What would be the best Renix to get the best kind of ignition on my f7p, 1.4 swap?

Is there any noticeable gains from running the different renix's? I mean mine has a terrible idle (also a F7P) but I'm assuming my bad idle is down to my bike carbs

scamp are you intending on running injection or carb? I assume carb because of the renix question but just want to know.

None of the renix units will have a clue what is going on, it's a high revving 16V engine with a fairly keen cam on it. All stock 300's are 8V, tame cam's, nothing like the same vacuum properties as individual carbs etc.

If you are on bike carbs *and* want the power that should come with them, along with correct running etc, you have to go mappable ignition.

The vacuum advance on any Renix will be thinking you are at full throttle most of the time given the manifold vacuum individual carbs give, I'd be surprised if the valves are shutting before the fuel is igniting when they start?

Grumpy Chris today I'm afraid, really not trying to tell people what to do. Best thing I guess is try and see which make it run best/idle best etc.

Chris_C wrote:None of the renix units will have a clue what is going on, it's a high revving 16V engine with a fairly keen cam on it. All stock 300's are 8V, tame cam's, nothing like the same vacuum properties as individual carbs etc.

If you are on bike carbs *and* want the power that should come with them, along with correct running etc, you have to go mappable ignition.

The vacuum advance on any Renix will be thinking you are at full throttle most of the time given the manifold vacuum individual carbs give, I'd be surprised if the valves are shutting before the fuel is igniting when they start?

Grumpy Chris today I'm afraid, really not trying to tell people what to do. Best thing I guess is try and see which make it run best/idle best etc.

Understandable Chris, I guess this is the more sensible option...

I've been reading about Megajolt (Although I've read about it requiring a 36-1 trigger wheel) as it will sort out my other issue of not having a rev limiter as it has one optionally built in

I'm running twin 40s, instead of individual bike carbs. I was of the understanding that it would run on the standard matrix, just without the full power output. Someone on here told me to find a thread that has all the different Renix graphs on it or look into megajolt.

Need some serious help guys

This has some good info in it

http://www.volvo300mania.com/forum-uk/v ... ilit=renix

That's an interesting read, I can see fitting megajolt being a bit of an issue regarding the flywheel but I might get in touch with them to see what advice they have. Cheers Dai (and Mac for the info).

My F7P runs, doesn't idle too well but it goes alright. You should probably try the Renix out first and get the car going and then look into stand alone ignition later. From what I can see to use Megajolt you need to run the Ford EDIS module and get a new crank position sensor/wheel as the flywheel on the F7P won't do the trick.

Or you could look into Megasquirt, a bit pricey and a bit of an overkill (due to the injection capabilities of MS) but you can just use the ignition side of this and have the option for throttle bodies later. An advantage of using MS is you could hook up a wide band lambda sensor and see how we'll your carbs are set up using their logging facilities.

Not optimal, but it can be made to work for sure. It's hard to say though what unit would be best as there's only the one advance curve graph floating around which is also posted in the topic which Dai mentioned.

Though by looking the green books, B200E untill -86 would have the "hottest" ignition curve, with 30 degree advance at ~2500rpm, other Renix boxes seem to have around ~22 there. Total advance seem to be around ~40 with these so it's nothing which can't work with a 16V F7P. These figures are without vacuum advance and it would probably work best without the vacuum advance, the renix end of the vacuum sensor left in free air. Then it's using the full throttle curve from basic advance of ~9 degrees to the full advance at ~40 degrees. This would equal quite what has been commonly used with 200-series hall-effect ignition when building ~150-170hp engines. It's a common procedure with 200-series ignition to disable the vacuum advance and set basic advance around 10 and max advance around 35 or 40 with N/A redblocks around 150-170hp. Same can be done with Renix.

Of course it's not optimal curve but if you compare it with the 200-series stock ignition, the curve of the stock hall-sensor ignition surely won't be any better there when tuning those engines at the same power levels and quite good results have been achieved.

Here's a one "recipe", copied from http://www.vrcf.fi which uses the 300-series Renix ignition. Not a F7P, but the power levels are similiar. This one had the VR-sensor position adjusted though to get the max advance to desired level. There's a dyno sheet also.


B230E
- lightened flywheel
- 96 mm bore
- 405 head, smoothed and shaved 2mm
- Cam-shaft 272/109/12 (Rintakari's "H+")
- Compression ratio 11,5:1
- Tubular exhaust manifold 4-1 (38-60 / 730)
- Exhaust 60mm and one 2,5" silencer
- Viscous fan removed
- LE-jet + stock intake manifold
- Renix without rev-limiter and VR-sensor position adjusted

http://crazyracing.pp.fi/pics/b230e_b23 ... 109_12.jpg

There are two differen't engine versions at the same dyno chart here, the curves for the engine with Renix are lighter ones, those curves which are bolded with bluepoint pen are for a bit "tamer" setup of the similiar engine (using 200-series hall-effect dizzy btw.. B230K based engine though, but also ran with LE-Jetronic, same cam but with compression around 10 only).

But as can be seen, Renix can be made to work with engines around 150-180hp quite easily. Not optimal but modified hall-effect sensor dizzies for 200-series aren't any better and those have been used for ages in 150-200hp N/A engines.



-Marko

still i can't understand why people build engine's and cars and start saving out on one of the most important factors of the engine's performance by insisting on using a factory system that is totally not designed for their engine/setup. a proper ignition system sets you back max 300quid and you'll have a easy way of getting more power out of your engine wich is more reliable too if it's setupped/programmed correctly.

Well mostly engines like described in my post, are built just for fun, from parts which you have at your shop laying around. "Useless parts, let's see what can we build from these"

Usually engines like that are also used in folk-race cars (http://en.wikipedia.org/wiki/Folkrace), where the car has to be sold for a fixed price after the race, if someone want's to buy it. So engines are usually done with a very low budget using many modified stock parts.

I wouldn't use Renix in a new build if I was building a car to my self, but my post was just to show that it's possible to use Renix if someone for some reason would wan't to use it.


-Marko