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Tuning 350 with vortec, intake, cam, 670TB, roller rockers, headers

Old 06-09-2009, 04:50 AM
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Car: 90 GMC C1500
Engine: 350 Vortec
Transmission: Dying 700-R4
Axle/Gears: Stock 3:08
Tuning 350 with vortec, intake, cam, 670TB, roller rockers, headers

I'm losing my mind trying to tune my $42 on my tbi, It has the Summit K-1105 cam: http://store.summitracing.com/partde...4+&appfilter=1 GMPP Vortec intake w/ Holley 670 tbi, full 1.5 roller rockers, L31 Vortec heads machined for extra lift, Summit CD ignition box rev limited to 5250. The problem i'm having is that i have no idea what i'm doing First of all, the blms are always too rich, changing the ve table doesnt seem to have an effect unless i change the whole table, Sometimes i could get the SA in tune (getting it as high as possable withour knock) I think thats the right way to do it, But a few days later i always seem to start getting knocks again. I'm running a $42 with autoprom, Its like before i installed the 670tb it had a good bit of torque, but now it had so little, it cant ever break a tire loose from a dead stop I was hoping that someone like fast355 (I really like his work and trust him) Could use this engine specs and make me a starter bin. I know you guys have worked very hard to get where you are now, and i'm grateful that you are shearing your knowledge with us, and i shouldn't be asking you to make me a bin, but i'm going insane trying to learn this
Old 06-09-2009, 02:10 PM
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Re: Tuning 350 with vortec, intake, cam, 670TB, roller rockers, headers

Have you located and used Fast355 spark table for Vortec? I would use that table for sure or get his suggestion as to what to tweek in it if it requires any. I would use a conservative SA table for sure to get you started. I dont see the need at this point to induce KC with adding spark.

As far as changing VE fuel tables globally to raise the BLM's that is fine. It appears your tables are fat so why not. It will take a few datalogs and burns to get you in ballpark.

Are you certain you are running on the .bin and not the limp mode? Key on you should see a blink of CE light and then stay on. every time you load a new bin watch for that as it confirms you are running on the .bin.

Your cam is close to mine. I dont see that as a big issue to tune. Your 670 TB is reasonably matched to the cam. Heads, intake, cam and TB are a good package.

That cam is for higher RPM operation(5700) and same on 670TB. Are you auto trans? Did you change the stall?

How many data logs have you run?

Last edited by Ronny; 06-09-2009 at 02:20 PM.
Old 06-09-2009, 11:00 PM
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Car: 1988 Firebird, 2000 GTP
Engine: 327
Transmission: 700R4
Axle/Gears: 9" posi, 4.11
Re: Tuning 350 with vortec, intake, cam, 670TB, roller rockers, headers

I was in the same boat up until Monday. Fighting horrible rich. I used the BPC formula which threw AE tables out the window. If you changed those to account for engine size and estimated HP, you might as well set AE% around idle in the 10-20 range. Here's a few things I had to do.
*Don't forget to shift your table to account for the change in vacuum if you are running a cam with more duration. This will lower vacuum by just a bit.
*Seems you are already able to get the car to run, but quadruple check for vacuum leaks.

Don't bother messing with spark yet. If you've done all your reading, that is what you'll need after you get a good grip on BLMs(I'm not there yet).

If you keep pulling fuel to get rid of the rich state, this would probably be why you are getting KC. Pulling fuel will lean you out and require less timing.

We are running very close to the same setup. My guess would be the your BPC is set higher than factory which threw your BLMs super high and you are still fighting to get them back down. I believe they are 124 for a stock 350(at least on mine) and I calculated 134 as my new BPC. This puked black exhaust and fouled plugs every time it was started. I've droped AE% from around 50% to 18% so far and I am still pulling.

Don't give up. Just load the Vortec spark table(might have got it from herehttps://www.thirdgen.org/forums/diy-...k-table-2.html, subtract 1 or 2 degrees from the table, look at what your AE% is at now, and if you are 100% sure you are rich, calculate for a BLM of 108 and load that. If you try to look at everything at the same time you are going to run in circles. Slow down and focus on one problem at a time. If you're already changing AE and SA you are way past needing a starter bin IMO.
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Old 06-10-2009, 07:44 AM
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Car: 90 GMC C1500
Engine: 350 Vortec
Transmission: Dying 700-R4
Axle/Gears: Stock 3:08
Re: Tuning 350 with vortec, intake, cam, 670TB, roller rockers, headers

Sorry for replying so late, Its got a 700r4 w/TCI shift kit, stock stall, I've done lots and lots of data logs, I will post a copy of my bin, and a log i've done with it. I've messed with a lot of things in it, (not sure if any were good) SA, VE, AE, My fuel pres. is at 15 or 16 right now, I hope it would have a nice lopy sound to it and idle at around 550. But after installing that 670 tbi, i've lost a lot of low end power, cant even break a tire loose on dry ground I'm lost..
Attached Files
File Type: zip
Bin and log.zip (94.8 KB, 16 views)
Old 06-10-2009, 10:12 AM
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Re: Tuning 350 with vortec, intake, cam, 670TB, roller rockers, headers

Are you certain you are running on the .bin and not the limp mode? Key on you should see a blink of CE light and then stay on. every time you load a new bin watch for that as it confirms you are running on the .bin.
Old 06-10-2009, 07:33 PM
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Car: 90 GMC C1500
Engine: 350 Vortec
Transmission: Dying 700-R4
Axle/Gears: Stock 3:08
Re: Tuning 350 with vortec, intake, cam, 670TB, roller rockers, headers

not in limp mode (i've ran it in that, its runs like crap!) Could someone look my .bin over and tell me what way i should go? It just feels like it just doesn't have a much power as it use to with a stock bin and lots of distributor timing. big loss in low end torque, and the throttle response isnt as good as it can be, I am not running an egr.
Old 06-11-2009, 10:40 AM
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Re: Tuning 350 with vortec, intake, cam, 670TB, roller rockers, headers

Do you still have the stock TBI unit? If so swapping to it would help with getting the tune in line. The large TB unit will hinder your tuning leaning curve. I would offer the opinion to do that then get the tune decent then consider adding the large TB unit back on and go for round two.

Granted the large TB unit will give you the high RPM HP the cam offers but if you can put that on hold for awhile you may find initial tuning more satisfying.

You may need higher stall.
Old 06-11-2009, 01:53 PM
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Re: Tuning 350 with vortec, intake, cam, 670TB, roller rockers, headers

Originally Posted by 91GmCVoRtEc
... changing the ve table doesnt seem to have an effect unless i change the whole table...
Open the VE1 table (the 3D table) in TunerPro. Check that the RPM is by column, and MAP is by row.

If not then the XDF file is incorrect.

RBob.
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