I finally got around to adjusting my fuel pressure to get rid of the surging past 3500 rpm in 3rd or 4th gear but the readings weren't as expected. I did all runs in 3rd gear.

For an ideal WOT I learned you should have 0.950-0.975 V readings from your O2 sensor, but I'm getting 0.920 at 3500 rpm and 0.870 at 4000 rpm with full pressure, adjusted tab to the top...

Prior to adjusting I had 0.880 at 3500 rpm and 0.840 at 4000 rpm.

I bumped my pressure to its max and still can't get close to what I need. Even in 2nd the max I had was 0.940 V meaning I'm essentially leaner than optimum even at max pressure...

It pulls to 4000 rpm nicely now in 3rd actually I'm getting it up to 4200-4300 rpm without the surging.

So should I take this as my excuse to get the holley 670 tbi or should I go get headers first?

 

I suggest headers..Headers you eill use no matter what induction you use plus there's a great deal on the classifieds ..

Dazisalsosellinga4barrelmanifoldfromaSuburbanfor$30thankyou

 

I was under the impression that .875Mv was ideal.

 

Well at max fuel pressure I got 0.870 If I go with AccelZ I'm in the clear, headers are on the way.. still haven't gotten rid of the surging, nothing left cept getting rid of the logs for real headers...

Next mod here I come... headers...

 

Hey Slade I'd go with the exhaust. When I built my TBI I did it backwards starting with the TBI, etc. In retrospect I should have done it from exhaust back as-it-were.

Anyway, I'm with Daz get the exhaust built up no matter what else you do the 305s really respond well to headers and free-flow. They are on my hit list too.

adious,
RP.

 

This is one of those rare times I wish I didn't have A/C or air tubes...

Prices on these parts are like asking for an arm and a leg... no impulse buying on this thing, that's for sure...

I'm going to refrain from a cat back system in the mean time.. one cost at a time... the 2 1/2 and the flowmaster will have to hold up...

I'm looking for a new place to live in the mean time, I'm probably relocating to Richmond Hill, if not north Toronto around Yonge.. north of steeles area.

I will eventually (before track day I hope) is get the headers and possibly a higher flow cat, although the replacement dynomax cat I got was a pretty good deal performance wise. The whole sound of the exhaust changed quite dramatically with that in. The stock one was pretty restrictive I think. All the flowmaster did was make it a bit more mellower in tone but a lot louder too.

For the cheapness in me, its saying go Flowtech shorty with air and y-pipe and get them coated. 1 1/2 primary to 2 1/2 will fit the dynomax cat perfectly.

For the "who gives a damn about money" its the slp 1 3/4 headers with air ceramic coated to 3 inch to 3 inch hi flow cat and then sadly reduce it to 2 1/2 until I can mix in the cat back next year...

In the middle of all this is hooker headers with 1 5/8 to 2 1/2 with air and comes with y-pipe.. no cat change here...

No matter which I go I don't think I'll do this myself... there are some jobs I just refuse to do again myself... fuel pump... headers... re-ringing...(if they go, 350 here I come)...

 

Slade, have you considered an exhaust cut-out? It will outflow a 3" cat-back for a fraction of the price. If you wanna get some major flow gains before track day, that's what I would suggest.