L-18 intake conversion from Arizona Speed
03-05-2004, 01:33 AM
#11
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Location: San Diego, California
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BajaVet:
I have always been a little concerned about the claims for this manifold. Considering the problems with the heads on the 496's and the stock exhaust manifolds I don't think 100hp is possible with just the MEFI4 that AS&M sells with the intake kit. We have been working with these engines for almost two years now and our manifold will be out in late April, but we know that a manifold alone, without our heads and our new cams is not going to make 100hp alone with ECM changes. If I were you I would call AS&M, ask for Jim the owner, let him know you findings and ask for his help. I spent some time with him in Miami and he seems like a real straight shooter. I think he will probably work with you and try to get closer to what you are looking for if you approach him nicely. Hope everything works out for you. If I can be of any help contact me toll free @ 866-496-8181 or e-mail me at [email protected]
Raylar
I have always been a little concerned about the claims for this manifold. Considering the problems with the heads on the 496's and the stock exhaust manifolds I don't think 100hp is possible with just the MEFI4 that AS&M sells with the intake kit. We have been working with these engines for almost two years now and our manifold will be out in late April, but we know that a manifold alone, without our heads and our new cams is not going to make 100hp alone with ECM changes. If I were you I would call AS&M, ask for Jim the owner, let him know you findings and ask for his help. I spent some time with him in Miami and he seems like a real straight shooter. I think he will probably work with you and try to get closer to what you are looking for if you approach him nicely. Hope everything works out for you. If I can be of any help contact me toll free @ 866-496-8181 or e-mail me at [email protected]
Raylar
03-05-2004, 10:38 PM
#12
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Tomcat
Those were GPS speeds and I agree with you that seems like quite a bit of prop slip. I've tried a number of different props on this boat and for some reason they all seem to have quite a bit of slip. I'm working with Darin at Houston prop on this right now but he said that he doesn't place much value on the slip value. He tried to explain to me why and I did not fully understand his explanation (probably due to my lack knowledge). The rev limter with the MEFI4 ecu is now set at 5400 rpm so I shouldn't have been close to the limiter.
Raylar
I did speak with Jim and the only advice that he could offer me was to remove the plates between the exhaust manifolds and risers as he thought that the exhaust might be restrictive.(I still have stock exhaust)
He reiterated that they were still dynoing these engines at close to 100 hp increases with this kit. I'm sure that removing these plates might help some but how much? Any ideas?
Any help with my prop slip issue would be appreciated as well. Bravo 1 drive 1:1.5 ratio. Previous owner installed an Imco lower unit with nosecone and appears to have 1-2" longer shaft than stock. I do not know how the lower unit affected performance after installed.
Thank you all.
Those were GPS speeds and I agree with you that seems like quite a bit of prop slip. I've tried a number of different props on this boat and for some reason they all seem to have quite a bit of slip. I'm working with Darin at Houston prop on this right now but he said that he doesn't place much value on the slip value. He tried to explain to me why and I did not fully understand his explanation (probably due to my lack knowledge). The rev limter with the MEFI4 ecu is now set at 5400 rpm so I shouldn't have been close to the limiter.
Raylar
I did speak with Jim and the only advice that he could offer me was to remove the plates between the exhaust manifolds and risers as he thought that the exhaust might be restrictive.(I still have stock exhaust)
He reiterated that they were still dynoing these engines at close to 100 hp increases with this kit. I'm sure that removing these plates might help some but how much? Any ideas?
Any help with my prop slip issue would be appreciated as well. Bravo 1 drive 1:1.5 ratio. Previous owner installed an Imco lower unit with nosecone and appears to have 1-2" longer shaft than stock. I do not know how the lower unit affected performance after installed.
Thank you all.
03-06-2004, 06:26 AM
#13
Again you dwell on HP. Sure it might have a 100HP gain but only a 30lb-ft TQ gain and hence the 3 mph gain.
Think TQ not HP.
Add a blower and gain 100 lb-ft TQ and gain 10mph.
Think TQ not HP.
Add a blower and gain 100 lb-ft TQ and gain 10mph.
03-07-2004, 11:22 AM
#15
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Posts: n/a
496 Mag
375 hp @ 4600 rpm
490 lb-ft @ 3200 rpm
http://www.gm.com/automotive/gmpower...d_brochure.pdf
496 HO
425 hp @ 5000 rpm
505 lb-ft @ 4000 rpm
http://www.gm.com/automotive/gmpower...p_brochure.pdf
375 hp @ 4600 rpm
490 lb-ft @ 3200 rpm
http://www.gm.com/automotive/gmpower...d_brochure.pdf
496 HO
425 hp @ 5000 rpm
505 lb-ft @ 4000 rpm
http://www.gm.com/automotive/gmpower...p_brochure.pdf
03-07-2004, 01:52 PM
#16
WOW! How about that, hit it on the nail- 30lb-ft TQ increase, 505 to 535! BINGO!
The 100HP increase was probably at 5400rpm where the stock was running out of steam and was only making 350HP and the ASM was making 450HP and so they can say +100HP increase but that doesn't mean 100HP peak increase.
that is why you need to see the dyno graphs and not relay on hype.
The 100HP increase was probably at 5400rpm where the stock was running out of steam and was only making 350HP and the ASM was making 450HP and so they can say +100HP increase but that doesn't mean 100HP peak increase.
that is why you need to see the dyno graphs and not relay on hype.
