equal length vs log manifold

[jimmeh]

hey guys i know there was a thread about the difference between the log and equal length manifolds. i came across a video that compares the two. enjoy
to view a video of the comparison click here (http://www.panekmechanik.com/Videos/FR%20Manifold%20Test.wmv)

[LowEk]

yeh the manifold can make or brake the way the car makes power. if its equal length try to make sure that all the runners on the manifold have a clear shot up or down to the turbo so they all preform the same i.e all have the same shot to the turbo.

[saxman]

someone go pick up a copy of corky bell's maximum boost, and learn a bit about manifold design.

full race isn't bad... definetely one of the better manifold manufactures among the consumer market producers of manifolds, etc... but the designs are far from ideal. There's a certain amount of settling that has to be done for space restrictions/reasonable prices for production, etc that go into it.

I'd be looking into the designs of the 80's f1 cars when turbos were still legal to see what an exhaust manifold really should look like.

[LowEk]

well show us a pic of what you think is a better design that works very well anyone?? im not in any way saying full-race manifold are the best.

[jimmeh]

CRP
http://i2.photobucket.com/albums/y38/Reaction360/B18C%20Beast/rofypics007.jpg
http://i2.photobucket.com/albums/y38/Reaction360/B18C%20Beast/rofypics008.jpg

A random manifold
http://i39.photobucket.com/albums/e174/mycrx/manifold.jpg

Full race
http://img119.imageshack.us/img119/1664/dscn15264dg.jpg
http://img151.imageshack.us/img151/8297/dscn15244zh.jpg

http://img151.imageshack.us/img151/4483/dscn15232rn.jpg

Spoolin Performance
http://img354.imageshack.us/img354/8333/p10005572vw.jpg
http://img354.imageshack.us/img354/502/p10005581kp.jpg

neukin
http://www.neukin.com/images/mani/dscn0643.jpg
http://www.neukin.com/images/mani/dscn0003.jpg
http://www.neukin.com/images/mani/dscn0536.jpg

[Slow96GSR]

Equal length will stop the exhaust from surging the turbo. If the exhaust reaches the turbo all at once you will get abnormal turbo response.

I have a page on it but I have to look for it.

[LowEk]

Equal length will stop the exhaust from surging the turbo. If the exhaust reaches the turbo all at once you will get abnormal turbo response.

I have a page on it but I have to look for it.

well what kind of manifold do you think works better?? got any pics im just curious as im think of turboing my car soon.

[Slow96GSR]

The one right above my first post is a example of a good mani. It's not one I would use if I wanted to keep the full size radiator. Sometimes the W.G. is on the side of those to help fit a full radiator. The Drag/Greddy/more kits come with the cast mani's and those tend to be a mani designed to fit better not flow better.

[ProECU]

I will post some information later when I get home, however in the mean time, for those who are interested, as per saxmans comments, search the OLD F1 turbo manifold designs, and also read some papers on turbo manifold design of the Old WW2 fighters. The same principles apply to motorvehicles.

Key points to note are;
1. Wastegate placement and effect on turbulence reduction prior to system equilibrium
2. Pressure differential in Intake System vs Exhaust system.

Collector design... I guess its important, however no where as important as the above.

[saxman]

on all of those ram horn manifolds, the wastegate placement is horrible.

I mean sure, it could be worse... at least it's on the collector, and not just off of one of the runners, but it's FAR from ideal.

[ProECU]

correct wastegate placement will improve turbo spool (prior to equilibrium) and assist in turbo longevity.

[BiGANG]

so can you show us a correctly placed wastegate piping on a manifold?

[wlee2]

mm this topic caught my eyes.. so i got curious.. and searched google.. and found this..

http://forums.evans-tuning.com/viewtopic.php?t=1606&highlight=&sid=ea50b818fa56f645cf2df59a864c16b6

i personally found it strange that the name Evan was in it =P..

just adding more stuff

i thought this would be an interesting read about giving priority to the WG instead of Turbo..

http://forums.evans-tuning.com/viewtopic.php?t=1198&highlight=f1&sid=2cdaae88a10043dc90b6ad034a3ee2a1


just thought i would add more =P reading previous link led me here..

http://www.hytechexhaust.com/honda/honda.htm

interesting design..

okok admittedly i think the bling of ramhorns look cool but this is funky =P..

http://www.hytechexhaust.com/honda/honda.htm

[LowEk]

its a US site for dyno tuning n stuff from what i have read previously he knows his stuff.

[superR]

no one has said what is wrong with a good log/tubular style manifold yet??

[ah789454]

no one has said what is wrong with a good log/tubular style manifold yet??
i dont think any one has said that there is something wrong with the log style. theyre just comparing the two. that all, although its is moving towards the design of a manifold:D

[Weq]

no one has said what is wrong with a good log/tubular style manifold yet??

i think it has to do with manifold backpressure, exhaust gas velocity and re-version. All of which a tuned length design has superior charactoristics.

gains of around 20kw atw is what is usually see going from a log to tuned length deisgn.

The thing is, all exhaust manifolds arnt created equal. Just like everything in the turbo world, you should find one which best suits your application and goals. There is no point having a wonderfully flowing head without a good intake and exhaust setup - and same goes for manifolds - no point in having an awsome manifold if u lack in other key area's.

[Weq]

ive been searching high and low for setups that give wastegate 'priority' but are yet to find any good examples.. it looks as though its not as important as all the theoriest make it out to be

http://www.forum-auto.com/uploads/200505/306s16_39_1116938762_bmw_f1.jpg

http://www.f1grandprixtours.com/images/sponsorpic6-l.jpg

http://www.f1grandprixtours.com/images/turbo-029.jpg

http://www.f1grandprixtours.com/images/turbo-032.jpg

on the exhaust housing
http://www.atspeedimages.com/donington_collection/cosworth_v6_turbo_f1_engine_turbo.jpg

http://www.statsf1.com/photos/moteurs/BMWM12.jpg

http://www.atspeedimages.com/donington_collection/cosworth_v6_turbo_f1_engine_side.jpg

http://home.tiscali.be/frans.bekaert/V6%20Turbo.jpg

[LowEk]

from the pics above it seams to be as long as they are equal length it does not matter to much look at the length of the runners on some of the pics above.

[ProECU]

something like this
http://www.importpowerhouse.com/images/Products/custom_turbo_manifolds_6_LG.jpg

and

even better, like this...
http://www.honda-tech.com/zerothread?id=1525959

[superR]

wird set ups, now lets come back down to earth and only make comparissions on manifolds that wont cost us huge bucks :( ! good to see it though....... someone organise for a testing day....we can all take our manifolds off and get them all flow tested ..........lol

[LowEk]

something like this
http://www.importpowerhouse.com/images/Products/custom_turbo_manifolds_6_LG.jpg

and

even better, like this...
http://www.honda-tech.com/zerothread?id=1525959


hey how do you think this second link manifold would work cos ive been thinking about if this type of manifold whould work well or not??

[Weq]

wird set ups, now lets come back down to earth and only make comparissions on manifolds that wont cost us huge bucks :( ! good to see it though....... someone organise for a testing day....we can all take our manifolds off and get them all flow tested ..........lol

its not just about flow, its about blancing runners and flow of an engine.. ANyways yeh, IMO on our street cars, other things take priority. Absolute power isnt gonna override everything else - like a/c, p/s, cost, experience and time ;)

[ProECU]

hey how do you think this second link manifold would work cos ive been thinking about if this type of manifold whould work well or not??

You obviously havent been listening or understanding the concepts.

Re-read.

[LowEk]

that manifold looks sorta similar to some of the the pics above. so as long as its equal length i dont see why it would really differ to any other equal length manifold.

[Weq]

<spoon>
what proecu is pointing out is a manifold which flows all runners into a wastegate as there primary function, is better then manifolds were the wastegate is an after-thought and tacked on at wierd angles.
</spoon>

[superR]

read this

http://www.honda-tech.com/zerothread?id=925312&page=1