manifold - power increase?

1st May 2007, 16:15

getting a 4-2-1 manifold eventually pending replies. on a mk1 vtr, standard spec but with open filter induction kit, how many bhp am i realistically looking to go up by if any?

cheers

1st May 2007, 16:50

1 or 2 i would say, car will rev more freeley though

mine didnt make any difference i dont think, still running standard zorst system at the moment though, got backbox to go on just need to save for centre section and thats me sorted!

1st May 2007, 16:51

hardly anything mate! ud probably see more of an increase with a ful exhaust over just fitting a manifold

1st May 2007, 16:58

Ud need to get a full system to get the full potential.

If your cat is in the manifold you'll get a noise increase but coupled with a full system you'll get a power increase.

How much BHP im not sure, ask Kam racing as he will be able to give you the best advice.

1st May 2007, 17:03

rep given were due, cheers for advice

1st May 2007, 17:12

You can get good gains from a 4 branch, only if combined with a full exhaust system.. more than 2 bhp. Look at how restrictive a standard one is compared to an aftermarket one..

1st May 2007, 17:16

The standard vtr exhaust system and manifold are nothing short of crap. The full system with manifold etc... will probably see not to bad a gain, how long is a piece of string though

1st May 2007, 17:42

With a full exhaust system and manifold you could see atleast a 5bhp gain i rekon.

Look at how much more gas will be getting out.. Afterall thats how you improve an engines performance and BHP by getting more air in and burnt fuel gasses out..

2nd May 2007, 09:42

can a raceland 4-2-1 fit a 1.1? cheers

2nd May 2007, 10:12

Quote:

Originally Posted by saxophone

can a raceland 4-2-1 fit a 1.1? cheers

different port spacing irc.

wouldnt waste money on a turtle anyway tbh

2nd May 2007, 10:14

I gained 10bhp by fitting,

GMC 4-1 manifold
BMC induction
Magnex full system

2nd May 2007, 10:17

Quote:

Originally Posted by Cloud

I gained 10bhp by fitting,

GMC 4-1 manifold
BMC induction
Magnex full system

unless it was run on the same rolling road, on the same day with the same ambient temp youll never know if thats true.

2nd May 2007, 10:46

Quote:

Originally Posted by andymanc

getting a 4-2-1 manifold eventually pending replies. on a mk1 vtr, standard spec but with open filter induction kit, how many bhp am i realistically looking to go up by if any?

cheers

a 4-2-1 should make more difference on a standard system, than a standard manifold on a full system. and the biggest gains are with changing the lot

2nd May 2007, 10:47

i would go for a supersprit 4-2-1. all there stuff has proven power gains

2nd May 2007, 11:07

Quote:

Originally Posted by Itsafastworld85

unless it was run on the same rolling road, on the same day with the same ambient temp youll never know if thats true.

What are you trying to say?

2nd May 2007, 11:12

if your only guna change one bit at a time change the manifold first

2nd May 2007, 11:17

Quote:

Originally Posted by andyvts98

i would go for a supersprit 4-2-1. all there stuff has proven power gains

they are better made than the racelands for sure and you pay double the price for the privilage.
The Raceland has also got proven power gains throughout the whole rev range also.

2nd May 2007, 11:20

yea i can't say what the raceland ones are like coz i haven't tryed them.

2nd May 2007, 11:27

i have a raceland and they are built nicely, bit of a twat to fot apparently.. I noticed plenty of gains with mine

2nd May 2007, 11:31

Quote:

Originally Posted by James_Bristol

i have a raceland and they are built nicely, bit of a twat to fot apparently.. I noticed plenty of gains with mine

I think most aftermarket manifolds are a bitch to fit, takes about 15 minutes to get standard off or on. Took me a good 1-2 hours to get the GMC on or off. You can't physically reach all the nut's propelly

2nd May 2007, 11:47

Yeah exactly cloud! The bloke who did mine, because i'm a fairy, i wasn't going to do it, lol. He is a custom exhaust maker and fitter and he struggled a bit, said the bolts were a bastard and looking at it now i dont know how he did it!! lol.

2nd May 2007, 11:56

same. can you lift the raceland ones up from the bottom? or down from the top?

2nd May 2007, 12:32

have no idea boss. lol

2nd May 2007, 12:49

Quote:

Originally Posted by James_Bristol

Yeah exactly cloud! The bloke who did mine, because i'm a fairy, i wasn't going to do it, lol. He is a custom exhaust maker and fitter and he struggled a bit, said the bolts were a bastard and looking at it now i dont know how he did it!! lol.

I came to the point were i started getting very mad, so i asked my grandad what to do. He got a spanner, put it in a vice and bent it at an angle so i could get at them all

2nd May 2007, 12:55

Good work!! lol.

Like i said i look at it and think, how the f*** did that go on! lol.

2nd May 2007, 13:26

Quote:

Originally Posted by andyvts98

same. can you lift the raceland ones up from the bottom? or down from the top?

from underneath unless you pull off the radiator etc..

3rd May 2007, 15:25

im going to get my raceland soon, what you think it will do with a de-cat and full ashley exhaust

4th May 2007, 01:22

they are pritty simple to fit once you have done a few, there is a nack to doing it

the nuts can be a twat to get to, you just need to be patient

cloud, you grandad had the right idea with bending the spanner, ratchet spanners are a good bet too

if anyone gets a new manifold, get a new exhaust gasket and new manifold nuts (studs too if they are in poor nick), you will also need a new set of bolts,springs,caps,nuts and gasket for the rear section of the manifold where it joins to the cat pipe. you may find that the old studs will unscrew from the headw hen loosening the nut, dont worry. take them out then clamp the middle part of the stud with mole grips or a vice. wd40 on the nut and wire brush the stud and around the nut. loosen the nut.
to re-fit, use 2 old nuts that run freely down the stud, put both nuts on the stud and lock them together using 2 spanners in oposing directions, then tighten the stud into the head using a spanner on the 1st nut (clockwise direction) ensure that the stud is tight. remove the 2 nuts by placing 2 spanners on the nuts, 1 spanner needs to go anticlockwise second spanner needs to stay still

then remove the 2nd nut. once the studs are back in place, fit the manifold and the new nuts

jobs a good un !

you will defo see a better gain with a manifold, de-cat and full system along with a decent filter.

4th May 2007, 10:29

Quote:

Originally Posted by boz

you will defo see a better gain with a manifold, de-cat and full system along with a decent filter.

Ive got a fairly wank filter but where i positioned it hopefully makes up for that. i got an ali tube that runs from the throttle body rown past the rad to the grille