998 Ti project
Turbo Mini Forums

hi all

I am currently building a 998 turbo engine and had recently purchased a specialist components 5 port injection kit. I will be using a gt1548 turbo and went to a local manifold builder to get an exhaust manifold made. he decided i should also have a new inlet manifold and made me a plenum and moved the injectors into the inlet runners.

I have been reading many many threads about injection and MS systems and learnt a great deal from all the wide varieties of set ups from people on this site and the more i read the more i am concerned that this will not work. Whilst i think the typhoon should still be able to handle the port injection i haven't done anything about widebands on the exhaust manifold only the standard o2 sensor in the exhaust.

I guess my question is, is this manifold a waste of time, should i go back to the more standard inlet manifold and also am i going to be limited by the typhoon in this type of setup or only by my ability to set it up properly

Any thoughts would be greatly appreciated

Cheers
Tim

the SC kit will work out of the box, but may not be the absolute optimum solution.

Some may advise not to use it, but with a sensible boost level and a good setup it will be fine.

As Andy said the SC will work as you got it.

I'm still learning about injection, but I would think if you were moving the injectors to the runners you may have to check that they are large enough capacity to support port injection. You would also have to consider adding a cam sensor to time the injectors and ideally a pair of widebands to allow you to balance the setup. There are some good threads on here for the last two.

Looking at the spec of the Typhoon it should be able to do port injection, but probably best to check with SC.

You would be best asking John Kimmins himself.

I thought the SC setup was configured as a "wet manifold" arrangement for simplicity, ie, to some extent it just replicates the carb thus giving a similar mixture spread across the cylinders as a carb - unequal but has worked for over 50 years.

Once you inject into the ports you need a sequential system timed to match valve opening - normal batch injection (which is fine on an 8 port engine with a single cylinder at the end of the runner) would just build up in the runner then mostly go into the first valve that opens, always the inner cylinders.

I'm sure the Typhoon can do sequential but you'll have to ask John if it can be timed to match valve openings as we can with the MS2/3.

But in any event, if you are using any form of port injection I would strongly recommend dual widebands, otherwise you just don't know what is happening, inners vs outers, only the average.

"The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."
(Professor Stephen Hawking (2008))

Let's put it in plan language. The guy who made you manifold is a dick. he has no idea about the problems of injecting a 5-port engine and has just applied a basic knowledge to a complex problem.

Don't use the new manifold it will not work. Use everything that SC sent in the kit.

Some info on my 998 turbo injection using the SC kit here http://www.turbominis.co.uk/forums/index.p...id=358245&fr=50

As you will see, no plenum required.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

Prescott Modified Series Production upto 1400cc course record holder
Oliver's Mount Modified Series Production upto 1400cc Hill record holder
Thoresby Park Modified Series Production upto 1400cc course record holder

www.twin-turbo.co.uk

Your new inlet manifold will work, but to get accurate fuel distribution you need an ECU that supports fully sequential, timed injection.

Stick with what you have from SC for now. When and if you want to increase the boost then you could consider port injection using your new manifold.

Edited by Paul S on 26th Apr, 2012.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."

Tim! i could have told you that tim has a kick as turbo mini.. post it up dude..

in saying that.. what power can the sc handle upto? and when should you consider port injection paul?

will what power are you pulling on the sc998?

they love the ozzie cluby cars

www.myspace.com/NickGalea

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."

On 26th Apr, 2012 Paul S said:

On 26th Apr, 2012 NickG said:
when should you consider port injection paul?

From 0 psi upwards

"The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."
(Professor Stephen Hawking (2008))

Thanks heaps for the comments guys. I am a novice at this but the amount i have learnt from reading all your ms trials and other build threads is amazing.

Im sure you feel you are constantly telling people the same old things over and over but just wanted to put the setup out there and see what you all thought

I had a feeling this would be the case, widebands it is.

Thanks again

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."