cam upgrade & big bore throttle body

[toby]

There's been talk recently of the slight loss in low down torque that a cam upgrade compromises.

But, is this compensated for when combined with a big bore throttle body (as this is claimed to increase torque) resulting in, say, a less noticeable loss in torque?

Who has the combination of big bore throttle body and higher lift camshaft?

There's also the question that, if the car revs more freely, then does it reach it's power band sooner meaning that the loss in low down torque isn't actually experienced in real world driving?

There's no reason we can't talk about MAF conversions either I suppose since tuning options seem to be growing in popularity.

I haven't had a chance to drive an E30 with fast cam in it yet, which is frustrating

[burrows]

ive got this combination but with the added extras of a dastek unichip and a itg panel filter, my power band is still futher up the rev range at about 3500- 4000 revs . but with these mods the car is quite good.

[M5pilot]

The combination of Schrick 284/272 cam, BBTB and MAF conversion does affect very low end torque (below 2500rpm) but after that the engine is far more entertaining to use.

Adding a 6 branch makes the low end even worse but the mod and top end get even better.

If your the kind of driver who doesn't like their gears then a cam is a bad option.

Careful which cam you go for aswell, the CAT CAMS lose your serious amounts of low end torque due to the high valve lift whereas the Schrick's have more or less standard valve lift but with much increased duration.

Sal

[Simon13]

i've just taken my Racing Dynamics 6 branch off my touring this weekend and fitted the log back on. The car is a slug! well it isn't but i can't notice straight away that it can't breath aswell as it revved like a loon before but it's more like standard now. I've got a catcam and the loss of torque is there but fitting the log back on has brought a bit back.

Let it breath and a MAF or MS type management on the mapping and it will fly for a 325! Big fat pipe from the air box to the throttle body with a great induction roar! up to you as it soon adds up!

[M5pilot]

The RD and BTB manifolds really do allow the engine to breath much better at higher rpms.

The last complete conversion I did was on Nadeem Hejazi's 325i sport (davetouring also owned this car).

That had a Schrick 284/272, BTB manifold, Sebring exhaust and a MAF conversion with an ITG.

The car went from being an typical 325i to something completely different. Low end under 2500rpm went a bit flat but over that it was a totally different animal. Once past 4000rpm it revved so well.

On the dyno it made 195 bhp and I had my M3 back then and the difference was not very much in a straight line.

I've also been in Geoff's H26 and it felt more potent than that and seemed to rev better.

In my opinion and experience of driving alot of modded E30's this is a really nice conversion to do, most people would be more than happy with it.

The best thing about it is that it gives excellent cruising fuel economy once it's had the MAF conversion done and been mapped for every load point

Sal

[toby]

All interesting input guys, cheers. It's the loss of low down torque that concerns me for real world driving.

Do Miller still make custom chips to suit a new cam, by say copying another and adapting it?

MAF bbtb and cam seems like the recipe I'd like.

[M5pilot]

I'd like to see what the Miller stuff does on a dyno in reality. It has the potential to be a great product but the mapping I've heard has a long way to go.

I'm confident that if I could get hold of a chip it would be no problem to make changes or break the code down and then move onto emulator type live remapping.

Sal

[toby]

The Miller did make an apparent 9bhp increased difference on a rolling road with DaveD's car on the NE rolling road day.

http://www.e30zone.net/modules.php?name ... &start=100

Sal, shhh don't tell them you can crack their code. I'm thinking they should develop a chip suitable for schrick & cat cam and provide all in at the same cost. It would be easy for them to do and would open up more interested customers for them. Their optional tuning pack is way too expensive and I didn't notice it still listed on their site.

Perhaps it would be interesting to compare dyno sheets of a standard 325i and a cammed up one as an example of the difference in low down torque lost. Anyone got any?

[M5pilot]

I can try and find one.

They can't just sit there and "make" a file for a cammed car. It won't be anywhere near right. To do the job properly a proper load point by load point remap is required.

All that's required is an emulator and a session at either our place or Bexleys.

Sal

[toby]

My speculation was them copying a chip already designed for a cam application with all the load sites already generically established in the same way that they copied and modified the map from the standard chip (I'm assuming).

[M5pilot]

doing it for a standard car is all good and well as the map already on the OE Eprom is there to be copied.

For a cammed engine you'd need a developed file already and I there just isn't one out there. Every engine will be different and a different alterations will need to be made.

This is the very reason people who want the job done properly opt for the Unichip with MAF as they get a real custom live remap done on the rollers making sure that every load point is optimised for fuelling and timing.

Example of how mapping is done.

Dyno is set for maxiumum speed of 20mph. Engine is revving at 2000rpm in third gear. The engine speed cannot exceed 2000rpm no matter how much the throttle opening.

We start at a light load and keep it there. Fuelling is adjusted to get say 14.7 AFR and then timing is adjusted to get near enough max power. We increase load to 25% throttle and do the same and carry on until we have full throttle. As we make adjustments we can see a live reading of AFR's and BHP at the rear wheels so everytime we make a change we can see if the effect gives a positive or negative effect.
The proceedure is repeated for 2500rpm, 3000rpm, 3250 rpm.......6000rpm etc etc.

So every throttle angle vs engine speed is precision mapped on the dyno to get the desired AFR's and ignition timing that gives good power.

Car is then road tested and minor adjustments will be made for smoothness.

This is just a very rough idea as to how proper mapping is done.

Now, how is someone sitting on their laptop going to develop a file to suit a car with modifications such as a camshaft which totally changes the fuelling and timing requirements? All they can do is have a rough guess. Big difference between a rough guess and the type of precision tuning I am talking about.

Sal

[toby]

Sal, thanks for your explanation and I understand all this but you are taking a different route from my question.

Of course chips have been made to suit higher life cams. I believe Ant has developed plug and play options for cam and chip applications. So premade files do exist. You, of all people, know this. It's a file like this that could be copied. No it's not perfect but then that suits me! I also think this has been done before by Miller.

I'm not a fan of the piggy back chip principle but of course I see your point about the benefit of live tuning. This also adds a lot of cost to the set up and I appreciate you are a trader but, no offense intended, I'm trying to take you out of the loop and get Miller to do it for a reasonable cost.

The Miller costs around £300 at present but MAF & rolling road & unichip has weighed in at £700+ and for that I'd rather go megasquirt and be able to have the inbuilt value-option of self tune and ability to diagnose with my own laptop.

Toby

[M5pilot]

Toby,

I appreciate your trying to save momey but it's such a false economy.

Pre made chips for something like cams are usually a complete and utter waste of time.

I have seen all of the chips out there for cammed cars and they are hardly any different to chips for engines without cams. No one has developed anything properly. The only place some work has been done is under full load conditions.

I've driven 2.7's with these so called developed chips and they drive like crap compared to similar specced cars with a proper remap.

A properly remapped MAF'd 2.5 has more part throttle torque and response at low rpms that a 2.7 with a off the shelf home made chip. This is an actual example, both cars had a BTB, BBTB, Cam and ITG.

For the 2.7 to have no more torque was shocking to say the least.

Before I had a rolling road or before I was selling chips I always recommended getting a car properly remapped because I knew the advantages.

Why don't you like piggyback systems? Do you understand how they work?

The Miller MAF system could easily be modified to suit a modified engine without havng to look into the code. I may even offer the upgrade myself as part of the package at some point with live remapping.

Sal

[reggid]

Sal what do you do with part throttle fuelling maps of cars equipped with O2 sensors given that in closed loop mode they adapt to 14.7:1 when this may not be the best AFR for part throttle response?

[toby]

Sal - it's the complete tuning package that I'm interested in. Something that compliments the cam to improve low down torque. I understand the principles of most things on cars since I have an interest.

I'd like to get the Miller maf but I want to be sure I can add a cam later without too much hassle. If not I may as well go MS.

[DaveD]

I have asked Miller the question but why not wait til after xmas ...miller tend to have a sale then ..that's when i bought mine

[toby]

Good thinking Dave, thanks for that. Cheers for your graphs, you have email.

[fowler]

well from what i have seen you can get 200bhp out of a stock 325 low comp engine on MS and Coil pack
all will be revealed soon.

[CHRISP]

I,ve seen it too .

[fowler]

and an M50 make 215 bhp

[Simon13]

well from what i have seen you can get 200bhp out of a stock 325 low comp engine on MS and Coil pack
all will be revealed soon.

i'm all ears! I'd like to go out with said engine!

[fowler]

ok I have 4 witnesses to this claim.

[Simon13]

what claim? bexleys rollers aren't allowed!

[Gunni]

well from what i have seen you can get 200bhp out of a stock 325 low comp engine on MS and Coil pack
all will be revealed soon.

I´m sorry, but 200hp from a STOCK engine,
meaning stock intake system completely and stock exhaust completly.
all internals stock as well.
If you can produce two dynographs from the same dyno non altered
to show this I would call you the greatest engine guru in the world.

MS does NOT make power, nor do coil packs.

[march109]

well from what i have seen you can get 200bhp out of a stock 325 low comp engine on MS and Coil pack
all will be revealed soon.

I´m sorry, but 200hp from a STOCK engine,
meaning stock intake system completely and stock exhaust completly.
all internals stock as well.
If you can produce two dynographs from the same dyno non altered
to show this I would call you the greatest engine guru in the world.

MS does NOT make power, nor do coil packs.

But doesn't the M20 have any potential the Motronic can't squeze out that MS can?

MS doesn't make power I understand that but can't it liberate a few from the old M20?

[Gunni]

Understand this.

at WOT on a stock engine you have maximum airflow shown as 100kpa on a map sensor.
that does not change with a MS or any engine management, meaning the engine is gulping in
as much air is possible. Wich again is the reason for no added power with a change in the air intake
anyway apart from ram tuning effects wich are minimal at best.

#1. Ign timing can be modded within the Motronic rom, and has been done since 1986 when the 325i came out,
you don´t think that any of the tuners would have found 30hp just lying around?

#2. Mixture can easily be changed within the ecu rom, you think there is 30hp to be had from richening the mixture
1 AFR point if the motronic is even wrong to begin with. 325i´s usually run about 13.5 AFR anyway stock
wich is perfectly acceptable on such a little stressed engine.


#3. Doing Dyno pulls is the real black magic of engine mapping . As constant conditions MUST
be kept the whole time, those things are known as variables and they effect the readings on the dyno.


#4. Just saying something on the internet doesn´t make it real

[march109]

I never said there was 30hp in there!

I'd like to see the dyno chart myself, if its real I'll be spending some money!

[Simon13]

Racing Dynamics manages 200bhp from a 2.5 but it was far from a stock engine by the engine. I bet it was lovely!

[Gunni]

I never said there was 30hp in there!

I'd like to see the dyno chart myself, if its real I'll be spending some money!

I wasn´t pointing that comment at you.
As you have not made the 30 free hp claim.

Also using Nitrous is not considered stock either.

I´ll bet all the money in the world that these claims are 100%
faked or misread.

*It´s best not to believe anything that is said to you, rather find out yourself.

[Kos]

the onlt way an m20 2.5 will make 200 bhp is with extensive head and cam vork, combined with a good manifold, but even then it is restricted by the inlet, so a decent induction system with heat sheids and a BBTB will help it along to increas air flow. then it needs to be set up .

BBR could get 200+ from and m20 2.5 many years ago, but when you had to pay £1500 for a head and cam back in 1995 that was expensive.

stand alone management on its own will only make the car more responsive and maybe a small increae in peak power.

[oguz327]

Is this gonna be one of those threads?

[Kos]

Is this gonna be one of those threads?

hey you can comment here, you had a few bits done and made 190ish bhp before your 2.7 conversion. a cam and head would have given you 200bhp

[Simon13]

RD 2.5 spec

204bhp@600rpm
193lbs@4800rpm

0-60mph - 7.3secs

top speed 143mph

spec

Compression is quoted at 10.2:1 - not sure o this as there is no mention of different pistons in the conversion, nor big bore throttle body, is there nothing to be gained from this mod then?
Cam- i don't know what spec
oversize valves - again doesn't mention sizes
gas flowed head of some sort
Re mapped ECU
Sport head gasket - increases compression ration by 0.3:1
6 branch and complete exhaust system with X pipe also before centre box

Cat versions lost 10brake so 194bhp for these

If only you could buy these bits still! would be a screamer even if it didn't make 204bhp!

[oguz327]

Is this gonna be one of those threads?

hey you can comment here, you had a few bits done and made 190ish bhp before your 2.7 conversion. a cam and head would have given you 200bhp

We will never know now

[Kos]

true, but you are in need of a head job imo !