S14 or S50?

S14 or S50?

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Discussion

e21Mark

Original Poster:

16,205 posts

172 months

Friday 13th November 2015
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I'm lucky to have an E30 M3 which I use for hoon duties here in Cornwall and occasional track days. It's modified with bigger Tarox brakes, shorter ratio diff, cage, carbon air box etc. Much as I love the s14 engine, I do want a bit more power, so I've been thinking of dropping in an s50 3.0 instead.

Ideally, I'd like a reliable 250bhp from the s14 so was thinking Schrick cams and proper standalone management? I know how expensive it can be to mod an s14 though, so would the £5k cost of the s50 swap be enough?

If I did go s50 I'd keep the s14 to go with the car, if I do ever sell it, or should I leave the e30 alone and buy an e46 M3 to go with it?

Mr_B

10,480 posts

242 months

Friday 13th November 2015
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If you want S50 power and track fun, I'd buy any old E30 and do the conversion on a cheap rolling shell. You'll probably have more fun, drive it harder and not be worried about junking a nice M3 should any track mishap happen. That said, if it's on the occasional trackday, have the E46 M3 and have a very nice usable everyday car into the bargain.

benny.c

3,473 posts

206 months

Friday 13th November 2015
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Is 250 bhp realistic? My Evo II has Schrick cams and a Motec ECU and made 238bhp when it was first converted. This was all before I purchased it so I have never really looked in to it TBH.

e21Mark

Original Poster:

16,205 posts

172 months

Friday 13th November 2015
quotequote all
benny.c said:
Is 250 bhp realistic? My Evo II has Schrick cams and a Motec ECU and made 238bhp when it was first converted. This was all before I purchased it so I have never really looked in to it TBH.
It's achievable but at a cost, which is why the S50 swap appeals. A pal of mine has just built his s14 to GrpA spec, with lairy cams, slide throttle injection, twin fuel rails etc. A parts bill of over £15k though and probably similar power to a £2.5k s54? It's a work of art though and certainly the route I'll go, when the lottery win comes along. smile

I'm leaning towards an E46 M3. I'm being emailed hi-def pictures over the weekend and it appears to have had the major concerns taken care of. The only problem really, is that I'm already looking at carbon fibre air boxes and free flow exhausts!

stevesingo

4,848 posts

221 months

Friday 13th November 2015
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What year M3 is it? Post '89 215ps have 28mm intake ports and 48mm ITBs which make getting 250mp easier than pre '89 26mm intake port 46mm ITB engines.

You have a carbon airbox and Maxx A/N?

Schrick 284/276 is the default road cam choice as this can be used with stock pistons, albeit, sometimes they cannot be timed to Schrick 106/106 specs if the head has been skimmed.

Airbox, A/N and 284/276 should net you 250-260hp, not the 270+ some people claim with such a set up.

Costs:

£800 Cams
£200 Adjustable Cam Gears
£200 Evo valve springs
£200 Miscellaneous parts (valve stem seals, shims, gaskets ect)
£200 New chip for A/N-John from S14Power can supply you a chip which will suit the cams
£150 Adjustable FPR (I've got a GrpA one you can have for £100)

Less than £2k if you do it yourself.

stevesingo

4,848 posts

221 months

Friday 13th November 2015
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benny.c said:
Is 250 bhp realistic? My Evo II has Schrick cams and a Motec ECU and made 238bhp when it was first converted. This was all before I purchased it so I have never really looked in to it TBH.
Carbon Airbox?

Rich_W

12,548 posts

211 months

Saturday 14th November 2015
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Remember that doing engine swaps on E30M3 is a good way of devaluing it. Yes, you'll have the original engine. But come selling time, you won't bother to put it back in (since it's more complicated than a straight in and out) and people who want an original one, simply will bypass your car.

Manual E46M3 would be my choice for track car anyway.

benny.c

3,473 posts

206 months

Saturday 14th November 2015
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stevesingo said:
Carbon Airbox?
No standard, but I'm always tempted by a carbon box for the noise alone.

stevesingo

4,848 posts

221 months

Saturday 14th November 2015
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benny.c said:
stevesingo said:
Carbon Airbox?
No standard, but I'm always tempted by a carbon box for the noise alone.
A carbon airbox will give a very useful improvement over the stock intake, AFM and air filter arrangement. You will need a change in engine management, MAXX A/N or such like. I've got a spare airbox and snorkel if you need one!

e21Mark

Original Poster:

16,205 posts

172 months

Saturday 14th November 2015
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Carbon airbox makes the whole driving experience so special, it's worth the extra cost for the noise alone.

Billy_Whizzzz

1,991 posts

142 months

Sunday 15th November 2015
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I sold an e30 M3 back in the day and always regretted it - to get an E36 M3. One of the charms of the e30 is that rasping 4 pot - I think you'd spoil it with the 6 cyl conversion. I now have a s54 engined Z4M which I adore - my advice would be keep the e30 as is and get an E46 with that S54 for the same price as a conversion...

e21Mark

Original Poster:

16,205 posts

172 months

Sunday 15th November 2015
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Yes, the s14 is safe and I'm probably going to go with Schrick cams & 4 branch.

I didn't realise just how tough it would be to find an e46 M3 (at lower end of price range) but there are very few coupe available and convertible just aren't my thing. I'll keep looking but don't want to end up with something needing cash thrown at it. I'd rather it went on the e30!

stevesingo

4,848 posts

221 months

Sunday 15th November 2015
quotequote all
4 branch?

The general consensus is that 4-1 exhaust manifolds which are available for the S14 are not suitable for engines making peak power below 8k rpm. Engines with Schrick 284/276 and even 292/284 tend to lose a lot of mid range torque when fitted with a 4-1 manifold.

That is not to say the stock manifold can't be bettered, I'm certain this is an untapped area for the S14. A 4-2-1 with correctly sized primary and secondary diameters and lengths would be something worth looking in to. I've yet to see such a manifold though.

e21Mark

Original Poster:

16,205 posts

172 months

Sunday 15th November 2015
quotequote all
stevesingo said:
4 branch?

The general consensus is that 4-1 exhaust manifolds which are available for the S14 are not suitable for engines making peak power below 8k rpm. Engines with Schrick 284/276 and even 292/284 tend to lose a lot of mid range torque when fitted with a 4-1 manifold.

That is not to say the stock manifold can't be bettered, I'm certain this is an untapped area for the S14. A 4-2-1 with correctly sized primary and secondary diameters and lengths would be something worth looking in to. I've yet to see such a manifold though.
I've just been reading up and come to same conclusion, so will leave alone for now. What would be the next step on from, or in addition to, the cams?

stevesingo

4,848 posts

221 months

Sunday 15th November 2015
quotequote all
e21Mark said:
I've just been reading up and come to same conclusion, so will leave alone for now. What would be the next step on from, or in addition to, the cams?
The next step is quite a large one I'm afraid. Ported head would be the next step. There are a couple of places I know of in Germany that will cnc port your head to Grp A or DTM specs. I have a '91 spec head which has 29.5mm intake ports 38.5 inlet valves and 32.5mm exhaust ports. Later heads were 30.5 and I believe 31.8mm was the largest intake port for use with slide throttles.

You can't go for longer duration cams than 284 without changing the pistons for some with larger valve cut outs.

In terms of power potential with a well set up engine CF airbox, 50mm exhaust header and free flowing exhaust

Stock head, stock compression, 284/276 cams-250-255hp
29.5mm head, stock compression, 284/276 cams-260-265hp
29.5mm head, 12:1 compression, 292/284 cams-275-285hp

You can stretch the above numbers by timing the cams for more top end power, and use a 4-1 manifold, but that kills the mid-range. 300hp is possible from 29.5mm head, 12:1 compression, 292/284 cams, but all the power is 5k plus.







Edited by stevesingo on Sunday 15th November 11:13

e21Mark

Original Poster:

16,205 posts

172 months

Sunday 15th November 2015
quotequote all
Looks like I'll just be going with the cams then. laugh I think I'll be happy enough with a reliable 250'ish anyway. Plus it'll mean I can get some new seats.

e21Mark

Original Poster:

16,205 posts

172 months

Monday 16th November 2015
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Do 292/284 require different pistons?

stevesingo

4,848 posts

221 months

Monday 16th November 2015
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If you want to time them anywhere near where they need to be,then yes. You might be able to time them in the 108/108 - 110/110 region, but that would probably give a worse power curve than 284/276 timed correctly.

m5pop

34 posts

114 months

Monday 23rd November 2015
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Would defo stick with the s14, I have a late m3 which is running 247bhp with alpha n and 284 shrick cams still on standard air box though.

e21Mark

Original Poster:

16,205 posts

172 months

Tuesday 24th November 2015
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Am definitely keeping the S14. smile

I'm having some fuelling issues though, so rather than start another thread, I figured I would ask you guys for some help.

Although my car appears to run fine, it is definitely running very rich and is considerably down on power. I've done the more obvious checks, like air filter and fuel pressure, but all seems well. That said, I believe the adjustable fuel pressure regulator isn't the best available. I'm just struggling to diagnose the reason behind the sudden rich running and power loss? I have ordered a new coolant temperature sensor but wondered if the air temp' sensor (in the air box snorkel) could be the culprit? If you disconnect the temp' sensor, when the engine is running, should it be obvious?

Thanks in advance.