sand_man

I know I mentioned how good I was at spending your money, but take a step back and think about this. The fuel head mod is approx US$600.00. EFI will run into the several thousands not even including the dyno time that I'm told is required to really tune it. It seems much cheaper to fix what you have...many have said that the CIS on these cars is pretty dependable.

Sameer

Guys,
Another thing, if after tomorrow I still run lean, I plan to do the EFI conversion so in the meanwhile isit ok to drive my car regularly off boost till I get my EFI kit together?

Sameer

Sandman,
I am eventually going to go EFI so why spend that extra $600, might as well just do it now.

sand_man

Well if that's the case, then I agree...don't monkey with the monkey

BrianKeithSmith

I've never quite understood why you should care about the CO%. Seems like you'd just stick it on the dyno, and adjust the fuel setting to where you need it. Gradually move up the RPM range, when you see the AFR go high, shut it down, adjust the fuel load, and then dyno again, do this over and over until you get it to a manageable level.

But like I said, I don't know why CO% matters. I've never understood that. (but I'm not an expert). I guess I've just never heard any other cars being tuned for CO%, not that they haven't been tuned that way, but I haven't heard about it I don't think.

That's just my thought. Stick it back on the dyno, once you confirm that their AFR gauge is working properly, and make small incremental adjustments with the fuel head screw until you hit a target AFR.

I seriously doubt you are out of fuel adjustment. Maybe on the Andial you are, but probably not at the fuel head itself.

Brian

Sameer

Brian,
If I increase the CO would'nt that fatten the fuel mixture helping it to achieve better a/f ratio? Surely I would get a better a/f ratio with 5% CO than with 3.7% CO which I'm currently running. Yes I might be running a little too rich at the low end but at least I will get a better a/f ratio minimising running lean?

BrianKeithSmith

Sure it'll fatten it more than likely. But all I'm saying is why do you care about the CO% (unless of course you have to pass certain emissions requirements).

You should be more concerned with AFR that CO, at least I would think. Sure, one is an indication of the other, a 5% CO isn't going to tell you what your AFR will end up being. All you'll know is that, yes, more than likely, it is getting more fuel.

Brian

Sameer

Brian,
Sorry, I get what your saying which is basically to work the other way round. Adjust the CO according to the a/f ratio.
Thanks, will do so tomorrow and keep you'll posted.

Earlierapex

three letters will answer your question: K29. You are pushing a LOT of air through that thing at the top end. Maybe one of Stephen's K27s would be better? Depends what you want after EFI...

Stephen is just finishing my EFI conversion with a K27HF2, so I'll let you know what the torque curve looks like with that setup. Should be about what you are looking for (hopefully 500 or so at the wheels...)

On your question of cost of the EFI conversion (from another thread), take your guestimate and double it. It's just damned expensive, no two ways about it.

-dc

DonE

Sameer - adjusting the CO will not get you close to the AFR you need to run. It has a very small affect on overall AFR and is used to fine tune a WUR that is working correctly or is set up correctly. For example, I could run 12.5:1 AFR and set the CO to 0%.

CIS AFR is dependant on the WUR allowing fuel pressure to act on the fuel head - lower WUR pressure, the lower pressure it uses on the fuel head, the more fuel is allowed to pass through the fuel head. Higher pressures from the WUR act to build pressure against fuel head and decrease the fuel flow. So, messing with the CO will have little or no result in an AFR that is that far off.

Quite frankly, I am surprised your motor is still running if you are running + 14:1 AFR on boost. I guess its possible the dyno probe is bad, but don't count on it.

As for the larger turbo, since the metering plate (before the turbo) moves to allow the metering pin to measure the fuel flow (and the twisting intake tubes of the CIS don't allow that much air to move), I seriously doubt the turbo is a problem. In addition, I ran three different sizes of turbos (two bigger and better than the K29) on my CIS without this problem.

Why isn't the Andial working correctly? Check it out before you go back to the dyno. It should give you some fuel, but again, if the WUR is working correctly, you WILL NOT GET FUEL. Again, the very first place to start is to measure the fuel pressures between the WUR and fuel head, cold and warm. I would bet they are very high.

One last thing - it is my opinion that if your CIS is properly tuned, you would be hard pressed to beat that system with EFI, all things being equal.

sand_man

Sameer, I'd seriously think about getting your CIS properly dialed in before writing it off for EFI.

jhunt@huntinter

Do you have the black fuel head or silver? If it is black then you shouldn't have any issues delivering enough fuel with the CIS at those HP numbers. I would suggest a tuning problem.

sand_man

One final thing that I'll add Sameer, then I'll fall down drunk off of my soap box, is that EFI isn't necessarily a cure-all-bolt-on-solution that will fix all of your problems. It might even prove to be a frustrating endeavor, albeit rewarding once running properly. When I initially entered the 930 world, I thought for sure that I'd go EFI - if for nothing else, the dependability. However, after reading about some disasters, including DonE's melt down following a firmware update, I'm thinking that a finely tuned CIS with either the black Euro fuel head or one modified by a tuner will serve me just fine. Different strokes for different folks, I guess. Who knows, maybe your car hasn't been running properly for quite a while now and having it tuned properly with what you have might give you a different perspective.

Miles965uk

If you wanna spend the money then go EFi id say- Sammer you have internal mods done already on your engine- this is not the limiting factor to more power! CIS is so if YOU went Efi then you could be gaining more power than most people with stock engines... in some ways you are wasting all that $$$ spent on the internals
Efi is expensive but maybe this might change in a few months when I have done mine- I am not saying anything yet because I havent got mine up and running yet...

Oh Sandman my man - didnt Don blow his engine because he didnt have a a/f guage at the time he was running super lean! I think if you have the onboard guages you need boost, a/f, & poss EGT and play it safe all the time I dont see why you could stay out of this pitfall...

Geoffrey

Derick, 500hp to the wheels with a standard 3.4l engine build and 964 cams with standard exhaust might happen at 1.2+bar of boost. From my experience all that you'll see will be in the range of 440-460hp at 1bar of boost with that type of build. 500rwhp and over generally requires significant air flow improvements (intake, cams, heads, exhaust, and a good turbo).