Need Help w/ Procharged HO 502 '97 K2500
02-02-2015, 06:00 PM
#11
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James:
This is good advice. I'll post some questions/statements within your text.
Thank you again for bring these issues to my attention. I certainly want to be able to use the ABS and such. Speaking of this, have you ever retrofitted ABS to a non-ABS vehicle before?.
I look forward to hearing more from you.
Ty
BTW: Do you have any idea what the going rate per hour is for someone to do Tig Welding?
This is good advice. I'll post some questions/statements within your text.
I wouldn't let the transfer case compromise the goals here. The autotrac case is doesn't have the greatest torque handling abilities any way. There is always the option of swapping it out to a manual case.
I've thought about this with all the increase in torque that is one of the few drivetrain components that hasn't been upgraded.
"Atlas" seems to be a real hearty transfer case and you can also run off either the front or rear wheels in case of a driveshaft failure.
Are you a fan of the Atlas products?
If you do decide to go with an aftermarket harness be sure transmission tailshaft sensor is feeding the PCM and not the one in the case, otherwise it will cause havoc in 4lo. The VSS in the transfer case supplies the instrument cluster and the ABS.
I am so glad you are mentioning these details as you are at this point talking over my head. I obviously have a lot to learn. I am located just North of Dallas in a suburb callas Frisco, Tx. If you have any recommendations on people who do this type(s) of thing I'd be happy to give them a call and start tackeling these things one at a time.
I just really need to understand all this technology in a similar manner as you do.
I checked out your trucks and they look really sweet.
The last boosted motor I've had was a GMPP HT383 shortblock with Edelbrock e-tec 200 heads, 1.6:1 roller rockers, 114LSA cam, and a marine intake with 63# Siemens injectors. It also had long tube headers and true-dual 3" exhaust with metallic cats. The transmission was a 4L80-E with a Gear Vendors overdrive andd 4.56:1 gears in a custom 10.5" rear with Eaton Posi. Boost came from a 2.3L Whipple overdriven to 10psi with a huge air-to-water intercooler.
As for the EFI, I ran this with the stock 1999 PCM (96-97 are the first generation and 98-2000 are the second generation of the "block box") It had an LT1 knock module installed in it. The transmission was controlled by a stand-alone TCI TCU left over from the days before we had the ability to tune these PCMs with TunerCATs. I had the IAT sensor moved to a bung after the intercooler. No MAF. No Whipple electronics or auxiliary injectors. A 2-BAR MAP sensor was used. Fuel pressure was regulated to 3 BAR instead of GM's usual 4 BAR using an Aeromotive regulator. The reason for this is that the factory pump can actually move a greater volume of fuel at the lower pressure. The injectors were Siemens 63#. Stock throttle body, 72mm.
Isn't a 72mm throttle body the same size as what came on my truck originally?
I had to toss the MAF early on because it was being maxed out at full power past about 4500 RPM. Getting the 2-BAR MAP to work was the trickiest. Basically, I went into every table that referenced kPA and manipulated the data. So, for example I'd start at 15 kPa, and then copy the values from the 20 kPa column into it. Then into the 20 I would copy the 30kPa values, and then into the 25 copy 40's values, and so on until I was putting 105kPa's values in the 55kPa column.
Using the rates of measures that you do, (kPa) are you an engineer of a transplant from Europe?
The rest of the table from 60 on had to be fabricated loosely based on the curve established by the existing values.
Here's that voltage table:
The hardest thing was getting it to idle. There 2-BAR MAP has half the resolution than a 1-BAR does and the slower processor int he black box PCM has a tough time making rapid adjustments. Once off idle though it ran perfectly. The timing was tuned for 91 octane.
Here's the engine bay:
And here's how it ran:
http://bertok.us/pics/0-120.mpg
This was on drag radials trying to figure how hot they needed to get to stick. (Answer=VERY, I did eventually get those tires to work and have photos with the front wheels in the air.)
http://bertok.us/pics/DR-Launch.mpg
After the 383 broke the snout off the crank from the blower torque I put a 454 into it. Drove it that way until replacing it with the 98 Suburban I drive now. I have a 3.3L Whipple and another intercooler for the Suburban's 502, but I haven't began the fab of that system yet. I will be running that with the factory PCM at first, with the possibility of a 411 and 2-BAR custom OS and coil per plug ignition later. I have smog to consider here and need to retain the ability to entirely swap back the Suburban's OEM 454 every two years. That was something that became impossible with the Tahoe.
I've thought about this with all the increase in torque that is one of the few drivetrain components that hasn't been upgraded.
"Atlas" seems to be a real hearty transfer case and you can also run off either the front or rear wheels in case of a driveshaft failure.
Are you a fan of the Atlas products?
If you do decide to go with an aftermarket harness be sure transmission tailshaft sensor is feeding the PCM and not the one in the case, otherwise it will cause havoc in 4lo. The VSS in the transfer case supplies the instrument cluster and the ABS.
I am so glad you are mentioning these details as you are at this point talking over my head. I obviously have a lot to learn. I am located just North of Dallas in a suburb callas Frisco, Tx. If you have any recommendations on people who do this type(s) of thing I'd be happy to give them a call and start tackeling these things one at a time.
I just really need to understand all this technology in a similar manner as you do.
I checked out your trucks and they look really sweet.
The last boosted motor I've had was a GMPP HT383 shortblock with Edelbrock e-tec 200 heads, 1.6:1 roller rockers, 114LSA cam, and a marine intake with 63# Siemens injectors. It also had long tube headers and true-dual 3" exhaust with metallic cats. The transmission was a 4L80-E with a Gear Vendors overdrive andd 4.56:1 gears in a custom 10.5" rear with Eaton Posi. Boost came from a 2.3L Whipple overdriven to 10psi with a huge air-to-water intercooler.
As for the EFI, I ran this with the stock 1999 PCM (96-97 are the first generation and 98-2000 are the second generation of the "block box") It had an LT1 knock module installed in it. The transmission was controlled by a stand-alone TCI TCU left over from the days before we had the ability to tune these PCMs with TunerCATs. I had the IAT sensor moved to a bung after the intercooler. No MAF. No Whipple electronics or auxiliary injectors. A 2-BAR MAP sensor was used. Fuel pressure was regulated to 3 BAR instead of GM's usual 4 BAR using an Aeromotive regulator. The reason for this is that the factory pump can actually move a greater volume of fuel at the lower pressure. The injectors were Siemens 63#. Stock throttle body, 72mm.
Isn't a 72mm throttle body the same size as what came on my truck originally?
I had to toss the MAF early on because it was being maxed out at full power past about 4500 RPM. Getting the 2-BAR MAP to work was the trickiest. Basically, I went into every table that referenced kPA and manipulated the data. So, for example I'd start at 15 kPa, and then copy the values from the 20 kPa column into it. Then into the 20 I would copy the 30kPa values, and then into the 25 copy 40's values, and so on until I was putting 105kPa's values in the 55kPa column.
Using the rates of measures that you do, (kPa) are you an engineer of a transplant from Europe?
The rest of the table from 60 on had to be fabricated loosely based on the curve established by the existing values.
Here's that voltage table:
The hardest thing was getting it to idle. There 2-BAR MAP has half the resolution than a 1-BAR does and the slower processor int he black box PCM has a tough time making rapid adjustments. Once off idle though it ran perfectly. The timing was tuned for 91 octane.
Here's the engine bay:
And here's how it ran:
http://bertok.us/pics/0-120.mpg
This was on drag radials trying to figure how hot they needed to get to stick. (Answer=VERY, I did eventually get those tires to work and have photos with the front wheels in the air.)
http://bertok.us/pics/DR-Launch.mpg
After the 383 broke the snout off the crank from the blower torque I put a 454 into it. Drove it that way until replacing it with the 98 Suburban I drive now. I have a 3.3L Whipple and another intercooler for the Suburban's 502, but I haven't began the fab of that system yet. I will be running that with the factory PCM at first, with the possibility of a 411 and 2-BAR custom OS and coil per plug ignition later. I have smog to consider here and need to retain the ability to entirely swap back the Suburban's OEM 454 every two years. That was something that became impossible with the Tahoe.
I look forward to hearing more from you.
Ty
BTW: Do you have any idea what the going rate per hour is for someone to do Tig Welding?
02-12-2015, 08:24 AM
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James:
This is good advice. I'll post some questions/statements within your text.
Thank you again for bring these issues to my attention. I certainly want to be able to use the ABS and such. Speaking of this, have you ever retrofitted ABS to a non-ABS vehicle before?.
I look forward to hearing more from you.
Ty
BTW: Do you have any idea what the going rate per hour is for someone to do Tig Welding?
This is good advice. I'll post some questions/statements within your text.
Thank you again for bring these issues to my attention. I certainly want to be able to use the ABS and such. Speaking of this, have you ever retrofitted ABS to a non-ABS vehicle before?.
I look forward to hearing more from you.
Ty
BTW: Do you have any idea what the going rate per hour is for someone to do Tig Welding?
James:
I really appreciate this detail.
How did you handle the exhaust?
Your sounded nice and sane.
Thanks,
Ty
10-04-2015, 10:23 AM
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Update
I have still been working with the tuner and he was able to get these numbers.
Max RWHP = 416
Max RWTQ = 463
This seems not to bad, however I still think it is on the low side.
I am running a 1 5/8 primary, 3.0 inch Shorty header could this be the reason>
The largest header I could find for the truck is a 1.75 inch, 3.0 collector
This difference is only .125/1000 of an inch difference, or 1/8 of an inch. (If I did my math right)
Would this make a ton of difference?
The exhaust is a dual 3.0 in, and a duel 3.0 coming out of a long single muffler similar to a Big Block 50 series. Even with this long muffler it is pretty loud.
I do find the power is mostly in the upper RPM's which seems it should be exactly the opposite give the cam and heads I'm using.
Does anyone have any thoughts on this?
Thanks,
Ty
Max RWHP = 416
Max RWTQ = 463
This seems not to bad, however I still think it is on the low side.
I am running a 1 5/8 primary, 3.0 inch Shorty header could this be the reason>
The largest header I could find for the truck is a 1.75 inch, 3.0 collector
This difference is only .125/1000 of an inch difference, or 1/8 of an inch. (If I did my math right)
Would this make a ton of difference?
The exhaust is a dual 3.0 in, and a duel 3.0 coming out of a long single muffler similar to a Big Block 50 series. Even with this long muffler it is pretty loud.
I do find the power is mostly in the upper RPM's which seems it should be exactly the opposite give the cam and heads I'm using.
Does anyone have any thoughts on this?
Thanks,
Ty
10-04-2015, 12:50 PM
#15
That problem you're having achieving "quiet" with the exhaust is something I am no stranger to, unfortunately. The Tahoe had SIX mufflers and two cats and was still loud as hell. It's the cam and all that boost that does it.
In the Suburban I had the 502 with the same heads and a pair of Hooker AeroChambers with a pair of Mangaflow 4" body round ones at the back just before exit acting as resonators. It was quieter than the Tahoe but it also never had boost. As you know with the Suburban you've got a TON of room underneath to add more resonators if needed. You've probably got some sections of straight pipe in there with your current system that would accommodate this. If you've got room in the back to add cans just before the exists they really help.
You had the right idea with the largest-body muffler. Big blocks need volume to smooth out the exhaust. If your system does not have a crossover that might be a possibility - crossovers also help reduce loudness but I feel like it's probably not worth the effort since both sides go to the same muffler already. The crossover would need to be aft of the forward O2 sensors by at least 12" to be safe. That will be actually before the cats which generally isn't preferable, but I know how far back the cats are on these trucks and they need to stay that way so they don't incinerate.
As for your concern that the shorties might be the problem - they're not, in my opinion. The gains you get from longtubes are much higher naturally aspirated than boosted.
I have Dynomation software and already have my 502 modeled in it. Send me a link to your cam card and tell me what your maximum boost pressure is and I'll come back with some charts.
You horsepower and torque are low, in my opinion. Somewhere there is room for improvement. It is characteristic of a centrifugal supercharger to come into power in the higher RPM, so I would call those observations normal.
I meant to ask you before if you ported the lower intake manifold. You may have noticed the ports on the Brodix heads perfectly match the gaskets but the intake manifold ports are considerably smaller. Let me know if you want to see a picture of that; I've got a few manifolds and the heads sitting on the bench right now.
In the Suburban I had the 502 with the same heads and a pair of Hooker AeroChambers with a pair of Mangaflow 4" body round ones at the back just before exit acting as resonators. It was quieter than the Tahoe but it also never had boost. As you know with the Suburban you've got a TON of room underneath to add more resonators if needed. You've probably got some sections of straight pipe in there with your current system that would accommodate this. If you've got room in the back to add cans just before the exists they really help.
You had the right idea with the largest-body muffler. Big blocks need volume to smooth out the exhaust. If your system does not have a crossover that might be a possibility - crossovers also help reduce loudness but I feel like it's probably not worth the effort since both sides go to the same muffler already. The crossover would need to be aft of the forward O2 sensors by at least 12" to be safe. That will be actually before the cats which generally isn't preferable, but I know how far back the cats are on these trucks and they need to stay that way so they don't incinerate.
As for your concern that the shorties might be the problem - they're not, in my opinion. The gains you get from longtubes are much higher naturally aspirated than boosted.
I have Dynomation software and already have my 502 modeled in it. Send me a link to your cam card and tell me what your maximum boost pressure is and I'll come back with some charts.
You horsepower and torque are low, in my opinion. Somewhere there is room for improvement. It is characteristic of a centrifugal supercharger to come into power in the higher RPM, so I would call those observations normal.
I meant to ask you before if you ported the lower intake manifold. You may have noticed the ports on the Brodix heads perfectly match the gaskets but the intake manifold ports are considerably smaller. Let me know if you want to see a picture of that; I've got a few manifolds and the heads sitting on the bench right now.
10-05-2015, 11:42 AM
#17
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Here is all the Engine information for you.
AFFORDABLE BIG-BLOCK PERFORMANCE WITH HUGE TORQUE AND 450 HP
With 450 horsepower and 550 lb-ft of torque, our 502 HO crate engine has power on tap for every need whether its a 69 Chevelle at the drag strip or the Suburban that towed it there!
The 502 HO is all about torque. It hovers just below the 500 lb-ft mark at only 1500 rpm and arcs gently above the 500 lb-ft level by 2800 rpm, remaining there through 4200 rpm. All those axle-twisting pound-feet are rooted in a stronger, updated four-bolt cylinder block that houses a forged steel crankshaft, forged and shot-peened rods, and forged aluminum pistons. In other words, its a super-stout assembly that is as durable as it is powerful.
Iron, rectangular-port cylinder heads keep the 502 HO affordable, and our crate engine assembly includes an aluminum dual-plane intake manifold, a water pump, 14-inch flexplate, balancer, and more. You add the carburetor, starter, and ignition system all available at chevroletperformance.com.
502 HO DYNO
Here is a direct link.
502 HO Big Block Crate Engine | Chevrolet
The Iron heads were replaced with the Race Rite Heads from Brodex:
Here are the specs:
Race-Riteฎ Big Block Series/26ฐ
Finally, the most user-friendly big block head on the market has been developed. BRODIX is now manufacturing a cylinder head that bolts directly in place of stock cast iron heads allowing reuse of the intake manifold and pistons. The most important improvement is that the exhaust ports are in the stock location eliminating header or manifold interference. The Race-Riteฎ rectangular or oval port is the answer for more horsepower, a hassle-free installation, and a great-looking engine compartment.
RR BB-O Exhuast
RR BB-O Exhuast
◄ Back Next ►
Picture 1 of 11
FLOW CHART CFM @ 28″ H20 (CLICK TO DISPLAY)
Package Heads
PS CB:
Valve Bowls Blended
PS MI:
Match Intake Port to FP 1211
(RR BB-R)
Match Intake Port to FP 1210
(RR BB-O)
Match Intake Port to BRODIX MG 2001
(RR BB-2 PLUS, STS RR BB-2 PLUS)
PS Valve Job:
Competition Valve Job
Intake Valves:
2.250 x 5.218 o.a.l. BR 81040
2.190 x 5.230 o.a.l. BR 70019
Exhaust Valves:
1.880 x 5.394 o.a.l. BR 81038
Valve Springs:
1.550 Hydraulic Roller Valve Spring BT 120121,
140 lb Closed, 365 lb Open,
1.950 Installed Height,
.600 Maximum Lift
1.550 Roller Valve Spring GA 1000,
240 lb Closed, 550 lb Open,
1.950 Installed Height,
.700 Maximum Lift
1.640 Roller Valve Spring MA 221424,
250 lb Closed, 745 lb Open,
2.050 Installed Height,
.800 Maximum Lift (Spring Upgrade)
Retainers:
1.550 10ฐ Steel CC 752
1.625 10ฐ Titanium MA 23640
Valve Locks:
10ฐ Jumbo CC 611
Rocker Studs:
7/16 BR 716L, AR RRS-4I
Guide Plates:
3/8 CC 4806
Valve Seals:
11/32 US VS529V
Facts and Related Components
Torque Heads:
70 ft-lb
Torque Rocker Studs:
40-45 ft-lb
Intake Gaskets:
FEL-PRO 1211
(RR BB-R)
FEL-PRO 1210, COMETIC C5430
(RR BB-O)
BRODIX MG 2001, COMETIC C5428,
FEL-PRO 1252-3 (RR BB-2 PLUS,
STS RR BB-2 PLUS)
Head Gaskets:
4.310 FEL-PRO 1027, COMETIC C5432
4.540 FEL-PRO 1017, COMETIC C5433
Exhaust Gaskets:
FEL-PRO 1411, COMETIC C5429
Head Bolts:
ARP 135-3601
Head Studs:
ARP 135-4001 (6 pt)
Accessory Bolt Holes Are Drilled
Spark Plug Starting Points:
CHAMPION RN12YC
for Pump Gas
NGK R5671A-8
for Racing Gas
Spring Pockets:
May be Step Cut to 1.625 -
Call for Details
Valve Angle:
26ฐ and 4ฐ Intake,
17ฐ and 4ฐ Exhaust
Angle Milling:
.0066 in Per cc
Flat Milling:
.0050 in Per cc
Angle Machining:
Available Upon Request
Dowel Shift:
Not Available
Pushrod Slots:
Standard
Stud Girdle:
Standard,
BRODIX 1230
Rocker Arms:
Standard
Lifters:
Standard
Pistons:
Standard
Pushrods:
Check Pushrod Clearance with Head Installed on the
Engine Block Before Final Assembly.
Intake Manifold
HV 2000 / HV 2001 / HV 2016 ( RR BB-R, RR BB-2 Plus,
STS RR BB-2 Plus)
EDELBROCK #7561 / HV 2007 / HV 2008 / HV 2017 (RR BB-O)
http://www.brodix.com/heads/big-bloc...block-series26
=============================
James:
I am very confused what I have in my engine that is wrong?
It is supposed to make tons of power (tq) between 1500 to 5500-6000 rpm
According to the DYNO sheets, 449hp at 5750 rpms with tq numbers at 410 max torque also at 5750 rpms.
This is rear wheel power, however these are high flow Oval Port aluminum Heads 2.25 in/1.88 Ex valves running 9-10 psi tuned to 93 octane. The iron heads with smaller valves 2.19/1.88 have square ports show on the DYNO that they make a lot of power much lower down in the RPM's.
I have a 4L80e tranny and a 4:10 Rear. 32 inch tires.
How much drivetrain loss is there with a vehicle like mine? 25%?
I look forward to hearing from you.
Thanks,
Ty O'Neal
10-05-2015, 11:46 AM
#18
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James here are the flow numbers on the Brodix Al Race Rite Heads.
The ones I have are at the top.
Ty
http://www.brodix.com/wp-content/upl...01/catalog.pdf
The ones I have are at the top.
Ty
http://www.brodix.com/wp-content/upl...01/catalog.pdf
10-05-2015, 12:51 PM
#19
I found enough spec on that cam (24502611) to get close with the model but I haven't found the seat-to-seat duration numbers. If you've ever found that please post.
I've already got those heads modeled - I have the CNC-ported version of the exact same casting on my 502.
Did you port the intake to match the gaskets?
I'm tying to get an idea for how the D1 is pulley'd. I'm not sure that's a large enough supercharger for that much cubes and unfortunately my software doesn't have ProChargers in it to choose from. I've got a Vortec V1-T trim though and they are similar enough and I should be able to figure it out.
I need a reference for the boost and RPM. Ideally something lower than where the graphs start to fall off. For example, what is the boost pressure at exactly 4500RPM and wide open throttle?
In the model I've got open right now very tiny changes in pulley sizes (drive ratio) are making huge differences in power. I'm starting the think the blower could be choking it instead of force feeding it.
Also, do you happen to know which tuning package was used to tune it? I've got TunerCATS OBD-II and EFI-Live and could have a look if you've got it.
Info needed if you have it:
1. seat-to-seat numbers on GM #24502611 cam
2. exact boost at 4500 RPM @ WOT
3. crank and supercharger pulley sizes
Take a look at the intake manifold pressure in the lower graph, subtract 14.7 and that's the boost number I am trying to make match your setup.
I've already got those heads modeled - I have the CNC-ported version of the exact same casting on my 502.
Did you port the intake to match the gaskets?
I'm tying to get an idea for how the D1 is pulley'd. I'm not sure that's a large enough supercharger for that much cubes and unfortunately my software doesn't have ProChargers in it to choose from. I've got a Vortec V1-T trim though and they are similar enough and I should be able to figure it out.
I need a reference for the boost and RPM. Ideally something lower than where the graphs start to fall off. For example, what is the boost pressure at exactly 4500RPM and wide open throttle?
In the model I've got open right now very tiny changes in pulley sizes (drive ratio) are making huge differences in power. I'm starting the think the blower could be choking it instead of force feeding it.
Also, do you happen to know which tuning package was used to tune it? I've got TunerCATS OBD-II and EFI-Live and could have a look if you've got it.
Info needed if you have it:
1. seat-to-seat numbers on GM #24502611 cam
2. exact boost at 4500 RPM @ WOT
3. crank and supercharger pulley sizes
Take a look at the intake manifold pressure in the lower graph, subtract 14.7 and that's the boost number I am trying to make match your setup.
