• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Performance improvements [rehash]

Share this page

U

usasma

Jedi Trainee
Offline
I've been reading posts and researching the topic of performance improvements for a while now. I'd like to solicit opinions on the cheapest and easiest way to get a decent performance increase out of my 74½ B-GT. The biggest problem is that it lacks "oomph" when going up hills.

It's got electronic ignition, K&N filters, and an exhaust system (ANSA I think).

So, what's your opinions on easy performance increases for the B? I'd like to keep it as cheap as possible (since she's going in for a body refinishing soon), but the wife has already ok'd shopping for a turbo/supercharger like the one from Moss.
 
You've pretty much got the same mods that I've got.
except ive gotta set of extractors on you

What sorta 0-60mph time does your B do? just outta curiosity
BTW, if you get the Supercharger kit. IM SO GOING TO HATE YOU! /ubbthreads/images/graemlins/cool.gif

Has anyone considered running cold air ducts from the front of the car to the air filters? Is it even worth doing?
 
I've considered the supercharger, too, but don't have the "disposable" funds right now.

One thing, though: How fresh is your engine? The common belief is that putting the kind of load that a supercharger will introduce will kill a fair to weak engine in no time at all.

Mickey
 
Not criticizing anyone's desire to increase HP but I find with these old cars, just cruising along is fun enough. I certainly don't see me trying to get a 1956 Healey to have a 0 to 60 time of 6 or 7 seconds.

Driving the car, feeling the air, listening to the exhaust pipe is enough for me.

Bruce
 
[ QUOTE ]
Driving the car, feeling the air, listening to the exhaust pipe is enough for me.

Bruce

[/ QUOTE ]
Ahh. I love hearing that. Sure I like to push my B, see what I can get out of her, but if I wanted a high performance vehicle, I'd be driving something else, you know?

I can't think of anything better than spending a day tooling around on the back roads with the wind in my hair. Doesn't matter if I'm going 45 or 75mph.
 
My problem is with tooling around the back roads. New England has it's fair share of hills, and the B-GT doesn't have much oomph going up them. I'm just looking for enough power to help out on the hills. The 0-60 time will have to wait until next spring since I've already put her down for the winter.
 
A Moss supercharger is the best bang for the buck right now. You can pretty much count on a 40% increase in overall power and with other modifications to the engine you can get a lot more. Granted it's expensive, but you can also save money by installing it yourself. Minimal experience and tools are required and it can be completed in a few dedicated hours of work.
 
"Has anyone considered running cold air ducts from the front of the car to the air filters? Is it even worth doing?"

That is actually what the factory did on their race cars. Look at some of the pictures of Sebring MGBs and you will see.
 
I think you are chasing a red herring as far as performance increases such as supercharging. My MGB slowly developed a decrease in hill climbing capability and general performance acceleration. After a continual degradation in this type of performance and kweaking carburetors and ignition timing with no results, I wondered if it did not have something to do with the camshaft. I was running a slightly enhanced camshaft (1/4 race) so I pulled the cam to look at it. I found a badly worn cam when compared to standard specifcation. I replaced the cam with a standard new cam and totaly eliminated the problem. The MGBs have inherently acceptable performance as far as low end torque and should not need supercharging. By the way, my camshaft is being driven by a dual chain. It is noisier than the standard single chain configuration and I do not recommend it. Dont supercharge or other mods until you are satisfied that the basic engine is OK.
 
"The MGBs have inherently acceptable performance as far as low end torque and should not need supercharging."

We don't "need" as much power as we already have, but more power never hurts. If we only used what we need, then we would all be driving inexpensive modern econoboxes! /ubbthreads/images/graemlins/wink.gif

"Dont supercharge or other mods until you are satisfied that the basic engine is OK."

Absolutely positively one hundred percent correct!
 
[ QUOTE ]
That is actually what the factory did on their race cars. Look at some of the pictures of Sebring MGBs and you will see.

[/ QUOTE ]
I google searched images for Sebring MGB and couldn't find any good examples of what I think EMGEB is talking about. The closest thing I could find were dual SU's fitted with air horns (or velocity stacks or whatever other name they have). If I'm not mistaken EMGEB is refering to an induction pipe that pulls fresh air directly into the carbs from outside of the engine bay... Something similar to what the "Import Tuners" use on modern cars to increase air density without the use of "forced air induction".

I'm not sure how well it would work on a carburated engine since (unless i'm mistaken) the point of "cold air intakes" is to allow the induction of denser air that the engine's computer system would compensate with more fuel, and the computer controls the mixture based on measured air induction and O2 content sensed in the exhaust. On carburated systems there is no mass air sensor to deal with, and no computer to control your mixture. So, I would suspect that such a contraption on a carburated system could lead to constant tinkering throughout the year due to the tempuration fluctuations (and there for air desnity). The closest thing to a mass air sensor that I've seen on these carbs (in it's end purpose) is a heat sensitive valve that automatically adjusts the air mixture based on the tempurature that is near it on the carb inside the engine compartment. So, a carb with this type of equipment would be prone to needing constant tuning due to the differences in temperature between the engine bay and the area that the air is being pulled into the carb from.

I'm just S.W.A.G.ing some stuff off of the top of my head here. I know there's bound to be someone that would know alot more about this topic than myself. So, if I'm wrong in my lines of thought, please do correct me and show me to the path of proper enlightenment for eking out more performance from a carburated engine without resorting to "forced induction". /ubbthreads/images/graemlins/smile.gif
 
Hey adam90009, are you planning to put that Camaro Motor in the B???? If you are what are you gunna do with the rest of the Camaro???I have an 84` Camaro and would love to have a parts car handy. I don't know why you would take from a Camaro to put in a B why not keep the right motor in the B fix the Camaro and drive it aswell!

Zack
 
In regard to the cold air ducts
I was refering to ducks from the front air darn to the air filters... but im guessing you would need to rig up some kinda manifold looking doohicky to ensure that BOTH 1+2 and 3+4 cyls breathe. Coz obviously you dont want to have one flowing excellent and one starved.

I bring this up because at the moment in Australia the seasons changing to summer and when driving my B around on hot humid days it seriously has absolutely no grunt. NOTHING AT ALL. Then the second i goto work at nite with the cold air, it makes a world of difference!

To rig up a cold air duct type system... is it something that the insurance companies would need to know about?
Or is it just like a wanky rice thing that they dont really care about?

Cheers
J
 
i'm around 99% sure that insurance companies wouldn't care if you have a cold air intake on your car or not. An intercooler would be more effective than just adding plumbing to pull air from in front of your radiator/airdam ducts. Yeah, i imagine yer right in thinking that you'd need to create a manifold of some sort to split the air flow before you got to your carbs to make sure you don't starve one or the other.

In regards to the airdam ducts, why not use those to pipe fresh air directly to your front brakes?
 
If you have it in the air dam it will suck up water and you do not want that. I relocated my air filter on my ZS carb into the air flow and wow what a difference. I did have the Camaro that was wrecked(it it a tree) and I already put the engine in my car and parted out the car on ebay and sold the car for scrap. But if you really want to make your MGB produce some power you will need some head work instead of these little things like cold air intakes. There are many things you can do for less money too like install a 25D Midget distributor or even a mechanical advance distributor(if you can find one) with a weber 45 side draught(soem people will argue that SU's are better and in some ways they are). I really wouldn't woudln't add a cold air intake to your car if it were mine. Add K&N air filters if you want improved air flow.
 
Adam, in regard to your post.
Ive already had my head changed and played with,
Ive also got my intakes done, same with the exhaust and header... Just looking to further increase that power.
btw. can u show me a pic of where u relocated it?
I'm curious as to how you did it...
Have u placed it up near the front air darn?

Cheers matey
Jarrod
 
What have you done to your head? About how much power are you making based on what you have done so far? I don't have any pictures of my ZS picutures online that I know about, but it will be completely different on your car. You will need to make a box to connect to both carbs and then have the front of it open toward the front of the car. Then you need to cut a hole(i would guess around a 3 inch hole or so) in the radiator suport to pick up the cold air before it goes into the radiator(by the way this is a high pressure area). Then connect a hose to the back of the hole and your box you have made with a single high flow air filter before the hole or somewhere before the carbs. And don't forget to add velocity stocks on the carbs too.
 
[ QUOTE ]
Ive already had my head changed and played with,
Jarrod

[/ QUOTE ]
Me too, but I still can't remember anything. /ubbthreads/images/graemlins/laugh.gif
D
 
lol
 
Back
Top