OK, here is the low down.
I took my car to the local drag strip last night for its first full pass since the D3-M/blow thru instal. The car ran way better then I expected. I will list the passes and some info as follows:
First pass:
ET- 11.083
MPH- 132.56
60'- 2.032
Basically I had a huge stumble and the A/F ratio was like 10.5:1. The car hooked fine just fell on its face on the launch.

Second pass:
ET- 10.462
MPH- 136.43
60'- 1.763
Fixed the stumble and took some jet out of it. The blower made ~15 lbs of boost at 7000 RPM where I shift. I was launching off the foot brake because I have the trans brake disconnected because of a bad solinoid. The A/F ratio was about 11.2:1.

Third pass:
ET- 10.324
MPH- 137.43
60'- 1.731
Didnt change anything because I was running out of time and the air was getting cooler. The A/F ratio didnt change though, remained at its leanest point 11.2:1.

All in all I am pretty happy. All the passes were on 93 octane pump gas. I know its still fat. I want to get it in the 11.8:1 to 12.2:1 range. Also I am really retarded on the timing. I am running 30* total with the BTM pulling 1*/pound of boost begining at 2lbs of boost. So at full boost I am at like 17* total advance. I know I should be able to run more timing. I am going to creep up on it and see what happens. Before I mess with the timing I am going to get the A/F ratio where I want it. I may have some video of it to post......if I do I will. Also, with the trans brake ..... does anyone know if the car will come out harder? It really left like a marshmallow. Just wondering.

 

The t-brake will definitely make a difference. What stall are you running? From what I read, for the t-brake you should launch on the 2-step set at about 800 RPMs lower than your stall.

137MPH should get you in the upper 9's! :tu:

 

FIrst off, congrats and you didn't blow or hurt anything. Second, I wouldn't do any jet changes to achieve the desired 11.8-12.0 A/F yet. Since timing is in the 17 total range and only 15 psi from that big blower, I'd just add boost or timing to get the A/F to start to lean out. Once you get the desired boost level and/or total timing and the A/F is not where you want it then I'd start with the jetting. Other than that you had a good first time out and now you see that the blow-thrus really don't work so well.

 

Congrats on the runs, sounds like there is a lot more left. Did jetting it down fix the stumble????

 

Changing the secondary pump cam fixed the stumble. It is still a little flat but not nearly what it was. I am going to mess with it and see if I can crispen it up.

 

Here are links to two passes I made with it:

http://www.zippyvideos.com/8059653381420306/run2/

http://www.zippyvideos.com/4724151051420416/the_last_run/

 

vega

looks good man. was watching your launch and it was real lazy on the foot brake. probably launched on 2lbs of boost. when you bring that thing up on the trans brake hang on.......you'll probabaly go 3 tenths faster from the launch alone.

 

I would do as Brent said, just give it some timing back, the timing with the same jets will start to lean the car up, you will have more lead in the timing and burn more of the fuel. THe timing is what is causing you leave so soft. You figure if you have any boost on the foot brake, you have less timing, when you jump on it you will have less timing. You are like running a launch controller the way you have it with timing retard. THat will make it leave much harder. THat is how I get my car out of the hole, with timing, you see how it leaves, I can change that at anytime with more or less timing. Good job, glad you are happy as you should be, very nice car.

Did anyone notice the car???

 

wow, i knew that thing was going to be fast. congrats on the passes. one of these days i'll see that beast in person.

 

that is one sweeet ride if you can leave on more boost i would bring a clean pair of underwear.

 

Nice passes!

Looks like there's a lot left in it, it leaves real mild & sounds a little lazy down the track to me?

 

HAHA and you forgot to say that you were at lebanon vallyey! Maybe ill see u there before they close, im trying to get my twin turbo 73 mach 1 up before they close this year. Also they say lebanon is a second slower then anywhere else do to altitude and poor track prep.

 

Congrats from one blowthrough Vega owner to another!

 

Thanks everyone for the support. I agree that the car is real lazy out of the gate. There are several reasons.
1) 4.10s in the rear with a 33" tire (old nitrous setup)
2) Powerglide
3) low boost (14psi)
4) no timing at all
5) no trans brake (solonoid went south, have to get another one)

I think the car has a lot left in it at this boost level on pump gas. I am going to gradually increase the timing to begin with. I am also going fix the trans brake. As for boost, I am running a 70 tooth crank and a 52 tooth blower pulley. I have a 48 tooth blower and a 77 tooth crank pulley that I am sure will make some real high boost. I really want to get it to run as fast as I can get it to go on pump gas before I step up the boost. I am thinking about adding an intercooler eventually so I could potentially run more boost on pump gas. For now....I am going to get this thing to go 140 MPH the way it is with some tuning. I think the trans brake will help me make some boost at the line which will get me a better 60' then its doing off the foot brake now. The car has gone 1.30 in the 60' on the spray in the past, so I know what the car can handle. I am hesitant on throwing gear at it right now because when I crank up the blower and make more boost I will need that gear. I eventually want the car to do 160+ MPH on race gas with the wick turned up. Anyway.....I will keep you all posted of what happens with future tuning and runs. I also need a vacume pump....I am leaking oil from the back of my intake now. I am going to do that ASAP.

 

cool vega , looks like i,m not the only nut still thinking vega,s are sweet cars to build , mine is a 75 hatchback , after many years of talking about the car i,m finally gonna start building it , my new job will allow me to do all the bending i need for the 25.5 cage and with all the info availiable on this site i will have all the internet help i will need to build a blowthru turbo sbc .

mikey

 

as for anyone noticin the car....on the last pass the lanes were already closed. we asked the guy workin there if we could bring the blue vega back in line. he said" hell yea. that car is bad ass"

 

ok, here is the story. I put more timing in it and had the BTM pull timing later but pull a little more timing. Basically I have more initial and it will make 4lbs of boost before it begins pulling timing but it will pull a little more timing per pound of boost. In the end I will be running 23* at full boost (15lbs) on pump gas. I tok the car out for a ride and all I can say is WOW. It is like I put nitrous on it. As soon as I stomp the gas it builds boost and just blows the 33"x18.5" ET streets off. I am totally amazed that a little timing made such a big difference. I am going to run it again hopefully this comming Saturday. I have a feeling that I am going to need my wheelie bars and I still dont have the brake hooked up. WOW....cant wait. I think I see 145+ trap speed on pump gas and maybe a mid 9 sec pass.

 

is this gonna happen at the shootout?

 

Not sure if I am going to go for the shoot out or just going to go to Test and Tune on the Saturday before the shoot out. I need to talk to Dan because he wants to run his at test and tune. It would probably be easier to bring both cars to test and tune on the same day.

 

Go to the shoot out and hand the fuel injected guys their A**