View Full Version : Log Vs Tubular manifolds
Right chaps as a few know I have a clio turbo, over the winter months I'm planning on making a few changes to it which will include strengthening both the engine and gearbox.
I figure that whilst its in bits I might as well make a few improvements and one area I'm looking at is the turbo manifold.
So it's a simple question, is it worth swapping out my current log manifold and having custom tubular one made?
Cheers
Steve
Adey aka Ewok
26-11-2010, 07:13
Is this on a c1j or a Clio lump? If it's on a Clio lump yeah go tubular
Yeah its for the F4R in my clio, I'm just looking at ways to increase flow through the whole system, and this seems to be an area which draws different opinions.
It's running 1.2bar and making good power but I'm a greedy so so I'm looking for a little bit more without running crazy boost.
http://i274.photobucket.com/albums/jj243/SP33DFOUR/Cars/Trophysep10.jpg
Some ideas that have been suggested to me are swapping my 2.5" turbo back exhaust out for a 3" turbo back system. Which I think might help a little.
Wilder cams have also been suggested but with Scoffs success using OE ones I think they should be OK for my moderate power levels.
I'll do some testing (as suggested by Mr Cooke) to see what sort of back pressure I'm getting in the log manifold and I'll also rig my zeitronix to my comp housing to see what pressure I have at the comp housing to make 1.2 bar at the manifold which should highlight any issiues with my intercooler and pipework system.
Any other suggestions on increasing my engine efficiency?
Andrew Cooke
26-11-2010, 13:12
full-race did some tests on log against tubular on a honda, and an SR20 engine, have a bit of a google.
You're really in the area where the T2 flange is a bit small, T3, or twin scroll is more like it, but, you really need to set the goals and budget, then work out how to make them meet. The problem is you're stepping further and further away from the budget mods.
Yeah, I discussed this with Ashy last night and we agreed that I'm getting a bit carried away. :ashamed:
It's a shame as I've got some great ideas, but cost is a major factor, I was quoted 650+VAT for a 3" turbo back system, so god knows how much a tubular manifold would cost. Then what happens if my intercooler is holding me back? then it'll be the turbo again, and it'll just be an ongoing cycle LOL
Andrew Cooke
26-11-2010, 13:24
when did Ashy get so wise :laugh:
when did Ashy get so wise :laugh:
:cooter:
It boils down to you needing to decide on what you want the engine to do. Nothing's for free when it comes to making more power. Something has to be sacrificed somewhere. A bigger tube manifold is going to be laggier than the stumpy cast one. Lairier cams arn't going to have the road manners and low rpm torque of stock ones. A bigger bore exhaust is going to be louder and so on.
Regards the exhaust though, you should try to measure the back pressure in the downpipe at peak power. 10psi would be bad I'd say. A few psi acceptable maybe.
As andy probably said to you, turbine inlet pressure will tell you a lot. Try and make a log of that vs. boost pressure. It'll help you to know what you can get away with regarding cam choice and timing.
Regards the 3" exhaust, do people really charge that much ? I'm in the wrong business :D
Adey aka Ewok
26-11-2010, 20:21
And me, 650+!! Im lucky they ditch alot of stainless at work so always knock up my own systems less the cost of flanges and boxes
I'll be honest I want 400bhp and feel that I'm pretty close to it at the minute. The problem is I'm at the stage (as Andrew pointed out) where all the cheapish mods have been depleted. As such the next step is gonna cost.
The options are.
JMS inlet systems £1500. Having witnessed Scoff pull 400+ on the standard inlet I feel I can give this a miss.
Bigger turbo £1000. I've only just bought my current one and feel that it's capable of flowing 400 so think it should stay.
Cams I already have a mismatched set of cat cams that Mr Cooke is hopefully measuring this evening. One is a inlet catcam 428 (272 duration) the other is a catcam 421 exhaust (269 duration) I'll be honest they came up for a price that could'nt be refused so thought what the hell.
Exhaust. I've been reading loads and pretty much everyone says that for over 300bhp you really want to have a 3" system some even suggest that 3" isn't enough for 400+ So its an area I'm really keen on. You only have to look at every evo and impreza out there and pretty much the first thing they do to free up the power is clash a bigger bore exhaust on there. I know alot of power can be squeezed through a 2.5" (as thats what mine has currently) but the ktec exhaust on there knocks abit and to be honest I'm not overly blown away by it.
Manifold. This really came about due to my custom exhaust idea. I figured if there was the slightest hint that I'd have this done in the future then I may aswell get it done whilst the exhaust is being made, otherwise I'll incur extra costs when I need a new down pipe mating to the turbo. I also considered having it made to take a T3 turbo and external wastegate.
Current thoughts are.
The log manifold should flow 400bhp as there seems to be plenty of civics out there running almost identical ones making far more power.
Cams, I might fit the 272 inlet just because I have it, however I feel the back presure could be an issue if I fit the wilder exhaust cam. By measuring the back pressure I will have a more accurate assesment of how bad it is.
Swapping to a t3 turbine housing, again its an area I'm interested in but it will raise problems as I'd need an external wastegate machining into my ceramic coated log manifold. Whilst it's not ideal it the T25 internally wastegate should suffice but its still something i'm considering.
Turbo back 3" exhaust, I'm pretty sure this is going to happen it seems the most logical area for improvement and the cheapest.
If anyone can think of any areas which might yield improvements then feel free to post it up as I'm just trying to gather as much info as possible before I make a costly mistake :)
Boost wise, RStuning said I was starting to suffer detonation at the top end and is reluctant to up the boost any further hence why I'm trying to increase airflow.
Rob@Backyardracing
26-11-2010, 23:11
what turbo is the car on now? you can go t3 with internal gate, and just get a t2/t3 adapter if you dont want to chop up, or change your manifold. that would be my choice, as you said, logs are fine for your power level. from what ive seen tubular manifolds are better suited to large turbines/high rpm setups, logs more streetable cars.
Rob@Backyardracing
26-11-2010, 23:14
R.E the exhaust, just get to a dyno and do a run open downpipe, if you pick up much power fit a bigger exhaust :)
BluntyR5GTT
27-11-2010, 08:40
id personally go for the 3" system and that inlet cam and see what gains they give then you can see where else the money might need spending to get the figures your after
TrixNFlix
27-11-2010, 09:13
R.E the exhaust, just get to a dyno and do a run open downpipe, if you pick up much power fit a bigger exhaust :)
:agree: a great logical thought, and just for the cost of a dyno run. :)
Big Steve - Raider
27-11-2010, 09:44
You only have to look at every evo and impreza out there and pretty much the first thing they do to free up the power is clash a bigger bore exhaust on there.
:laugh: That and to give them the whole Tommy Mak feel!!.. Eh Bill?!! :wasntme:
Adey aka Ewok
27-11-2010, 09:46
What was causing it to det would be my concern?
Andrew Cooke
27-11-2010, 09:57
What was causing it to det would be my concern?
exactly, boost per se won't make it det.
Adey aka Ewok
27-11-2010, 10:33
exactly, boost per se won't make it det.
you explained it to me as the manifold could cause det?
I'm not 100% sure it was suffering det, as Paul didn't actually mention it when it was on the dyno. He tuned it so I had good EGTs and everything else was good, however I developed an oil leak from the dog poo oil inlet I bought from ktec so we called it a day as we didn't want the car going on fire with the oil leaking on a red hot turbo.
Anyway I was supposed to go back to Pauls last week but the software update for my boost vs speed hasn't ben finished yet. I mentioned to him about upping the boost and it was then he mentioned I was suffering det.
Rob that's an awesome idea my only concern is if I break the system at the turbo outlet then the hot exhaust gases will hit directly onto my brake master cylinder 6" away. The next break in the system is just before the power steering rack and everything will be directed at the steering rack, gearlinkage and undebody.
Out of interest, what sensor are you going to be using to measure the hot side pressure? Issue will be temperature unless you use fluid cooling or a long capillary, that's if you’re going to want an electronic signal to log, or are you intending a mech gauge and eye-ball it?
Speedy, was measuring the pressure in the downpipe not an easy enough test ?
Out of interest, what sensor are you going to be using to measure the hot side pressure? Issue will be temperature unless you use fluid cooling or a long capillary, that's if you’re going to want an electronic signal to log, or are you intending a mech gauge and eye-ball it?
Long capillary is how I did it. I had one from the manifold and another from the downpipe. I could generate 1 bar in the downpipe alone when I was at about 450hp and a 2.5" system. The engine would make about 2-3% more power with the exhaust removed (leaving only the downpipe) and the downpipe pressure would drop to nearly nill.
I'm not sure whats the best way to go about measuring the back pressue in either manifold or down pipe.
Idealy I can cobble something together with a 1/8npt thread I could use my EGT probe hole on my manifold. For down pipe measurements the only convienient point is the lambda probe whole which I believe is an M18 thread.
However the weather up here is abysmal at the moment so taking it out to test isn't happening :wasntme:
If anyone has any good pointers or tips how to measure the back pressure then fire them my way, all advice greatly appreciated. :D
Matt Cole
27-11-2010, 16:30
Am i missing something?:scratch: you need a 1 bar gauge, drill a hole, screw it in before the silencers. See what it reads. Above 2 psi not good. This is at idle. Not sure what readings are sensible at full chat.
I could generate 1 bar in the downpipe alone when I was at about 450hp and a 2.5" system
Surely that knocks the 3" system idea on the head?
Surely that knocks the 3" system idea on the head?
Problem is, I don't have anyone elses data to compare with but for me it didn't make a massave difference. 3% of 450hp is still 13hp though. Since steve wants to increase the downpipe diamater too then he might expect to see a 10hp gain maybe. Pure conjecture that though !
Andrew Cooke
27-11-2010, 21:52
Problem is, I don't have anyone elses data to compare with but for me it didn't make a massave difference. 3% of 450hp is still 13hp though. Since steve wants to increase the downpipe diamater too then he might expect to see a 10hp gain maybe. Pure conjecture that though !
Didn't you run with the inlet cam in the retarded position?
Didn't you run with the inlet cam in the retarded position?
Yes, but the timing was variable by then and I had optimised it the best I could with an open downpipe in mind. At OE timing I had better midrange and HP to about 1.5 bar. After that HP would suffer. At higher boost it needed a lot of retard.
Didn't you run with the inlet cam in the retarded position?
Oh but you're thinking it might make more difference with steve because of his standard timing. Could be :)
Andrew Cooke
27-11-2010, 23:00
Oh but you're thinking it might make more difference with steve because of his standard timing. Could be :)
exactly that, oh and his log manifold, smaller turbine....
Powered by vBulletin® Version 4.2.5 Copyright © 2024 vBulletin Solutions Inc. All rights reserved.