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Turbo Manifolds 2008
what is the general rule of thumb with regards to turbo manifolds?
because i had a Ram horn custom built and now my car is slower.... boosting with the Log the power was raw and viscious.now with the tubular i have lag and the boost response is weak. i have derived my own theory. Smaller cc's need LOG! |
Re: Turbo Manifolds 2008
SPLOG FTW !!!
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Re: Turbo Manifolds 2008
Originally Posted by ososlohatch
SPLOG FTW !!!
i can understand the design but the reality when boosting a log compare to a tubula, LOGr is far more intense/Vicious |
Re: Turbo Manifolds 2008
dude, what dont you get ? everyone already said everything that needs to be said.
logs work good logs spool faster logs make shity top end power logs suck for high hp wtf more do you want ? |
Re: Turbo Manifolds 2008
can you not have the best of both worlds with a custom manifold? if you can this is the manifold i seek!!!!!!
Anyway as i said before the Fastest Honda im my state runs a Log and he is a gewd 1-2 seconds faster than anyone else!!! My new concern is, Log Generates more thermal efficency/heat. and your intake temp is directly related to how much you can boost on a given fuel. so is this one of the reason why tubular is said to be more superior? because you would beable to booost more?
Originally Posted by one2many
logs make shity top end power
logs suck for high hp wtf more do you want ? |
Re: Turbo Manifolds 2008
There is way too much to type on this subject. Most is theory. End result is we know a few things.
1) Solid merge collectors help a ton. A lack of a decent/good collector really fucks up air flow and drops efficiency 2) Reversion is the enemy of any engine, especially turbocharged engines. Minimize reversion on a turbo engine and maybe even have some scavenging, you are doing the right thing. 3) There will always be a compromise between low end, midrange, and top end power. Having all three is basically impossible. Pick one to focus on based on your needs or live with the fact you can have mediocrity over all three. 4) There is theory that says you can run a small volume exhaust manifold and use large wastegate(s) to minimize reversion. This has never been tested/proven to my knowledge. 5) The sooner you can pressurize the manifold, the faster your turbo will spool. Why do ram horn manifolds typically make more power/psi than logs? Ramhorns have a larger volume and the merge collector allows air to flow more efficiently resulting in less reversion. Why do log manifolds spool faster? The volume is smaller so less air is needed to pressurize the system, thus the system pressurizes earlier. My thoughts have always been to either run short/equal volume/length larger diameter tubing/pipe with a nice merge collector and wastegate priority or longer equal length/volume smaller diameter tubing/pipe with a nice merge collector and wastegate priority. Which one is priority #1? I'd say the collector as it's the most easily conceivable and achievable. As for the other points, ---- if I know. Buy a welder and some material and get to work. PS: Whatever you choose, your cams, wastegate, and turbo have to work with it. Downpipe always is bigger is better. |
Re: Turbo Manifolds 2008
this was my log
http://memimage.cardomain.net/member...55_55_full.jpg this is what i got now http://i243.photobucket.com/albums/f...ot-04/mani.jpg |
Re: Turbo Manifolds 2008
dude, finish your spaghetti
i'm not one for flaming, but you are being irritating. multiple threads of it. seriously. if you keep it up i'll put on the hmt cap for a few minutes and flame you till i feel better. i've just been shafted pretty bad (someone sold my skyline for 1200nz when i had 4k of suspension and sounds, 2k of labour, 3 - 5k of car, and countless hours/dollars making it mechanically mint. i dont need you asking dumb questions. i might flip out. 9 - 15knz lost. so gutted. and nothing i can do. stupid nz laws, never let a woman run your country. |
Re: Turbo Manifolds 2008
hey dude i get what you are saying!
and im gonna agree with you. this Turbo manifold debate started when i was pushing 150bhp, so i thought if the car got more power the lag will dissapear, now the car is pushing 100bhp MORE and i still got the same problem. I was told that the benifits of the tubular manifold's FLOW will make itself very clear and i will grow to love the tubular manifold. but that hasn't happend so basically ive got one Tuner's Opion vs Another's so what do i have to do. i have to find out for my self. So now im looking for a Design that is gonna give me the balance of both manifold design's. I know i was on your case about methonal injection(PS: im not asking any more Q's on water/meth), i understand that the car will boost more, even if i make 100bhp more im sure im still gonna have the weak boost response. thats why i was asking about ADVANCEING timing. the car isnt as competitive as it should be for the power it is making..
Originally Posted by Inquisition
3) There will always be a compromise between low end, midrange, and top end power. Having all three is basically impossible. Pick one to focus on based on your needs or live with the fact you can have mediocrity over all three. all i wanna do is get over the quatermile line FASTER...... |
Re: Turbo Manifolds 2008
1/4 mile = top end
check out the oem manifold on the bpt and f2t, its a basic good design for good spool and good flow. for spool minimise volume for flow maximise smoothness i'd never use a log mani, but its tricky to make a good flowing manifold very compact. doable though. i'd go for top end anyday. if you have spool issues, perhaps your turbo is oversized for your application. like the other guy said you can only have one of the three things happening well. the other two will be less than perfect. |
Re: Turbo Manifolds 2008
do some dyno runs. put the log on and run it. then throw the tubular on and run it. it would be good info to have posted up and that would show you the difference. i dont know where your at but by me you can get 3 runs for like 80 bucks. just see if you can run once then pull your car off and swap ---- out and run it again for the same price. it would show you the difference in the power band and what not.
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Re: Turbo Manifolds 2008
run a mini ram, they're bottom mount.
http://www.omenspeedworks.com/images/pagan-2-done-1.jpg theyre a good split between ram and log |
Re: Turbo Manifolds 2008
To add on to what Inquisition said about scavenging and preventing reversion in a log mani, cam overlap is a key factor in bumping up both of those. It helps promote scavenging by utilizing some of the forced air being pumped into the engine to help keep the exhaust moving quickly, and at the same time obviously prevents reversion. The only big losses are a drop in boost pressure (very slightly and can be made up for with a boost controller) and a slight drop in bottom end power and slightly later spool time.
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Re: Turbo Manifolds 2008
that manifold pictured is pretty nice, it would be hard to do much better as a high end geared compromise between decent spool and outright power.
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Re: Turbo Manifolds 2008
Originally Posted by fe3tcourier
that manifold pictured is pretty nice, it would be hard to do much better as a high end geared compromise between decent spool and outright power.
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Re: Turbo Manifolds 2008
1 Attachment(s)
what style manifold do i have ? and can you guys pick out any floors from the photo's?.
Im still running the Standard turbo camshaft, when going to a tubualr manifold should one aslo increase the lift in the cam? i have heard increasing the duration on a turbo cam will decrease performance. Im defiantly going log as the Tubular hasnt worked out for me. Which manifold would supply more flow? Both of these manifold with supply better spool than the loggy? 4-2-1 Manifold Attachment 21903 Or Pure Log http://www.rcautoworks.com/images/uploads/IMG_2754.JPG |
Re: Turbo Manifolds 2008
the first one is nice for a log. if the inner runners were also curved and angled toward the merger, it would be better, but its good.
the second one uses the rounded both ways T pieces for 2 and 3, i dislike those because they offer no direction to the escaping gas and significant reversion could/will occur. try http://www.mx6.com/forums/1g-mx6-forced-induction/ for f2t mani pics and places like http://www.clubprotege.com/ for bpt ones. |
Re: Turbo Manifolds 2008
That first on you just posted will flow smoother than a straight log. I think it's pretty sexy.
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Re: Turbo Manifolds 2008
Originally Posted by Schwitzer Turbo
what style manifold do i have ? and can you guys pick out any floors from the photo's?.
Im still running the Standard turbo camshaft, when going to a tubualr manifold should one aslo increase the lift in the cam? i have heard increasing the duration on a turbo cam will decrease performance. Im defiantly going log as the Tubular hasnt worked out for me. Which manifold would supply more flow? Both of these manifold with supply better spool than the loggy? 4-2-1 Manifold https://i238.photobucket.com/albums/...s/DSC00754.jpg Or Pure Log http://www.rcautoworks.com/images/uploads/IMG_2754.JPG Hi Schwitzer , have a look at this link , gives a good explanation on turbo camshaft selection and the different characteristics that a log manifold and tubular header tuned length manifold prefers in turbo camshaft profiles. Schwitzer can you quote you camshaft specs please ? http://www.forcedinductions.com/help.htm Turbo Cam Selection 101 How to select a turbo cam Duration: Duration is critical to a turbo setup since its probably the single most important event of a turbo motor (i.e. time valve sits open and closed). Since the air is being forced instead of drawn into and out of the combustion chamber, duration will be your largest variable on how that incoming/outgoing air is managed. Duration when using a manifold or log design on most turbo cams is usually about 6 degrees more intake duration than exhaust duration (226/220, 240/234). This is mainly because a manifold/log design will typically see higher then a 2:1 pressure ratio in the exhaust ( as high as 4:1 with some logs). By using a reverse split duration this will somewhat help prevent from getting exhaust gas reversion. Duration when using an efficient header setup with most turbo cams will usually be (230/230, 224/224) or better known as a dual pattern cam. The thinking is with the exhaust backpressure being only 2:1 you can leave the exhaust valve open a little longer then if the exhaust backpressure was 3:1 or higher. Also some of the new turbo designs produce a much lower backpressure with the advent of better flowing turbine wheels and housings which further decrease the total amount of backpressure created by the system. Overlap: Overlap definition, is the time period when both the exhaust valve and the intake valve are open at the same time. The exhaust valve needs to stay open after the piston passes TDC in order to use the vacuum created of the exiting exhaust gases to maximize the amount of exhaust gas drawn out of the cylinder. The intake valve opens before TDC in order to use the vacuum created by the exiting exhaust gases to start drawing the intake charge into the cylinder. This sequence of events above are controlled by the duration and LS (Lobe separation) of the cam. On a typical N/A motor this is essential since you have no pressure being developed on the intake side to push the charge into the combustion chamber. The problem with this event is a turbocharged motor will create a larger amount of backpressure on the exhaust side. Due to this event the above definition will not apply. Reason being is, when the intake valve opens at BTDC, the burned gasses in the chamber will exit out the intake since the pressure is lower than the exhaust. Since this is true you would not want to open the intake valve until the piston has started going down, ATDC. This will lower the combustion chamber pressure till it's below the intake manifold pressure. To calculate the overlap of your cam simply follow these steps below: **Example turbo cam:** Duration @ .006 218/212 Lift .544/.544 lift Lobe Separation (LS) 114 Add the intake and exhaust durations Divide the results by 4 Subtract the LSA Multiply the results by 2 Overlap is -6.5 Degrees of overlap **Example N/A cam :** Duration 236/242 Lift .568/.576 Lobe Separation (LS) 112 Add the intake and exhaust durations Divide the results by 4 Subtract the LSA Multiply the results by 2 Overlap is 15 Degrees of overlap Above was the process on how to calculate your cams overlap. As you can see, the overlap in the 2 cams differ greatly. Running the N/A cam example on a manifold setup would be a horribly in-efficient setup and the engine would be operating well below its potential output. While running the example turbo cam would work well even with the most in-efficient of the header systems out there. Typically a overlap ------ of -8 degrees to +2 is a safe bet. Of course this will differ with whatever combination header, turbo and exhaust is used, so those #'s could be higher or lower. Lift: How much lift should I get in my cam? Well that will depend on your heads' flow characteristics. To choose the correct turbo camshaft, you really need to know how your cylinder heads flow. Reason is if your cylinder head flows X amount of air at X amount of lift, choosing a cam that has a lift much greater then that will gain you nothing except extra heat and premature wear of the valve spring. Airflow through a head reaches a peak as the valve is opened, then starts to drop off as the valve is lifted beyond that peak. Most of this of this will hold true to definition, but with a forced induction motor, valve lift is not as critical since the incoming air is pressurized. A good rule of thumb is to select a cam that will lift the valve 20-25% past its peak flow point. So be the definition above if your head flows best at 0.500" of lift, use a cam that will lift the valve between 0.600" and 0.625". The reasoning behind this is, if you lift the valve only to its peak flow point, then the valve only flows best when it's wide open. The cycle is brief and would only happen once per stroke. So to benefit from you peak flow the most, you want to lift the valve past its peak. That way the valve will pass its peak flow twice in the cycle. The result is more flow during the opening and closing event of the valve. You do not want to raise the valve much past the peak flow though, or you lose total flow by going too high. Calculating the best lift: 0.500 X 1.20 = 0.600 0.500 X 1.25 = .0625 Conclusion: There are way too many factors to just say XX cam will make XX power with your combo. Things like "114LS is best, or 117LS, or ..etc", are just blanket statements. Backpressure, RPM range, boost level, target horsepower, A/R of turbo, turbo frame (T3, T4, T6/Thumper), head flow, cubic inches, and even location of turbo...etc. All of these factors are extremely important in determining the cam that best suits your needs. There is no rule of thumb with a turbo cam. There are too many variables and the only way to get the right cam is to take all of those your parameters into consideration, and only then can a proper cam be selected. All of the points of reference above are just to get you on your way to building the best and most powerful turbo system for you. Study your design and ask questions along the way and you will be smiling the next time your opponent lines up next to you. Feel free to contact us for your needs. Also once you have read this and want to know the theory behind turbo charging, check out our advanced look at the engineering behind turbochargers. |
Re: Turbo Manifolds 2008
Originally Posted by slo_crx1
To add on to what Inquisition said about scavenging and preventing reversion in a log mani, cam overlap is a key factor in bumping up both of those. It helps promote scavenging by utilizing some of the forced air being pumped into the engine to help keep the exhaust moving quickly, and at the same time obviously prevents reversion. The only big losses are a drop in boost pressure (very slightly and can be made up for with a boost controller) and a slight drop in bottom end power and slightly later spool time.
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Re: Turbo Manifolds 2008
you want your runners to all collect in a 4-1, or a SMOOTH 4-2-1 for best performance, but keep the pipes as short as possible in the process.
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Re: Turbo Manifolds 2008
Originally Posted by FPV_GTp
Schwitzer can you quote you camshaft specs please ? Camshaft - Lobe Height Intake 41.2689 mm Exhaust 41.2698 mm Valve Timing - Intake Opens (BTDC) 8 deg. Closes (ABDC) 52 deg. Valve Timing - Exhaust Opens (BBDC) 52 deg. Closes (ATDC) 8 deg. Valve Stem Thickness 6.0 mm if that doesnt make sense scroll down to engine specifications alpha 1 NA vs turbo http://www.iformation.co.za/scoupe/gtvset.htm |
Re: Turbo Manifolds 2008
Theres no overlap on that cam. EL manifolds won't work well for your application.
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Re: Turbo Manifolds 2008
Originally Posted by Inquisition
Are you suggesting more or less overlap or independent upon the setup? Either way I agree overlap is a key ingredient when picking a manifold. Basically if you are going to run EMP:IMP of 1:1 or close to, lots of overlap with a big cam = big power. This is new fangled turbo theory, but it works. You make a lot more power because you actually end up with some scavenging. Old turbo theory which also works, just not as well is, smaller cam with no overlap for when your EMP>IMP by a great deal. This doesn't really promote scavenging but minimizes reversion. This works, just not as well as new fangled turbo theory seems to.
have a greater tendency to increase exhaust scavenging. Less overlap is required with a ram horn or equal length design. As long as a low pressure ratio is kept on the exhaust side of a log manifold increasing both duration and overlap can be quite beneficial. Exhaust A/R and exhaust size comes in to play as far as pressure is concerned, and it's not uncommon to see 2 to 3 times the amount of exhaust pressure as compared to boost pressure when hitting the limits of a smaller turbo. For example, the last .48/.60 50 trim t3 I ran on my old b16 was reaching around 35-40psi of exhaust pressure when compared to the wimpy 11psi that was being put into the motor. An upgrade to a .63 a/r housing dropped a considerable amount of pressure, as well as a nice smooth straight 3" exhaust (or 3" open dp in that situation ;D). |
Re: Turbo Manifolds 2008
Originally Posted by Inquisition
Theres no overlap on that cam. EL manifolds won't work well for your application.
So thats why my car pick up so much lag/lost performance? So should i stick to this manifold and change cam? or go for the loggy/4-2-1? ---- looks like this topic bitt off more than i can chew... But we getting there.. This is the SPec 1 cam stat's im assuming its worse then mine APB Camshaft - Lobe Height Intake 41.0837 mm Exhaust 41.2698 mm Valve Timing - Intake Opens (BTDC) 14 deg. Closes (ABDC) 42 deg. Valve Timing - Exhaust Opens (BBDC) 52 deg. Closes (ATDC) 8 deg. |
Re: Turbo Manifolds 2008
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Re: Turbo Manifolds 2008
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Re: Turbo Manifolds 2008
Wow, good luck finishing welding those runners, I hope you have tiny fingers and a miniature TIG to match.
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Re: Turbo Manifolds 2008
Originally Posted by Schwitzer Turbo
Im assuming Equal Length manifolds is EL/Ramhorn/tubular.
So thats why my car pick up so much lag/lost performance? So should i stick to this manifold and change cam? or go for the loggy/4-2-1? ---- looks like this topic bitt off more than i can chew... But we getting there.. This is the SPec 1 cam stat's im assuming its worse then mine APB Camshaft - Lobe Height Intake 41.0837 mm Exhaust 41.2698 mm Valve Timing - Intake Opens (BTDC) 14 deg. Closes (ABDC) 42 deg. Valve Timing - Exhaust Opens (BBDC) 52 deg. Closes (ATDC) 8 deg. |
Re: Turbo Manifolds 2008
Originally Posted by Schwitzer Turbo
can you not have the best of both worlds with a custom manifold? if you can this is the manifold i seek!!!!!!
Anyway as i said before the Fastest Honda im my state runs a Log and he is a gewd 1-2 seconds faster than anyone else!!! [color=pink]My new concern is, Log Generates more thermal efficency/heat. and your intake temp is directly related to how much you can boost on a given fuel. so is this one of the reason why tubular is said to be more superior? because you would beable to booost more?[/color] do you need "TOP END POWER/HIGH HP" to run gewd 400m times? |
Re: Turbo Manifolds 2008
it doesnt even make sense really.
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Re: Turbo Manifolds 2008
1 Attachment(s)
Originally Posted by switzy boy about to be flamed to ----
I have registering wit these 2 forums and scanning threw them(24 hours) and havent found the Info you were refering to, if there is anyting in specific you wanted me to check out let me know so i can Stop Bugging HMT Tongue
SECONDLY, YOU ARE A ------- IDIOT. YOUR INABILITY TO USE GOOGLE IMAGE SEARCH IS SECOND TO NONE. wait, that needs more fire SECONDLY, YOU ARE A ------- IDIOT. YOUR INABILITY TO USE GOOGLE IMAGE SEARCH IS SECOND TO NONE. seriously, STOP ------- PMING ME, that is not how you get someone to continue to be helpful. it is how you piss them off. ON MY FIRST PAGE OF RESULTS, I GOT THIS : Attachment 21883 HOW THE ---- COULD YOU MISS IT???? flame away.... |
Re: Turbo Manifolds 2008
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Re: Turbo Manifolds 2008
Okie i got the Point. gonna go give the Design specification to my mate. We be back in a Few weeks and let y'all know how it turned out...
C-YA |
Re: Turbo Manifolds 2008
Originally Posted by fe3tcourier
firstly, "or similar"
SECONDLY, YOU ARE A ------- IDIOT. YOUR INABILITY TO USE GOOGLE IMAGE SEARCH IS SECOND TO NONE. wait, that needs more fire SECONDLY, YOU ARE A ------- IDIOT. YOUR INABILITY TO USE GOOGLE IMAGE SEARCH IS SECOND TO NONE. seriously, STOP ------- PMING ME, that is not how you get someone to continue to be helpful. it is how you piss them off. |
Re: Turbo Manifolds 2008
i can tell him that the basic layout and desing of that manifold is close to ideal.
short as possible runners smooth as possible runners no reversion with each cylinder delivering to the turbo independently it looks rough because its 15 years old and cast iron. its also too small internally because of the particular engine that that one is for, but the one on the bpt makes 300whp no worries and is near enough to identical to that. |
Re: Turbo Manifolds 2008
Originally Posted by fe3tcourier
i can tell him that the basic layout and desing of that manifold is close to ideal.
short as possible runners smooth as possible runners no reversion with each cylinder delivering to the turbo independently it looks rough because its 15 years old and cast iron. its also too small internally because of the particular engine that that one is for, but the one on the bpt makes 300whp no worries and is near enough to identical to that. |
Re: Turbo Manifolds 2008
Originally Posted by circleburner
Awsome post, you should retract your LARGE WORDED POST, and make this a sticky, this post cover's alot of ---- i have never seen before, i have never need to know this stuff cos my setups just work. you sure taught a few old dogs some new tricks. This post set's in motion a diffent style of thinking, NUUBS do your research, HEAVY research
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