Upgrade or not?

[WiseOwl]

Hi Guys,

Bought my 2004 2.5i in May 2018.
Paid £5,500 for it and for the extra power I'm very tempted to upgrade to the 3.0is.
Mine is being valued currently at about £2,600 trade in, is the upgrade worth the cost?

I changed from a 3.5 v6 Merc so the power drop is noticeable currently.

Thanks, I appreciate your advice and any alternatives that I haven't considered.
(The "M" is not an option, I don't want to spend £10k+, budget is about £5k + my trade in)

 

[brillomaster]

well, a 2.5i to a 3.0si is about an extra 70 bhp, or 35% power hike, so it'll definitely be noticeable. the only way to get more than 260bhp in a BMW would be either go M (too pricey) or add turbos (think 335i or 135i). An E89 with a 2 litre turbo will feel faster, but might not actually be that much faster, and may be out your price range.

other alternatives would be something like a Porsche boxster (age and engine will vary with price) or maybe a Nissan 350z is well in that price range, and offers around 290bhp, albeit in a heavier, more GT oriented package.

 

[WiseOwl]

the only way to get more than 260bhp in a BMW would be either go M (too pricey) or add turbos

I had received a quote from Baileyperformance in Shropshire to turbo my 2.5i, full conversion little over £5k and would give claimed 350bhp.

I must admit I like the idea and I have heard the M54B25 engine has forged internals, good for 400bhp max.
My only concern would be the age of the engine, boosting a 14 year old car doesn't sound wise.. and what supporting mods would be required, brakes etc.

Is boost a ricer pipe-dream or does this option carry any merit?

 

[True-Blue]

the only way to get more than 260bhp in a BMW would be either go M (too pricey) or add turbos

I had received a quote from Baileyperformance in Shropshire to turbo my 2.5i, full conversion little over £5k and would give claimed 350bhp.

I must admit I like the idea and I have heard the M54B25 engine has forged internals, good for 400bhp max.
My only concern would be the age of the engine, boosting a 14 year old car doesn't sound wise.. and what supporting mods would be required, brakes etc.

Is boost a ricer pipe-dream or does this option carry any merit?

If you really want to keep your current car, and only want dramatic performance ‘some times’ rather than ‘all the time’ I’d look at NOS, it would cost a lot less than £5k and much easier to return the car to standard in future if you wanted to sell it.

 

[True-Blue]

https://www.noswizard.com/car-nitrous-kits/wet-car-nitrous-kits/efi-wet-nitrous-kits/efi-wet-street-car-nitrous-kits.html

Have a read 8)

 

[Piper1]

the only way to get more than 260bhp in a BMW would be either go M (too pricey) or add turbos

I had received a quote from Baileyperformance in Shropshire to turbo my 2.5i, full conversion little over £5k and would give claimed 350bhp.

I must admit I like the idea and I have heard the M54B25 engine has forged internals, good for 400bhp max.
My only concern would be the age of the engine, boosting a 14 year old car doesn't sound wise.. and what supporting mods would be required, brakes etc.

Is boost a ricer pipe-dream or does this option carry any merit?

That price for that much gain to me seems way too good to be true. If it is that would put every ESS kit on non M to shame. From reading pokey britches write ups over the years on his non M I think he mentioned the intake manifold not being able to handle think over 9psi on the M54 so there's quite a bit more I think you're going to run into than what 5k would put for a budget.

That and a lot of support mods to a base preface lift 2.5 as you mention

 

[buzyg]

A wise man once said. If you want a realy fast modified car, start with a fast car. Use your hard earned to get the best bang for your buck now. Then if you find you have a few Bob spare in a few months time, then you can modify that and get a realy fast car. The 30si is the best bang for your buck in an E85. :wink:

 

[Mr Tidy]

I think a 3.0Si has a similar power output to a 3.5 litre V6 Merc (265 PS v 272 PS respectively IIRC).

It'll definitely feel noticeably more powerful than a 2.5i!

Your best bet might be to get a test drive in one, or maybe you could find a local forum member with one?

I would rather swap to a more powerful model than modify - you're much more likely to get more of your added investment back when sale time comes around! And modifying doesn't stop at the engine, there's suspension, brakes, etc.

Good luck anyway.

 

[WiseOwl]

Thank you for all your advice guys, I very much appreciate you taking the time to talk about yet another "more power" thread which I imagine are a dime a dozen.

I think maybe a 3.0is may be the way to go, and perhaps look into an ESS charger down the line.
I haven't found any ESS suppliers/fitters in the UK so far so any links you may have I'd thank you for also.

Going to have a read up re: the Nos situation also, maybe a 3.0is with Nos would scratch the itch and allow for sensibleness 99% of the time.

 

[Vanne]

You'll be on this merry go round soon enough again if you upgrade to the 3.0. just cut the middle man, and grab an M. You'll be glad you did. If you super charge, you'll be in M money anyways after all is said and done.

 

[griffnut]

Why not buy a TVR Chimaera 450, a lot lighter car with bags of boot space. Great power to weight ratio and a soundtrack to match.
If you find a good one, they are reliable to run as well.

 

[buzyg]

Why not buy a TVR Chimaera 450, a lot lighter car with bags of boot space. Great power to weight ratio and a soundtrack to match.
If you find a good one, they are reliable to run as well.

IF you find a good one.. :wink:

 

[Tinker15]

Why not buy a TVR Chimaera 450, a lot lighter car with bags of boot space. Great power to weight ratio and a soundtrack to match.
If you find a good one, they are reliable to run as well.

IF you find a good one.. :wink:

There are good ones about but they don’t come cheap. Prices have been increasing steadily over the last few years. I sold my 450 in April this year for £14k.

 

[buzyg]

Why not buy a TVR Chimaera 450, a lot lighter car with bags of boot space. Great power to weight ratio and a soundtrack to match.
If you find a good one, they are reliable to run as well.

IF you find a good one.. :wink:

There are good ones about but they don’t come cheap. Prices have been increasing steadily over the last few years. I sold my 450 in April this year for £14k.

OP's budget is a way short of 14k, from his original post. :wink:

 

[ph001]

If you like your current car's spec, colour etc then I would definitely be tempted with a NOS install given what you have said. The 3.0si is a lovely engine but it's not £5k better then the 2.5 imho. NOS will get you at least if not more power than the 3.0si for a hell of a lot less money. Admittedly you would lose a bit of boot space and have to buy gas every now and again but probably not as often as you think. You tend to only drive them 'enthusiastically' a very small percentage of the time when you take into consideration roads / traffic (depending on where you live).

 

[WiseOwl]

Hi again guys,

Ok, so I thought I'd give a bit of an update as I am still researching the best solution.

Most recent valuation of my car is 2k (which im gutted about tbh) but this is trade value not private sale.

M Style have a garage based in Essex which supply and fit the ess charger, costs are roughly £5.5k and 500 odd miles away from me.
https://www.mstyle.co.uk/ess-supercharger-system-e85-z4-3-0i-350bhp-8psi.html

I've spoken to Wiz of Nos and they can supply and fit a 100shot kit for £1.2k however refills are a 200 mile round trip for me.
https://www.noswizard.com/car-nitrous-kits/wet-car-nitrous-kits/efi-wet-nitrous-kits/efi-wet-street-car-nitrous-kits/sb150is6-nitrous-kit-complete.html

So, the current plan for best bang for buck, is upgrade to a 3.0si and get a remap.
https://www.celtictuning.co.uk/services/performance-stats/bmw/z4-e85-e86-2002-2008/petrol/35si-261-bhp-2002-2008-ECU-remap-chiptuning/stage-1#t3-content

It's taken a fair bit of research to come back to this conclusion, I am now starting to look into exhaust options I would really love to break that 300bhp without FI.... but that's a tall order I know.

Feel free to add your comments and or any experiences you are aware of from the links i've added.

Thanks again for reading.

 

[mmm-five]

So, the current plan for best bang for buck, is upgrade to a 3.0si and get a remap.
https://www.celtictuning.co.uk/services/performance-stats/bmw/z4-e85-e86-2002-2008/petrol/35si-261-bhp-2002-2008-ECU-remap-chiptuning/stage-1#t3-content

That's the remap says it's for the 35si (which doesn't exist) and also lists the Z4M as a 35si, so with such basic errors on their website, would you trust them with your ECU?

...and I also doubt you'd get 20bhp over factory figures on a normally aspirated engine, with no other changes.

 

[mr wilks]

You should see at least £3k from your 2.5i unless its mega miles & there are decent 3.0Si out there for £6k (if not less) so in real terms your costs to upgrade could be as little as £3k :? bearing in mind you are also getting a facelift car so , fresher lights ,possibly Msport seats if yours hasn't ? same with Msport s w & with the 262bhp N52 a very quick car too :driving:
Id start by sticking yours on ebay , forget the mod nonsense

 

[ph001]

You have absolutely zero chance of getting an N52 over 300bhp unless you put some crazy cams on it, do a ton of breathing work on it and rev it to the moon. It will probably be pretty awful in the lower rev range.

I’m not sure I understand your 200 mile trip for a nitro refill, you can order the bottles online.

 

[skelters]

There'll be a thread on here with the info on the remap Marlon had.

That took the 3.0si up to around 285bhp allegedly.

There's plenty of info on the SI engine and some info saying it's pretty much at its limit with the standard tuning. Think it was something like an extra 7bhp was available when it came out originally.

Before looking at any of the upgrade options you should perhaps look at driving one, test out an M if possible too. Check out running costs etc.