intake manifold modification

[Ben-e-boy]

Draw through flow bench will only tell you half the story Ben. My situation has changed a bit in my life and my flow bench and dyno I had no room to store, A very old friend asked for a long term lend so he has it to do a project.. Otherwise I would gladly offer to test your manifold..

Thanks..good luck with the new path.

Ben to comment without being critical here the system is good but the only issue I have found with testing a system like that which I have had in the past with a KKK turbo is you stuff up flow capacity hence turbulence with the small connection cooler to manifold. Bench testing will tell you nothing here you have to bench the cooler and manifold together. And Yes Ben I tested this system against my now system. And yes it does flow better in the pre torque max rev area mmmm a lot better. Now you are using a bigger cooler than I am which is fine but more volume and funny things happen to flow in the manifold when you speed up volume with that connection type. Also remember I am using water/methanol pre turbo injection as I have always done so I just do not need such a big cooler any more. Hence why I have gone for the cooler connected directly to the plenum.

Ben remember this stuff is all 1% ers now.

PS I forgot YES you can go to big, Hence the half size cooler hehe. But I don't know what to big is as yet..

Very interesting, I suppose if were to increase the 3 inch joiner gradually, and a bit of dyno time and see what comes off it.

I do like the 1%ers 5x 1%ers is 5% and 5% of power/torque at current figures is 9kw and 38Nm, just shy of the 200kw/800Nm combo and a noticable increase

[MudRunnerTD]

Great Thread. Should combine this into the 200kw club thread maybe?

Thanks Oldmav, your articulate and clear. Clearly knowledgable far beyond where I'm at so thanks for sharing.


I'd be interested to hear your view on Air/water IC setup too. I'd also be interested in some pics of your Methanol/water injection setup too.

Cheers MR

[nissannewby]

Yes Oldmav is highly knowledgable and his knowledge retention is insane. He certainly is a top bloke for sharing it all.

I'm sure he will be along shortly to tell you the benefits of w2a cooling and his methanol ( which I will be utilizing on my GU ) and I'll warn you now a second mortgage might be necessary with the motivation he will give you lol.

[OldMav]

Thanks..good luck with the new path.



Very interesting, I suppose if were to increase the 3 inch joiner gradually, and a bit of dyno time and see what comes off it.

I do like the 1%ers 5x 1%ers is 5% and 5% of power/torque at current figures is 9kw and 38Nm, just shy of the 200kw/800Nm combo and a noticable increase

The 4 inch does do a bit. I actually fitted a 5 inch on the manifold lol it did give a increase on the dyno Kw and Nm. Which gave me the motivation to do the current cooler manifold system.

[OldMav]

Great Thread. Should combine this into the 200kw club thread maybe?

Thanks Oldmav, your articulate and clear. Clearly knowledgable far beyond where I'm at so thanks for sharing.


I'd be interested to hear your view on Air/water IC setup too. I'd also be interested in some pics of your Methanol/water injection setup too.

Cheers MR

Mmm this is probably two whole new threads lol.. A bit of background first. I have had to change my front radiator inner panel 3 times now due to not enough metal left to hold the radiator so from that you can guess how many front mounts I have played with. I am also on my second bonnet but I have only tried 3 top mounts but they got modified many times. Water to Air I have only had one core the one I still have it is a Garrett core and bloody expensive. But I have had many different distribution chambers fitted for different systems.

My opinion only here but I did fit probes in and out to all of them and used a fluke meter which will data record. First top mounts compared to a W/A cooler you just cannot compare. Reason the temps are just way to erratic even with a fan fitted under them. Even with the last one I built which was 725mm long and 400mm wide 75mm tube and fin, fitted with 2 spal 14 inch fans fitted under it, This one was a front mount original I was testing. The temps were still way to erratic and I still saw above 90C without pre turbo injection, at odd low speed situations, you just cannot get enough air off the bonnet to get them to be stable on a GQ. And yes I know a GU bonnet does work a lot better due to its greater angle. But still they do work well just not as well as a W/A.

Front mounts I spent a lot of time with this system I liked them a lot but truly trying to compare to a W/A cooler its just not fair. Even the cooler mentioned above as a front mount which worked better by far as a front mount just doesn't cut it compared to a W/A but still it was damn good and kept temps at a nice 50 to 55 C but do any sort of sand work and mmm 90 to 140+ C is seen easy, no water injection.

Remember here this is all done on a total stupidly Blueprinted and balanced engine which more often than not produced 180rwkw.

Water to Air well no question, no doubt what so ever, total stable temps, general driving about, traffic or just wheeling about it is rare to see 5C above ambient. My old radiator/condensor which was about 100mm smaller than my new condenser I saw 50C a couple of times but 2 x14 inch spal fans set at 50C would turn on in anger for a few minutes, temp would plummet to ambient. But usually the fans would do erratic switching for a bit because they were to good.

Now I really have to mention here I use Water Methanol pre turbo injection so my compressor outlet temps never ever get above 100C. On the KKK turbo which is about the size of a 3071 with out pre injection it can reach 180C quite easily in anger. Oddly enough I drove about a lot without any cooler due to mods or leaks or just sh#t playing. I had a 3 inch tube set up so I could easily fit for those times I didn't have a cooler but this tube had two large W/M jets fitted along its length plus the usual pre turbo injector. Well sadly this system worked better than any air to air I ever fitted. Buuuut it used water at near the rate of fuel haha. I remember one time playing in the sand I used up my 100 litre under tray water tank in 20 minutes. I mention this because it really is a good option for the lower tune engine if you have the room to fit a good size water tank, due to tune it wouldn't use the quantity my engine needed to cool the heated compressor air.

Any way I have been using W/M since my first diesel Landrover then a H then 2H then my Mav and a number of V8 petrol engines in between and a few fool mate who thought I knew what I was doing lol. Now days it is a lot easier to set one up with safety. I use a coolingmist system about $1000 for one of these units but that with 2 jets solenoids filters flow meter etc etc. This is the only system you would dare use for pre turbo injection the other units just are not progressive enough or have the failsafe system built in. I do not advise people to do as I do pre turbo injection, it does take a bit of knowledge and some balls to do it. There is risk but todays coolingmist is near bullet proof but there is still a high risk of wearing away your comp wheel fast if you are not careful. But for me the benefits out way the risk, comp billet wheels are cheap now days. For this top end engine, W/M and pre turbo injection can easily take a 180rwkw engine to 210rwkw concretive no extra fuel. But the main reason for W/M even in small volumes will lower EGT 100C on our TD engine so you can add more fuel/boost to get more power/torque.

There are many reasons to use water methanol or just water but I am only outlining here why I use it. That being pre turbo injection lowers out put temps dramatically not only that it tricks the comp wheel into thinking it is a bigger turbo hence faster spools and faster higher torque rise more boost with more volume due to lower temps. It lowers EGT's where you need too, for towing or hard playing. And it cleans your engine of carbon including rings so you do get a better seal hence you can extend your oil changes. Because you get less carbon deposits transfer to your oil. But the best part you can just use water its free and in a diesel it adds torque and power via the steam engine effect so it adds to the combustion force to drive the piston down and again its free fuel in other words for free power. Truly outside of a turbo this is the biggest bang for your dollar, no other mods can equal the benefits and free power gain of water injection or add a 50/50 mix methanol and you get a nice extra power boost.

As said I could right a book about these subject and to be fair it really does need another thread to do it justice.

[tassie wombat]

Thanks again for sharing your wealth of knowledge mate,I'm sure the forum will benefit from the advice that you give as the other site has for many years,and just remember, I'm more than happy to kick one of the kids out of their bedroom just so you've got a nice comfy bed to sleep in after a big day of tuning my wagon! 😁

[sooty_10]

Maybe you should write a book Pete. A how to modify and tune the powerful TD42 for dummies Would probably sell quite a few in auto stores. A question about water only, what water do you use? Can you use tap water? Area dependant on how heavy it is? I'd be keen to give it a look in if I could get an easy source of water and potentially a dual purpose water tank, drinking/injection. If touring how hard would it be to source a viable water source, with decent drinking quality filter? Looks like a few questions but it is really one long one

[Alitis007]

Very interesting OldMav and thanks for sharing. I have tinkered a little bit with petrol intake systems and have found larger throttle bodies show on a dyno a 5kw increase and larger plenum about 7kw on std internals at higher rpm but with a cam you can potentially gain up to an extra 50kw on top of what the cam would normally produce. Another thing as you would know petrol systems are alot more sensitive than diesels, so why don't they make a tuned length runner plenum system ? Wouldn't that help direct the air to the valve?

[nissannewby]

No real difference in the sensitivity mate. Due to our diesel being a slow revving motor and only making its peak torque and hp so low in the rev range we cannot achieve the velocities that a petrol can to make a tuned length runner work. Also in a turbo application a diesel is on boost pretty much the entire time your driving, Oldmav's ute Makes boost at idle. To allow us to get better values we require the shortest possible distance to the valve to allow better cylinder filling, filling the cylinder more efficiently increases our volumetric efficiency and in turn our turbo works better for our low speed engine.

Most of this stuff is all for to help the turbo work the way it was designed, ideally what we are wanting the achieve is a drive ratio for the turbo at 1:1 or better (imp:emp ratio). When we achieve this we can push ve above 100%.

[OldMav]

Back on topic, Good Question Alitis007 As you say, petrol's are a lot more sensitive than a diesel in the N/A area. This is due to a diesel has twice the compression ratio and a higher operating vacuum. You can use all the petrol tuned length formula's to calculate a ideal torque point if you factor in compression ratio and the extra air required for diesel fuel energy. But the tube lengths gets very long, then response time in the tube becomes a even more greater issue, and cylinder filling ability starts to counteracts volume transfer so it negates any gains. I have spent a lot of time investigation this idea. And I did build a long tube runner to plenum using a front mount cooler results were dismal and I mean very dismal I lost 50+rwkw and the EGT gauge reacted like a tacho. I never got this system of the dyno but it was really only to prove my own theories. I did try different length tubes just on trial and error to see what the torque curve did. The results were as the tube lengths got shorter and shorter I gained more kw and the torque curve became flatter and higher the shorter the tube runner got. I even tried bell mouths in the plenum no difference none at all. Using this real world stuff and using this info on the bench I found 110mm to 115mm from the centre of the valve was the ideal and no vacuum locks in the runner. So that leaves you about 20mm max for a runner past the head. Which doesn't leave much room to fit injector tubes between the runners. Now for the reason why here which is we are using pressure and no vacuum hence why the tube length gets shorter and shorter as the boost pressure rises. So the tube length I have given here is for the ideal of 30 psi at 2100 rpm to gain the best torque rise etc etc.. More pressure or less pressure will change this but not by a great deal for example 115mm is 20 psi..

Cam shafts mmmm I have limited experience here but a lot of knowledge from research I can tell you the over lap cannot be made shorter otherwise your EGT will shy rocket as you add more boost/fuel/power. So a regrind is not a option for our TD. Because you cannot put metal on the cam lobe you can only remove it to change the profile. Doing this you have to reduce the overlap. So its a very BIG NO to a regrind. The only option is to have a new billet made so you can increase the overlap and increase the duration and or total cam lift. But there are some tricks we can do like increase the rocker ratio which increases all these values but same of these values may not be ideal. You also could change your lifters to mushroom lifters then uses the extra duration to regrind the cam for a increased overlap and lobe centres. The STD T cam we already have is quite good anyway so unless you are after over 900Nm and 230+rwkw it a waste of money for returns to your dollar. Besides that our crank will not survive this sort of neck snapping torque value. But there is good gains to be had with overlap times as we can offset EGT's hence use a much tighter turbine AR but its not really the ideal way to gain Spool times, Besides that we really want to increase out Volumetric efficiency so the below 1:1's EMP (exhaust manifold pressure) to IMP (intake manifold pressure) is the best way to go .