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KitsonRis

Improving 535i Performance

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So I am happy with the way my E34 535i looks, sounds and currently drives. But I am sure there is a little more to come performance wise. I’m currently on holiday in the North York Moors (blimey it’s a nice area) and to get here on the motorway it was perfect and nice for driving around here. But coming up the steep hills it was seriously lacking, sometimes my fault for the wrong gear at the wrong time! I’m not after M5 performance or a track monster but I am sure it could be a little more eager or quicker to pick up the power as once going it’s fine. What are the options? 

 

It it is going to have the valve clearances checked in the coming months and possibly new coil pack, leads and dizzy (new spark plugs last year) so that should be something. That along with an oil change I am hoping to bring it back to close to standard power as possible. But anything else? I would like to get the bushes changed for Powerflex ones for a bit better handling to go with the Bilstein shocks. Possibly a tubular manifold might be on the cards in the future to go with the exhaust. 

The only other things I can think of are cams, LSD or lightened flywheel. I did see a set of triple Webber carbs for sale recently and that was seriously tempting, but seemed like going backwards. Throttle bodies would be the dream. Oh and I am not after forced induction, I still want to be able to waft about in it. 

The issue is I’ve not had any experience in doing performance upgrades in this kind of car and a google brings up nothing firm. 

What have people done or know what things I should be looking at? 

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AIUI the e34 535i is tuned to run a cat but doesn't in the UK and so a chip/ remap livens the M30B35 up a bit.

 

Having been through similar with my M535i i'm not sure i'd bother going beyond a stainless exhaust for sound and perhaps a cam.

 

I did schrick 284 cam, porting of head, remap, fritz manifold and system plus a K&N and finished with 233BHP which is 15 BHP for £££ assuming i started with the 218BHP book figure.

 

The next stage was a EMS to try and pull it all together such as UNI-Q but if i was doing it again i would supercharge.

 

But of the mods i did i would say map and cam made the most difference the FB manifold did sod all in my experience!

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Those mods seem like the level of what I would be willing to do. I am not after anything mega, just a bit more noticeable kick. I will look at those and see what is involved/best way to do this. 

 

Didn’t realise that about the cat - being a bit simple here but how does the chip work? Is that something I could do or will it need a professional with a rolling road? And how easy is it to map? Will it need a dedicated specialist in these engines or a generic decent mapper as I know of a good local one (not one that just chucks a map on a diesel Golf for the lols) 

 

From what I have read the limiting factor on the M30b35 is the fact it’s 12 valves so going ITB’s is a bit pointless, shame as they look and sound amazing and something I always wanted to do. 

 

Ive always wanted performance cams, never got around to it in my old track Clio (because I bought the E34!) so if it makes the best difference then it could be done! 

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At this sort of age it would be a generic map i would think so either the exixting chip is replaced or over written.

 

I'd try Enda tuning on her first i think.

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May not be up your street but this is a very good write up by a mate who swapped the 3.64 lsd in his 535i for a 3.91 open from a 735i auto. Even if you don't go that way it is still a good read. I actually get a mention but really I just held his coat :)

http://www.bimmernut.com/forum/showthread.php/41386-Diff-Swap-Research-Swap-Procedure-and-Effect

 

 

 

 

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I know that works but for some reason it doesn't sit right with me on a road car. Probably because I still want a sensible cruise.

My other long term goal with the m535i was to fit an e34 m5 6 speed box. Essentially it was the dog leg ratios plus the o/d of the h pattern box. Would have been the ultimate e28 box I reckon sadly it never happened.


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11 hours ago, whiskychaser said:

May not be up your street but this is a very good write up by a mate who swapped the 3.64 lsd in his 535i for a 3.91 open from a 735i auto. Even if you don't go that way it is still a good read. I actually get a mention but really I just held his coat :)

http://www.bimmernut.com/forum/showthread.php/41386-Diff-Swap-Research-Swap-Procedure-and-Effect

Just got around to reading this, a very good write up! I knew what a diff does but that added a lot more info into why the ratios are different, something I didn’t know. That is something to consider, but might be the last thing to do as like @duncan-uk says I wouldn’t want to ruin a good cruise. But with a possible 6 speed box from an M5 (again something I didn’t know was it was a 6 speed) could work as I assume like most speeds the 6th gear is quite long? 

Not sure what diff I have in mine currently, pretty sure it’s not an LSD though. Easily checked though next time it’s in the air. 

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Where in North Yorks are you KitsonRis…?

 

I'm surprised at your comment re lacking power up hills etc. as my 535i Sport which I believe is standard and not lacking on the power front has no issues with pace. I'm also in N. Yorks FYI.

 

If interested I have a rare Jim Conforti/Turner Motorsports Chip for the e34 535i 5 Speed Manual car. It could be just the small power boost you're looking for. ;)

I never got round to fitting it and i'm considering selling my car soon as I have an ever increasing fleet and another e34 coming out of retirement.

 

C.

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The 535i was mapped at the factory to run a catalytic converter. That needs to run hot to work, so the ignition timing is retarded and mixture leaned out just enough to do this. All E34's are cat prepped whether or not it has one, so a good remap with advance the timing and richen it up to give another 10 bhp or so, but much better throttle response. The standard cam is pretty tame at @ 252 degrees and the factory exhaust very effective. A shite aftermarket exhaust (Bosal, Walker, TiMax etc) makes a big difference.

 

If yours is an F plate car, it will most likely have the 3.45 diff which just overgears it. Later ones from late 1989 onwards had a 3.64 which makes them much more lively. A 3.91 would still be OK tbh. Around 22/23 mph/1000 in fifth is ideal. 

 

A 3.64 diff would be peanuts, around 100 quid. They rarely wear out so there's little demand. 

Edited by Sir Anthony Regents-Park

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2 hours ago, cableguy said:

Where in North Yorks are you KitsonRis…?

 

I'm surprised at your comment re lacking power up hills etc. as my 535i Sport which I believe is standard and not lacking on the power front has no issues with pace. I'm also in N. Yorks FYI.

 

If interested I have a rare Jim Conforti/Turner Motorsports Chip for the e34 535i 5 Speed Manual car. It could be just the small power boost you're looking for. ;)

I never got round to fitting it and i'm considering selling my car soon as I have an ever increasing fleet and another e34 coming out of retirement.

 

C.

I was staying in Robin Hood’s Bay for the week, currently on the way back home south now. I know it’s not a performance car but I just thought it was lacking a little at times I thought, had to really think about the right gear and there wasn’t any give if it was wrong, had to give it a load of right foot in 1st coming up the hill of Robin Hood’s Bay. A chip if it’s plug and play could be tempting...any more info on it? 

 

1 hour ago, Sir Anthony Regents-Park said:

The 535i was mapped at the factory to run a catalytic converter. That needs to run hot to work, so the ignition timing is retarded and mixture leaned out just enough to do this. All E34's are cat prepped whether or not it has one, so a good remap with advance the timing and richen it up to give another 10 bhp or so, but much better throttle response. The standard cam is pretty tame at @ 252 degrees and the factory exhaust very effective. A shite aftermarket exhaust (Bosal, Walker, TiMax etc) makes a big difference.

 

If yours is an F plate car, it will most likely have the 3.45 diff which just overgears it. Later ones from late 1989 onwards had a 3.64 which makes them much more lively. A 3.91 would still be OK tbh. Around 22/23 mph/1000 in fifth is ideal. 

 

A 3.64 diff would be peanuts, around 100 quid. They rarely wear out so there's little demand. 

It’s a custom exhaust and a lot more free flowing than standard. But thanks for that info on the timing. Something else to look at. 

I think it was built in 1988 and registered in December 1989. Just been cruising on the motorway at 70mph doing a tad over 2k rpm in 5th, not sure if the diff can be worked out from that? 

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Have a search around as there seems to be plenty of info on the chip. Hopefully Sir ARP can offer more info if his old man wrote the mapping. Take huge power gains from a chip with a pinch of salt, however a few horses or small gain can sometimes make all the difference. ;)

 

Your car seems set up to cruise, whereas my 535i Sport Manual is doing 2500-2600 at 70mph so the diff as mentioned above could be another way of helping.

 

C.

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7 hours ago, KitsonRis said:

Just got around to reading this, a very good write up! I knew what a diff does but that added a lot more info into why the ratios are different, something I didn’t know. That is something to consider, but might be the last thing to do as like @duncan-uk says I wouldn’t want to ruin a good cruise. But with a possible 6 speed box from an M5 (again something I didn’t know was it was a 6 speed) could work as I assume like most speeds the 6th gear is quite long? 

Not sure what diff I have in mine currently, pretty sure it’s not an LSD though. Easily checked though next time it’s in the air. 

Just for fun, I dug out the gear ratio figures. Pretty sure they are correct:

M5 3.6            535i

3.51                 3.83          1st

2.08                 2.20           2nd

1.35                 1.40           3rd

1.0                    1.0             4th

0.81                  0.81           5th

3.91                  3.64           Diff

 

M5 3.8 6 speed top gear ratio is 0.83 and diff is 3.23

 

Edited by whiskychaser

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1 hour ago, cableguy said:

Have a search around as there seems to be plenty of info on the chip. Hopefully Sir ARP can offer more info if his old man wrote the mapping. Take huge power gains from a chip with a pinch of salt, however a few horses or small gain can sometimes make all the difference. ;)

 

Your car seems set up to cruise, whereas my 535i Sport Manual is doing 2500-2600 at 70mph so the diff as mentioned above could be another way of helping.

 

C.

Cool, will do some googling now I’m home and have some spare time this weekend. Yeah not after massive gains, just a little extra. Also I got it wrong, it was near 2.5k rpm at 70mph! 

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Is there any specialists that would do a head rebuild? Distance as close to Gloucester as possible but travel shouldn’t be an issue.

Thinking about getting my head and inlet ported and polished to go with a Schrick cam etc (plus then I know it’s been done and another thing ticked off the restored list!) but would rather take it to someone who has got plenty of experience with these engines than some generic garage. I’m not sure the guy I used last time would do this kind of work despite being another classic BMW enthusiast. 

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That's a LOT of money. It's very labour intensive and your won't have much change from a couple of grand that doesn't include head work btw. I'd get the ECU remapped first, I really would. You won't see much benefit from head work as they're pretty good as they are. 

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I think my porting headwork (standard valves) was £800 and a refurbed head and shrick cam was £400 used and though you cold feel the effect of the cam i'm not convinced it waa worth the money but was fun trying.

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Personally I don’t want to do this for big gains, I would turbo it for that. It’s more of like making sure it is solid for years to come and to have a bit of fun. I haven’t had a lot of time to do much research on this yet, but no doubt there will be a compromise of what I want to achieve versus cost and effort. 

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I've just found a guy who can live remap the old motronic. Hes just done my E30 and my new favourite man! Will be way better than any chip but obviously more expense than £40 for a chip 

 

I'd get it running properly. Is the air flow meter in good order? This will effect performance 

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4 hours ago, Bumbaclut said:

I've just found a guy who can live remap the old motronic. Hes just done my E30 and my new favourite man! Will be way better than any chip but obviously more expense than £40 for a chip 

 

I'd get it running properly. Is the air flow meter in good order? This will effect performance 

Oh really, that’s the way I would want to go tbh as I’d rather have it done right than a chip. 

Not sure? I think it is working? How do I check that? Something to check on google on my lunch tomorrow 

 

Also these plans might have to be put on hold for a year now as I need the cash to buy a house. I do hope this means I don’t need to sell it either. 

Edited by KitsonRis

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