My Vortec 350 Hotcam TBI build + Questions
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Car: 1991 RS Camaro
Engine: 350 TBI
Transmission: 700R4
Axle/Gears: 3.42 Posi
My Vortec 350 Hotcam TBI build + Questions
I've been collecting parts for years to make this build happen. This all started as a budget build from a set of 062 vortec heads I purchased for $100 off craigslist about 8 years ago. I then picked up a Vortec 350 for another $200 with a cracked head. Once my 700r4 started slipping the top of 2nd gear I abused it to its death. One day I only had 1st gear and reverse. That really set this project in motion for the last year and a half. My L03 is still sitting her in the garage with about 200k on it. It still ran strong and is one of the most reliable engines I've ever had. I feel bad pulling it since its been so good to me over the years but I needed a new power plan so now was the time. I didn't go LS for couple reasons. 1. I really love that classic small block sound. Nothing sounds better in my opinion. 2. I was on a budget and picked up parts a little at a time until it was possible. Everything from headers back to the rear end was setup for this in mind. My main goal is > 300whp or just under 400fwhp.
My Build is as follows:
350 Vortec 880 2 bolt main block 167k miles from a 96 Tahoe (rings, bearings, Honed cylinders, all new gaskets, oil pump)
Re-used stock Crank, rods, and pistons.
Comp pushrods
GM Single roller timing set
062 Vortec heads from a 330 horse crate motor. Valve job, new seals, LS3 springs and Comp 787-16 retainers
Felpro 1094 steel shim gaskets
Approx 9.6:1 compression
Lt4 Hot Cam
GMPP 1.5 Self Aligning Roller Rockers
Edelbrock Performer 2116 Intake
Modified Transdapt TBI adapter
454 TBI, large base footprint, 17084304 injectors (scored at the junkyard for $25. Lucky me.)
Swapped throttle linkage from SBC TBI and welded it on for 700r4 TV cable.
14 Inch Edelbrock with K&N (touches hood insulation but the hood shuts!!)
Hooker 2055 Headers, Y Pipe, 3" inch Catco cat & 3" Dynomax catback
Rebuilt 700R4 with shift kit, 2025rpm Precision converter (was free). I need to return to my trans guy to make it shift higher. Currently shifts 4400 - 4700k RPMS. He gave me weight and spring kit just need to go back and get it tuned. I just wanted to get the fueling as close as I can before going higher in rpms.
10 Bolt Rear with 3.42 gears, Eaton Posi and Moser axles.
ACDelco 241 fuel pump
Founders LCA's and Panhard rod.
Questions:
Which adapter plate should I use for a large base footprint 454 TBI? The one I have now is leaking at the IAC. The one I have is a transdapt for a smallblock TBI but has been machined out for 2" bores. It's centered on the manifold. I've seen front and rear mount but cannot find another 2" adapter that is centered.
I have the 28psi spring plus the 17084304 injectors. Are the 17084304 454 Injectors 75lb/hr or 80lb/hr? I keep seeing both all over the internet and I need to know which I should set for the BPC in the EBL Flash calibration. Right now its calculated for 75lb/hr and 28psi.
I'm running somewhat rich at idle and getting black soot in the driveway after startup. My wife hates it. It idles pretty good and sounds awesome. I know part of this is tuning but I often wonder would going to a vacuum referenced FPR help with that because the fuel pressure would be lower at idle? I'm thinking the Aeromotive AEI-13301. I wouldn't mind putting a FP Gauge too. Does anyone have a list of proper fittings for TBI?
I'd like to raise my shift points to 6000k rpms 1st to 2nd shift. Maybe 5800k or so on 2nd to 3rd. Does this sound good given my setup?
I have my base timing advanced but I cannot tell exactly how far advanced it is because the vortec plastic cover only shows a mark at 0 degrees. It seems to like base timing a bit advanced but its not accurate for tuning. I'm pretty sure its > 6 degrees advanced. Should I set this back to zero and just let the EBL do its thing? The reason I ask is because I keep getting spark knocks and I have been retarding those cells in the SA Main table over and over again.
I also plan to purchase a wideband o2 for further WOT tuning. Any suggestions?
All in all the car seems to run okay and is a nice upgrade from the L03 but I know its missing power. I realize this is in the tuning and other things but I need to get the TBI and adapter setup right and go from there. I'm only seeing 80kpa at WOT and I've read it should be closer to 100kpa at WOT. This tells me I'm loosing vacuum and that is the next thing I'm going to tackle. I feel like this thing should roast the tires from a stop but its not there yet.
I've attached a few pictures for fun and reference. I'm looking for some answers to these questions so I can get it tuned 100%.
Most of all thanks to thirdgen.org and RBob's EBL. I couldn't have pulled this off without all of you and I refuse to throw a carb on it.
My Build is as follows:
350 Vortec 880 2 bolt main block 167k miles from a 96 Tahoe (rings, bearings, Honed cylinders, all new gaskets, oil pump)
Re-used stock Crank, rods, and pistons.
Comp pushrods
GM Single roller timing set
062 Vortec heads from a 330 horse crate motor. Valve job, new seals, LS3 springs and Comp 787-16 retainers
Felpro 1094 steel shim gaskets
Approx 9.6:1 compression
Lt4 Hot Cam
GMPP 1.5 Self Aligning Roller Rockers
Edelbrock Performer 2116 Intake
Modified Transdapt TBI adapter
454 TBI, large base footprint, 17084304 injectors (scored at the junkyard for $25. Lucky me.)
Swapped throttle linkage from SBC TBI and welded it on for 700r4 TV cable.
14 Inch Edelbrock with K&N (touches hood insulation but the hood shuts!!)
Hooker 2055 Headers, Y Pipe, 3" inch Catco cat & 3" Dynomax catback
Rebuilt 700R4 with shift kit, 2025rpm Precision converter (was free). I need to return to my trans guy to make it shift higher. Currently shifts 4400 - 4700k RPMS. He gave me weight and spring kit just need to go back and get it tuned. I just wanted to get the fueling as close as I can before going higher in rpms.
10 Bolt Rear with 3.42 gears, Eaton Posi and Moser axles.
ACDelco 241 fuel pump
Founders LCA's and Panhard rod.
Questions:
Which adapter plate should I use for a large base footprint 454 TBI? The one I have now is leaking at the IAC. The one I have is a transdapt for a smallblock TBI but has been machined out for 2" bores. It's centered on the manifold. I've seen front and rear mount but cannot find another 2" adapter that is centered.
I have the 28psi spring plus the 17084304 injectors. Are the 17084304 454 Injectors 75lb/hr or 80lb/hr? I keep seeing both all over the internet and I need to know which I should set for the BPC in the EBL Flash calibration. Right now its calculated for 75lb/hr and 28psi.
I'm running somewhat rich at idle and getting black soot in the driveway after startup. My wife hates it. It idles pretty good and sounds awesome. I know part of this is tuning but I often wonder would going to a vacuum referenced FPR help with that because the fuel pressure would be lower at idle? I'm thinking the Aeromotive AEI-13301. I wouldn't mind putting a FP Gauge too. Does anyone have a list of proper fittings for TBI?
I'd like to raise my shift points to 6000k rpms 1st to 2nd shift. Maybe 5800k or so on 2nd to 3rd. Does this sound good given my setup?
I have my base timing advanced but I cannot tell exactly how far advanced it is because the vortec plastic cover only shows a mark at 0 degrees. It seems to like base timing a bit advanced but its not accurate for tuning. I'm pretty sure its > 6 degrees advanced. Should I set this back to zero and just let the EBL do its thing? The reason I ask is because I keep getting spark knocks and I have been retarding those cells in the SA Main table over and over again.
I also plan to purchase a wideband o2 for further WOT tuning. Any suggestions?
All in all the car seems to run okay and is a nice upgrade from the L03 but I know its missing power. I realize this is in the tuning and other things but I need to get the TBI and adapter setup right and go from there. I'm only seeing 80kpa at WOT and I've read it should be closer to 100kpa at WOT. This tells me I'm loosing vacuum and that is the next thing I'm going to tackle. I feel like this thing should roast the tires from a stop but its not there yet.
I've attached a few pictures for fun and reference. I'm looking for some answers to these questions so I can get it tuned 100%.
Most of all thanks to thirdgen.org and RBob's EBL. I couldn't have pulled this off without all of you and I refuse to throw a carb on it.
#2
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Re: My Vortec 350 Hotcam TBI build + Questions
You are definitely going to need more stall with that cam. 3200 minimum. I myself have used the zeitronix zt2 wideband and controller with great success. I know whence had my ZZ5.0. The ZZ4 cam needed to be 6 degrees advanced to even run in the base timing. I'd get a standard timing cover or get an old timing tab and fab it to the vortec cover. I have pics of how I did mine for my LT1 if that would help you. With your combo on a good tune, 310-325rwhp is very doable.
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Car: 1991 RS Camaro
Engine: 350 TBI
Transmission: 700R4
Axle/Gears: 3.42 Posi
Re: My Vortec 350 Hotcam TBI build + Questions
Sweet thanks for the reply. I'm not going to change the stall any time soon. The last thing I want to do is pull out the trans after all the work I put into it. Maybe down the road. I also didn't want to have to rev it up driving around town which I do a lot. I can say it doesn't like low rpms much and starts to get happy after 2000 rpms. The Hotcam RPM range is 1,800-5,800 so I thought it would be better than the stock stall. A friend gave me the stall free which is nice.
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Car: 1991 RS Camaro
Engine: 350 TBI
Transmission: 700R4
Axle/Gears: 3.42 Posi
Re: My Vortec 350 Hotcam TBI build + Questions
You are definitely going to need more stall with that cam. 3200 minimum. I myself have used the zeitronix zt2 wideband and controller with great success. I know whence had my ZZ5.0. The ZZ4 cam needed to be 6 degrees advanced to even run in the base timing. I'd get a standard timing cover or get an old timing tab and fab it to the vortec cover. I have pics of how I did mine for my LT1 if that would help you. With your combo on a good tune, 310-325rwhp is very doable.
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Car: 1988 Trans Am
Engine: L03
Transmission: 700R4
Axle/Gears: 10 Bolt 2.73 Open
Re: My Vortec 350 Hotcam TBI build + Questions
I have no answers, but look forward to following along. A very interesting engine build to me.
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Car: '86 Camaro, '94 Camaro, 3 others
Engine: LG4 ->L29, L32->LR4, L36, LG4, L31
Transmission: 700R-4, T5WC, 4L80E, SM465, 4L60E
Axle/Gears: 3.42, 3.23, WTB/WTT 2.93
Re: My Vortec 350 Hotcam TBI build + Questions
A 2400-stall 12" is plenty loose for the HOT cam. The 3.42s aren't enough, you'll need 3.73s to get a decent cruise RPM for that cam.
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Car: 1991 RS Camaro
Engine: 350 TBI
Transmission: 700R4
Axle/Gears: 3.42 Posi
Re: My Vortec 350 Hotcam TBI build + Questions
First gear is almost non-existent as it is when I went to 3.42 from the 2.73. Unless I put the pedal down most of the way it will go into 2nd immediately. I bet you may be right about the cruise rpms.
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Car: 1983 G20 Chevy
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Re: My Vortec 350 Hotcam TBI build + Questions
There is a marine adapter that fits a large base TBI but it is much thicker and would require a drop base air cleaner to fit.
Last edited by Fast355; 12-04-2016 at 09:08 PM.
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Car: 1991 RS Camaro
Engine: 350 TBI
Transmission: 700R4
Axle/Gears: 3.42 Posi
Re: My Vortec 350 Hotcam TBI build + Questions
UPDATE:
I reset my base timing to 0 degrees. I updated the my SA - Initial SA to 0 in the bin. I then reset the SA tables in my bin to the stock 3000 bin vortec tables. it picked up a considerable amount of power especially at higher RPMS.
I'm still having some issues at take off. I notice if I take off part throttle it will spin a little then grab and feels like it has more power than if I take off with WOT. I was hoping for full tire spin if i mash the throttle from a stop. I know the stall has something to do with it but I know it has more power there somewhere.
I reset my base timing to 0 degrees. I updated the my SA - Initial SA to 0 in the bin. I then reset the SA tables in my bin to the stock 3000 bin vortec tables. it picked up a considerable amount of power especially at higher RPMS.
I'm still having some issues at take off. I notice if I take off part throttle it will spin a little then grab and feels like it has more power than if I take off with WOT. I was hoping for full tire spin if i mash the throttle from a stop. I know the stall has something to do with it but I know it has more power there somewhere.
Last edited by bluers91; 02-13-2017 at 04:10 PM.
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Car: 1983 G20 Chevy
Engine: 305 TPI
Transmission: 4L60
Axle/Gears: 14 bolt with 3.07 gears
Re: My Vortec 350 Hotcam TBI build + Questions
UPDATE:
I reset my base timing to 0 degrees. I updated the my SA - Initial SA to 0 in the bin. I then reset the SA tables in my bin to the stock 3000 bin vortec tables. it picked up a considerable amount of power especially at higher RPMS.
I'm still having some issues at take off. I notice if I take off part throttle it will spin a little then grab and feels like it has more power than if I take off with WOT. I was hoping for full tire spin if i mash the throttle from a stop. I know the stall has something to do with it but I know it has more power there somewhere.
I reset my base timing to 0 degrees. I updated the my SA - Initial SA to 0 in the bin. I then reset the SA tables in my bin to the stock 3000 bin vortec tables. it picked up a considerable amount of power especially at higher RPMS.
I'm still having some issues at take off. I notice if I take off part throttle it will spin a little then grab and feels like it has more power than if I take off with WOT. I was hoping for full tire spin if i mash the throttle from a stop. I know the stall has something to do with it but I know it has more power there somewhere.
As for that spark table, seem to remember that is one from a stock vortec truck Not at all what you are looking for as even my stock cam Express van was a slug on that spark table. This is pretty much my go to start off Vortec timing table for 93 octane fuel. It has worked well as a staring point in trucks, vans, and even cars with both the stock cam and mild performance cams.
Last edited by Fast355; 02-13-2017 at 08:51 PM.
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Car: 1991 RS Camaro
Engine: 350 TBI
Transmission: 700R4
Axle/Gears: 3.42 Posi
Re: My Vortec 350 Hotcam TBI build + Questions
Not sure why you would do that? The Vortec heads need more advance for startup and to function in EST Bypass /Limp Home mode. 6-10° is in the right area. I have the Lunati Hotcam in my Express and it starts best with 12° of crank timing. Above 200°F coolant temp I do have it at 8° to keep it from kicking back on the starter when I am heatsoaked from towing.
Thanks for the table you provided. I'll try advancing the base a little again and use your table to see what happens. I hope you're correct.
I'm assuming the other two are PE related. I have yet to touch those or AE in the EBL since I'm still learning and the car has been running pretty good but I know its not optimal. I'll give those a look and match them with whats in there. Do you know the names of those tables in the EBL?
I'm also around 6000ft elevation which I'm sure makes some difference.
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Car: 1991 RS Camaro
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Re: My Vortec 350 Hotcam TBI build + Questions
At first glance that SA table is much hotter than the one I'm running.
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Car: 1991 RS Camaro
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Re: My Vortec 350 Hotcam TBI build + Questions
Heya Fast355 I typed in the SA table manually, kept my base timing at 0 and flashed a new tune into my EBL. I'll admit I was skeptical at first thinking it would be too advanced but the car responded well to it. It's smoother and seems a bit faster. It sounds a little different too above 5000 rpms. It only had some spark knock at 3600 rpms and 80kpa. Keep in mind i'm running at higher elevation and 91 octane fuel for now.
I dug through my EBL tables and I think the other two relate to the SA - PE Adder vs Gear/RPM table. Does that sound right?
The next thing I may try messing with this table and attempting to advance the base timing to 6 degrees.
I dug through my EBL tables and I think the other two relate to the SA - PE Adder vs Gear/RPM table. Does that sound right?
The next thing I may try messing with this table and attempting to advance the base timing to 6 degrees.
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Car: 1983 G20 Chevy
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Re: My Vortec 350 Hotcam TBI build + Questions
Heya Fast355 I typed in the SA table manually, kept my base timing at 0 and flashed a new tune into my EBL. I'll admit I was skeptical at first thinking it would be too advanced but the car responded well to it. It's smoother and seems a bit faster. It sounds a little different too above 5000 rpms. It only had some spark knock at 3600 rpms and 80kpa. Keep in mind i'm running at higher elevation and 91 octane fuel for now.
I dug through my EBL tables and I think the other two relate to the SA - PE Adder vs Gear/RPM table. Does that sound right?
The next thing I may try messing with this table and attempting to advance the base timing to 6 degrees.
I dug through my EBL tables and I think the other two relate to the SA - PE Adder vs Gear/RPM table. Does that sound right?
The next thing I may try messing with this table and attempting to advance the base timing to 6 degrees.
Last edited by Fast355; 02-14-2017 at 08:47 PM.
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Car: 1991 RS Camaro
Engine: 350 TBI
Transmission: 700R4
Axle/Gears: 3.42 Posi
Re: My Vortec 350 Hotcam TBI build + Questions
Ok I went from this:
To this:
I'm not sure about the E10 but I'm pretty sure it is. I've seen that 10% Ethanol on the gas pumps around here. I'm not sure if all stations have it or not. Haven't really paid too much attention to that tbh.
Since I don't have a wideband yet I'm not sure about the AFR's I'm running. When I get one I can dial that in. For now I've just been winging it with VE Learns via BLM's but not sure how things are above 3600 RPM. My datalog shows my DC% never getting over 50 above 5000 RPM so there is still plenty of fuel.
To this:
I'm not sure about the E10 but I'm pretty sure it is. I've seen that 10% Ethanol on the gas pumps around here. I'm not sure if all stations have it or not. Haven't really paid too much attention to that tbh.
Since I don't have a wideband yet I'm not sure about the AFR's I'm running. When I get one I can dial that in. For now I've just been winging it with VE Learns via BLM's but not sure how things are above 3600 RPM. My datalog shows my DC% never getting over 50 above 5000 RPM so there is still plenty of fuel.
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Car: 1991 RS Camaro
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Re: My Vortec 350 Hotcam TBI build + Questions
I'm also running the copper ACDelco plugs. I always ran them in my L03 too. The Vortec plugs are just a little shorter.
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Car: 1991 RS Camaro
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Re: My Vortec 350 Hotcam TBI build + Questions
Yes you are correct however they stick out shorter on plug wire end giving enough clearance for the exhaust.
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Re: My Vortec 350 Hotcam TBI build + Questions
Ok I went from this:
To this:
I'm not sure about the E10 but I'm pretty sure it is. I've seen that 10% Ethanol on the gas pumps around here. I'm not sure if all stations have it or not. Haven't really paid too much attention to that tbh.
Since I don't have a wideband yet I'm not sure about the AFR's I'm running. When I get one I can dial that in. For now I've just been winging it with VE Learns via BLM's but not sure how things are above 3600 RPM. My datalog shows my DC% never getting over 50 above 5000 RPM so there is still plenty of fuel.
To this:
I'm not sure about the E10 but I'm pretty sure it is. I've seen that 10% Ethanol on the gas pumps around here. I'm not sure if all stations have it or not. Haven't really paid too much attention to that tbh.
Since I don't have a wideband yet I'm not sure about the AFR's I'm running. When I get one I can dial that in. For now I've just been winging it with VE Learns via BLM's but not sure how things are above 3600 RPM. My datalog shows my DC% never getting over 50 above 5000 RPM so there is still plenty of fuel.
Something definitely seems wrong with the DC readings there. At 28 psi your 74 lb/hr injectors are about 110 lb/hr. With 2 injectors at 110# ea and a BSFC of 0.5 lb/hp/hr you are only feeding 220 hp worth of fuel at 50% duty cycle!!!!! I think we found your lean condition. Even if your engine was finely tuned and running a BSFC of 0.45 lb/hr/hr you are only feeding 245 hp worth of fuel into the engine. In your datalogs, what does the narrowband o2 sensor read at WOT? I would shoot for atleast 850 mv preferably closer to 900 mv without a wideband. If it runs a little rich it is less likely to put holes in pistons like running lean will.
All I can say is stay out of higher rpms and WOT until you get a wideband on it before you end up hurting much more expesive parts.
This is what I have on my Express van. Works very well.
Last edited by Fast355; 02-15-2017 at 12:50 PM.
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Car: 1991 RS Camaro
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Re: My Vortec 350 Hotcam TBI build + Questions
A datalog from a few days ago at WOT 100% TPS is showing anywhere from 875 - 950mv.
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Re: My Vortec 350 Hotcam TBI build + Questions
This was before swapping timing tables from a few days ago. Also the MPH is about 20 off because my VSS is for the old 2.73 gear.
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Re: My Vortec 350 Hotcam TBI build + Questions
One thing you can do adjust your PE TPS to 90% and raise your minimum rpm up to 5,000 rpm and datalog progressively to higher throttle openings and higher rpms. The factory Vortec trucks do not enter PE until 90% throttle. Watch your Integrator (INT) if you see it rise sharply, followed by the BLM you are running lean.
At 6,000 ft I do not expect you to be down more than 15% from sea level. That is still 340-360 HP range, well above your 220-245 HP worth of fuel you are currently feeding your engine. That gms/sec calculated reading is also a tell tale to me that something is off. I was running over 250 gms/sec on a stock TBI head engine with a LT4 cam. It is based on your displacement scaler and VE table.
At 6,000 ft I do not expect you to be down more than 15% from sea level. That is still 340-360 HP range, well above your 220-245 HP worth of fuel you are currently feeding your engine. That gms/sec calculated reading is also a tell tale to me that something is off. I was running over 250 gms/sec on a stock TBI head engine with a LT4 cam. It is based on your displacement scaler and VE table.
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Re: My Vortec 350 Hotcam TBI build + Questions
Ok I'll give those PE changes a try and do some logging.
Do you think I should add any fuel in the VE table above 3600 or just see what happens with the logs after the PE change?
Do you think I should add any fuel in the VE table above 3600 or just see what happens with the logs after the PE change?
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Re: My Vortec 350 Hotcam TBI build + Questions
I know you are going to send me the .BIN, but I am at work away from my laptop and TunerProRT.
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Re: My Vortec 350 Hotcam TBI build + Questions
Honestly speaking those look to need a lot of work. The VE should peak around 4K with that cam and should smoothly increase from low map to high map and from lower rpm up to peak and then gradually taper off above.
When you send that .bin, send me a couple of datalogs with it. For a startup map, I would start at the 3,600-4,000 rpm, 100 KPA range with about 95% VE. As you go higher rpm it should drop about 3% points each 400 rpm cell. As you drop in rpm it should decrease about the same amount. As you shift left to lower KPA, it should drop about 3% with each 5 kpa change in MAP. You can create the vertical column first, then copy and remove 3 from each successive copy all the way to the 20 kpa row. It will take some VE learns to get the thing correct, but the VE table would be a better overall shape and value to start with. I have been known to build an engine combination on DD2003 and use the VE from that program for the 100 kpa row as a starting point. It is a bit of a crude method, but it works for me better than starting with something unknown.
EDIT...I was just playing with Excel....Looks better with 3% drop per 5 KPA. Edited my post to keep people that may read this later from being confused
When you send that .bin, send me a couple of datalogs with it. For a startup map, I would start at the 3,600-4,000 rpm, 100 KPA range with about 95% VE. As you go higher rpm it should drop about 3% points each 400 rpm cell. As you drop in rpm it should decrease about the same amount. As you shift left to lower KPA, it should drop about 3% with each 5 kpa change in MAP. You can create the vertical column first, then copy and remove 3 from each successive copy all the way to the 20 kpa row. It will take some VE learns to get the thing correct, but the VE table would be a better overall shape and value to start with. I have been known to build an engine combination on DD2003 and use the VE from that program for the 100 kpa row as a starting point. It is a bit of a crude method, but it works for me better than starting with something unknown.
EDIT...I was just playing with Excel....Looks better with 3% drop per 5 KPA. Edited my post to keep people that may read this later from being confused
Last edited by Fast355; 02-15-2017 at 04:29 PM.
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Re: My Vortec 350 Hotcam TBI build + Questions
I just sent you all the info.
One thing I've noticed is that I never hit 100kpa ever. The max I can hit at 100% TPS is 80kpa.
I am also concerned that my adapter plate does not cover the IAC entirely so there could be some lost vacuum there. See this picture from when I was mocking it up. Note there is a gasket underneath it that I cut to fit later. This is a modified transdapt sbc adapter i had machined open for the 2 inch bores. I'm looking to replace it but haven't figured out which way to go yet.
One thing I've noticed is that I never hit 100kpa ever. The max I can hit at 100% TPS is 80kpa.
I am also concerned that my adapter plate does not cover the IAC entirely so there could be some lost vacuum there. See this picture from when I was mocking it up. Note there is a gasket underneath it that I cut to fit later. This is a modified transdapt sbc adapter i had machined open for the 2 inch bores. I'm looking to replace it but haven't figured out which way to go yet.
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Re: My Vortec 350 Hotcam TBI build + Questions
If you have Excel, try this as a starting point for the VE tables.
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Re: My Vortec 350 Hotcam TBI build + Questions
I just sent you all the info.
One thing I've noticed is that I never hit 100kpa ever. The max I can hit at 100% TPS is 80kpa.
I am also concerned that my adapter plate does not cover the IAC entirely so there could be some lost vacuum there. See this picture from when I was mocking it up. Note there is a gasket underneath it that I cut to fit later. This is a modified transdapt sbc adapter i had machined open for the 2 inch bores. I'm looking to replace it but haven't figured out which way to go yet.
One thing I've noticed is that I never hit 100kpa ever. The max I can hit at 100% TPS is 80kpa.
I am also concerned that my adapter plate does not cover the IAC entirely so there could be some lost vacuum there. See this picture from when I was mocking it up. Note there is a gasket underneath it that I cut to fit later. This is a modified transdapt sbc adapter i had machined open for the 2 inch bores. I'm looking to replace it but haven't figured out which way to go yet.
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Re: My Vortec 350 Hotcam TBI build + Questions
Hey Fast355, speaking about the VE tables, did anyone come up with something like this for the EBL?
Wondering how close something like this would help the newcomers.
Wondering how close something like this would help the newcomers.
Stock Engine with Stock exhaust will be 80-85% VE
Stock Engine with a good breathing intake and exhaust will be 85-90% VE
Modified engine with good heads, cam, good intake and exhaust will be 90-95%.
For the record I have used this method on engines that would not even start on a stock chip tune with success.
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Re: My Vortec 350 Hotcam TBI build + Questions
When I changed the PE TPS to 90% and above 5000 RPMs it became a dog above 3k. I reverted it back to the original settings since it didn't seem to like it at all.
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Re: My Vortec 350 Hotcam TBI build + Questions
I took it for a quick drive like this and seems okay. I started data logging and VE Learns again and the EBL is pulling some fuel. I'm going to stick with it for a bit and do a few more learns and data logs and let you know the results. So far the DC% went up a little bit but I wasn't able to test much above 5k RPMS due to too much traffic.
When I changed the PE TPS to 90% and above 5000 RPMs it became a dog above 3k. I reverted it back to the original settings since it didn't seem to like it at all.
When I changed the PE TPS to 90% and above 5000 RPMs it became a dog above 3k. I reverted it back to the original settings since it didn't seem to like it at all.
It probably will pull some fuel, because this generally ends up with the VE table a bit higher than it needs to be, but better to be rich than lean.
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Re: My Vortec 350 Hotcam TBI build + Questions
Attached is the latest log with your new VE Table after a learn or two. I was able to do a high rpm run in that log. The DC% is getting over 50 now but not much more than that. It definitely feels like its making more than 240hp. I'd find it hard to believe its not making more than 300. Then again it feels fast to me on the butt dyno especially after driving an L03 for more than 15 years. It feels as fast as its ever been at high rpm.
I can reset the PE TPS to 90% and make it above 5000 rpms again tomorrow and try another log. It just didn't seem like it would ever get to high rpms when I did that but I didn't give it much chance either.
I can reset the PE TPS to 90% and make it above 5000 rpms again tomorrow and try another log. It just didn't seem like it would ever get to high rpms when I did that but I didn't give it much chance either.
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Re: My Vortec 350 Hotcam TBI build + Questions
Attached is the latest log with your new VE Table after a learn or two. I was able to do a high rpm run in that log. The DC% is getting over 50 now but not much more than that. It definitely feels like its making more than 240hp. I'd find it hard to believe its not making more than 300. Then again it feels fast to me on the butt dyno especially after driving an L03 for more than 15 years. It feels as fast as its ever been at high rpm.
I can reset the PE TPS to 90% and make it above 5000 rpms again tomorrow and try another log. It just didn't seem like it would ever get to high rpms when I did that but I didn't give it much chance either.
I can reset the PE TPS to 90% and make it above 5000 rpms again tomorrow and try another log. It just didn't seem like it would ever get to high rpms when I did that but I didn't give it much chance either.
Last edited by Fast355; 02-15-2017 at 06:17 PM.
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Re: My Vortec 350 Hotcam TBI build + Questions
This is what I have currently. I messed with it early on but came back down to these numbers. I had it idling higher before but I like the lower idle. It sounds really good with the Hot Cam.
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Re: My Vortec 350 Hotcam TBI build + Questions
I was tuning away doing VE Learns and my trans went kaput. I shattered the input drum into many pieces. Anyhow my Transmission builder Pro Trans Plus (http://www.protransplus.com) is really good ripped it apart for me and we found the issue. I'm now back on the road and we tuned the governor with better shift points. It feels like a whole different car now.
Fast those tables you hooked me up with are doing rather well. I'm going to lay low on too many changes until I get a wideband o2. I did pull back some of my AE and it made it much more responsive when hitting the gas. It was dumping way too much AE when you hit it. I could see it on the data log and pulled it back 10% at a time until it felt good. I have a few other issues to work out on the car and ran out of budget at this point. So I'm going to focus on some of those mechanical issues and come back to tuning a little later.
Fast those tables you hooked me up with are doing rather well. I'm going to lay low on too many changes until I get a wideband o2. I did pull back some of my AE and it made it much more responsive when hitting the gas. It was dumping way too much AE when you hit it. I could see it on the data log and pulled it back 10% at a time until it felt good. I have a few other issues to work out on the car and ran out of budget at this point. So I'm going to focus on some of those mechanical issues and come back to tuning a little later.
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Re: My Vortec 350 Hotcam TBI build + Questions
Here is my shattered input drum. We think it was weakened already or someone did some neutral drops in my car when I wasn't around.
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Re: My Vortec 350 Hotcam TBI build + Questions
I'd like to go back to the recommendations from back before the first of the year about needing a looser, 3200 stall converter and needing more gear than a 3.42 for highway cruising with a cam as mild as the LT4 Hotcam ..... am I missing something?
I'd think on a street car, 2200-2400 stall would be perfect. That cam makes good low-end power. Any more stall that that, and I'd think you'd have serious traction problems, blowing the tires off in the first 60'.
And I think 3.42s are the perfect street gear. Depending on the tires, that would put you cruising at 70 mph around 2220, 2300 rpm. That's in the LT4 Hotcam's powerband, so I don't think you'd be downshifting every time you hit a small hill.
I can tell you daily driving my 3.42 T5 car, I'm in 5th gear by 40 mph, and never have to downshift on hills.
I'd think on a street car, 2200-2400 stall would be perfect. That cam makes good low-end power. Any more stall that that, and I'd think you'd have serious traction problems, blowing the tires off in the first 60'.
And I think 3.42s are the perfect street gear. Depending on the tires, that would put you cruising at 70 mph around 2220, 2300 rpm. That's in the LT4 Hotcam's powerband, so I don't think you'd be downshifting every time you hit a small hill.
I can tell you daily driving my 3.42 T5 car, I'm in 5th gear by 40 mph, and never have to downshift on hills.
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Car: 1991 RS Camaro
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Re: My Vortec 350 Hotcam TBI build + Questions
I'd like to go back to the recommendations from back before the first of the year about needing a looser, 3200 stall converter and needing more gear than a 3.42 for highway cruising with a cam as mild as the LT4 Hotcam ..... am I missing something?
I'd think on a street car, 2200-2400 stall would be perfect. That cam makes good low-end power. Any more stall that that, and I'd think you'd have serious traction problems, blowing the tires off in the first 60'.
And I think 3.42s are the perfect street gear. Depending on the tires, that would put you cruising at 70 mph around 2220, 2300 rpm. That's in the LT4 Hotcam's powerband, so I don't think you'd be downshifting every time you hit a small hill.
I can tell you daily driving my 3.42 T5 car, I'm in 5th gear by 40 mph, and never have to downshift on hills.
I'd think on a street car, 2200-2400 stall would be perfect. That cam makes good low-end power. Any more stall that that, and I'd think you'd have serious traction problems, blowing the tires off in the first 60'.
And I think 3.42s are the perfect street gear. Depending on the tires, that would put you cruising at 70 mph around 2220, 2300 rpm. That's in the LT4 Hotcam's powerband, so I don't think you'd be downshifting every time you hit a small hill.
I can tell you daily driving my 3.42 T5 car, I'm in 5th gear by 40 mph, and never have to downshift on hills.
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Re: My Vortec 350 Hotcam TBI build + Questions
so a) I was saying a 3200 converter and more gear than a 3.42 would be too much
and b) if you're having those kinds of traction problems with an LT4 Hotcam and 3.42 gears, you need to rework your timing and fuel tables to pull some bottom end power out, get better tires, check your LSD, or all of the above.
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Re: My Vortec 350 Hotcam TBI build + Questions
ummmm ......... yeah
so a) I was saying a 3200 converter and more gear than a 3.42 would be too much
and b) if you're having those kinds of traction problems with an LT4 Hotcam and 3.42 gears, you need to rework your timing and fuel tables to pull some bottom end power out, get better tires, check your LSD, or all of the above.
so a) I was saying a 3200 converter and more gear than a 3.42 would be too much
and b) if you're having those kinds of traction problems with an LT4 Hotcam and 3.42 gears, you need to rework your timing and fuel tables to pull some bottom end power out, get better tires, check your LSD, or all of the above.
LSD is in good shape and its spinning both tires for sure.
If I want it to launch better I can pull some timing yes but its so much fun now.
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Re: My Vortec 350 Hotcam TBI build + Questions
He lived in Macon Ga at the time (I believe, it may have been Savannah). Anyway, he drove over a hundred miles in his Camaro to get to Atlanta Dragway, cooled it down, pulled up to the line with the tires he'd driven it in on and full exhaust, left the line just off-idle and cranked out either a 12.03 or a 12.08. No juice (That's NOS to you Millenials).
If I remember correctly, he had a stock Corvette converter and he didn't have drag radials on it. His chip tune was mail order.
I think that thread is the best read on here.