best 16v manifold for 150/160bhp

1. user_4681 Saxperience Post Whore Joined: Dec 2004 Grimsby United Kingdom (England) Posts: 5489 SUPERCHARGED saxo vts

   #1 22nd February 2010, 18:00

   im building up a new 16v engine for my track car. it does get used on the road too so it cant sit too low.
   
   id like to buy a new stainless 4-1 manifold not a raceland please. i want 4-1 as its best for high end power on the vts
   
   i am considering the GMC manifold but will this be too free flowing on a set of newman p3 cams and standard inlet?
   
   i have seen others janspeed (steel and sit too low), raceland not keen at all, miltek are 4-2-1 and theres supersprint but unsure 4-1 or not??
   
   cheers
   stew
2. raunchz Saxperience Addict Joined: Jul 2005 Solihull / Bournemouth Posts: 14233 2015 Lapiz Blue Golf R

   #2 22nd February 2010, 18:04

   All 4-1's tend to sit reasonably low due to the 4 pipes coming around and under the sump.
   
   I'm running a Piper 4-1 and it seems to be fine clearance wise (I'm lowered roughly 30mm)
   
   The GMC won't be too free-flowing for cams and standard inlet !! The benefit too is that it should future proof you.
3. Sophia_Bush Saxperience Post Whore Joined: Jan 2007 Shropshire Posts: 9994 Moonstone Blue 106 GTi

   #3 22nd February 2010, 18:06

   that miltek one you got stu will do the job fine, my old cammed gti made 148bhp through it so pretty close to what you want
4. Ryanp Super Moderator Joined: Feb 2004 Tonbridge United Kingdom (England) Posts: 38236 Vtr, 172, throttle bodied track slut

   #4 22nd February 2010, 18:09

   the pugsport manifold that I have which is designed for over 200bhp and power at very high rpm is a 4-2-1.
   
   I personally wouldnt be to hung up on 4-1, vs 4-2-1.
5. user_4681 Saxperience Post Whore Joined: Dec 2004 Grimsby United Kingdom (England) Posts: 5489 SUPERCHARGED saxo vts

   #5 22nd February 2010, 18:21

   some interesting replys. i sold that miltek for £200.
   
   i do want stainless and later on this year i will want ITB's.
   
   i wanted to call GMC today but think they shut at 5? i also want one of the ATB's but want it now...
6. yr51ocw Frequent Poster Joined: Oct 2005 Posts: 751

   #6 22nd February 2010, 18:57

   at only 150/160 bhp, it would be surprised if any of the manifold on the market would be a restriction. If that is the target, i wouldnt get hung up on 421 vs 41 design, and go for the one that will provide most cost effective
7. user_4681 Saxperience Post Whore Joined: Dec 2004 Grimsby United Kingdom (England) Posts: 5489 SUPERCHARGED saxo vts

   #7 22nd February 2010, 19:18

   is that taking into consideration that I will be having ITBs later this year.
   
   on newmans P3/708 that will equate to 165bhp?
8. 3cott Saxperience Forum Bum Joined: Mar 2008 Rotherham Posts: 4614 Black mk2 vts

   #8 22nd February 2010, 19:53

   Supersprint?
9. user_10176 Saxperience Post Whore Joined: Jun 2006 Ramsey st marys, peterborough Posts: 8288 Saxo's, Corsa (Daily)

   #9 22nd February 2010, 19:58

   well i am using a racland mani with no porblems with ph3 and bodies and running 160 bhp on the northampton motor sport rollers
   
   andy
10. JamesRm Forum Section Moderator Joined: Aug 2008 Liverpool Posts: 15517 Saxo VTR

    #10 22nd February 2010, 20:28

    tbh i would still get a 4-2-1 for the extra power lower down.
11. user_15516 Saxperience Post Whore Joined: Apr 2007 Posts: 6640 Integra DC5R & VTS

    #11 22nd February 2010, 20:29

    Raceland is fine for 185ish bhp IIRC?
12. user_10176 Saxperience Post Whore Joined: Jun 2006 Ramsey st marys, peterborough Posts: 8288 Saxo's, Corsa (Daily)

    #12 22nd February 2010, 20:37

    yer mine is the 4-2-1, and they are not too bad, biggest problem with them is fitting!
    
    andy
13. scot-ish Established Member Joined: Apr 2009 just aroon the corner Posts: 1509 Audi S5, Corsa, Defender 90 CSW

    #13 22nd February 2010, 20:53

    piper. its the best one ive had.
14. user_4681 Saxperience Post Whore Joined: Dec 2004 Grimsby United Kingdom (England) Posts: 5489 SUPERCHARGED saxo vts

    #14 22nd February 2010, 21:01

    whats the standard one rated at and is it that bad?
15. user_15516 Saxperience Post Whore Joined: Apr 2007 Posts: 6640 Integra DC5R & VTS

    #15 22nd February 2010, 21:02

    Quote:

    Originally Posted by sexy_gt whats the standard one rated at and is it that bad?

    I don't think it's massively restrictive, but it's cast iron so weighs a ton. Raceland is a nice addition for the money imo - mine went on no problem... no cutting down studs etc.
16. Olly Saxperience Forum Bum Joined: Dec 2008 Meerkat Harborough Posts: 2638 Saxo vtr mk 2

    #16 22nd February 2010, 21:45

    Think im going to cheap it up and get a raceland tbh! 180hp hopefully
17. Ryanp Super Moderator Joined: Feb 2004 Tonbridge United Kingdom (England) Posts: 38236 Vtr, 172, throttle bodied track slut

    #17 22nd February 2010, 21:49

    I honestly dont see an issue with running a raceland.
    
    DaveP got some fantastic results next to a 4-1 on the rollers, hence why everyone started buying them
18. Rich84 Established Member Joined: Jun 2006 Liverpool Posts: 1163 16v ax V6 vag

    #18 22nd February 2010, 21:52

    one of the lads done back to back runs with a BTB mani and a supersprint on the rollers a couple of years ago,
    
    
    supersprint gave better gains, that was with just breathing mods
    
    but as ryan said, there's nothing wrong with a copy of a good maniflod i.e raceland
19. KamRacing Saxperience Addict Joined: Nov 2006 A farm shed in Aylesbury Posts: 14916 Corolla AE86 Peugeot 205 B18C (in bits)

    #19 22nd February 2010, 21:59

    the raceland is more a copy of the janspeed rather than the supersprint. Despite the poor QC (they have been a little better recently in fairness) the raceland has been seen to cope fine with cars up to 180 brake
    
    If money is more readily available and you turn your attension to the supersprint / piper options the biggest difference is the quality of materials used.. and more notably in the supersprint the perfect welds and bends
20. Rich84 Established Member Joined: Jun 2006 Liverpool Posts: 1163 16v ax V6 vag

    #20 22nd February 2010, 22:01

    Quote:

    Originally Posted by KamRacing the raceland is more a copy of the janspeed rather than the supersprint. Despite the poor QC (they have been a little better recently in fairness) the raceland has been seen to cope fine with cars up to 180 brake If money is more readily available and you turn your attension to the supersprint / piper options the biggest difference is the quality of materials used.. and more notably in the supersprint the perfect welds and bends

    i stand corrected
21. saxo_ron Saxperience Forum Bum Joined: Jun 2007 Newcastle Upon Tyne Posts: 3017 Honda DC5, Gruppe M and j's racing

    #21 23rd February 2010, 08:38

    Was it qep that did the testing of manifolds for georgeL's engine and found the raceland only became restrictive at 202bhp? SSC a few year back that was
22. rushy_23 Saxperience Hardcore! Joined: Aug 2004 West Mids Posts: 15392 '98 EK9 N1

    #22 23rd February 2010, 09:13

    My only gripe with the Supersprint 421 is that it being a two peice deisgn, you often get slight blowing!
    
    Still need mine welding up.
23. Ryanp Super Moderator Joined: Feb 2004 Tonbridge United Kingdom (England) Posts: 38236 Vtr, 172, throttle bodied track slut

    #23 23rd February 2010, 14:18

    Quote:

    Originally Posted by rushy_23 My only gripe with the Supersprint 421 is that it being a two peice deisgn, you often get slight blowing! Still need mine welding up.

    my manifold 3 piece and is blowing lol. I to need it welding up
24. axsaxoman Saxperience Forum Bum Joined: Jan 2003 Scotland Posts: 3380

    #24 23rd February 2010, 15:46

    180 is absolute limit on a racleand ,so if that is your target --it would not be your best choice .
    the manifold is only part of the ex system .so unless you look at ALL the harmonics associated with the ex side of the engine ,in relation to cam spec and inlet length you will never get perfection.
    the only reason the works rally car use a very long 4-2-1 was space and an attempt to get round the "black hole" in the map at around 5k(caused by wild cam duration).
    i DON,T WANT TO START THE SAME OLD DEBATE ABOUT 4-2-1 VERUS 4-1 AGAIN .
    its been done to death and no actual back to back was ever done --as no one would spend the money on remapping each time they swopped manifolds from one make to another.
    If you look about you will see std cars with 4-1 manifolds --so they can,t be that bad for torque + mild cams
    the best impartial advice i can give you is buy a book -- and read about harmonics .
    "4stoke performance tuning " --a haynes book -- shouldn,t be too heavy ,but read ALL of it including effect of cam profile + inlet etc.
    all the forumlae are there for working out primary size + length ,where the collector should be + where the first box should be
25. raunchz Saxperience Addict Joined: Jul 2005 Solihull / Bournemouth Posts: 14233 2015 Lapiz Blue Golf R

    #25 23rd February 2010, 16:13

    Quote:

    Originally Posted by axsaxoman 180 is absolute limit on a racleand ,so if that is your target --it would not be your best choice . the manifold is only part of the ex system .so unless you look at ALL the harmonics associated with the ex side of the engine ,in relation to cam spec and inlet length you will never get perfection. the only reason the works rally car use a very long 4-2-1 was space and an attempt to get round the "black hole" in the map at around 5k(caused by wild cam duration). i DON,T WANT TO START THE SAME OLD DEBATE ABOUT 4-2-1 VERUS 4-1 AGAIN . its been done to death and no actual back to back was ever done --as no one would spend the money on remapping each time they swopped manifolds from one make to another. If you look about you will see std cars with 4-1 manifolds --so they can,t be that bad for torque + mild cams the best impartial advice i can give you is buy a book -- and read about harmonics . "4stoke performance tuning " --a haynes book -- shouldn,t be too heavy ,but read ALL of it including effect of cam profile + inlet etc. all the forumlae are there for working out primary size + length ,where the collector should be + where the first box should be

    Spot on book by G.Bell - love reading it and learning about it all ! Well worth buying !
26. yr51ocw Frequent Poster Joined: Oct 2005 Posts: 751

    #26 23rd February 2010, 16:16

    its very very simplistic and doesnt take into account all of the parameters that affect the exhaust geometry.
    
    i would suggest this for a little more indepth (yet far from perfect) reading
    
    http://www.amazon.co.uk/Scientific-E.../dp/0837603099