Second Take at the Sacramento Raceway

[georryan]

Ok well I dragged my car again and this time with much better results.

My first run was a 16.8, and I was beaten by a guy drivnig a new malabu and pulled a 16.512 but my trap speed was 84 mph compared to his 82 mph.

My second run was my best, and that was 16.53 and a trap speed of 86.6 mph. The guy who beat me creamed me. I bogged that one down on the start as well.

My third run was horrable. I dropped the clutch too fast (the one time I tried to rev it, and I wasn't ready so I ended up reving it too high because the light was already on the second to last one) and just burned my clutch, and when I shifted into second I missed my shift. The whole ordeal cost me a second off my best time about, and I ended up with a 17.3 but my trap speed was 84 mph, so I think if I had done that I would have been in the low low 16s - high 15 second time frame. I'm not sure though. That run also had my best reaction time (.2 seconds compared to the .4 on all the other ones).

My last run wasn't much to talk about, my slowest trap speed and another 16.8 mph.

All in all I think she ran fairly decently. I couldn't tell really if it was holding back at all. It was holding back a lot the day before and I put a few gallons of Cheveron in there and she picked right up again.

I also don't know if it would have been faster with the stock exhaust or not. I have the 3 inch right now, and by looking at the vrg3 scan tool I'm pushing 9-10 psi of boost at the manifold, compared to the 8.9 I'd see stock (sea level just about). I have no idea if those are good numbers or not, but they are a lot better than what I did on my last run around with a faulty boost control solenoid. I don't know if I'll make it over there before I put on my intercooler or not. We'll see. It depends on when Ciper gets them out.

-Ryan

[douglas vincent]

Did you do the runs during the day or night? How hot was it out? How much does your rig weight? And I take it you have a turbo?



The reasons I ask these questions is that I am running about the same e.ts with my NA but with a 79.8 trap. I am having to shift into 4rth just before the trap and I have no real power in 4rth.

My best with my NA was last weekend with a 16.601 et, 79.8 trap and a 60' of 2.193. I was running at night in about high 60% weather. I also had a brand new clutch and was pretty much dumping the clutch at 6000 rpm to get these times. I didnt let up on the gas either when shifting. Until the supercharger and nitrous get hooked up, there is no way I can get a better time because this run was about perfect in my eyes.

My point being is that you should be able to shave serious time off your et if you are a 5mt turbo. The secret is you have to, and should be able to get, a sub 2 second 60'.

Of course I have no idea how hot it was for you there and how much your car weighs. Mine weighed in (with me) at 2950. If I was running with my seats in and hotter temps I would be lucky to break the 17's.

[georryan]

What my car's weigh in I don't know but I had a half a tank of gas and all my usual stuff in it. It is a turbo and I wasn't really dropping the clutch. the first few runs I didn't even rev it off of the line. My clutch isn't the origional, but it has quite a bit of miles on it probably and it isn't a high performance one by any means. I'll have to check my 60' times. I'm not sure were it says that on the slip, but I'm guessing it will make sense when I look at it.

The temperature was fairly warm: low to mid 90's I think. Thawa ought to know how hot it was. Maybe it was really high 80's. It cooled off quite a bit in the evening, but I did my worst time then as well.

I didn't have to shift into fourth, although I did pretty much redline 3rd by the time I was done. I don't know were the rev limiter kicks in on 3rd but I'm guessing it is close to 90.

[douglas vincent]

90 degrees on the tarmac is a serious time killer. On a cooler day and if you wanted to abuse your clutch, you should be pulling low to mid-15's without a problem.

Goto

http://www.scoobymile.com

for time comparisons

[georryan]

All the sti's there were doing 13.5 and 13.6 it looked like.

[legacy92ej22t]

Ya, driven well and in cool temps a stock Legacy turbo should run mid to high 15's. Your 3" exhaust might hurt your low end torque a bit too, for now, until you start adding boost and get intercooled.

[georryan]

I was wondering about that.

[legacy92ej22t]

Like I've said before, it isn't 'bad' for the car, it just hurts low end a bit until you run higher boost. Once you turn the boost up it will be amazing though! I was stock except for my exhaust last year at the Shootout and I was kickin' everyones ass in the rain. lol

[BAC5.2]

Rain = Natural IC-Spray.

16.5 in a Turbo Legacy!? WTF? Stock, they run 16 flat (as per all car mags I've read). Brat4by4 ran a 15.7 on shot suspension and bald tires with his only mod being a lightweight flywheel.

After my exhaust and boost massaging, I'm expecting a low 14, high 13. That's about as fast as I wanna go for the time being

[Brat4by4]

Don't forget elevation, temperature, and humidity. That's one heck of a high temperature to drag in. I sit around 1000' above sea level, also.

And it is impossible for your exhaust to hurt your torque. Less restriction equals faster spool which means torque comes on faster. If you want to see my car at full boost at 2k rpm, let me know, i'll try to snap a pic or take video or something. read cobb tunings website about turbo exhaust.

[legacy92ej22t]

And it is impossible for your exhaust to hurt your torque.

Well, I certainly don't agree with that. If it wasn't possible for the exhaust to hurt torque and bigger was always better then why don't you put a 6" TBE on your car? I garauntee that if you did your turbo might spool really fast but you wouldn't have any low end torque.

[Brat4by4]

read cobb tunings write up on the subject. bigger is better, but once you get past a certain point it is a matter of diminishing returns.

you are confusing turbo and na applications.

Pipe diameter does have an effect on flow rates as well, but again it is not the major factor in most cases. 2.5" may flow enough for 300-350 h.p. without being a restriction. 3" is usually capable of flowing 500-600 h.p. before becoming a restriction. This is assuming that you have designed the rest of the system up to par. There are also full 3.5" systems and those that start out at 4" and taper down. Unless you are making over 500-600 h.p. anything over 3" is a case of diminishing returns and in most cases has no advantage. There is more to gain going from 2.5" up to 3" than there is going from 3" to 3.5". A 3" system will not loose torque compared to a 2.5" system if designed properly. In fact if designed properly 3" may be capable of making better low end torque than 2.5". Again, since the way to make the most torque with a turbo exhaust is to get the turbo to spool-up as quickly as possible, it should be the main goal of the entire exhaust system and good flow after the turbo is one way to achieve it. We use 3" as we want our system to flow enough to be capable of coping with a customer's changing goals. Properly designed we can offer it to the big power crowd while still appeasing the low end torque club.

http://www.cobbtuning.com/tech/exhaustdesign/index.html

[legacy92ej22t]

Well, Cobb would probably know better then me. ;)I don't know though, I still don't totally agree. When I was completely stock except for my 3", my low end seemed to suffer just a bit. I'm not saying it was a major difference but it was noticable. When I ride in a stock SS, low end still seems better, in say 1st, then it does in my car at 14-15 psi. I'm only talking about the extreme low end though.

I would like to see a pic of you being fully spooled by 2k rpm. That seems very impressive. Well then again, are you running stock boost levels?

[georryan]

Sacramento is basically sea level. So now you guys got me thinking that my car just isn't performing right. Which I'm way inclined to agree with. If it consistantly runs at that problem speed then what would consistantly slow the car down? I had wrx rims and tires, but so did Brat when he ran. Could it be a fuel pump, or something else? It just seems weird that the whole car would feel like it was normal for the most part and be a heck of a lot slower.

Ok, well I'm looking at my time slips, and if the 60' is the first mark on the time slip which I'm guessing it is then my 60' were all 2.4 something or another. At least I'm consistant. All my reaction times were .4 something, except for one.