Best way to choke a 408 N/A..... unported GMPP L92 Intake FTL!
#21
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Bottom line, most intake elbows and 90mm TBs choke flow when compared to a proper 4 barrell throttle body place on top like the intake engineers intended.
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2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
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2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
#22
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you are looking for something more like:
http://i31.photobucket.com/albums/c3...s6/WS6/099.jpg
that would work but it is hard to Maf tune and filter.
http://i31.photobucket.com/albums/c3...s6/WS6/099.jpg
that would work but it is hard to Maf tune and filter.
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![](https://ls1tech.com/forums/signaturepics/sigpic210_1.gif)
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
![](https://ls1tech.com/forums/signaturepics/sigpic210_1.gif)
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
#25
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If you could run this with a carb you'd see some impressive power. Tests I have seen with LS7 engines running the GMPP single plane with EFI cost over 30hp over a carb setup. This was comparing a 4bbl ttb directly to an 850 carb.
Just for kicks try putting on a borrowed carb and regulating the fuel pressure and run it again on the dyno. You'll be shocked with the results. Warts and all............
Good luck,
Richard
Just for kicks try putting on a borrowed carb and regulating the fuel pressure and run it again on the dyno. You'll be shocked with the results. Warts and all............
Good luck,
Richard
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#28
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If you could run this with a carb you'd see some impressive power. Tests I have seen with LS7 engines running the GMPP single plane with EFI cost over 30hp over a carb setup. This was comparing a 4bbl ttb directly to an 850 carb.
Just for kicks try putting on a borrowed carb and regulating the fuel pressure and run it again on the dyno. You'll be shocked with the results. Warts and all............
Good luck,
Richard![Happy](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_stretch.gif)
Just for kicks try putting on a borrowed carb and regulating the fuel pressure and run it again on the dyno. You'll be shocked with the results. Warts and all............
Good luck,
Richard
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#30
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The intake is not your problem at all...my intake is completely untouched. It will flow more than enough for a 408....I'm spinning this 454 to 6800. Just trying to help get the facts out.
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#32
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Patrick, im sure you know already but they finally got ahold of the rocker arm guy. You are back in business!!!!!!
Im thinking with the rockers in check you are going to see 760ish with some full pulls
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Mike, your combo is soo mismatched it doesnt matter what you do at this time. No one can fix it without spending a good chucnk of chance. perhaps you have the weakest l92 topend setup...Maybe its a record for ya.
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Hmmm, carbies make more power than injection? The motor only sees a certain amount of flow and air speed. Plus fuel mixture. I am guessing the 4barrel TB you tested was 1000cfm. Obviously this motor responded better with and 850cfm carb. If the TB flowed the same as the carb and afrs were the same there shouldnt be any difference. Only being the EFI setup would be more suitable for street use.
I would like to see how it would respond to a Harrop Engineering 8 TB flat slide setup
I would like to see how it would respond to a Harrop Engineering 8 TB flat slide setup
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#34
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pwebb's motor has the same elbow and TB..... although they aren't untouched. the elbow has been epoxied to kill the dead spots in it and increase airflow with less turbulence.
Patrick, im sure you know already but they finally got ahold of the rocker arm guy. You are back in business!!!!!!
Im thinking with the rockers in check you are going to see 760ish with some full pulls
possibly even more. ![Devil](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_devil.gif)
Mike, your combo is soo mismatched it doesnt matter what you do at this time. No one can fix it without spending a good chucnk of chance. perhaps you have the weakest l92 topend setup...Maybe its a record for ya.
Patrick, im sure you know already but they finally got ahold of the rocker arm guy. You are back in business!!!!!!
Im thinking with the rockers in check you are going to see 760ish with some full pulls
![Happy](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_stretch.gif)
![Devil](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_devil.gif)
Mike, your combo is soo mismatched it doesnt matter what you do at this time. No one can fix it without spending a good chucnk of chance. perhaps you have the weakest l92 topend setup...Maybe its a record for ya.
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The motor pic posted is mine. I just switched from an elbo 90mm TB and really didn't pick up much if anything. I did get alot of hp under the curve but I also ported my Vic Jr. which was flowing 290cfm with the heads attached before. But my elbo is noting like the designs you guys run as I can care less about my cowl. Mine was just a 4in 90* pipe with flanges on it.
#36
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Considering a lot of competition engines run with restrictor plates etc Id suggest there are other ways to get air in there other than going big.
How about port efficiency and velocity, cam design etc?
You might have to optimise what you have by changing parts to match instead of using semi mismatched stuff.
Or just force some air in there
How about port efficiency and velocity, cam design etc?
You might have to optimise what you have by changing parts to match instead of using semi mismatched stuff.
Or just force some air in there
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#37
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Hmmm, carbies make more power than injection? The motor only sees a certain amount of flow and air speed. Plus fuel mixture. I am guessing the 4barrel TB you tested was 1000cfm. Obviously this motor responded better with and 850cfm carb. If the TB flowed the same as the carb and afrs were the same there shouldnt be any difference. Only being the EFI setup would be more suitable for street use.
I would like to see how it would respond to a Harrop Engineering 8 TB flat slide setup![Happy](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_stretch.gif)
I would like to see how it would respond to a Harrop Engineering 8 TB flat slide setup
![Happy](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_stretch.gif)
#38
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well, considering I can get the intake ported, and the elbow can be looked at, I dont think I am done yet. The car did make "decent" power. Just not 480rwhp. My heads are fine, and I have a good cam. This new cam did much better and actually didnt fall off until 7000 when he let out. The other 244/248 died at 6200. This one also had much more lowend tq. Rick at Synergy did a good job. He cant fix the 91kpa issue, which can be attributed to the maf/intake/elbow combo.
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#39
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I agree with PatrickG. Maf tunes are for stock cars. There is NO need for a closed loop tune when you KNOW what you are doing/looking/listening for. Judson @ SAM said himself "Its very hard to beat a two carb setup on a tunnel ram." To me speed density tunes and carbs are one in the same. I REALLY want to try my hand at tuning but my time is EXTREMELY limited.
We had quite a few problems with reversion using a carb on this intake with these heads BTW. Had to use 3 inches of spacer to get it to idle.
We had quite a few problems with reversion using a carb on this intake with these heads BTW. Had to use 3 inches of spacer to get it to idle.
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They used to fit carbs to V8 supercars in Australia when on a budget with single plain manifolds. They lost hp and torque and greater average hp over a 8TB harrop manifold flat side efi. And I dont see motoGP bikes make 240rwhp from 800cc with holleys strapped to them.The aussie V8 supercars make 700hp from 5 L with injection. History shows you are one of few to get such results
In your case a 100hp loss shows something poorly miss matched. That manifold and Big *** 1000cfm+ TB was to big, either that or someone cant tune SD with such a massive camshaft. History shows efi wins the majority hands down.
In Wizes case. A stock 6L will get 99kPa. How you only get 91kpa gets me stuffed. Thats like a blocked vaccum cleaner! A typical efi manifold likes a single TB but single planes work better with a carb or 4B throttle body. That elbow will restrict flow as that manifold isnt designed to work with it. Unless FI is brought into equation.
So there is no doubt a carb will make more over the current setup. How come you dont ditch the elbow and MAF and tune SD, will see results then, only other option is to fit a weiand warrior.
cheers