Hyper4mance2k

iTrader: (40)

Plus 500 cfm carter is way over carbing the engine. Try 4-6psi of fuel pressure. It could be a bad float valve, bad float, or excessive fuel pressure.

Bearzah

iTrader: (6)

Im running a carter 6psi pump.
Its not fuel pressure. I could rebuild the carb i guess.
Maybe i'll take another look at my holley 390cfm... Try to figure out why my idle circuit isn't working

vxturboxv

iTrader: (2)

You are running to much fuel pressure and it's pushing past the needle seats at idle. A rebuild might work...It would allow less fuel to get past the needle seats.

If you don't have a FPR get one, they are cheap. Try lowering fuel pressure to 3psi at idle. You don't need alot of press with a carb. Just watch the WB02. I bet it helps and it's an easy solution...

Bearzah

iTrader: (6)

Tore appart my holley to try and figure out the idle issue.
Found a couple things...

The power valve hole on the base plate was replaced with a screw in plug... Guess i won't be using my power valve circuit. lol

There were several holes on my main body where it faces the metering block which were blocked by my metering block gasket (both prim and sec)... They looked like air passages. I cut those out of the gasket. I guess the rebuild kit i bought wasn't specifically for this carb.

I will try re-installing the holley tomorrow after work... Bummer it's had the choke assembly removed... Maybe i can swap one over from another holley.

Cross fingers

vxturboxv

iTrader: (2)

Stop trying to wish it better and fix the thing!
If you had the thing apart you need to replace the needle valves and seats on the floats and main idle circuit. . Then turn down the pressure and you'd be fine....

Bearzah

iTrader: (6)

Huh???

You need to go back and read my thread...

The holley is NOT on my car.. Was rebuilt less than a month ago, but, was taken off because it wouldn't idle. I'm running an old carter 500cfm right now and worked on my holley last night sense it was already OFF

vxturboxv

iTrader: (2)

Gottcha.... But it doesn't matter what carb your running, they all work the same way. If its puddleing up at idle it can only be 2 things. To much fuel leaking around idle circuit. Or fuel pushing past the needle seats on the floats.

Bearzah

iTrader: (6)

Understood... But, I was never able to get the holley to idle before, so, I don't know YET if the holley will have the same problem... keep in mind the carter idles fine... consistant 12.0-12.5:1 AFR. ONLY after idling for a while will it be momentarily richen upon bumping the throttle/reving a bit.

The carter is OLD and in need of a rebuild, so, I wouldn't be surprised if the majority of my problems could be traced to the carter carb... AND I DON'T expect the problem to go away with a different carb as I believe the fuel is pooling in the turbo which will happen with any carb used.

I'm mearly hoping for a little more horsepower from the holley and more tuneability... LOL... i REALLY don't want to start a holley vs AFB debate. I respect both and run both. I have an Edelbrock AVS on my 78 Ford F-250 and a Holley on my 66 Chevelle Malibu. I just KNOW the Carter pirched on my 7 needs some help.

yetterben

puddling equals BOOOOOOOM!!!!!

Bearzah

iTrader: (6)

Thanks for the input yetterben... do you know a way to eliminate this problem? ... besides converting to blowthrough

Spiker

This is a question that I asked another member of the forum but no reply... "I have read your posts on your Cartec setup. I have the same setup in BAE. I have a 12a street port, run 6lbs boost and a holley 390 mech secondaries, 9lb fuel pump regulated to 6lbs with canister fuel filter and an AFX wideband. Here is my problem I can get enough fuel to run great on steady throttle and acceleration but when I let off the throttle on deceleration to down shift it goes very lean and tries to stall and sometimes does. I run 56 main jets and 67 secondaries. I have tried various combo's with jetting but get the same result. I think I have a bit of a recovery issue, where the carb needs to feed and transition better from full vacuum to an idle condition and back up through the rpm's. It does seem to help if I set the secondary butterflies open just a bit, but this makes a high idle situation." I am very interested to see what results you get with your holley.

Bearzah

iTrader: (6)

sadly... The holley has defeated me again. Still wont idle and carter back on

Bearzah

iTrader: (6)

i think i'm gonna give it another shot tomorrow. I'm suspecting the power valve circuit. Sense i'm still running a power valve but the vacuum port on on the base plate for it is pluged... That would mean the power valve is always open... I would imagine this would adversly affect the idle.

So. I took out the plug in the base plate tonite and will try again tomorrow. Wish me luck

Bearzah

iTrader: (6)

ugh... nervious. my car smoked a bit this morning. Was TERRIBLE to start as was snowing and cold. I was running late for work, hit 10psi of boost a couple times and noticed a trail of smoke behind me... looked white (water seal), but, I'm not sure as it's so cold outside. The car still runs fine though. I was running late as I said, so, I didn't really have time to dick around with it. Man, I hope I didn't pop my motor. gah
Will update this afternoon....

Bearzah

iTrader: (6)

well.. IF it turns out to be a coolent seal issue, I might try some radiator stop leak like ALUMASEAL:

www.rx7club.com/showthread.php?t=750774

it seemed to work for him.

Maybe I'll turn my boost down a bit although even the Cartech instructions say 9-10psi is ok as long as tuning is good... running locked timing at 10* L / 0* T and fairly rich mixtures, I would think I'm tunied pretty safe.

Thoughts???

Bearzah

iTrader: (6)

No smoke... Woot
My window washer just started leaking and i think it hit the exhaust. I lean on it to much when i work on the car :/

I tried the holley carb again and still no idle... Gah... I give up.

I tuned the boost down to 8-9 psi also.

Bearzah

iTrader: (6)

I finally rebuilt my Carter carb and measured the bore diameter to figure out my carb size...
http://www.buickperformance.com/carter.htm

Turns out my carb is 400cfm after measuring 1.435" on both primary and secondary bores... NOT 500 like I thought. Better fit for my application??

Seems to run a lot better after rebuild.

I guess I might need to port my wastegate. After a shift or two at full throttle my boost raises above my set point. Damnit.... maybe the linkage is just sticking again and not opening enough.. gah

Should have known this whole process would be easy..LOL

Bearzah

iTrader: (6)

3" exhaust ordered today... Will start fabing as soon as i get it.
http://www.mandrel-bends.com/catalog...r-kit-875.html

What should i expect as a difference to my current setup?

i am running a 2.25" 90* downpipe into a short section of 2", another 2.25" 90* bend into 2.25 " piping.... Don't give me $hit... it's what I had when I put everything together.. LOL. This goes through a 2.25" magnaflow muffler than through a magnaflow tailpipe muffler.

i will replacing everything with 3" pieces, eliminating the mid-system muffler and making my new 3" fit onto my existing tailpipe muffler.

PercentSevenC

Heh, I had the same problem with my washer fluid container. I finally just took it out, since I never use it anyway.

I bet you'll be a lot happier with 3" exhaust. The turbo will spool faster, and you'll make more power everywhere. On the downside, if your wastegate is already having difficulty keeping up, a bigger exhaust is only going to make it worse.

As for the carb, I'd have preferred a 500, or at least a 450. Draw-through isn't like blow-through, because the atmosphere isn't pressurized. So you actually do need a larger carb. It should still work alright, you just might be missing out on a little top-end.

Bearzah

iTrader: (6)

Whew... that's good to hear about the exhaust. It will be a large effort as i will be doing it myself and I'm glad I will see a difference.

I'm also thinking of piping my wastegate gases back into my my exhaust rather than dumping to atmosphere... It's pretty damn load.

With running a Wideband A/F Sensor, would it be best to tie in my wastegate gases AFTER the O2 sensor or before... or does it really make a difference? NOTE: my sensor is about 3 feet behind my turbo.

Thanks Guys!!

Bearzah

iTrader: (6)

LOL.. I think his exhaust may have got a bit HOT...

vxturboxv

iTrader: (2)

Your air to fuel ratio won't change if you plumb the sensor before or after the WG.

Wow! IMO thats a little over kill on exhaust! Looks like a pain in the butt for the 1/2 HP you'll gain at your current boost/power levels. Not to mention added weight etc... But more power to you for taking it on. If you ever decide to go blow through and make some big boost/power you might be able to take advantage of exhaust that big. Either way.... it sure will look cool!

Bearzah

iTrader: (6)

I'm curious if the larger exhaust will make the turbo spool "whine" any more pronounced... That would be cool

I plan on "modifing" the wastegate flange to transition from a little over 2" to 3"... like tapering of a horn.

Here is a pic of my plan... What u think??

Bearzah

iTrader: (6)

3" exhaust in place.. What a pain in the a$$. It is a tight fit over the axle... In fact it touches a bit on the upper crosslink linkage (I think this is the name)

I didn't end up porting the wastegate flange as I really didnt have a lot of material to play with.

The BIG question... is there a difference in performance???

OH MY GOD!!! It's a different car!!!

I actually had to tune my wastegate actuater down a bit because the boost rises so much guicker and higher than before. Full throttle in 1st and 2nd can only by done in a straight line on dry pavement if I want any hope of control

It's consistantly increasing HP throughout the rpm range now. I eliminated the intermediate muffler so its straight exhaust from the downpipe to the rear magnaflow muffler now. Its a little louder than I antispated, but, worth it.

The turbo is quite a bit louder now. It sounds pretty wicked through the exhaust.

I will work on uploading a picture of my old downpipe so you can see why I had the urgency in wanted to replace it

PercentSevenC

Yep. With a turbo, the bigger the exhaust the better, to an extent. Fortunately, a turbo makes a fantastic muffler, so you can get away with a lot less muffling than you could NA.