Eggenbeefburger Grp2 e21 BMW 320

[Hoobs]

I go and collect it once I get back from Cornwall next week.

I cannot believe the difference in my car. It feels so much better than it did before. It was OK but just felt a bit clumsy. I can't explain exactly but on the limit, especially when oversteering, it was never a smooth transition. I'm sure the lack of PAS and an e36 rack meant that steering was heavier than ideal but it was more than that alone. Anyway, having moved the steering column slightly and brought the steering wheel slightly nearer my chest, I have far more control. It feels lighter too. Combined with the extra engine performance, it has really transformed the whole car.

When the guys at Pristine did the cambelt last week, they found the old one had been fitted one tooth out. Now I know this might sound daft, but is there any possible reason why someone might deliberately do that? I mean the engine seemed fine and there certainly didn't appear to be a problem with timing. It just seemed a bit odd and I have always thought that one tooth would be enough to have an adverse effect on running? What do you guys think?

Finally, do you think I should cam my engine?

[Mikey_Boy]

^^^

Great stuff! Car looks fab....

If you are running a 6 branch on an M20, I would definitely fit a cam to make the most of it - a little leftfield, but Newman cams are very very good IMO...

[Hoobs]

Thanks for the positive comments.

I think I'm going to start looking for a cam that gives maximum torque as opposed to outright power. I'll combine it with the MAF conversion in order to make the most of it.

I'm down in Cornwall and running the car around for a few days has meant I have been able to get more used to it. I'm still surprised at just what a difference the splitter has made and how 'together' the car feels as a whole.

On a side note, I went and saw the Cornwall Air Ambulance crew today and they asked me to pass their thanks to anyone that's made a donation. Thank you!

http://uk.virginmoneygiving.com/fundrai ... arkBrown12

[Brian28]

Hi Mark, you need a reground camshaft to Schrick 272 degree profile for a very reasonable £150 posted. Bought it (used but good condition) months ago intending to fit to mine and it's still on the shelf, unless things change it'll be there for a long time waiting for me to get anything done with it.

[HairyScreech]

From what i have learnt over the last couple of years some head work will give better results than just a cam.
Nicely executed head work will produce a similar gain to a cam without the loss of low speed torque a cam causes.
A big cam on these engines can be looked at like a quick fix to increasing air flow, you get more air in by opening the valve for longer rather than making what is there work better. Its kind of like having a bad exhaust design and just making it all 10% bigger rather than fixing the design.

Rec valves in the UK do larger inlet valves that will work with stock seats, this with some head work will come to around the price of the cam (if you know someone who can do it) and will produce a larger average gain that the cam.
And lets face it an average gain rather than a peak gain is what you are after for an engine that will have to lug an e30up a hill. Its no good having 400hp at 20,000rpm if you need to pull weight.

[Hoobs]

I must admit I had always thought there were minimal gains to be had by flowing an m20 head. I did have a feature (Car & Car Conversion I think?) where Dave Walker spent some time trying to improve upon BMW's effort. He concluded it just wasn't worth the effort.

The larger inlet valves sound worth going with. Would you suggest running the standard cam with them or just something milder than 'full race'?

Any idea what I could get from a healthy 2.5 that runs a head to the spec you suggest, a MAF conversion and decent 6 branch? I've heard all sorts of power figures (Fritz always say a chip and there 6 branch will realise 200 brake from an otherwise stock 2.5! ) but what's a good, achievable output for a 2.5?

[Speedtouch]

Well, fitting the cambelt on one tooth out would certainly knock the power!

Alpina's C2 2.5 achieved 192bhp with some light head work, 268/268 cam, six-branch, BBTB and chip.

You'll struggle to get 200 bhp on a N/A M20B25.

[HairyScreech]

I have heard that before, but with all respect to mr walker its a load of bollocks, the m20 head may not have the level of gain that a rusty pinto head has but there is plenty of room there for work. Things like the kent head peak at around 60% efficiency, the 885 peaks around 80% which leaves less to be found. (per square inch so not an absolute)
Nasty 70s ford heads pick up flow in orders of magnitude, the bmw stuff your only looking at 10-30% without reshaping the ports. With the ports re-shaped and the valve size increased then the sky is the limit.

There is no way a b25 will ever get to 200hp with just a 6 branch and all the chip will do is provide correct fueling.

The increase in inlet valve size is significant, a 43.5mm valve provided a 7.5% increase in the available valve area and imo (and many others) the m20 suffers from too little inlet valve. The beauty of making something bigger in this application is the flow literally scales with size, so there's about 7% minimum just in that.
Obviously if going for the larger inlets then there is the need to recut the seats, this means multi angle seats, this will make the benefits even greater.
I wouldn't bother with the exhaust its fine up to about a 45mm inlet.
This combined with some basic work to the casting could well see decent benefits.

I try not to make predictions and much prefer to let a dyno sim do it for me. (i am using a version of engine analyzer pro atm)
using the b25 model i built to look at the b28 and making the relevant changes i am jumping from 168hp stock to about 180hp with no other alterations, the 6 branch makes it 195hp, and using the 9.7 comp pistons sees another 5hp with more torque.
that is all still using the stock cam profile.
(however a 2.8 short block puts another 20hp on that combination but that's another story)

The m20b25 uses a stock cam that would be considered fairly hot in a 4v head, and the 272+ duration cams are really quite large when compared to other applications. (For comparison the biggest cam kent do for a zetec without upgrading to solid followers is 278)
A cam is considered to really wake these engines up because quite simply there low compression and comparatively average flow means the dynamic compression is not great, boosting the flow and the static compression will get the dynamic compression up and will wake things up a lot more than a cam can on its own, the cam is a sticking plaster to mask the issue rather than solve it.
A good example is to ask why the m50b25 is 195hp stock?
considering it is all the same realistically in bottom end terms same bearings, same piston skirt design, roughly the same chamber shape, same block material, same lack of windage control, similar external accessories.
The gain is all in the increased compression and the improved head. Why to people covet the 4v design? increased valve area and improved flow.

Of course the later engines have something else that benefits the m20 hugely, a better management system.
The entire m50nv system has been fitted before and i am quite sure the whole m50tu system could be done as well, the advantage being that it would be able to run a tuned m20 without the losses and quirks that the m1.3 imparts.
(i said before i will post the info i looked at to do the conversion and i will actually get onto it today while helping the mrs ebay stuff.)

[HairyScreech]

Well, fitting the cambelt on one tooth out would certainly knock the power!

Alpina's C2 2.5 achieved 192bhp with some light head work, 268/268 cam, six-branch, BBTB and chip.

You'll struggle to get 200 bhp on a N/A M20B25.

I'm glad you posted that while i was typing, that puts my simulation bang on in the ball park.
Its nice to be able to validate things against the real world when you simply dont have the finances to go out and do everything.

As for the cam belt issue i just though thats a question for the sim.

i think 1 tooth is about 4 degrees.
Stock with 6 branch its 177hp and 175lb
4 degrees retarded is 180hp and 178lb
4 degrees advanced is 173hp and 176lb

So i guess it depends which way it was out......

[Hoobs]

i think 1 tooth is about 4 degrees.
Stock with 6 branch its 177hp and 175lb
4 degrees retarded is 180hp and 178lb
4 degrees advanced is 173hp and 176lb

So i guess it depends which way it was out......

Unfortunately I don't know but this was the dyno print-out when the only mod was a 'wild' chip from Speedtouch. As I said before, it seemed to run sweetly enough although I was a little disappointed that it wasn't even making factory power.

As well as now being timed correctly & clearances done, it now has a decent quality 6 branch fitted. I plan to return to Surrey Rolling Road once home again next week. It certainly feels better than before but that could just wishful thinking? I'm definitely thinking of going for some head work if I don't opt for an engine swap.

[Speedtouch]

I'm glad you posted that while i was typing, that puts my simulation bang on in the ball park.

Its nice to be able to validate things against the real world when you simply dont have the finances to go out and do everything.

As for the cam belt issue i just though thats a question for the sim.

i think 1 tooth is about 4 degrees.
Stock with 6 branch its 177hp and 175lb
4 degrees retarded is 180hp and 178lb
4 degrees advanced is 173hp and 176lb

So i guess it depends which way it was out......

It took you an hour to type your post after mine?

Surely, advancing it a bit would give a small power increase, and retarding it slightly less - otherwise, why would conventional distributors have centrifugal advance weights to give more advance with increasing rpm?

[Demlotcrew]

From what I understand, you need some restriction on the inlet ports as it promotes higher gas velocity, higher inertia supercharging, better fill and ultimately higher cylinder pressures.

Maybe Mr Walker knows his heads?

Andrew

[DanThe]

I'm glad you posted that while i was typing, that puts my simulation bang on in the ball park.

Its nice to be able to validate things against the real world when you simply dont have the finances to go out and do everything.

As for the cam belt issue i just though thats a question for the sim.

i think 1 tooth is about 4 degrees.
Stock with 6 branch its 177hp and 175lb
4 degrees retarded is 180hp and 178lb
4 degrees advanced is 173hp and 176lb

So i guess it depends which way it was out......

It took you an hour to type your post after mine?

Surely, advancing it a bit would give a small power increase, and retarding it slightly less - otherwise, why would conventional distributors have centrifugal advance weights to give more advance with increasing rpm?

Distributors and cams are very different

[HairyScreech]

From what I understand, you need some restriction on the inlet ports as it promotes higher gas velocity, higher inertia supercharging, better fill and ultimately higher cylinder pressures.

Maybe Mr Walker knows his heads?

Andrew

Indeed, just hogging ports out to as large as they will go will only cause an increasein flow at the expense of velocity, this will probably lead to a peak gain and a total fail at all other areas.

The 885 ports are a bit on the large side stock but have some pretty awful casting issues (as does the m52 head i have just acquired, couldn't believe it) simply fixing these is of a fair benefit.

The reason for a particular size is the need to keep velocity in the port high in order to maintain the inertia filling effect. Without which VE of over 100% would be near impossible.

Modifications that improve the shape of the port rather than the size are what's needed.

Tbh the 885 port needs the floor filling to really get the best out of it, but even still using the 731 would mean new seats and a lot more port work and a thinner casting. Swings and roundabouts.

And yes my post did take an hour as i had to run the sim while posting as i hadn't tried that particular combination on the new software.

Edit - oh and its not so much about restriction in the inlet its more about a cross section of the right size so that the air is channeled into it and speeds up. (bernoulis principal for any that want to look it up further)
If done right this can be accomplished with minimum restriction in a similar manner to a venturi.

If this stuff is your bag then i recommend checking out the speedtalk forum, its mostly small block chevy waffle and there are a lot if people stuck in the past but there are also a lot of very clever experienced guys on there.
Www.speedtalk.com

[Hoobs]

Lots to think about.

Just in the door from Cornwall and the old girl never missed a beat. Few hairy moments on the A303 thanks to standing water and Toyo 888 combo! Kept me focussed!

Long shot I know but is anyone here going to Brands on 20th?

[Theo]

Who's running the day at Brands?

[Hoobs]

Circuit Days (it's an evening session)

I'm taking my car back to Surrey Rolling Road on Saturday so should be able to see what difference the six branch has made. The cam belt is no longer one tooth out either. I'll try and get on the scales today too.

Anyway, a couple of pics from Crystal Palace last week.

[Hoobs]

Had the car on the Surrey Rolling Road dyno again today, so I can see if the 6 branch made a real difference.....or not.

Well, it made 170 and as you can see, there is a slight improvement right across the rev range. The mixture leans off at the top though and I probably lose a couple of brake as a result.

I think the future is m52 shaped. I'm just going to enjoy the car for now. Once winter comes it'll be M3 arches, bigger rims and m52.

[Speedtouch]

Good result - how many miles has the engine done, and is that at the flywheel?

Also, is yours a low compression 25 6E engine, or the later 25 6K?

[Hoobs]

Good result - how many miles has the engine done, and is that at the flywheel?

Also, is yours a low compression 25 6E engine, or the later 25 6K?

tbh, I'm not sure? I'll take a look next time I take to bonnet off. As for age & mileage, again I have no idea. The car started life as a 316 but was upgraded by someone on the zone. It was then sold to someone else, who threw in the cage & seat, but sadly he died last year. I bought the car from his widow. Because it was an unknown quantity we gave it a full and thorough service and that was when we noticed the cambelt being a tooth out. It seems like a good, tight engine though. I've done 3 track-days and a couple of sprint events with no hassles, so far.

I am currently having thoughts of a Nissan SR20 engine. Thoughts?

[Hoobs]

I'm looking at what to do as the next stage of mods and am thinking it's likely to be removal of the boot floor and rear bulkhead. We'll also take a section out of the rear valance to aid air flowing from under the car.

Just wanted to see if anyone else has already done this and if so, are there any things to watch out for?

I'm looking at using alloy sheet, to replace the steel we take out, but also adding an extra diagonal to the cage. The standard doors will be replaced with fibreglass, along with M3 arches and rear quarters, to accommodate staggered 16'' rims & wider rubber. I'm also on the look-out for a smaller fuel tank & swirl pot. Once that lots been done, it'll be M52 time.

[Hoobs]

Ordered M3 arch kit today, from the good folks at Pesch Motorsport. I only got the arches & side skirts though, as I'm not looking to pretend it's an M3. I just think the box arches look better than the alternatives on an e30.

http://translate.google.co.uk/translate ... md%3Dimvns

Kind of look I want, although sticking with satin finish.

[redcar]

Cool, how are you going to join the rear arches. Are they fibreglass?
Are the arches going to be tubbed also?

[Demlotcrew]

Mark what currency are the prices in?

Also Im looking forward to what you think you will be able to make work with regards to staggered 16" wheels with wider tyres.

Unless you are planning on running different outer diameter tyres?

[Hoobs]

I think it's Polish but the cost for both front wings, both rear quarters and the side skirts was £340 delivered to the UK. The quality of their stuff is very high too.

I'm not entirely sure on rims yet Andrew? It may well be that I simply stick with usual M3 choices.

These would be nice though.

http://www.ebay.co.uk/itm/360463249087? ... 1712wt_794

[ross_jsy]

If it is Polish Zloty, a fibreglass bootlid is coming in at nearly £400

Also they are the exact pictures that ABS motorsport use. You sure they are legit?

[Hoobs]

I must have the currency wrong then, as the whole kit is about that price. The bootlid is less than the front wings, which were £145 a pair.

Yes, they're definitely legit - I think Duracell (with the yellow race e21 who's on here) bought the group2 tii kit they list) A few other people I know of used them too.

Czech Republic I think?

[Demlotcrew]

Ive got those on my car in my sig!

They are really really nice wheels, perfect for everything, light, good offsets, great brake clearance and they are staggered!

Only problem are the tyres. No one makes a decent range of 16" R tyres, which is why I asked what your plans were.

You might have to run a larger outer diameter tyre on the rear, but then you have clearance issues when trying to keep to optimum ride heights.

You might be able to get away with a 195 50 16 on the front and a 225 45 16 on the rear (R888) but thats just a rough guess, need to look at their site for numbers.

This is a 225 45 16 R888 on a 8j rim with an offset of ET5



Problem with those is that they are too big, heavy and unless you have a Turbo M52 they will slow you down.

[Hoobs]

I'll start searching out tyres a bit nearer the time. I noticed the rims in your sig just after I posted (honest! ) and they certainly suit an e30. The arches won't be here for a few weeks yet but I hope to have them on by September, when the m52 swap is planned. Mind you, I have some serious saving to do before either.

I'm off out to the local weigh-bridge shortly and am hoping for sub 1000kgs. I'm unsure how much fuel is in the tank though.

On the subject of fuel. Has anyone got a suggestion for an aftermarket gauge that will work with the OE sender?

[Demlotcrew]

Looking forward to the number from the bridge!

Stack do a very nice fuel gauge, that will work 100% its a little fiddly to setup as you will need to gradually fill the tank etc, but its worth the effort.

Can I ask why you wanted wider arches? Im running 40mm extra track over stock and no major rubbing with 225mm section tyres. I don't think I would want to go any wider without extensive custom suspension parts.

[Rallyprep_UK]

What offset / size are your wheels andrew ?

I have E36 M3 wheels (staggered) and the rears rub ever so slightly with 215/40/17's.

I need 17's to clear my front brakes though, ideally I would like to get 16's on it. I have heard that some 16's fit over the E36 M3 brakes. None which I have tried have done.

Will

[Demlotcrew]

The fronts are ET20 and the Rears are ET25 (the BBS LM Reps)

For track I run Khumo V70s on Hartge 16" Classics ET24 with 20mm spacers so the effective offset is ET4.

Both wheels clear AP 6pots with 330mm disks (Hartges = just).



Problem with 17s is that you cannot get the ride hight down far enough without extensive front and rear arch tubbing.

[duracel79]

I must have the currency wrong then, as the whole kit is about that price. The bootlid is less than the front wings, which were £145 a pair.

Yes, they're definitely legit - I think Duracell (with the yellow race e21 who's on here) bought the group2 tii kit they list) A few other people I know of used them too.

Czech Republic I think?

We bought a few panels. Very thin and lightweight, pretty good fit as well.

[Rallyprep_UK]

Thanks for the info

Problem with 17s is that you cannot get the ride hight down far enough without extensive front and rear arch tubbing.

That is exactly what I am finding, also it is hard to find good tyres in 215/40/17.

My next step is to roll the arches...

[Demlotcrew]

I think you will have to go for a 205 620 R17 but even this means you would have to find an extra 20mm+ of clearance over the 16"s.