Magnus of Forrester Manifod?

[nolv4v8]

I'm in the market for an intake manifold and I narrowed it down to these two. I have searched, but no one has ever done a straight comparison so I want to hear everyones opinions. Here are my mods:
98 GSX
7 Bolt bottom end(until spring)
1G head(fresh rebuild, mild port/polish)
HKS 272/272 Cams
SBR GT13
Dejon Race FMIC
...And everything else to support the above.
Any advice/info is appreciated. Thanks. Also if anyone has any before/after dyno numbers let me know.

 

[Groomz]

From the dyno numbers on the Magnus and the good quality of it I would say go for the magnus. It looks better and is dyno proven for more horsepower.
www.magnusmotorsports.com
50+hp isn't bad for 500$.

 

[kilurv8]

Both manifolds have their advantages. The Magnus weighs less because it is sheet metal but the forrester is cast and is much stronger. The forrester also comes pre tapped for NOS and you can drill and tap anywhere on the manifold for vacume fittings, Intake temperature sensors or anything else you would want.

Magnus has gone 9s on his 2.4 liter race car and AMS has gone 9s in their 2.0 liter evo 2. So you know both are more than capable for any power you would like to make.

Both have dynoed great gains and there are many testimonials from each. I have the forrester and am extremly happy with it. The phonlic spacer is a benefit for the forrester as it keeps the intake manifold cooler thus the intake charge is cooler. By how much I dont know. I also like the fact that the forrester has radiused entries into each runner and is also designed like a velocity stack. If you do some searching, there are horsepower gains in a thread out there for the forrester but I can't remember off the top of my head. I know that there were significant gains on a 16G and tremendous gains on a much larger turbo without the loss of mid range power.

As you can see I am biased to the FRH but both are good manifolds. Personally, I feel that the FRH is a better deal and has more features for the price but that is just me. Take it as you wish.

 

[DSMSpyder99]

you cant go wrong with either both have been proven

 

[98TsiAWD]

I think Im gonna buy an FRH manifold. I like the fact I can tap into it for anything I need, and the phenolic spacer is a big plus. The weight sucks tho

 

[bigfoot]

One more consideration, the Magnus is the flashy manifold. And thats why I prefer the Forrester, it's stock looking. The DEQ smog nazis look your car over real good around here.

 

[DSMJim]

Just for information the Magnus manifold has radius (velocity stack) style entries into each runner as well.

 

[Groomz]

Either manifold is golden compared to stock intake manifolds, so you aren't getting a worse product with either aftermarket manifold. Although the Magnus is very new to the market, I haven't read a bad review of it , so I would recommend it also. I like its bling shinyness also, so I'm a little biased. Plus in Texas, they don't even pop the hood for inspections.

 

[hostile]

What about the install, which one is easier to just bolt on and run... Do both of these manifolds have the throttle body in the stock position? If not were you able to get the wires to reach the stock throttle body?

 

[FastRthenU]

I installed a magnus one on a buddies car. Lets put it this way
A fair bit of work, and not much fun

 

[hostile]

Yeah were going to install a BJ intake on my buddys car, it is definantly not a bolt on either.

The forrester looks pretty close to stock when it ins installed, if the TB is in the same place it would probably be pretty simple.

 

[jdmawd]

Originally posted by FastRthenU
I installed a magnus one on a buddies car. Lets put it this way
A fair bit of work, and not much fun

no joke but its worth it. I personally would not want to do it again with a motor thats in a car.

 

[DSMJim]

yeah thanks dsmawd. im about 60% of the way through my Magnus install right now and i'm crying thinking about going home and finishing it up...

 

[talonted_one]

I heard a nasty rumor that the magnus manifold only flows 2% more air than the stocker. Does anyone have first hand knowledge on this?

 

[DSMJim]

Originally posted by talonted_one
I heard a nasty rumor that the magnus manifold only flows 2% more air than the stocker. Does anyone have first hand knowledge on this?

I just don't see how that could be true. Looking at the stock intake manifold and the way it's designed I just can't see it. Here are some pics I took of the two together.

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I'm not air flow expert but which one looks like it can flow more air and has the least restrictive path to the motor? Remember the whole point of the intake manifold is for a larger plentum and shorter runners which make all the HP up top. A small plentun long runner manifold is for low down torque. They designed the stocker this way to give the car more torque before the turbo came on to help eliminate people's feelings of turbo lag which was alwasy advertised by other manufacturers as a bad thing. I may agree that the magnus manifold doens't flow more air at 3000rpm but I doulbt that is true at 5500-8000rpm which is where we all want the power anyways.

Do I care that I "might" have lost some torque between 3000-5500? Not really, I have my two step set at 5750rpm and launch there so why would I care? When I'm racing on the highway I always downshift so im higher in a band then that, so I hardly worry about it there either...

Just my 2cents...

 

[DSMJim]

Also incase anybody cares I thought I would throw this in this thread as well. I changed to a 1G throttle body when doing my intake manifold. Here is a pic of the two together so you can exactly how much difference there is.. 52mm vs 60mm.. In person its much worse looking then this picture...

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[talonted_one]

does anyone have any flow numbers on these manifolds?

 

[DSMJim]

I just found this write up on the Forester manifold on the net..

http://www.jakelatham.com/1gDSM/projects/forrester_manifold/index.shtml

Check out what he says at the end:

Results & Impressions
The short version: It wasn't the right mod for me. The manifold made great power up top. From 5K to 8.5K, the top-end was great, even better with what I already had with my L1R. On boost, I couldn't detect any noticable changes or losses even down low in the midrange, 3500-5,500.

So what didn't I like? Two things: First, off-boost performance took an enormous hit. Below 3,500 RPM, when not on full boost, the car felt awful, like it could barely pull itself around. Second, transient boost response took a big hit too. After spending all the money on a good-responding ball-bearing turbo, I lost most of that benefit with the Forrester's large plenum.

So, while the dyno graphs seem to be accurate in absolute power output, it appears they don't tell the whole story of non-full throttle and transient driving characteristics. If I had kept the car longer, I would have removed the manifold, since it was that unenjoyable (for me) to drive on the street.

When drag racing, the manifold was a great piece. But, for the on-off type of racing of road racing, autocrossing, and especially street driving, IMO, the manifold was a poor choice. If you are looking for good low-end torque, try a Cyclone, which probably would have been my next move, or perhaps the Magnus intake, which is having good results.

 

[jdmawd]

After spending all the money on a good-responding ball-bearing turbo, I lost most of that benefit with the Forrester's large plenum.

This is why the magnus has a tapered plenum. My spool up and transient response was unaffected when I introduced the intake to my setup. I also did not notice any change in off boost drivability.

 

[44pirate]

Originally posted by jdmawd


This is why the magnus has a tapered plenum. My spool up and transient response was unaffected when I introduced the intake to my setup. I also did not notice any change in off boost drivability.

What setup were you running when you introduced the Magnus.
You have changed your setup a few times.
I just bought one and all my couch racers here are telling me I will loose a lot of low end torque.

 

[jdmawd]

Originally posted by 44pirate


What setup were you running when you introduced the Magnus.
You have changed your setup a few times.
I just bought one and all my couch racers here are telling me I will loose a lot of low end torque.

I was running the PTE 50 trim thats the only thing different. Ask your couch racers how much low end they lost when they installed the magnus on there cars

 

[44pirate]

Originally posted by jdmawd


I was running the PTE 50 trim thats the only thing different. Ask your couch racers how much low end they lost when they installed the magnus on there cars

My Talon is my daily driver and I also have the 50trim. Do you recommend the manifold for daily driving.

 

[greathuskie]

i dont see why taht guy would buy a FRH intake mani for autocrossing..or any IM for that matter?

 

[jdmawd]

Originally posted by 44pirate


My Talon is my daily driver and I also have the 50trim. Do you recommend the manifold for daily driving.

Granted I don't drive my bird daily. However the car has no drivability issues. I live in a very urban area with list of stop and go traffic and very steep hills for example.

 

[44pirate]

I guess I'll just bolt the thing up and give it a whirl and let you all know how it goes. THnaks JDMAWD