Author Topic: What is worth it and better at the same time???? (Read 7138 times)

no1_jazz · « **on:** November 17, 2007, 09:54:14 AM »

Hi guys I was wondering if you could help me...

Rite what is worth doing? And which has a better outcome as overall performance, off the line and top end?

Putting a turbo into a 31.8IS M42 or simply super chipping it?

Which would give you more power and excellent bottom and top end speed.

All help much appreciated in advance.

Cheers Jazz

kowalski · « **Reply #1 on:** November 17, 2007, 12:49:35 PM »

well a chip will net you 5-8hp depending on the kind of chip you get. a turbo will get you 70-_00 hp. one costs 60-350$, the other costs 1,000-10,000+ depending on how crazy you want to go.

Febi Guibo · « **Reply #2 on:** November 17, 2007, 01:34:47 PM »

if your car is a daily driver, consider the supercharger option

sheepdog · « **Reply #3 on:** November 17, 2007, 05:03:20 PM »

You can only reasonably get 10-15hp over stock in an m42 for a few hundred bucks.

To get more costs a lot of money. Just how it is.

That is not to say you cannot make good power but the problem is that BMW put some limitations on the engine that really cause headaches while trying to get lots of power. The 2 biggest problems are the head and the cam profile. The head is quite restrictive and the cam is not helping. Another is the fuel system, it is really not built for more than about 200hp, some will even say 180hp is hard on it.

no1_jazz · « **Reply #4 on:** November 19, 2007, 09:36:28 PM »

Cheers Guys, My car is an everyday car but as I’m studying at the same time i hardly get to enjoy it!!!

I was considering the turbo conversion but allot say that the BMW engines do not like allot of heat and already they do not have a good cooling system and by installing a turbo in, it will heat allot of things up which then will cause more problems to other engine components. So now guys I’m not to sure what to do I know one thing is that I am getting a 3.91 LSD installed.

What am looking for is a very good well almost the best bottom end i can get with this car as well as the top end speed. So any more advice on how to achive my goal with this very ole M42 engine

Cheers Guys
Jazz

sheepdog · « **Reply #5 on:** November 19, 2007, 09:51:37 PM »

Why 3.91?
It will do little for the top end speed (and will hurt the bottom end), the car is just plain out of power. Gearing cannot really help there. It will lower your rpm during cruising though.

Cooling system, easy fix, bigger radiator.

no1_jazz · « **Reply #6 on:** November 20, 2007, 06:14:21 AM »

Quote from: sheepdog;37994

Why 3.91?
It will do little for the top end speed (and will hurt the bottom end), the car is just plain out of power. Gearing cannot really help there. It will lower your rpm during cruising though.

Cooling system, easy fix, bigger radiator.

Dammn that’s not good news, everyone I have spoke to told me that an 3.91LSD will improve bottom end performance as well as top end performance. I personally would not know too much about it so guys don’t think I have already gone out there and brought an lsd of any sort, I am still in the investigation stage lol so guys I need to know what will benefit the m42.

Which is the best LSD for performance which gives crazy bottom end and top end performance?

and cooling systems true can do with a bigger rad? but how much more would that cost? and is it hard to install?

Cheers for the help and advice so far guys.

Jazz

Ruger · « **Reply #7 on:** November 20, 2007, 06:23:07 AM »

No lsd will give your car bottom end or top end performance.

an lsd with shorter gears will get your car off the line quicker and the gears will be shorter aiding acceleration but sacrificing some top speed where as longer gears will kill your down low but will allow the car to accelerate to a greater top speed assuming your engine can push it there.

stock afaik is 4.10, 3.91 is longer

without a gearing change just adding an lsd will do little for straight line speed, maybe get it off the line cleaner on a 5000rpm launch

no1_jazz · « **Reply #8 on:** November 20, 2007, 06:45:28 AM »

Quote from: Ruger;38008

No lsd will give your car bottom end or top end performance.

an lsd with shorter gears will get your car off the line quicker and the gears will be shorter aiding acceleration but sacrificing some top speed where as longer gears will kill your down low but will allow the car to accelerate to a greater top speed assuming your engine can push it there.

stock afaik is 4.10, 3.91 is longer

without a gearing change just adding an lsd will do little for straight line speed, maybe get it off the line cleaner on a 5000rpm launch

Thanks for the information Ruger, so what�s the best solution to achieve the best in both bottom end and top end speeds?

In addition if I install LSD of some sort would I have to alter my gearing to compliment the LSD to its full potential? Is LSD even worth it or is the standard 4.10 Diff which I already have in their good enough?

What�s the best way to achieve maximise performance bearing in mind I am not doing the turbo conversion but am thinking about super chipping it...... so let�s take it I already have it supper chipped and I want to still improve, because I think this is what�s really going to happen. The turbo conversion costs too much.. It�s crazy just for 60 � 70 bhp more.

Cheers

Jazz

sheepdog · « **Reply #9 on:** November 20, 2007, 11:47:26 AM »

LSD will only add traction in slippery situations. It does nothing to add power. Basically if one wheel slips, the other continues pushing forward. In a normal diff, the wheel that slips will receive all of the power and spin more, slowing the car.

It has drawbacks in a street vehicle though.
On slippery surfaces, it can cause you to spin. When one wheel spins, power is sent to the wheel with traction, with a normal or open diff, the slipping wheel will get all of the power and the other will get none of little, the car pretty much continues forward but feels like you have lost power, the LSd, will send power to the other wheel, pushing the car out of line, and in a turn can overpower that wheel causing it to lose traction as well. Now both wheels have no traction and you are in a corner, does not take a rocket scientist to figure you will spin.

While many will tell you it is great and is even better for racing, consider that the Lotus Elise came with an open diff and no limited slip option for a while because Lotus found it was faster without LSD. LSD can upset chassis dynamics.

sheepdog · « **Reply #10 on:** November 20, 2007, 11:54:54 AM »

A turbo setup may only get you 60 or 70, but keep in mind, in these cars, that will exceed e30 M3 power to weight. You will be beating many Mustangs at that point instead of losing to them badly.

Also, a properly prepped motor (lower compression, new cam) can make those numbers shoot sky high. I have heard rumors of 400-600hp, though I have also heard rumors of higher but also that the bocks break at 600.

Of course this costs lots of money, figure over $12k all said and done.

Once you have a chip, you can cut or mod the air box, though that is arguable as a benefit.
Coil on Plug may get you 1hp, but it is a good upgrade to make as it costs less than good plug wires and lasts far longer.
Cams can get you a few HP, but they are over $1000.
Head porting could get you a few, as well as intake port and polish, again bank...

The only real true increases in performance will come from chip, lightened flywheel, close ratio transmission or removing weight from the car.

After that, a performance rebuild, turbo, or blower is necessary. Rebuilds cost $3500 to around $8 or $9k, Blowers, about $4k, turbo, sky is the limit, it can be cheap if you know what you are doing and do it yourself with junkyard parts, or you can pay thousands, depends on how much power and your time/skill level.

The other option is an engine swap, which I am working on what our best options are, since everyone recommends the S52, which will ROYALLY screw up our handling as it is a longer engine and weights TWICE as much and costs thousands to get put in. There are some potentially great swaps for us, but all are non BMW.

Also somewhere between 200-300hp, you may want to swap to a stronger diff.

no1_jazz · « **Reply #11 on:** November 22, 2007, 07:41:41 AM »

Guys sorry for the late reply, I have just been caught up with these assignments all done now so time to relax and talk more e30’s. Lol

Rite I am more likely to get the super chip at one stage? And not the turbo
Which superchips are good for the m42 engine? Any specific ones which run well with the engine?

With regards to LSD I now understand if I am going to get the 3.91 LSD of a 325i sport I will have to alter my gearing. When you say sort the gearing out I do understand that the gears have to be re adjusted to some sort but what exactly and how would it compliment the LSD and what gears do I have to alter 1,2,3,4,5 or all?

Guys all I’m after is some crazy asss pick off and some quality mid range pick up i.e. if I’m cursing at 60mph in 4th gear and when I put my foot down I want to feel the g force pull me back and the car flying past 100mph after shifting it into 5th of course.

Guys I’m sorry if I have not made myself clear enough but if I haven’t please just let me know.

All help is appreciate

Many thanks guys
Jazz

bigbody · « **Reply #12 on:** November 22, 2007, 11:48:22 PM »

superchip is a made up term.

sheepdog · « **Reply #13 on:** November 23, 2007, 01:32:50 PM »

Quote from: bigbody;38193

superchip is a made up term.

Actually it is a brandname.
http://www.superchips.com

kowalski · « **Reply #14 on:** November 23, 2007, 01:40:07 PM »

Quote from: no1_jazz;38148

Guys sorry for the late reply, I have just been caught up with these assignments all done now so time to relax and talk more e30’s. Lol

Rite I am more likely to get the super chip at one stage? And not the turbo
Which superchips are good for the m42 engine? Any specific ones which run well with the engine?

With regards to LSD I now understand if I am going to get the 3.91 LSD of a 325i sport I will have to alter my gearing. When you say sort the gearing out I do understand that the gears have to be re adjusted to some sort but what exactly and how would it compliment the LSD and what gears do I have to alter 1,2,3,4,5 or all?

Guys all I’m after is some crazy asss pick off and some quality mid range pick up i.e. if I’m cursing at 60mph in 4th gear and when I put my foot down I want to feel the g force pull me back and the car flying past 100mph after shifting it into 5th of course.

Guys I’m sorry if I have not made myself clear enough but if I haven’t please just let me know.

All help is appreciate

Many thanks guys
Jazz

do not go to a 3.91. the way you would have to alter your gearing if you did go to a 3.91 is to change all the gears so that its the same as having a 4.10 in the rear. the rear end gearing, or any gearing is not your problem in this case. you problem is lack of power.

you will never have that feeling without going to a stroker or forced induction of some sort, whether its a turbo or a supercharger. or a motor swap, or buying a new car of course.