I really don't think you're going to find much in terms of bolt-ons for what you're looking for. The factory plenum is designed extremely well and losing it like the E30 with the ITG filter isn't the best call as then you lose the resonance tuning offered by its design. The reason massive open plenums work on the E30 M3 and the E46 M3 Csl is because the E30 M3 is lighter and the loss of midrange power isn't noticed as much (Personally I think the OEM S38 plenum should be maintained because the more power under the curve the better) and with the E46 M3 they have Double Vanos which makes up for most of the lost midrange while not restricting the engines ability to breathe in the upper rpm's like a resonance assembly like ours does. That being said there is no reason why the S38 cant be improved it would just take time and money.
The only real improvements that would be possible in my mind would be to build a lighter carbon fiber plenum (less weight better heat resistance than Al) that retains the resonance assembly and its tuned lengths (thats the tricky part) while increasing the depth (see tricky) of the velocity stack mounting area (where the velocity stacks enter the plenum from the throttles) so that it would be possible to try and incorporate a hybrid S38/S54 velocity stack (airhorn) and possibly take advantage of the S54's velocity stack design which appears to promote low speed flow. To see if there are any benefits of the S54 inlet design the hybrid S38/S54 velocity stack would have to maintain the S38's length and diameter but mimic the S54's inlet design, you may even be able to keep the OEM plenum if you could make the design work.
Eh, Ive rambled long enough lol personally I have other projects I want to tackle first that I think will yield a few more usable benefits but I have been itching to laser scan the S38 and S54 velocity stacks into solid works to toy with. Below is a pic of the S54 velocity stack in a Csl plenum so you can see the inlet geometry I'm speaking of.
my car will be ready soon.... It will go to the dyno with the plenum... than, I will remove ir and try out some airhorns, to see the real gain on it...
I will open a thread and post results as soon as I have them...
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'95 3.8 6speed ///M5
You wash your car like it was your firstborn child, you tend to its needs like it was your own body, you rotect it like it's your family, then you drive it like you stole it.
my car will be ready soon.... It will go to the dyno with the plenum... than, I will remove ir and try out some airhorns, to see the real gain on it...
I will open a thread and post results as soon as I have them...
What exactly are you planning on trying what do you have done to your car electronics wise that will allow you to run without the MAF? Can we get some more details on what you've been working on?
What exactly are you planning on trying what do you have done to your car electronics wise that will allow you to run without the MAF? Can we get some more details on what you've been working on?
I rebuilt my engine with OEM new parts, oil pump, water pump, all hoses, everything new.... upgraded timing chain as well, as seen on the board.... all bearing shells changed... light weight JE pistons raised compression to 12,7:1 to run with ethanol, some work in the cylinder head as well, in the exhaust.... new valves, iconel ones for the exhaust as well, 0,5mm bigger than stock ones (both admission and exhaust).....
in 10 days the engine will be reinstalled in the car, than I will run for while so everything can get to its right place, after that we will remove the plenum, MAF, etc, and decide some new camshafts for the engine.... Alpha-N, and try out some airhorns to see which one suits better for the project....
I rebuilt my engine with OEM new parts, oil pump, water pump, all hoses, everything new.... upgraded timing chain as well, as seen on the board.... all bearing shells changed... light weight JE pistons raised compression to 12,7:1 to run with ethanol, some work in the cylinder head as well, in the exhaust.... new valves, iconel ones for the exhaust as well, 0,5mm bigger than stock ones (both admission and exhaust).....
in 10 days the engine will be reinstalled in the car, than I will run for while so everything can get to its right place, after that we will remove the plenum, MAF, etc, and decide some new camshafts for the engine.... Alpha-N, and try out some airhorns to see which one suits better for the project....
basically that.... sorry for my english
Sounds like a pretty sweet project what improvements have you done to the fuel system to accommodate the additional flow required to run on pure ethanol? Are you going to run a standalone? I'm not too sure I would eliminate the variable resonance plenum and run plenum-less. You're going to lose quite a bit of low end power and driveability and make a rather peaky engine and running just airhorns exposed in the engine bay is going to take in a lot of hot air and is far from ideal. Personally if your set on a new plenum I would try and mimic the E46 M3 Csl plenum design as there is plenty of room besides having to accommodate the oil filter housing (can be remote mounted using E60 M5 parts) and you could use the Csl air filter (I have one and can cad it up) and then with that and a nice air pickup point you could play with varying air horn designs. Id be more than happy to work with you on this especially with making a hybrid S38-S54 horn design to compare it back to back with the standard S38 velocity stack design to see what benefits can be had even in the Csl style plenum. Knowing what the velocity stacks can do outside of the variable resonance design could actually be quite beneficial for what I would like to do. Let me know sounds fun and good luck man.
Sounds like a pretty sweet project what improvements have you done to the fuel system to accommodate the additional flow required to run on pure ethanol? Are you going to run a standalone? I'm not too sure I would eliminate the variable resonance plenum and run plenum-less. You're going to lose quite a bit of low end power and driveability and make a rather peaky engine and running just airhorns exposed in the engine bay is going to take in a lot of hot air and is far from ideal. Personally if your set on a new plenum I would try and mimic the E46 M3 Csl plenum design as there is plenty of room besides having to accommodate the oil filter housing (can be remote mounted using E60 M5 parts) and you could use the Csl air filter (I have one and can cad it up) and then with that and a nice air pickup point you could play with varying air horn designs. Id be more than happy to work with you on this especially with making a hybrid S38-S54 horn design to compare it back to back with the standard S38 velocity stack design to see what benefits can be had even in the Csl style plenum. Knowing what the velocity stacks can do outside of the variable resonance design could actually be quite beneficial for what I would like to do. Let me know sounds fun and good luck man.
Thanks for your post, now to answer some questions:
Fuel System will have a new fuelpump and the injectors are going to have some work...
no stand alone, piggy back, no need for stand alone
I am not sure about it as well, I will have the exhaust covered with termotape, thats for sure, and the use of the car for me is "warlike" only, track days, some high speed trips, and lots of fun, so the loss of torque in the low range is not a big issue for me, as long as it compensates in the top rage.... the new rev limiter will be set aboout 8500 and 8800rpm, depends on the dyno results etc, and after nem camshafts, of course... the head is already prepared for that with new valves and coils....
The velocity stacks are the real X in the question, this is the only thing I have no idea right now what to do, but of course I am open to sugestions!
If you want to make part of it and help us here, you can email me paulo at ndaracing com , and we can have some chats about it toguether with the other guys that are helping out in the project...
more than one year after this thread, my project is still in course... hahaha
My engine is ready, it is running on pure ethanol, 13,2:1 compression ratio (JE custom made pistons) and 0,5mm bigger valves, on inlet and outlet....
I have a catcams set as well, forgot now not instaled yet because I was searching for a good engine management system to do it.. decided to kick it and go with Motec M800 with some optionals.... my project consists in running a second line of injectors at the entrance of the horns... studyied a lot before deciding doing it, and realizerd that this is a good way to do so, if well done of course....
first I will install the camshafts and make a proper mapping with the motec.... after that, my next step will be assembling somehow a big plenum on it, I dont know yet.... that is why I got back to this topic, making some research on the forum for this issue...
my car has already achived 307whp on dynojet, I have the graphics posted in this forum already, just dont remember where....
I dont know if the best is to bump this old thread or to make a new one...
Exciting stuff Paulo ......... I look forward to hearing of your progress , especially in relation to your Catcams , as we are fitting these to a customer's car at present and running a standalone engine management system , mapped to suit .
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