Newbie asking about m42 tuning

[patrick85]

This has probably been done a thousand times already, but i'm new so forgive me.

I want a bit more power from my e30 318is. The engine is out at the minute so i figure now is the time. Also i'd like to point out i'm not rich so cost is a factor.

Thanks for any help.

[jagtech2002]

well i guess it all comes down to how much you can afford and your technical knowledge, without sounding brash mate!

[Gwynleym10]

have a read of this thread....

http://www.e30zone.co.uk/modules.php?na ... ic&t=28199

and this one

http://www.e30zone.co.uk/modules.php?na ... ic&t=40329

[keggy]

prob best startin off wid a zone chip n big bore throttle body from the zone shop mate

[patrick85]

well i guess it all comes down to how much you can afford and your technical knowledge, without sounding brash mate!

Technical knowledge isn't an issue. I'm a mechanic in a BMW, Ford, Mitsubishi dealership. But I can afford **** all.

I'll check out those threads, thanks everyone.

[jaistanley]

First thing you can do then is reset the cam timing. Mine was way out when I got the car and it made the idle unstable and reduced the low down torque. SOme people advance the inlet a bit which might be worth investigation..

You could fit the M44 chain tensioner whilst you're at it for peace of mind, but probably not neccassary if you're timing gear is silent.

These engines responde well to mapping I hear.

Jai

[bigj]

Hi had my is mapped today,was suprised how much difference it's made up to 163bhp from 118.
bbtb is v good cured the flatspot at 3k ish and throttle response is so much better

[benjy]

I take it they are rear wheel power fiqures? Sounds good to me!! Is it just a BBTB youve fitted with a remap?

[tim_s]

I take it they are rear wheel power fiqures? Sounds good to me!! Is it just a BBTB youve fitted with a remap?

er no. that would be like an m3 figure rwhp.

[Huge]

Hi had my is mapped today,was suprised how much difference it's made up to 163bhp from 118.
bbtb is v good cured the flatspot at 3k ish and throttle response is so much better

BigJ, where did you get the BBTB and the remap done?
What was the cost??
Cheers

[bigj]

Benjy, wish they were m8 .97.7 rwhp a lot of tranny losses? just tb at the moment itg to follow then some cams when the card recovers a little.

Huge i got the bbtb and remap thru the zone shop m8 speak to Sal he'll sort you out.
I did a full service and changed any hoses etc before remap

[tim_s]

97.7 rwhp is very low! even for the 118 its quite a low figure. mine factory made 106 ish iirc, 113 with megasquirt doing the fuelling (still motronic timing). whats responsible for the massive losses?

[bigj]

Not sure Tim, noticed slight wobble on d/s rear wheel cos the weights had come unstuck
don't know if it was that. Is rwhp measured or calculated?

[tim_s]

no, rwhp is measured, the flywheel horsepower is the one that is calculated. The rolling road normally does a coast-down to calculate the flywheel figure, and for some reason your losses are absolutely huge by the sounds of things. under 20% is usual for a rwd car.
why was your original power figure so low btw?

the old bosch rollers i used (shepsevo3's) at castle combe don't calculate flywheel horsepower, but are tried and tested at wheel figures and i'm happy that i got accurate figures.
i do find it really interesting, because i'm intrigued at the high flywheel figures people are getting with the 318is.

when I r/r my I know the engine was tip-top as I've since disassembled it since and it was low miles fsh, it had great compression on all cyls, i'd had it diag'd recently and replaced TPS and cam sensor, in fact I brought carsoft with me to the rollers to diag it when pissing around with MS, it had elec fan, sebring exhaust, coolant ran straight from block to head etc. We spent a few hours on the rollers testing various things and setting up megasquirt making sure everything was spot on, and in 4th gear (1:1) we made 107 rwhp on motronic iirc. This was with high 13s AFRs throughout, which is how they fuel out of the factory. With MS fuelling we made 113rwhp, bringing the AFRs down to around 13.0:1. In other words I can understand a few horsepower gained at the flywheel by adjusting the fuelling, and mb there's a bit more to come from adjusting the timing.

i know the car felt as fast as any other 318is as I've driven a few others, it also held its own against my bro's more powerful m44 e36 (bit heavier though), so i reckon those wheel figures are about what a 318is should do.

But by normal calculations mine made around factory flywheel figures using a 20% transmission loss.

[EndaW]

Stock losses (according to the dyno handbook from dynapack) on the rwd bmw is 24.4%
A dyno doesnt measure rwhp, it measures torque, the hp is a calculation of acceleration/de-acceleration.
Anything that effects acceleration or de-acceleration will effect the results and a dyno is only a "guestimate" at best.
It was never designed to test power in the first place.

[tim_s]

Stock losses (according to the dyno handbook from dynapack) on the rwd bmw is 24.4%
A dyno doesnt measure rwhp, it measures torque, the hp is a calculation of acceleration/de-acceleration.
Anything that effects acceleration or de-acceleration will effect the results and a dyno is only a "guestimate" at best.
It was never designed to test power in the first place.

yeah yeah i know. but the rwhp is a product of torque and rpm, whereas the flywheel figure is an estimate.

[bigj]

If stock losses are 24% what would account for my 40% loss?
patrick while your engine is out you might look @ swapping flywheel I think one of the m20 single mass ones fit not sure but think its 320 one. I'm sure someone will tell u for certain .

[tim_s]

bigj, m20 flywheel is a waste of time, you need to change the throw out bearing, starter gear and clutch pressure plate, the pressure plate is heavier anyway so you don't end up saving much weight.
so your flywheel figure was 163, wheel 97.7? Thats over 60% loss. i have no idea why your losses are so high, handbrake or brake disk binding or something maybe? i'd be surprised if it was caused by a slight wheel wobble. the sceptic in me suggests that the transmission losses were probably correct on the 118 figure, and incorrect on the 163 figure, as thats way too much difference between the two figures.

[schuey]

I noticed the mention of the big bore throttle body and remap on this thread but there appears to be nowt in the zone shop?????

was the remap of the standard setup or does it require a new chip first,I know alot of standard ecu's are remappable.

Is the bbtb a homemade affair/modded standard item or a different thing altogether,Im all up for diy mods!
Was told by an old school mechanic yesterday of cheeky mod on the airflow meter to in effect richen the mixture-bit of trial and error but it made a noticible difference with my big ass filter on,free too!(apart from even worse economy)
Cheers

[appletree]

I can deffinatly recomend the ITG filter from the zone shop, alot better than a K&N or a universal fiter that i tryd before. it also sound amazing!

BBTB is aproper bought item not a poor DIY job. although DIY is still good if done right.

[appletree]

Hears a link to when i took my IS to the rollers and what i found

the "after market filter" was NOT an ITG

http://www.e30zone.net/modules.php?name ... ic&t=38696

[bigj]

Cheers tim for that m8 didn't realise the pressure plate was so heavy saved me some work.
schuey the bbtb is a modded standard one ,the remap is done on via obd skt and loaded onto a new chip

Tim your prob right about the figures the car feels alot stronger now it pulls better from low revs
there is a definite improvement .
I've only driven 1 other IS n that was in poor cond so can't really compare but it feels almost as quick as my old sport. it just handles the twisties round here better