turbo a e28 2.7

[Luke 0]

how much pressure would a 525e motor take. as i am looking at slaping a turbo onto it.

cause im building a track/club day car. and want more power

[bmw.maniac 1]

I know nothing about turbos, but don't they work at higher revs (as opposed to a super charger that works at lower revs) so fitting one to a low revving eta engine (that redlines at 4500rpm) would be rather pointless?

[Luke 0]

I know nothing about turbos, but don't they work at higher revs (as opposed to a super charger that works at lower revs) so fitting one to a low revving eta engine (that redlines at 4500rpm) would be rather pointless?

well i was looking at putting a higher reving head on it

[Mike 1]

Your question is pretty vague sorry, and much more to a build than just "slapping" a turbo on. What head are you going to use? this will affect the C/R. any strengthening mods to the motor like o-rings or head studs? what engine management were you planning on? intercooled? drive-train upgrades?

all those factors affect how much boost you can safely run. if you're a bit lost on all of that you'll definately need to read up a bit more. e30tech.com has heaps on info on turbo M20's.

[Luke 0]

Your question is pretty vague sorry, and much more to a build than just "slapping" a turbo on. What head are you going to use? this will affect the C/R. any strengthening mods to the motor like o-rings or head studs? what engine management were you planning on? intercooled? drive-train upgrades?

all those factors affect how much boost you can safely run. if you're a bit lost on all of that you'll definately need to read up a bit more. e30tech.com has heaps on info on turbo M20's.

Well you kind of missed my point. hence the reason i asked how much pressure (meaning, how much boost would a stock block would take.

and for the head ill use e28 2ltr head, that should give me a little more rev range

[topcat 11]

to run a 'safe' setup i recommend 6-12psi. stock internals and stock head gasket.

want to go further??? dont see why you couldnt run 25-30psi, just like the jap's.

but that involves a full re-build,with rods,pistons,flash HG,head studs,head mods

basic rule to follow;

in a perfect setup (efficient) 15psi boost = 100% more hp over factory

m20 bottem ends are surposed to be good for 500hp.

this is going to be a great tread,

[CamB 48]

Well you kind of missed my point. hence the reason i asked how much pressure (meaning, how much boost would a stock block would take.

and for the head ill use e28 2ltr head, that should give me a little more rev range

I'm not sure he did miss the point - you are being a bit vauge.

Stock block - heaps

Stock rods - heaps

Stock pistons - depends on if you tune it right

Stock head - depends, but more than enough

Stock headgasket - depends on if you tune it right

Stock headbolts - depends on if you tune it right

Stock fuel pump - heaps

Stock injectors - bugger all

And in any case, it depends on the turbo and how good the intercooling is. Not all 15psi is created equal.

Edited October 27, 2008 by CamB

[Mike 1]

Well you kind of missed my point. hence the reason i asked how much pressure (meaning, how much boost would a stock block would take.

and for the head ill use e28 2ltr head, that should give me a little more rev range

no i didn't. 15psi with a low comp head, intercooled, good exhaust, decent managemeent and tuning is going to be much safer than running a hi-comp head, tiny turbo, poor management at 10psi. (note: hi-comp for turbo is not a bad thing, just need to be more careful with tuning). What boost is safe to run depends greatly on your setup.

as other have said, with a good tune the stock block will take heaps, but thats not going to be your limiting factor.

[Luke 0]

ok thanks guys,

Sorry for sounding rude mike, was half asleep..

As for the turbo its self. i would be looking at somthing off like a GTS25T or a VF8.. but the hole, turbo thing wont be getting done within the next 8 to 10 months, wanna sort my gearbox problem first

Edited October 28, 2008 by OmEn

[Boost Junky 1]

M20's redline at 4500?

[Silver Fox 43]

M20's redline at 4500?

525ee motor.

[JiB 0]

M20's redline at 4500?

I think they mean the B27 motor? My B25 is only starting to pull at 4,500rpm.

[Boost Junky 1]

Oh duh b27 yea makes more sense haha

[CamB 48]

Those turbo's might be a bit small for what you want - they'd choke off the top end (assuming you change the head, etc).

For a M20B25 or B27 I think you need more like a mid-sized T3/T4.

[bekker 7]

I'm really keen to know how you get on. I don't claim to know much about forced induction on BMW's (or anything else come to think of it) but I figured a turbo B27 would, due to its low redline, setup kinda like a turbo diesel. It's also why I thought a supercharger may be a good option for this motor - boost the low down torque. But turbo diesels work well, why wouldn't this?

I'm most interested because I like the idea of increasing power, not massively, without having to tear the engine down and do a HP rebuild.

Am I right in thinking (from what was said earlier in the tread) that on a stock engine, you could double the power output (with forced induction)?

Why is turbo charging so much more popular than supercharging? From purely an engine bay point of view is supercharging an easier install?

That's more than my daily allowance of questions.

Cheers

[No name user 379]

the amount of boost you run means nothing,its how much cfm it can withstand

every turbo has a flow rate based against the hp you want to make

ive done diesels making 500hp and rev to 3k on low psi,get the idea?

the supercharger takes 33% of crank power to turn it

turbos take between 5-7% depending on the threshold point and the unit its self

[Guest FrantiC]

I'm really keen to know how you get on. I don't claim to know much about forced induction on BMW's (or anything else come to think of it) but I figured a turbo B27 would, due to its low redline, setup kinda like a turbo diesel. It's also why I thought a supercharger may be a good option for this motor - boost the low down torque. But turbo diesels work well, why wouldn't this?

I'm most interested because I like the idea of increasing power, not massively, without having to tear the engine down and do a HP rebuild.

Am I right in thinking (from what was said earlier in the tread) that on a stock engine, you could double the power output (with forced induction)?

Why is turbo charging so much more popular than supercharging? From purely an engine bay point of view is supercharging an easier install?

That's more than my daily allowance of questions.

Cheers

With boost, yes you can double the engine's output power.. Though achieving that can take alot of $$$ and effort, but it is achievable.

Diesel motors are completely different. They run high compressions like 22:1, as they pretty much run off of compressing fuel and detonating. In a petrol engine, the fuel must be ignited and burn to give it the best power. Detonation is BAD.

The low redline is there as the head can not rev any higher than 4500rpm (single valve springs, 4 journal cam). Reving it any higher it just wouldn't last, and the cam will not allow it to make much power past 4500rpm anyways as the stock b27 is a low HP high torque motor, with max power achieved before 4500rpm.'

You would need a pretty small turbo to boost low and spool up before the 4500rpm mark (idealy around 2200 for max boost), But this is where the motor peaks in torque. A stock b27 has either 10:2, or 11:1CR so adding boost is already not a good idea as the compression is too high (causes detonation- where fuel mixture blows before it is ignited)

It's a waste of time. The ETA head flows sh*t, The compression is way too high. The head in incapable of revving any higher to handle the extra power.

Do what I did, Get the better flowing 885 head from the e30 325i's, Add a thick Steel headgasket for a CR of about 8:7/8:8:1, Stick it on the b27 bottem end and you have a high flowing, higher revving (double valve springs) boost ready 2.7L motor.

Edited September 28, 2009 by FrantiC

[No name user 379]

With boost, yes you can double the engine's output power.. Though achieving that can take alot of $$$ and effort, but it is achievable

NOT ALWAYS THE CASE

Diesel motors are completely different. They run high compressions like 22:1, as they pretty much run off of compressing fuel and detonating. In a petrol engine, the fuel must be ignited and burn to give it the best power. Detonation is BAD.

THEY ARNT WHEN IT COMES TO MAKING POWER

The low redline is there as the head can not rev any higher than 4500rpm (single valve springs, 4 journal cam). Reving it any higher it just wouldn't last, and the cam will not allow it to make much power past 4500rpm anyways as the stock b27 is a low HP high torque motor, with max power achieved before 4500rpm.'

You would need a pretty small turbo to boost low and spool up before the 4500rpm mark (idealy around 2200 for max boost), But this is where the motor peaks in torque. A stock b27 has either 10:2, or 11:1CR so adding boost is already not a good idea as the compression is too high (causes detonation- where fuel mixture blows before it is ignited)

AGAIN NOT THE CASE HIGH COMP CAN WORK WELL EVEN ON PUMP GAS,SETUP AND TUNE CAN OVER COME ALOT IF YOU KNOW WHERE TO AND HOW TO DO SO

It's a waste of time. The ETA head flows sh*t, The compression is way too high. The head in incapable of revving any higher to handle the extra power.

IF YOU REVESE ENGINEER PROBLEMS CAN BE OVER COME,IM NOT SAYING YOULL PULL 8K OUT OF IT BUT YOU CAN IMPROVE OVER WHAT IT IS.

Do what I did, Get the better flowing 885 head from the e30 325i's, Add a thick Steel headgasket for a CR of about 8:7/8:8:1, Stick it on the b27 bottem end and you have a high flowing, higher revving (double valve springs) boost ready 2.7L motor

IM IN NO WAY BAGGIN WHAT YOU SAY BUT FOR SOME REASON ON THIS SITE EVER TIME I PASS ANY IDEAS OR ANOTHER OPINION IT GETS WALKED OVER OR BAGGED.

IVE DONE ENOUGH OVER THE LAST 20 PLUS YRS TO HAVE SOME IDEA WHAT TO DO WHEN IT COMES TO TURBOS,

THERES MANY WAYS TO SKIN A CAT

[Guest FrantiC]

Dude, I haven't bagged what you said in any way, I directed my answer directly to the questions asked.

Yes you can run boost on high compression, but it isn't a good idea. 11:1 is abit too much, especially for an m20. The higher the compression ratio is, the lower amount of boost you will b able to force into the motor as it will start knocking and detonating very easily. They are also much harder to tune engines with a higher CR.

Diesel turbo is a completely different story to a petrol turbo motor. Different characteristics, power outputs, fueling, ignition etc. There isn't much comparing the 2 other than exhaust gases spinning a turbine forcing air into the motor. Everything else is pretty different, in terms of how the power is made with this forced air.

It's a waste of time. The ETA head flows sh*t, The compression is way too high. The head in incapable of revving any higher to handle the extra power.

IF YOU REVESE ENGINEER PROBLEMS CAN BE OVER COME,IM NOT SAYING YOULL PULL 8K OUT OF IT BUT YOU CAN IMPROVE OVER WHAT IT IS.

That is a waste of $$$, The head requires too much work to have it even remotely near the 885 head which is far superior and already ideal and readily available to go on the b27 bottem end.

And trying to get double the amount of power output from a standard N/A motor (take the m20b25 for example, 171hp), double HP would be 342HP. No way you will get 342HP out of an m20b25 on the cheap.

Not making any personal attacks here, Just mostly my opinion and a fair bit of debate I guess.

Edited September 28, 2009 by FrantiC

[No name user 379]

well i disagree on the diesel side of things

as for the rest that you cant get double the power without spending big dollars?

ill call back my customers that have

ill let you now what a m30 can do stock,i have a 635 and a 535 to do,

i would tell about my m50b25 but I'm sure most wont believe me anyway

still guys like mike delmont got a reasonable result from my setup,

but it does stand true in here about being ignored,whether its a BMW or not they all make power the same way at the end of the day its not rocket science

and like most out there the BMW is a great car but still just that,a car

i wouold say who i am but i dought it would mean much i here

Edited September 28, 2009 by crunchy

[Guest FrantiC]

There is a difference between making double figures and making double figures Reliably.

I no way doubt it is possible, of course it is, but I just don't think it is something you can do properly without spending the money.

How much do your 'customers' pay and what are some stories of double figures from stock?

[No name user 379]

There is a difference between making double figures and making double figures Reliably.

I no way doubt it is possible, of course it is, but I just don't think it is something you can do properly without spending the money.

How much do your 'customers' pay and what are some stories of double figures from stock?

go read my column in the nzpc mag,and do a back track over the last 11 yrs I've written for them and the list of cars ive done.

i believe there's a few world records in there some where,but don't take my word for it

[CamB 48]

Yeah John - please don't argue with Steve. He's been doing this for longer than you've been alive, and we (as a forum) would do well to encourage him to stick around. When my 2002 is up and running, I'm going straight to him for a turbo to match it.

It may simply be a different definition of $$$ and effort. For instance, $5k to double the output on an M20 could be considered cheap or expensive (I think its cheap), but that is doable if you can fabricate and weld well.

[No name user 379]

Yeah John - please don't argue with Steve. He's been doing this for longer than you've been alive, and we (as a forum) would do well to encourage him to stick around. When my 2002 is up and running, I'm going straight to him for a turbo to match it.

It may simply be a different definition of $$$ and effort. For instance, $5k to double the output on an M20 could be considered cheap or expensive (I think its cheap), but that is doable if you can fabricate and weld well.

thank you for that but i guess in all fairness to him everyone has a different way of doing things.

considering a stock rebuild using oem parts would set you back 3-4k then aftermarket upgrade parts are cheaper thus you can build a good engine well and on a budget.

a well setup turbo sized to suit any car can make numbers a be responsive and make power on lower boost if you look into things with a open mind

high compression can be over come but the ecu and tune is most important but you still make good power,the mechanical strength of parts are your limits even with heads that dont flow well you can still find power if you reverse engineer as in flow bench the head first and work out its limits you ll better result.

i also base the cams used on flow bench numbers

not alot of point using a cam with .400" lift when the head runs out of flow at .350", thats called over camed.

im not a big fan of thick head gaskets to lower compression,reshaping the head chamber and piston bowel gives a better flame area and more thermal bang thus greater exhaust energy for better turbo response.

big cams do work well on turbos with more overlap for the same reason.

and on that note i very much enjoy helping people to the best of my knowledge to which is why ive written for the nzpc mag FREE for the past 11 years, i believe that way im doing it for the right reason.

im far from being right about everything and i don't confess to know it all.

i guess based on things ive posted on here before and the response it gets my back up as i dont get alot of spare time even for my own projects or family.

Edited September 29, 2009 by crunchy

[*Glenn* 854]

The problem in here Steve is, a few have a little knowledge about something, and then they seen to become experts overnight about everything and talk alot of sh*t at times.