Friday night Test n Tune - SRT Forums

base_model_95 · 09-07-2009, 09:04 PM

Friday night i went out for a test and tune and i was rather confused with the times/mph that i was running. I was wondering if a few of you guys had any opinions on the situation. My first pass was made on street tires with my exhaust cutout open, heres the slip.

2.261
5.963
8.824
86.38
11.240
13.255
113.06

My second pass was with the cutout open and on the slicks

1.904
5.357
8.169
86.60
10.595
12.643
111.31

3rd pass was cutout closed (i forgot to open it) on slicks

1.898
5.308
8.087
88.93
10.459
12.472
113.03

4th pass cutout open on slicks

1.888
5.364
8.199
86.49
10.636
12.680
111.63

I find it very wierd that with the cutout closed it seems as if its making no effect at all. faster time and higher mph, now the fastest time with the car ever to date. (did not have cutout at this time)

1.816
5.138
7.894
88.21
10.282
12.290
112.17

The setup is a 2.4L srt internals, 2.0 cams, srt turbo, box intake, megasquirt, 3" 02 housing, 3" dp, 3" E cutout, middle of the car goes to 2.5" with a cherry bomb turbo muffler (baffled) and a few of other mods

Blackbird1084 · 09-08-2009, 03:38 AM

Do you have a scangauge? It seems like it may be picking up some knock with the cutout open and thus pulling timming and lowering your mph. Just stick with the cutout closed till you can find out if it's picking up knock.

popejoshpope · 09-08-2009, 03:41 AM

ive heard you loose top end torque with an open dump, from MANY people who know alot about srt's specifically

pantherballhp · 09-08-2009, 10:56 PM

turbo's need backpressure and sometimes open exhaust like that can hurt ya a lil

base_model_95 · 09-08-2009, 11:35 PM

does anyone really see much a gain with the 2.0L cams? i was debating going back to the stock cams to see what that will do. does my trap speed seem right with this setup and remember i am in a 1st gen weighing about 2500 pounds with me in it. (guessing)

mmench · 09-09-2009, 08:20 PM

hmm. im a first gen'er to and i trapped that much runing a 13.9 (2.1 60 ft, boost leak from hell keeping me at 8 lbs that night). i dont know your set up but im runnig the stock 2.0 with a srt turbo setup on it. im in a full weight 98r/t
im sure if i could get the DR's to hook better and not spin till mid way into 3rd i can easily dip into the mid-low twelves... that and actually run full boost (13-15)

mmench · 09-09-2009, 08:21 PM

wats your afr's like, wat trans, and such also ?

Rhunter · 09-09-2009, 08:28 PM

You are probably pulling timing with the cut out open.

Remember, having it open will raise boost plus increase air flow so it WILL change your AFR's.

Try monitoring your AFR's and your KR with the cut out both open and closed.
Also Race gas is your friend. throw in some race gas to combat the probably knock

You will probably gain 2 mph on your trap speeds with higher octane and the cutout open.

Rhunter · 09-09-2009, 08:30 PM

Quote: Originally Posted by popejoshpope

ive heard you loose top end torque with an open dump, from MANY people who know alot about srt's specifically

You may loose some torque down low but will more than make up for it up top.

popejoshpope · 09-09-2009, 11:56 PM

Quote: Originally Posted by Rhunter

You may loose some torque down low but will more than make up for it up top.

Its just weird because ive heard the exact same thing from respectable people and they swear up and down that open dump isnt benificial

base_model_95 · 09-10-2009, 06:45 PM

Theres no knock control, the car pulls very hard in 1,2,3 4th seems a little sluggish, (need more hp) i was running the 3.55 trans but currently the car has a 3.94, as that night i blew the 3.55 trans. at the beginning of the year i ran the 3.94 trans and trapped around 111mph shifting into 5th lol. i was 4-5mph faster by the 1/8th though. i am spiking 21- holding 17-18 psi.

The setup consists of 2.4 stratus engine,srt internals, 2.0L head milled 0.040, 2.0L cams, srt turbo ported compressor housing, 3" 02 housing, 3" dp, 3" e-cutout, box intake manifold, stage 2 injectors, 255lb/hr fuel pump, return line, aeromotive 1:1 fpr, megasquirt, k sport coils, all solid mounts, 4 puck sprung clutch, HD pressure plate, 22x8x13 E.T. drag slicks

Rhunter · 09-10-2009, 07:03 PM

Quote: Originally Posted by popejoshpope

Its just weird because ive heard the exact same thing from respectable people and they swear up and down that open dump isnt benificial

I hear ya man,

I used to think the same thing. I picked up 3 mph consistantly

with the pipe opened. I think the difference was the race gas, 110 octane + open downpipe = faster trap speeds.

also Needs Wings suggest you let the car run for about 2 mins for the PCM to adjust.

base_model_95 · 09-23-2009, 10:07 PM

Has anyone every tried avgas? its 100 low leaded fuel that is used in small aircrafts. the amount of lead is very minimal and i dont have a cat on the car. (2grams lead per gallon of fuel) i was thinking of using some as another local racer used this in his car at the track and was sucessful. will i notice any difference with the car in its current tune? or will advancing the timing be the way to go? Also avgas has aparently a lower chance of knock, i currently use sunoco 94.

anyone ever use this and have any luck?

Thanks

NJ DSM · 09-23-2009, 10:17 PM

Quote: Originally Posted by Rhunter

I hear ya man,

I used to think the same thing. I picked up 3 mph consistantly

with the pipe opened. I think the difference was the race gas, 110 octane + open downpipe = faster trap speeds.

also Needs Wings suggest you let the car run for about 2 mins for the PCM to adjust.

couldnt say it any better. throw some 110/116 or at the least some 100 in there and give er hell

bayshore power · 09-25-2009, 08:27 PM

They are all the exact same runs 111.3 - 113.0 that less then 1.7 MPH from the best to the worst pass what are you confused about?