Why cant I hold big boost?

[postal]

I read up and asked questions about Ford 9" rears and drum brakes. People told me if I went with the big ford drums I would be able to hold big time boost. They where talking like 20+ pounds. I can only hold about 8-10. Any suggestions on what may be messing me up?

TIA: Jason
p.s I filled out some signiture stuff lets see if its going to show

 

[postal]

Hey cool it worked!

 

[Razor]

Look who's bitchin....Mr. 1.4 60 foot

I would chriten that converter and suspension..leave the launch thing alone..gees

Worry about making 132 through the traps..that should be your goal..if it aint broke...dont fix it

 

[postal]

I have a tendency to take my car to the track after changing multiple things, finding problems, and then spend awhile addressing the different issues that I found. I know guys always preach the one part change at a time and I agree in general with this theory. The problem is the nearest track is too far away and its a big pain for me trying to set things up so I can go. In the end I mainly find my self tinkering with the car in my spare time, checking it out on a back road, and racing very little. So now I'm in the "fix the bugs stage" and it will probably be 2 months before the car sees the track again.

Heres why I think I need to look into my brakes:
1. Mike Licht told me a long time ago that to make my turbo work properly I need to launch at 15#'s of boost.
2. People told me before I bought my 9" to go with the big drum brakes because I could hold 20+ psi.

I will admit that I have already exceeded my goal for 60' times. I was hoping to get low 1.5's. Before I went to the liquid IC, rear suspension pieces, and the 9" my best 60' was 1.698 launching at 7#'s.

Jason
p.s: 72 pounders on the way along with a few other fuel system changes. I think when I can get enough fuel to the rail then I'll be able to tune it out. Once thats all dialed in I think I'll start seeing the mph go up. 132 mph! I'd be tickled pink if a saw a 123 out of it.

 

[Razor]

You dont need 72's to get 123. 50's will do that.

I feel your pain on the other tuning issues..its like you get to the track and everyone expects your car to be running top notch..and when it runs bad..its like..whats the problem..

Check your rear cylinders and prop valve. If your so inclined..I think if your getting a 1.4 60 foot you dont have to worry about the 15 lb launch

 

[postal]

Well I'm buying 72's because it looks like my 50's should be going static for the MAF readings I'm getting. Doesnt "going static" mean that they are no longer pulsing but being held open? I just figure that it will be to hard to fine tune it if they're going static. I know from before that my car ran harder at less boost once I got it tuned out better. Its not really costing me very much money to go to the 72's and a new chip (most of the money is coming from selling my old inj's and chip). I think 72's will be overkill on my current set up. I do however have a built short block ready for a set of ported heads and intake. Once I get done playing around with pushing a stock long block I'll put in the new motor. I would be worried about idle and driveability with the 72's but I have been doing some searches and people are saying they idle and cruise better than 50's ( personally I dont see how).

Ill keep you guys posted as I try to get this thing figured out.

Thanks for the input: Jason

 

[The Swede]

Hi gang!

I saw that the discussion went over to speed.......

I have layed down plenty of 122 passes with stock injectors!

Guess it's way over the limit but it can be done!

 

[Razor]

Um..ahh.. you forgot to mention the ecm... the stock ecm cannot handle the 72's unless its injector drivers are modded..

I dunno why you say its maxed out.. what proof besides airflow. Your performance doesnt say they are. 50's are good for 124 at least..you are no where near that..yet

Lately been seeing a lot of goofy posts related to the extender MAF readings. On top of that..I've seen direct scan say a car running 11.90's with 50's was over 100 percent on the injectors.. My car is in the 70's at my power level..so take info as you will...no extender..I will do some back to back inj readings latter this summer..

Looks like you have too many fires brewing at the same time..time for you to move closer to a track..

Figure your fueling problem then go race the car..max out what you have..then mod

 

[turbov6joe]

I have a set of 50's turned down to 72% duty cycle and run nearly 120 MPH....this is with alky injection as well.

 

[postal]

Hmm..... You guys have me all confused. I think mph is best indicator of HP on same car or two cars set up the same. Not sure if I can realy compare mine directly to you guys though. I'm running a 9" non lock up and hit overdrive probably atleast 150' before the end of the track. Its hard to judge disatnce but if I run over 112mph I hit overdrive(doesnt this hurt my mph on the big end). I'm also running a Ford 9" and something about where the pinion meets the ring gear isnt in the center so it eats up more HP to turn it(so its supposed to hurt my mph). Also the harder you launch doesnt your mph tend to suffer abit? Plus you guys are also spraying alky which is taking away from some of the fuel you need.
On my old set up I picked up 6 mph from tunning it out. That was 6 mph improvement on a car that felt like it was running strong. On the new set up Ive run 96.3 or so in the 1/8th with the car not running right. You can feel a studder in it as your going down the track. I figure buy the time I get it running right, and then tuned out I should be over 100 in the 1/8th.
PLUS I got a built short block ready to go. Once I'm done messing with the stock long block the new motor is going in and I'll be shooting for mid 10's. All this and the fact that 72's are supposed to idle nice and run real good on the street makes me think they're the way to go. I'm not saying I think I need 72's, but that if I do or have out grown my 50's then 72's seam to be one of the popular choices.
I have bought things for turbo buick cars that I wasnt happy with before. If these 72's wind up being a a mistake Ill let you guys know. Its not going to cost me much to try them though. I'm buying them used so if they dont work out I should be able to get most of my money back out of them. I figure if it doesnt work I'll lose less than $100 if I resell the pieces. If they do work then its cage time because the track will shut me down for sure.

Jason
p.s: How the hell does some body run 122 mph on stock injectors