1G extrude honed intake vs SMIM??

[fastfive0]

ok I have a 1g intake manifold extrude honed from FFWD that came with my 2.3longblock. My question is will I see substantial gains (ie 35+hp) by switching to a JMF race/drag or a Magnus SMIM? $550+ for intake is not worth it to me if its only 10-15hp. It is worth it for 35+hp! I need real world experience here! Mods are in my profile

 

[untouchablecc]

I may be a bet off here but im trying to be as accurate as possible. I was reading dyno sheets an i cant remember if it was on here or on another site. The dyno was a evo with 16 turbo back exhaust an that was it. The torque on the curve went at 65 degree angle to about 2500 rpm an then flatlined across the chart an then the peak hp came in around 6500 rpm.

With the magnus intake it changed the whole torque curve to one long upward sloping line as with the hp curve an made them identical. I think the large runners drop to much torque an turn this engine into a honda motor that is all top end. Just my 2 cents. If you want full race car an every inch you can get out of it you can to make peak hp go for it. If you like your bottom end i wouldnt get it.

I had one, it was pretty an loved the bling aspect but shep went 11s with a stock intake mani so good enough for me. I took it off an sold it an dont regret it i have much more lower end power.

 

[habitatguy187]

I think the large runners drop to much torque an turn this engine into a honda motor that is all top end.

Wonder how much this would affect him though since he has a stroker

 

[talonDSMerr]

FFWD claims they tested their extrude honed manifold to a competitor's sheet metal version, with one-sided results. I also know low end torque is helped by the longer runners of the 1g manifold compared to the short runners of sheet metals.

 

[untouchablecc]

Very good point. For that kinda money though i wonder if he can pick up another 35 hp elsewhere. I think knowing what your goal is would be the first move an if getting every bit out of the engine is what you want then get it.

 

[e85_4g63]

The gains you'll see are going to be based more so on your turbo choice. It's kind of up in the air because you have an HX40, but I think your on the Mitsu hotside based on the FP mani in your profile, which would hurt flow up top where a SMIM would really shine. Not to mention the 264 cam isn't helping things up there either. I'd say you'll def. see some gains, how much exactly depends on your tune, boost level, etc. Based on your profile, I'd say get DSMLink or some other engine management over doing a SMIM at this point.

 

[toofast82]

Your'e running a Holset Hx40 with 264/272 so i would think you would benefit quite a bit as far as hp is concerned above 6,000rpm. I read a recent thread where a guy gained 50hp+ with one of the new style smim over a major vendor smim from a few years back. Here's another thread with a mild and wild setup
http://www.dsmtuners.com/forums/bol...-performance-sheet-metal-intake-manifold.html

 

[talonDSMerr]

Keep in mind that a lot of comparisons involving sheet metal intake manifolds and horsepower increases are done comparing them to the cast stock intake manifold, with it's rough internal surfaces. How much better does extrude honing make it?

 

[JEFFREYCASTGSX]

I think some little power is to be gained, due to the shorter runners.

 

[toofast82]

I think some little power is to be gained, due to the shorter runners.

plus the larger and better designed plenums with velocity stacks. A friend of mine installed a Forrester intake on a FpRed car, and there were big gains up top! Unfortunately I don't have any dyno sheets to back this up

 

[crimsondragon]

IMO, if you run an HX40 on a 2.3 stroker, I personally think going with a JMF would be great. It all depends on your setup though. I like to be an all around guy and spread my power out evenly with a bit more power up top for a street/strip car. That's why I bought a used JMF. If I don't like it, I didn't lose much on it. Also it is my belief that if you're running anything that gives lots of low end like an E3 16g, I'd invest in something that'll put that power more towards the middle. 272/272 cams would do just that. But that's just my style. Take it with a grain of salt.

 

[turboglenn]

Didn't see this corrected... Longer runners equall more torque...take the 5.0 mustang, tons of torque is what made it feel fast, but it 22 inches of runner length to make that car have sucha broad power band and this is the same reason it fell so flat on top and why the gt 40 intake dropped low end and gained top end...bigger plenum and shorter runners..

rule of thumb short runners are for top end screaming, long runners are for street style torqe... Hell even our stockers drop down and then wrap back upwards to make the best torque it can while fitting in it's confined space

 

[Black_Bullet]

Hawver Motorsports Inc.

Heres a dyno sheet off Hawver's site. They make intake manifolds out here in Fl.
This is on a 16g setup coming from a stocker and the Hawvers results were impressive imo.
Though this is a cast mani, my point is smim can have worthy gains on even small turbo cars, and your running a hx40 and stroker so the results would be even bigger for you.

 

[RipperXX]

Personally I wont go with a SMIM, I will either go with a Hawver manifold or honed stocker. I have seen the inside of extrude honed stock manifolds and it's pertty darn smooth, add to that I would guess the runners are likely a mm or two wider after the process. So theres a good bit of airflow picked up without losing any bottom end. It depends on what your goals are though.



If you want more power pulling out of the corners, keep what got or go to the Hawver. IMO your best gain might be from getting a set of FP cams meant for a stroker engine.

 

[pur97tsifwd]

FP green. Stock cams. Stock intake (blue) VS Extrude honed (red) back-to-back dynos

ABEL Racing
Under tech info

 

[Calan]

Does anyone know of a company that will extrude hone your stock manifold? Or what kind of $$$ we're talking?

I'm thinking about doing this on my new stroker. My runners are so rough...it's just hard to even look at them

My only concern is if it can screw up the airflow balance between cylinders. From what I understand, the process acts like any fluid; it takes the path of least resistance, and would therefore allow the runners to potentially be uneven. Also, what does it do to thin corners and casting flaws?

Edit:

I see the BHP will do it...for only $600 or so. OUCH

Looks like I'll learn to live with my rough IM

 

[Boosted98gsx]

Extrude Hone vs SMIM? There is no contest or comparison. A properly designed and built SMIM will beat an extrude honed manifold against the wall (in larger turbo applications).

 

[RipperXX]

There for two different use's IMO.