what is too large of specs intake/exhaust with duration @ .050 to not have any vacum and cause problems with running issues on a tpi efi car?

 

Jeff, gimme about 2 weeks and I'll tell ya

I have a 112* cam going in, and I'll tell you if it idles better than the 110* I have in there.

 

what would be the exact specs on that thing as far as the way it would look?

here's the deal, i'm being told my current tunning problems are because of the cam so i'm trying to find out how to select the right one for my application. my cam was chosen by comp cams for what i wanted to do so now i'm trying to narrow it down to see what could be wrong with my motor.

i should not have to hold the pedal to the floor to start an efi car while praying my plugs don't foul out every damn time.

 

I'm running a 230/236 @.05 comp xe282hr cam ground on a 110 LSA. No problems with idle. I do notice a lot less vacuum at idle when braking. I am tuning it with Tunercat.

 

lsa? sorry i'm a little slow with this.....

how is your start up? i'm assuming your still running efi right, then how do you start it?

 

LSA=Lobe Seperation Angle, 110 is the degrees between lobe centerlines. Less seperation angle adds to the overlap which moves the power range up in the RPMs. A 114 LSA would have less overlap than a 110 LSA cam that had identically ground lobes. Overlap lowers low rpm cylinder pressure which cause lope, lack of vacuum, but pulls the intake charge in with the exhaust leaving the cylinder (scavenging).

To start mine I turn the key, and it starts up very easily.

I am running a ported stock speed density TPI.

It is in the tuning.

 

that's what i believe too....just can't find a tunner.

well i'm learning.

the cam is 230/236 @ .050 with 111.0 lsa

damn thing won't start without 12* of timing and the pedal to the floor and then it's spitting out fuel like crazy.... have to play with the throttle to keep it running until the it warms up and the o2 starts reading....

 

If your car is a 91, then you need to lower the ve tables in your chip and increase the timing. The running rich is because the lower vacuum signal of the cam is telling the fuel pressure regulator that a load is on the motor and it is adding fuel.

Chip tuning will cure this.

 

Yup.

Now if only I ever worked on a SD computer I'd help ya Jeff, but I have only done MAF.

www.thirdgen.org go to the DIY ECM tuning board.

 

i have...same old answer. search, read it yourself, etc.

i have been but i can't do it all....takes alot of time to figure out everything starting from scratch.

 

If you have someone close to you that burns chips, like rediroc-z28, then you can do it. Have him come over and using the .bin I send you, you will have to make small changes using vemaster or the other ve programs. That's what clubs/friends are for, everybody learns something.

 

sounds great, if you could send that to me i'd appreciate it greatly!

 

so i put it at 12* of timing on the gun with the copper wire disconnected and the tab level at 0 lining up perfect. the car starts and revs fine but won't drive down the street without backfiring.

after the wire was plugged in and the battery reconnected and i took a short trip with the car i checked the timing at 3,000 rpm and it's at 40*.

i have no idea what to set the timing at, still working on that .bin file though and i'll have it to you tonight.