clark31
Forum Newbie
Posts: 80
Loc: Mesa, Arizona
Reg: 04-15-09
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04-29-09 10:17 PM - Post#1688240
Does any one know a site that has header comparisons with a dyno or even manifolds for the 350 tbi? I want to know what Is the best and If there are any problems with them.
Here is 1 dyno result
http://www.carcraft.com/featuredvehicles/ccrp _0407...
1989 Chevy Suburban 2wd r1500 with 5.7L 350sb tbi and 700r4 (mods) are 'Headman' long tube headers,3" y-pipe, magnaflo high flow cat and super 44 flowmaster
2005 GMC Yukon Denali XL |
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clark31
Forum Newbie
Posts: 80
Loc: Mesa, Arizona
Reg: 04-15-09
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04-30-09 11:02 PM - Post#1688962
In response to clark31
bump
1989 Chevy Suburban 2wd r1500 with 5.7L 350sb tbi and 700r4 (mods) are 'Headman' long tube headers,3" y-pipe, magnaflo high flow cat and super 44 flowmaster
2005 GMC Yukon Denali XL |
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clark31
Forum Newbie
Posts: 80
Loc: Mesa, Arizona
Reg: 04-15-09
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05-01-09 10:43 PM - Post#1689712
In response to clark31
anyone?
1989 Chevy Suburban 2wd r1500 with 5.7L 350sb tbi and 700r4 (mods) are 'Headman' long tube headers,3" y-pipe, magnaflo high flow cat and super 44 flowmaster
2005 GMC Yukon Denali XL |
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Axelrod
Senior Member
Posts: 562
Reg: 02-23-04
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05-02-09 11:09 AM - Post#1689950
In response to clark31
I remember Jake, that was an old Caltran cast off that they (Carcraft) did a makeover on. You'll note they did a number of external things to get a very respectable pickup of TQ and HP. You won't go wrong following their proven path.
Here's the deal with shorty headers, they are more efficient than the stock log manifolds but most of your gains will come higher up on the curve. If you go with a Tri-Y design like Doug's or Thorley, you'll pick up low and mid range TQ which is what you want with a truck. The Tri-Ys are more expensive than shortys.
A similar article from their sister publication Chevy High Performance: http://www.chevyhiperformance.com/techarticles/148...
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1983G20Van
Super Senior Member
Posts: 3178
Loc: Bedford, Texas, USA
Reg: 11-13-02
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05-02-09 08:36 PM - Post#1690248
In response to Axelrod
I remember Jake, that was an old Caltran cast off that they (Carcraft) did a makeover on. You'll note they did a number of external things to get a very respectable pickup of TQ and HP. You won't go wrong following their proven path.
Here's the deal with shorty headers, they are more efficient than the stock log manifolds but most of your gains will come higher up on the curve. If you go with a Tri-Y design like Doug's or Thorley, you'll pick up low and mid range TQ which is what you want with a truck. The Tri-Ys are more expensive than shortys.
A similar article from their sister publication Chevy High Performance: http://www.chevyhiperformance.com/techarticles/148...
I like the Tri-Y design headers myself, but don't overlook the shortys. They can have great gains, even at lower rpms. Its been a while since I played with a stock TBI 5.7 as I am playing with Dodge engines now and only Chevy I mess with is my Vortec TPI in my 83 G20 Van.
I put a set of JBA Shorties on the 4.7 in my Dodge Ram and the biggest gain was 41 RWTQ at a mere 2,500 rpm. Higher rpm gains were far less. I can FEEL the torque everytime I accelerate. The gains were very healthy from 2,000 through 3,500 rpm and tapered off at higher rpms.
My engine responded VERY well to a Superchips programmer, volant cold air intake, JBA shorty headers, magnaflow cat-back dual exhaust, and 4.7 HO cams. Not apples to apples, but just a good idea on how the power and efficiency of an engine can be improved.
I went from 178 RWHP, 223 RWTQ, and 13 mpg city, 18 mpg highway to 225 RWHP, 305 RWTQ, and 15 mpg city. I have seen an incredible 22 mpg on the highway running 70 mph.
| 1983 G20 Van, 350 TPI, Ported 906 Vortecs, Edelbrock 3817 Base, ASM oversize runners. Reed Custom Roller cam, 700r4, 12 bolt with 3.08 gears, Doug Thorley Tri-Y headers, true duals |
Edited by 1983G20Van on 05-02-09 08:53 PM. Reason for edit: No reason given.
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1983G20Van
Super Senior Member
Posts: 3178
Loc: Bedford, Texas, USA
Reg: 11-13-02
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05-02-09 09:29 PM - Post#1690277
In response to 1983G20Van
I don't plan to turn this thread into Dodgetalk, but I wanted to show an example of what a few bolt-on parts can do to help an engine breathe and perform. I am also trying to improve just how dramatically the combined parts improved the performance of the originally mediocre engine Stock it only had 235 HP @ 4,800 and 295 ft/lbs @ 3,200. (Jeep 4.7 HO was 265 @ 5,200 and 330 ft/lbs @ 3,600)
Here is a stock dyno from Superchips, actually a comparison of their 91 octane tune.
This is after the changes I made. The only internal engine change was a pair of Jeep Grand Cherokee HO 4.7 Cams (Makes the engines powerwise identical). Sligthly more duration on a tighter LSA, gained power ALL the way across the useable torque curve.
The JBA shorty headers gave GREAT low-midrange torque gains. I will stress again I gained power over the whole curve with the shorty headers and the biggest gains were between 2,000 and 3,500 rpm.
The Volant intake made a noticeable difference in top-end power. I initially purchased a K&N which is NOT worth the money. All it did was make my truck louder, but sucking hot air at the same time actually made it LOSE power over the stock air box. I returned it and found the Volant for $50 less through Stillen Performance
I have never seen another 4.7 run like this and mine is in a 5,200 lbs Quad Cab Ram with the factory 20s and 33" tall tires. 3.92 gear FWIW.
Edited by 1983G20Van on 05-02-09 09:38 PM. Reason for edit: No reason given.
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clark31
Forum Newbie
Posts: 80
Loc: Mesa, Arizona
Reg: 04-15-09
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 05-02-09 11:27 PM - Post#1690305
In response to 1983G20Van
Wow, thanks for the input. I don't like k&n myself (over-rated) But I was always told to go with long tube headers and make sure they are 1-3/4". That was word of mouth, thats why Im looking for numbers. I wanna see the improvements
But those numbers from those jba shortys are great. Is that the crome ones you installed? Is ceramic or crome better? Does it make any difference on power?
Also what y-pipe should I use? I changed the rest out, everything past the y-pipe. I want this thing breathing best as possible.
1989 Chevy Suburban 2wd r1500 with 5.7L 350sb tbi and 700r4 (mods) are 'Headman' long tube headers,3" y-pipe, magnaflo high flow cat and super 44 flowmaster
2005 GMC Yukon Denali XL |
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1983G20Van
Super Senior Member
Posts: 3178
Loc: Bedford, Texas, USA
Reg: 11-13-02
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05-02-09 11:57 PM - Post#1690313
In response to clark31
Wow, thanks for the input. I don't like k&n myself (over-rated) But I was always told to go with long tube headers and make sure they are 1-3/4". That was word of mouth, thats why Im looking for numbers. I wanna see the improvements
But those numbers from those jba shortys are great. Is that the crome ones you installed? Is ceramic or crome better? Does it make any difference on power?
Also what y-pipe should I use? I changed the rest out, everything past the y-pipe. I want this thing breathing best as possible.
The ones I bought were actually the plain stainless ones, no coating. The picture show different, but I pulled it off of a vendors website just to show the design. I would find it hard to believe a simple coating would impact HP/TQ. It "MIGHT" keep the exhaust gases slightly hotter and help scavenging but I doubt it.
My Cats and therefore Y pipe are stock although I am sure changing them out would be a great addition.
1 3/4" primaries are for something you want to breathe well up top, not a low rpm truck engine. If anything I ran 1.5" primary headers on my 350 TBI in my G20 Van and it gave it a huge torque boost. The primaries on the JBAs on my 4.7 look to be 1.5" but I did not measure them. I only choose the JBA's because of the lack of Tri-Ys for 4.7 Dodge engines as well as they were the cheapest at $315.00.
My favorites are still Tri-Y, but they are expensive. I have Doug Thorley 315Ys on my van now. 350 TBI block with Ported Vortecs, Edelbrock TPI Vortec Base, Stock TPI top-end and runners, Custom grind hydraulic roller cam. Even with a dying 700r4, stock torque converter and 3.08 gears, it would MOVE
.
I could not believe how well the stock intake runners, plenum, and Tri-Y headers exhausting into 2 1/2" pipes, a flowmaster dual 2 1/2" to 3" Y, high flow cat, into a magnaflow single 3", dual 2 1/4" out exhaust system held on making power past 6,000 rpm
http://s243.photobucket.com/albums/ff172/Fast355_ a...
| 1983 G20 Van, 350 TPI, Ported 906 Vortecs, Edelbrock 3817 Base, ASM oversize runners. Reed Custom Roller cam, 700r4, 12 bolt with 3.08 gears, Doug Thorley Tri-Y headers, true duals |
Edited by 1983G20Van on 05-03-09 12:04 AM. Reason for edit: No reason given.
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clark31
Forum Newbie
Posts: 80
Loc: Mesa, Arizona
Reg: 04-15-09
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05-03-09 09:53 AM - Post#1690390
In response to 1983G20Van
That van gets up and goes. isn't those rpm's kinda high for a v8? I'm used to imports (4 bangers) and I know that with headers the 4-2-1 is for torque and the 4-1 is all hp. but the shortys kinda confuse me and I haven't seen any 4-2-1 headers for a 350 yet. But I also hear about cracking and I don't want that. I want good headers.
1989 Chevy Suburban 2wd r1500 with 5.7L 350sb tbi and 700r4 (mods) are 'Headman' long tube headers,3" y-pipe, magnaflo high flow cat and super 44 flowmaster
2005 GMC Yukon Denali XL |
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1983G20Van
Super Senior Member
Posts: 3178
Loc: Bedford, Texas, USA
Reg: 11-13-02
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05-03-09 05:00 PM - Post#1690629
In response to clark31
That van gets up and goes. isn't those rpm's kinda high for a v8? I'm used to imports (4 bangers) and I know that with headers the 4-2-1 is for torque and the 4-1 is all hp. but the shortys kinda confuse me and I haven't seen any 4-2-1 headers for a 350 yet. But I also hear about cracking and I don't want that. I want good headers.
Thanks...It runs even better now with a solid transmission, higher stall torque converter, and aftermarket TPI runners.
The rpms are kinda high, but I setup the engine when I built it, to run to 6,500 rpm with complete reliability.
The Tri-Ys are 4-2-1 and are manufactured by Doug Thorley. I bought mine used on ebay and have been running them for 2 1/2 years. The coating was discolored before I even got them, but the construction is very solid. With a properly constructed and supported exhaust system, I believe cracking will never be an issue. They seem to seal very well using the stock L31 Vortec graphite looking exhaust gaskets.
The JBAs were also very solidly constructed.
I feel the ones that are crack, leak prone are the ones that are constructed cheaply. There are plenty of them. Try to avoid the $100 special jobs that have paper thin tubes, thin flanges, cheap welds, etc. You generally get what you pay for with headers and I do not like paying for them twice and installing them more than once.
These are the Doug Thorley Tri-Y (4-2-1 design), shortly after I got them.
| 1983 G20 Van, 350 TPI, Ported 906 Vortecs, Edelbrock 3817 Base, ASM oversize runners. Reed Custom Roller cam, 700r4, 12 bolt with 3.08 gears, Doug Thorley Tri-Y headers, true duals |
Edited by 1983G20Van on 05-03-09 05:02 PM. Reason for edit: No reason given.
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1983G20Van
Super Senior Member
Posts: 3178
Loc: Bedford, Texas, USA
Reg: 11-13-02
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05-03-09 07:50 PM - Post#1690733
In response to 1983G20Van
I never did find conclusive testing showing both headers or even shorty and long tubes tested on the same engine. I did look into the headers you would use on your rig. The good headers are spendy, $$$ but IMO worth it. If you could find either used, like I did with my Thorleys, you could be money ahead. Either set will set you back $500-700 but will last practically forever and give great gains. I would not be pushing them, if I did not own a set of each and had not played with cheaper, lower quality headers. I have been down that path and it was not fun. I have had a set of flowtechs and hedmans go south and constantly leaked. A leaking header on an EFI engine will pull oxygen across the 02 sensor, which will trick the computer making it believe the engine is running lean which adds fuel, and really kills your gas mileage.
Here is the Thorley Setup for your truck.
JBA offers direct fit shorties as well, but I could not find a decent picture of them.
These are the pictures that convinced me to buy my JBAs for the Ram. You can plainly see just how well they are built.
| 1983 G20 Van, 350 TPI, Ported 906 Vortecs, Edelbrock 3817 Base, ASM oversize runners. Reed Custom Roller cam, 700r4, 12 bolt with 3.08 gears, Doug Thorley Tri-Y headers, true duals |
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clark31
Forum Newbie
Posts: 80
Loc: Mesa, Arizona
Reg: 04-15-09
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05-03-09 08:14 PM - Post#1690743
In response to 1983G20Van
The jba's look professionally done that's for sure. And the stock manifolds sure are ugly lol. Thanks for looking for me. I have tried some search engines looking for them too. No luck thanks again
1989 Chevy Suburban 2wd r1500 with 5.7L 350sb tbi and 700r4 (mods) are 'Headman' long tube headers,3" y-pipe, magnaflo high flow cat and super 44 flowmaster
2005 GMC Yukon Denali XL |
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