Has Anyone Gained Hp From Cdi Ignition Alone

[TurbostyleR]

Hi all,

Just curious to see how many people have installed a CDI ignition system on their cars and actually experienced an increase in HP just on the ignition upgrade.

At the moment im not maxing out my spark however I do have an MSD DIS4 just sitting around and i was wondering if it would increase HP just by upgrading the spark?

The motor is an SR20DET making around 380-390rwhp on around 17psi of boost...

[WetGTR]

From what I understand just installing it would not get you any gains but that is because you need to tune for those gains. The better spark will burn the fuel more efficently but to take advantage of the power gains you need to tune your ECU.

So to answer your question - No.

It's like all good upgrades, needs tunning. Good thing to install though, most of the time this is one area that has been always over-looked.

[RB30-POWER]

if you have closed your gaps a significant amount to acheive that power, then by adding the complete CDI modules and high energy coils, you are going to be able to open the gaps back up, get a larger spark and more efficient burning of the mixture.

not to mention it will be more reliable, if your plugs get a little old worn, fouled/whatever the ignition system will still have the power to jump the gap under high cylinder pressures.

you should notice a fair gain in response, even if the outright power doesn't increase by a huge amount.

[Busky2k]

It definitely cant hurt to use. Especially if you can open up the gaps with them!! Also the soft rev limit looks cool...

Why not install it and found out the results??

Edit- seems this Firebird gained 2 tenths at the track with one;

http://mods.firebirdv6.com/msd/

Edited November 1, 2005 by Busky2k

[sky30]

id be interested to know the results aswell, so give it a go...

[campbell]

i run a digital 4 msd ignition with 6 v8 supacoil packs three bosch ignighters and 2 digital amplifiers..

i foun with this set up the spark out put could kill a cat ... but yes driving standard and this set up their is a big difference in hp

[TurbostyleR]

cool thanks for the response guys.

Yeah i'll give it a go, from what i hear i have nothing to lose, i just have to get some mercury outboard coils...

[Busky2k]

Why not just use the stock coils? You'll have to muck with the wiring a bit though...

[TurbostyleR]

I have been advised not to use the standard coils by many workshops and tuners - however i have seen them work with the hks twin spark cdi systems so ill see how i feel on the day, i might just leave the standard coil packs in there and see what happens

Edited November 1, 2005 by TurbostyleR

[WetGTR]

You can use standard coil packs no problem.

It's just that using something like the mercury outboard coils or bosch coils are mainly used for methonal or NOS applications where they want that bit extra so it's considered an over kill - but I like over kill.

Have you got a good price on these Mercury Outboard Coils TurbostyleR?

Been looking for a good price on them.

If anyone can get good prices on them, please let me know.

[Sydneykid]

Standard coils are designed to fire once per ignition cycle. Whilst CDI fires multiple times per ignition cycle. Hence you should use a coil designed to fire multiple times per ignition cycle, otherwise you are wasting a good deal of the CDI benefit. Mercury outboard coils are designed to be used with CDI, that's what they have standard.

cheers

[TurbostyleR]

thanks Syd Kid - i was actually looking forward to your response in this thread!

I remember doing a search on this topic and you stated the exact same thing which is why Im looking into sourcing those mercury outboard coils.

Just a quick question though - I have read recently (on a forum) that you cannot use the MSD Ignition system and external coils on Power FC equipped Silvias - im not too sure if this includes skylines (Im assuming it does as they would run similar ignition setups?)

Can you please shed any light on this topic?

[Sydneykid]

thanks Syd Kid - i was actually looking forward to your response in this thread!

1. I remember doing a search on this topic and you stated the exact same thing which is why Im looking into sourcing those mercury outboard coils.

2. Just a quick question though - I have read recently (on a forum) that you cannot use the MSD Ignition system and external coils on Power FC equipped Silvias - im not too sure if this includes skylines (Im assuming it does as they would run similar ignition setups?)

Can you please shed any light on this topic?

<{POST_SNAPBACK}>

Suggestion follow;

1. Yep, I find I am repeating myself a lot lately, the search button must be hard to find.

2. I have never actually used a CDI system with a Power FC, we use the Motec CDI's with Motec ECU's. There are basically 2 types of igition systems involved in the various models of RB's that result in fundamentally different Power FC's. Loosely they are what I call "separate ignitor" and "ignitor on coil".

Logically I can't see why you couldn't use a 6 channel CDI with either of the Power FC styles. But maybe the problem is the lessor models of CDI's with 2, 3 or 4 channels. Neither of the Power FC's wouldn't like the joined cylinders (wasted spark) that would result from using one of those lessor models.

Maybe that is the real issue, not that Power FC's won't work with CDI's in general. I suspect that I will have to face up to that problem sometime next year as I am nearing the limit of the standard coils on the RB31DET. I will cross that bridge when I come to it.

cheers

[rob82]

I have personally seen a gain of about 40awkw on a 400awkw wrx running autronic. Though we were running about 30psi of boost.

[TurbostyleR]

coolies thanks for the response!

I think im pretty sure in what your saying.

Since Im only using an SR20DET 4 cyl motor, and since i have a 4 channel CDI ignition system i dont see how it would be a problem...

the only problem is figuring out how to wire this sucker in! :S

[WetGTR]

I have been looking into CDI setup's a bit further.

I have just purchased the Autronics 500R CDI unit which has 4 input drivers which I can only use 3 of them on a 6 cylinder engine in a wasted spark setup.

I also looked at my Autronics SMC ECU and noticed there are only 4 output drivers anyway which means I can only run the wasted spark setup.

I noticed a few people using the MSD DIS-4 setup and they too have only 4 inputs, so on a 6 cyclinder car you must run the wasted spark setup.

First check your ECU and find out how many output drivers you have before you start looking into the CDI side. No point getting a 6 channel CDI which your ECU cannnnot drive. Manybe the reason so many people are using the MSD DIS 4 (4 driver units)

The Motec systems have 6 channel drivers and their CDI's have 6 input channels - the ideal setup!

I spoke to my tuner and another very high regarded tuner and both explained the difference between Motec systems and the Autronics CDI setup and they both said that the coils will have to work out twice has hard as it fires 2 spark plugs (1 being wasted) but can recover very easily as aftermarket coils were design to run 4-6 cylinder engines anyway.

In saying this they did state that the stock coils will do the job anyway but they are not designed for CDI and become heat soaked much more easily in a continuing high demand situation.

[RB30-POWER]

you dont want to use the standard coils anyway.

you want to get rid of all the weak links in the chain.

[WetGTR]

I agree, the standard coils would be the weak link but not to a major degree.

This being said the coils are not too expensive anyway and worth the expense if your in a high HP bracket, otherwise I don't think that its worth it.

Mercury Outboard coils are @$75.00 each x 6 = $450 plus leads, brackets and other installation costs.

Maybe the money could be spent on mods to take advantage of the extra spark, ie; a tune which I beleive will give an overall better result.

If budget allows - get everything!

[RB30-POWER]

doesnt the cdi unit supply like 500V to the primary side of the coil instead of the standard 12V?

i cant beleive the standard coils will like that for long.

whats the spark energy from the average CDi unit? its about 40kV output versus standard ignition of about 10-20kV correct?

plus the multiple sparking will be a bonus.

[sky30]

What sort of power gain is expected from a CDI in a high horsepower engine( 350+RWKW)????