Rotrex M42 Build - 285bhp little update

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appletree
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Fri Oct 24, 2008 10:14 pm

Well with the coming of winter comes another project how ever this time the targets alot higher than it was before and this time the engine is going to be rebuilt low comp by Ant to make sure its capable of handaling the large amount of boost needed to reach my BHP goal.

What is the goal??? well if VAG 20v T's can get to 300bhp with not much in the way of major tuning then i can 't see why with alot of work, due to it being a older engine, i cant get mine to 280-300 brake.

Heres a Current pic of the car for anyone who's intrested :D
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I'm still going to be sticking to the Superchargers and not swopping to turbos as i love the whine and the way theres instant boost with the superchargers.

So far i've been gathering a few bits togeather ready to start doing things when i take the car off the road in winter, so far ive bought two iner coolers, one saab and one Volvo type, both simular but with different porting.

Unfortunatly neither of them will be able to satnd the high boost pressure with out balloning and then blowing the end atnks off so i'm going to use them to mock up the set up and then get an ally one made to the sime size so i know it will fit in with out having to modify the carsfront pannels.

Been busy at work to making a stainless swedish style inlet plenum although it would be better made of ally i dont have access to a ally welder or ally for that matter. i'll get some pics up when i can,

I've also bought all the pullys to swop the M42 "V" belts to M43 flat belts this means if i needed to i could use the same belt to run the charger as other ancillerys, wether this is a good idea or not i dont know as least if i had two belts if the supercharger belt snapped the water pump and alternator would still be working if in needed to say limp the car to the next service station.

The two next big things to sort out are the lower compression ratio and the supercharge trim.

ive been speaking to a company called TTS performance who are the distibutor for Rotex chargers in the UK and they have suggested i go for the biggest one they do in the C30 range the -94 size as this will do 250-400 bhp range , alittle larger than the one i thought i'd need the -84 that runs 200-320bhp but the lad i spoke to seamed to realy know his product and also had good knowledge of the other kits and cars that they have charged in he past and what charger they used to get what power.

The same lad suggested i only drop the Cr to 9.5:1 as he use the same setup (-94 trim) on civics running 10:1 however to me this still seams alittle high for me as i was thinkin more along the lines of 8.5:1 however maybe the middle ground of 9:1 would be better?

think i'am going to need to be running around 20psi boost to get to 280-300bhp

Any one got anythoughts? all help and advise welcome

Cheers, Matt :cool:
Last edited by appletree on Thu May 24, 2012 8:15 pm, edited 18 times in total.
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Gunni
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Fri Oct 24, 2008 10:27 pm

my thought, turbo on stock engine , easy 300hp.
With great challenges comes great engineering.

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GrindCulture
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Sat Oct 25, 2008 2:48 am

Gunni wrote:my thought, turbo on stock engine , easy 300hp.
Although that may be the case it will be a hell of a lot more reliable with custom internals. As I read somewhere once before; high power, low cost, reliability. Pick any 2...

Will be watching this thread intently, gotta love the 4pot turbo action :wink:
Not in E30s any more :(
appletree
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Sat Oct 25, 2008 6:31 am

I can remeber reading a Performance BMW mag some time ago and seeing an E36 318is with de-comp plate and a big turbo from greece and it was supposidly running 500BHP on standard internals! now as far as i can see it wont be running like that for long!

My idea is to keep the car and this engine for a long time which is why i'm going to be doing it properly which i know will cost me, but its no good doing it on the cheep the complaining when it only runs for a week then blows up!

As said i'm keeping with the supercharger as i love the respose and the noise, the rotrex chargers are also very efficient the C30-94 can return up to 80% efficiency 8) which is as good if not a little better than a turbo were as my current Eaton M45 is only getting around 50-55% :(
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appletree
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Sat Oct 25, 2008 7:06 am

Heres a few pics of the inlet maifold i've started making up

First cut up some3" 45 and 90 degree pipe bend to make half sections using an angle grider and then a flap pad to finish the edge off, heres them just mocked up.

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next thing was to tack them togeather and stich weld the bottom of the pipe work to a big section of box to make sure it keeps it shape when welding and doesnt distort. then i tacked the middle section in the top to joint the 45 and the 90 bend to geather :D

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And heres a pic of it nearly ready for welding, just got to tack in the other plate. Making the top and bottom plates was a pain in the ass but i think the patiants has pain off as they fit realy well and will make welding them in easyer :D

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Gunni
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Sat Oct 25, 2008 10:14 am

Manifold is taking a nice shape.

key in reliability and longevity is tuning.
With great challenges comes great engineering.

Gunni
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hoshy
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Sat Oct 25, 2008 10:30 am

Gunni wrote:Manifold is taking a nice shape.

key in reliability and longevity is tuning.
Sounds like somebody has an interest in tuning this one :) And I don't blame you mate.

Matt - this is gonna be one fucking sweet project! I'm still hoping we can get ours head to head before you take it off the road so I really need to pull my finger out! Either way I'll be keeping my eye on this one dude!
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appletree
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Sat Oct 25, 2008 10:32 am

ya, gunni cant agree more, does anyone think it would be a good idea to put a parshal divide down the centre of the manifold say 2" back from the inlet opening and 2" back from the outlet side to help split the airflow to cylinders 1/2 and 3/4 and also to as support? :D
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appletree
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Sat Oct 25, 2008 10:49 am

hoshy wrote:
Gunni wrote:Manifold is taking a nice shape.

key in reliability and longevity is tuning.
Sounds like somebody has an interest in tuning this one :) And I don't blame you mate.

Matt - this is gonna be one ******* sweet project! I'm still hoping we can get ours head to head before you take it off the road so I really need to pull my finger out! Either way I'll be keeping my eye on this one dude!
No worries mate, mine will still be running in its current spec for month or so yet, feel free to drop me a line any time mate. not intrested in M62 supercharger for yours are you as an upgrade?? ive got a spare one that will be going on ebay soon :D
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hoshy
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Sat Oct 25, 2008 11:02 am

appletree wrote:
hoshy wrote:
Gunni wrote:Manifold is taking a nice shape.

key in reliability and longevity is tuning.
Sounds like somebody has an interest in tuning this one :) And I don't blame you mate.

Matt - this is gonna be one ******* sweet project! I'm still hoping we can get ours head to head before you take it off the road so I really need to pull my finger out! Either way I'll be keeping my eye on this one dude!
No worries mate, mine will still be running in its current spec for month or so yet, feel free to drop me a line any time mate. not intrested in M62 supercharger for yours are you as an upgrade?? ive got a spare one that will be going on ebay soon :D
No no no :) I'm not making anything more complicated than it needs to be!

Probably after I've got this up and running I'll sell the whole lot and look at an s50 :)
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Sat Oct 25, 2008 11:17 am

Hello matt, How was your holiday? your is is going to be mental with that rotrex on it! Fancy making another one of those inlet manifolds to match the itb's you sold me? Ive gotta pop down and see this once its done! good luck buddy!
appletree
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Sat Oct 25, 2008 11:21 am

Yes thanks mate it was good, hows your build going? i havent seen a thread yet!! i could make another but it would be to heavy in stainless for what you need, you'd be better with carbon fibre or fibre glass :D i needed it more for the strength although i would have used ally if i could have found some one to weld it up at a desent price and who wouldn't mint me keep going and trying it then bringit back and doing abit more :D
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HarvyS
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Sat Oct 25, 2008 12:16 pm

Its going slow at the moment, its just trying to get the time to do everything. Im going to go the cf route like you suggested but need a mould to make it off and then the time factor comes in again! not enough hours in the day! Are you running a standard inlet port size? If so i might be able to twist the arm of my welding tutor and see if he'll make you one up in ally! I would say i'll gas weld you one but I don't think either of us would be happy with the finish! lol!
Last edited by HarvyS on Sat Oct 25, 2008 4:12 pm, edited 1 time in total.
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Gunni
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Sat Oct 25, 2008 4:03 pm

appletree wrote:ya, gunni cant agree more, does anyone think it would be a good idea to put a parshal divide down the centre of the manifold say 2" back from the inlet opening and 2" back from the outlet side to help split the airflow to cylinders 1/2 and 3/4 and also to as support? :D
Don´t do that, allow the manifold to "self" adjust, if you purposely divide things you might make a bad manifold worse/per individual cylinder filling
hoshy wrote:
Gunni wrote:Manifold is taking a nice shape.

key in reliability and longevity is tuning.
Sounds like somebody has an interest in tuning this one :) And I don't blame you mate.

Matt - this is gonna be one ******* sweet project! I'm still hoping we can get ours head to head before you take it off the road so I really need to pull my finger out! Either way I'll be keeping my eye on this one dude!
I like to tune lot´s of things :)
With great challenges comes great engineering.

Gunni
@ 2012 VEMS group buy !!
Karan
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Sat Oct 25, 2008 4:24 pm

nice work!
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DieselMeister
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Sun Oct 26, 2008 4:58 pm

Sweet project for an already awesome car - keep the progress updates coming :thumb:
appletree
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Thu Oct 30, 2008 10:28 pm

look what turned up at work when i got back from site today!

Looks a a realy nice bit of kit, only thing that i would change on it is to have bigger bolts than 4 M6's to hold it on to the bracket.

heres the pics, very compact, its a c30-94 the biggest they do in the c30 range 250-400bhp

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the two intercoolers i bought off ebay also came ones from a saab and has 45degree doward inlet and outlets and the others a Volvo one with 90degree inlet and outlets.

The Volvo one

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The Saab one, larger flow channels ( if thats what there called) but smaller in depth and has slightly smaller inlets.

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Lastly the two togeather the Saab one in front.
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:cool:
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Karan
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Thu Oct 30, 2008 10:37 pm

are you getting a full ally one made...as those stock plastic end tanked ones can be dodgy at higher boost.

theres plenty of cheapies on ebay :cool:
jaistanley
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Thu Oct 30, 2008 11:58 pm

That looks like a fun piece of kit. Are you sticking with the stock internals?

What's the efficiency of a unit that size at the boost/flow rates you'll be running? Will you need a massive intercooler?

I'd love to strap a big one of these to my S50 :cool:

Awesome project man. Liking the inlet manifold design. Neat sollution.

Jai
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appletree
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Fri Oct 31, 2008 7:44 am

Best i can do is give you the link to the rotrex data sheet on there web site.

Direct link to the sheet in PDF mine is the last graph C30-94
http://www.rotrex.com/pdfs/Rotrex_Techn ... e_V4.0.pdf

My pressure ratio is around 2.2 which gives me around 74-76% effiecency.

As regards the internals the crank is forged anyway and ive bought some forged rods from australia, and Ant is going to be building the bottom end up for me with some low comp pistons, yet to speeck with him but i think it will be around 9:1 using what ever company he uses for his pistons.

The only other thing i want to look at is the soidium cooled valves the engine has i think it might be worth swopping these for solid ones given the power goals i'am aming for :D Dont want them to get hot and drop off. :cry:

The idea with the intercoolers is to use them to use them to mock everything up then if they fit get a firm to make one up in ally.

Only thing is now looking at the size of the charger its looking like its going to have to go on the pass side of the engine as its alittle big which is a pain as it means the flow of the charge cant go from one side of the bay to the other throught the intercooler, instead it will have to go in at the bottom the the intercooler and the come out on the top both on the pass side which wont be great for flow and not that easy to pipe to as i will have do some clever pipeing not to have to cut up the body.

Going to wait and see what Ant comes up with as he is also working on a bracket also, although i dont know what size of charger he is using :D
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Fri Oct 31, 2008 11:30 am

Sweetness.

One thing that I'm very curious about is the power / torque delivery of the C30. I'd assume that given the design and type of charge that it swells with revs but that you can swan around under 3.5krpms with enhanced torque if you so please? Does the power tail off at the top of the rev range?

Also, it's hard to tell how noisy the charger will be from the videos I've seen. It's good to hear it but a balance versus the exhaust / induction would be good.

Jai - did you see the video of the S50'd E30 M3 with the C38 on it? Hubba.
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Fri Oct 31, 2008 11:52 am

Heres a video to show the sound of noise you get, i think you will still get a bit of belt whine but not as much as i get at the minute with the eaton which is louder than my exhaust with just a back box in the system.



Love the noise between the gear changes :cool:

As regards the power delivery they do make boost from very low RPM but gain boost all the way to the redline making more and more boost all the time, where as my current eaton has loads of torque low down but runs out of boost at higher rpm it runs 8psi at 3k and at 6.5k :D
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Fri Oct 31, 2008 5:55 pm

IIRC those centrifugal SC's are very quiet, it's the screw noise we all associate with the whine you get from older SC's.

Manifold looks great! Can you get the SSteel in 3inch?

Fozz
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appletree
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Fri Oct 31, 2008 6:04 pm

ya i can get lengths or 45 or 90 d bends from 1" to 4" in 1/2" incraments from work 316 or 304. But no 3 1/2" for some reason
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Fri Oct 31, 2008 6:36 pm

Cool, I'd like to pick up the same list as you, in 3inch, just cos everything else is 3inch :cool:

I've got the stock manifold flange cut off and need some ali pipe to have some stubbs welded on, then silicone hose connections to the runners off the manifold. Maybe even give me some length adjustment too.

I can't TIG but I can just mig, so stainless seems best idea for me, I'll leran to TIG when I can afford one.

Could you pm me some prices? also did you bandsaw them in half?

The plate facing the head, or outside of the manifold is going to be aprox 100 x 560mm, any chance have any sheet too?

Fozz.
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DieselMeister
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Sat Nov 01, 2008 12:27 am

appletree wrote:Heres a video to show the sound of noise you get, i think you will still get a bit of belt whine but not as much as i get at the minute with the eaton which is louder than my exhaust with just a back box in the system.



Love the noise between the gear changes :cool:

As regards the power delivery they do make boost from very low RPM but gain boost all the way to the redline making more and more boost all the time, where as my current eaton has loads of torque low down but runs out of boost at higher rpm it runs 8psi at 3k and at 6.5k :D
Cool - thanks. Fozzy as well.

BTW - I want that Integra. No, scratch that - time to get my rusty sport sorted and boosted!
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Sat Nov 01, 2008 10:59 am

Nice project :cool:

Have you thought about using E85 fuel(or LPG) ?

Might be handy for track days to give you a bigger margin of error to avoid det' ?

Dave could easily make you a map for it, just make sure you've got an E85 out let near you, i know there's a Morrisons not far from Dave's that sell it.
rix313
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Sun Nov 02, 2008 12:47 am

Interesting stuff :)

We use Rotrex chargers on the cars at work, the owner came to visit once in one of his twin charged f430's :mad:
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Tue Nov 04, 2008 9:44 pm

Bump - appletree, what are you doing on the management side? MS or VEMS? Also, brakes? :wink:
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hoshy
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Wed Nov 05, 2008 9:46 am

DieselMeister wrote:Bump - appletree, what are you doing on the management side? MS or VEMS? Also, brakes? :wink:
Perhaps sticking with the Emerald from the current setup?
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Wed Nov 05, 2008 8:59 pm

Cool. I'm not an expert but I read with interest! Anyway, how does Emerald compare to MS in terms of features and price - broadly equivalent? More "up market"? I've got a web-phobic friend who's thinking about FI for his 318is. Working on getting him signed up :)
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Mon Nov 10, 2008 7:51 pm

Done a bit more to the plenum at the weekend and managed to get it welded up, had to cut the large opening of it to make it fit correctly as the angle was all wrong and made the inlet point to the fop of theinner wing, it alot better now but i still think it could do with a 45d bend pionting down to make it line through :D

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A rough idea as to how the inlet will fit and were the supercharger will go :D

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had abit of spare time to day so set up a "work bench" much to the girlfreinds dislike :evil: and stripped the housing off the charger to rotate it as the oil in-out has to be at the top of the gearbox.

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Inside the rotrex

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With a bit of space to draw things out and work on another spare IS engine ( i now have 4, cheers Kedge) i was able to start making a mock up of the mount from ply-wood.

The motor mount

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Afew pics of how it will al sit, the mount will be made of two parts which will be bolted togeather at the 90d bend.

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And alittle bit of engine porn for you this is an engine my freinds having built to go in a TVR segaris! :twisted: :cool: nothing like a bit of inspiration :D
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GrindCulture
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Mon Nov 10, 2008 8:57 pm

That inlet manifold looks really good, top work :cool:
Not in E30s any more :(
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Wed Nov 12, 2008 12:48 pm

you should try a company called Pace they make good Front Mounted Intercoolers. I had one on my fiat coupe turbo i was running 280bhp and i had no probs what so ever..

i am currently doing a supercharged m42 my self but will just be using the mini cooper one to start with..
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Wed Nov 12, 2008 7:20 pm

inlet looks brilliant. good work
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