Frankspeed modified manifold vs 421 manifold.

[Mattl]

I know the 421 manifold is the more desirable of the two, but whats the difference in performance? And is the difference worth the cost/hassle?

Thanks in advance, Matt

 

[frank]

i had 1 dyno,d before and after matt, and it showed 6hp difference (i had other mods at the time) the downpipe is also pretty restrictive, so you would get more benefit from the mani if you fit a lloyd system with it

 

[skymera]

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I know the 421 manifold is the more desirable of the two, but whats the difference in performance? And is the difference worth the cost/hassle?

Thanks in advance, Matt

I think the upside to Frankspeed manifold is that you can still have the standard cat. With a 4-2-1, you lose the cat and it can be a major faf at MOT swapping it all over.

i had 1 dyno,d before and after matt, and it showed 6hp difference (i had other mods at the time) the downpipe is also pretty restrictive, so you would get more benefit from the mani if you fit a lloyd system with it

6? That's pretty impressive. To be honest, I expected zilch or 1-2.
What other mods were you running? :

 

[frank]

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What other mods were you running? :

this was back in 08 iirc probably a bigger downpipe/2nd decat and induction kit, and i think i was running the piper cams by then.
where the stock primaries go 4 into 2, the port is a lot smaller than the headports (and that restriction has to flow 2 cyls eh)

 

[reflexuk]

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I think the upside to Frankspeed manifold is that you can still have the standard cat. With a 4-2-1, you lose the cat and it can be a major faf at MOT swapping it all over.

I'll 2nd that. I passed mot with Frankspeed manifold, primary cat and 2nd decat.

 

[AJC]

Mine passed the MOT with a frankspeed fitted with a non coilpack cat with a lloyd system, give (me, anyway) a bit more poke at the top of the rev range, but that may just be my engine type

 

[Mattl]

Not too worried bout MOT as engine is going into a classic mini. Was just wondering if its worth fabricating a tubular Mani. Sound like the answer is yes.

Sent from my GT-I9100 using Tapatalk 2

 

[Mattl]

Gonna be attempting it this weekend. Thanks for the replies all