someone please give advice

[dom85m30]

i have a 1989 535i and i recently installed the performance head from metric mechanic i do alot of street racing i i run against some fast cars and win by a few car lenghts but yesterday i took my car to new england dragway and i coulndn't get no better time then a 16.2 but the guys that i street race with where getting time of 14.8 i want to know y i wasen't no where near there time if my car is faster then thiers

[Alexlind123]

Is your car an auto? If so, thats about the times you should be getting stock. These cars are not made for street racing/off the line acceleration. You should buy an old american V8 muscle car.

[dom85m30]

Is your car an auto? If so, thats about the times you should be getting stock. These cars are not made for street racing/off the line acceleration. You should buy an old american V8 muscle car.


no my car is a manual with a 3.91 diff

[BillionPa]

do a dyno run and see what your torque curve looks like, there could be something interfering with proper engine operation.

[dom85m30]

do a dyno run and see what your torque curve looks like, there could be something interfering with proper engine operation.


what kind of things are we talking about that can be interfering i'm thinking of now putting in bigger injector and a adjustable fuel pressure regulator maybe this will help

[Ausmpower]

Hmm........... You sound like a troll.....
Answer these questions for me and I'll be able to help:

1. what cam are you running?

2. what chip are you running?

3. what rpm are you shifting at?

4. why would you put in an adjustable reg on a stock motor (head doesn't count)?

5. what exhaust are you running?

6. what headers are you running?

7. why go for bigger injectors if all the manifolds are stock and you run the flap type AFM?

8. why wouldn't you turbo it?

Who fitted the new head? the valve timing could be off by a tooth.

"3.91" diff ratio HMMMMMM don't think so...... try 3.90.

[dom85m30]

Hmm........... You sound like a troll.....
Answer these questions for me and I'll be able to help:

1. what cam are you running?

2. what chip are you running?

3. what rpm are you shifting at?

4. why would you put in an adjustable reg on a stock motor (head doesn't count)?

5. what exhaust are you running?

6. what headers are you running?

7. why go for bigger injectors if all the manifolds are stock and you run the flap type AFM?

8. why wouldn't you turbo it?

Who fitted the new head? the valve timing could be off by a tooth.

"3.91" diff ratio HMMMMMM don't think so...... try 3.90.

i'm using a 272 cam with a jim c chip, i shift at the 6800 mark and i figure a adjustable reg to add more gas to compensate for the extra air from the ported head, the headers are stock can't find and a performance set, exhaust is stock, the manifold is also ported ,don't have enouggh money for turbo and i will check the timing cuz that could be an issue and what u mean not 3.91

[Ausmpower]

i figure a adjustable reg to add more gas to compensate for the extra air from the ported head, the headers are stock can't find and a performance set, exhaust is stock, the manifold is also ported, what u mean not 3.91

O.k you have a ported head (with a debatable flow increase) but it is still choked by the stock exhaust and AFM so your gain would be negligable.

If it IS flowing any more air than stock the AFM would compensate anyhow and the EGO would stop it going lean. I have yet to see an NA M30 go lean with bolt on mods if the fuel pump is healthy.

I'd be looking at getting the cam timing checked first, then fit a free flowing exhaust, MAF conversion (then dyno it to see you've only gained 20 hp).

Diff is 3.9 not 3.91 ratio unless it's not an E34 diff....

What "272" cam is it (brand)?
How much lift?
Hollow or Solid?

[dom85m30]

O.k you have a ported head (with a debatable flow increase) but it is still choked by the stock exhaust and AFM so your gain would be negligable.

If it IS flowing any more air than stock the AFM would compensate anyhow and the EGO would stop it going lean. I have yet to see an NA M30 go lean with bolt on mods if the fuel pump is healthy.

I'd be looking at getting the cam timing checked first, then fit a free flowing exhaust, MAF conversion (then dyno it to see you've only gained 20 hp).

Diff is 3.9 not 3.91 ratio unless it's not an E34 diff....

What "272" cam is it (brand)?
How much lift?
Hollow or Solid?

ok i understand that i need the exhaust done and a maf coversion i just don't understand why it is running slower then when it had the factory head and would u know of a place where i can get the headers

[Rigmaster]

My advice: Stop street racing- stick to the dragstrip.



If the diff is a 3.9X, then it's a 3.91, not a 3.90- but it doesnt' really make a difference. Basically a 3.91 diff has 43 teeth on the ring gear and 11 teeth on the pinion, making it a 3.90909090909090909090909 ratio- if you want to get nitpicky. :P



Bret.

[Bill R.]

:)



ok i understand that i need the exhaust done and a maf coversion i just don't understand why it is running slower then when it had the factory head and would u know of a place where i can get the headers

[Felixdacat]

Your running slower with new head? Well lets see. Do you have the stock throttle body? Stock MAF? Stock Headers?, Stock Exhaust?.....You do have ported intake and a ported head. With the stock parts above, you will be bottle necking the air coming into the engine, and out of the engine. You will need to upgrade these parts to get a good flowrate. Also get an exhaust designed for the car. don't get a random one. This could also increase power loss, and possibly damage the engine without the correct back pressure. If I'm not close to what the deal is somebody please inform me.

[Scott H]

but I laughed my ass off when I caught this one....


Jeff N. is that you ? :)

[Martin in Bellevue]

:)
Thanks for opening the door, Bill.

Here goes,
I think you've lost compression with that metric mech head on a stock m30. I also think compression goes down with the metric mech flat top pistons, but that isn't so germaine to your query.
Dyno comparisons show the metric mech head on a stock m30 block to be down on both torque, and horsies. I can repost the dyno sheets, taken at the same dyno on the same day, if Jeff's fragile ego could take it; it can't. Also, metric mech's 'sport' cam doesn't seem to be great in the m30.
A maf, or map conversion would help a bit, but the cost isn't insignificant. There are headers available for the m30; I have some RD headers from Scott H. They prolly aren't marginally cost effective, when comparing these expensive upgrades to the return a tcd turbo kit provides.

[Mitch90535im]

My advice: Stop street racing- stick to the dragstrip.
Bret.

I would second that.

[dom85m30]

I would second that.

so i guess i was better of with the stock head and for exhaust i was thinking on going with 2 2.5 all the way does that sound good enough

[Rigmaster]

so i guess i was better of with the stock head and for exhaust i was thinking on going with 2 2.5 all the way does that sound good enough


Nah, you need a 4" exhaust with an 8" fartcan muffler, remove all the seats to save on weight, you can just use an old milk crate to sit on. Don't forget the seatbelt delete mod.



;) ;)

[Kalevera]

You were better off with the stock head, any way you shake a stick at it.

[Ausmpower]

Why not just buy a pre made rice mobile?

[Ausmpower]

Now he has lower compression so why not turbo it?

[Ausmpower]

fit E46 M3 alloy panels, CSL carbon roof, 20" wheels, Altezza tail lights, ///M badges all over it.

It's an Executive Express not a rice boy racer!!

[Jeff N.]

However, I'm happy with my car at this time. It's running nicely as the short block loosens up. Still would like to trade some top end HP for some bottom end torque but all it all, it's pretty fun.

Martin's right. You did loose compression with the MM head. You never did say what cam your running. While Martin and I disagree about this, it's my opinion that it's the MM cam, not the MM head that changes the compression. He thinks the chamber is bigger; I'm not so sure. I do know that with a longer duration, your static compression does go down.

So let's look at what you did. You added head flow and a longer duration cam. You added more fuel as well.

Lets look at the net effects:

Torque killers:

Bigger ports = less low end torque
Hotter cam = less low end torque
Potentially too rich mixture = less low end torque

In return, you car should be making some better power at the top end - likely 4500 RPM plus. However, if your mixture's off, you may have killed any benefits.

Try this:
- remove your adjustable FPR and go back to the stock setting
- verify you have your cam installed correctly. Degree it in.

What makes me semi qualified to suggest this? Hmmm...check the sig line maybe.

Jeff