of the oldest guides there is.. Along with the variable of what type of filters the S&Bs replaced and what condition those other filters were in, conventional thinking would always place the MPH as a result of the mod.

 

[Chuck 98 RT/10]

If you've dragged your Viper enough times to have a good idea of what the times should be with or without the mod and you feel the slips are accurate then you're probably right about the mph increase.

But if you haven't raced that much then realize that ET can vary significantly from one day to the next. I've been at the dragstrip on nights when everyone was running .5 slower than their usual.

 

[jamie furman]

I did multiple back to back dyno sessions testing the smooth tubes/K&N's and there was no measurable power gain.

Your 1/4 time improvement is due to several things:

1) Driving
2) Weather

You can tell by your 1/8 mile time that you have considerably improved your launch, shifting and traction.

I agree, theres no way tubes and filters could pick a car up like that. Its more than likely driver improvement as the times are still around average gts times and the car has been modded so its actually still below average. Not a knock on you or the car, just stating that I think the weather and or you improved not the hp.

 

[FikseGTS]

good runs.... the weather changes everything, go go the track again and do before/after runs swapping out the smooth tubes and K&N's for the stock components....

 

[darkostoj]

The whole day and 5-6 runs every slip had a trap speed of 118...after the tubes/filters over the whole day and 5-6 runs every slip had a trap speed of 120.

that was enough to convince me, but who knows

 

[Chuck 98 RT/10]

The whole day and 5-6 runs every slip had a trap speed of 118...after the tubes/filters over the whole day and 5-6 runs every slip had a trap speed of 120.

that was enough to convince me, but who knows

Take the stock filter and tubes to the track and swap them out repeatedly throughout the day. Make sure you run the same lane every time.