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How much HP with stock FI


caen fred

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I have a 1983 NA engine, and would like to push it to the limit of the sleeper concept!

 

That is, stock looking but upgraded components...

 

 

 

I already have a 60mm throttle body, Rising rate fuel regulator, K&N, I plan on using the camshaft I had for my triple delortho set-up… and of course my 6/2/1 header and twice pipe (for the sound).

 

 

 

I am not after 250 hp, just the max of a stage 2 concept. I think my cam would need more fuel than the stock ECU can manage… do you think a MEGASQUIRT could help me run larger injectors, or manage better than the actual one…

 

 

 

Has anyone used this stockish route before? I need to have a stock looking engine bay and can not use turbo anymore (too much hassle with the French cops!)

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Caen fred,

I understand the want to maximize the stock components of your car, but I'll tell you that it an uphill battle. I was running the stock turbo components to their maximum and you definatly sacrafice drivability for performance. Start looking into the megasquirt. You really can't beat the price $190 for MSI and $250 for MSII. This will provide you with full control of any injectors that you want to put in. The great thing is too, that you can keep all your stock components (sensors, distributor, injectors, fuel rail,....) I am also a bit confused as to why you are using a rising rate regulator. If it is the type that I am thinking of, it will only rise the fuel pressure under boost and will do nothing under vacuum. This type is used in conjunction with the stock regulator. Is this what you are using?

-jeremy-

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Stroke and bore the L28 out to 3.0 or 3.1 liters

 

Add more compression (10.0:1 to 11.0:1 cr)

 

Install a much bigger cam (290 degrees)

 

Do some mild head port and bowl work

 

The intake runners can be opened up a little on the ends (as far as your porting tool can reach)

 

An aftermarket efi would work the best. I would spend the extra time and money and get an efi with ignition timing control.

 

Stock turbo injectors with a little more fuel pressure should get you to 250 hp.

 

To maximize performance, install a stronger clutch (240mm) and a LSD diff to apply the extra power to the pavement.

 

The stock efi can give enough fuel even with the stock non-turbo injectors if more fuel pressure is used, so more fuel is no problem. The problem with the stock efi is the lack of programmability and air flow restriction from the small intake ports.

 

Good luck with your sleeper.

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I would spend the extra time and money and get an efi with ignition timing control.

 

I agree, no one at this point should be installing megasquirt without using MSnS to provide ignition control. It is a freebie for the spark part, it has been proven by many, many people and it is documented for installation.

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The stock FI with the flapper door AFM is not very good for performance. We have a guy here named z-ya who has built a 10.5:1 compression engine with flat tops and an N47 head. Running the stock FI and stock cam he was able to put down 165 whp. I have read here and elsewhere that the stock FI can't adapt to a much larger than stock cam (I think I've read that the 490/290 is too large for the stock FI--correct me if I'm wrong), and that your engine is going to need a larger cam if you bump the compression that high. Even if you don't the stock L series is way undercammed, so a bigger cam would be a good idea regardless of whether you bump the compression up. If you were to run MSnS or some other aftermarket FI system you could work around the flapper door and the cam limitations, and then you might be able to make some real power. The stock FI is a huge limitation, so if you can get rid of it you'll really make it easier on yourself. Keep the manifold if you want it to look stock, but get rid of the ECU and the flapper door AFM and you'll be way ahead of the game.

 

Kinda sounds like this is your game plan anyway...

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Ive been looking into megasquirt for a while now as well. I think I will finally take teh plunge and buy a V3 board at the end of the month.

 

The stock ECU sucks big time. ditch it. the actual ECU bit is very limited and will go on a linear fuel/rpm curve after 3500RPM under WOT.

 

IF you want to keep it stock LOOKING, here is what you should do.... have the intake extrude honed and have your head ported. get a set of turbo injectors and a megasquirt. the turbo injectors should be enough fuel for ANY street driven L series NA motor. then, if you wanted to keep it stock LOOKIING, get a turbo AFM and remove all the guts, the flap all of it. maybe a bmw AFM would be bigger and still look stock? but yes, a cam a 60MM TB and all that good stuff and you should be well on your way.

 

oh yeah, maybe look into a Maxima N47 head. I dont know what they were called in Europe, but over here we have a RWD sedan powered by the L24E engine. the head had 39cc chambers and makes for about 11.5:1 compression on a flat top ZX block. From what I hear about fuel in europe and high octane content, that compression number shouldnt be a problem. anyway.......

 

as far as electronics go, you cant really go wrong with megasquirt. then you can sell your RRFPR to someone else and recoup some of the initial investment!

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Gotta be careful on the Euro octane measurement. They do it differently than we do here. We are RON + MON / 2, I believe they are just RON or just MON. So when they say they have 95 octane gas it isn't the same as our 95 octane. Its more like 92. Here: http://www.btinternet.com/~madmole/Reference/RONMONPON.html

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So with a Megasquirt I could bypass the AFM ?

It doesn't need the info from the AFM ?

If I understand, the one from the turbo ZX is bigger... so once it's empty of all the internals, it's like a plain empty chamber? Should I run some kind of PVC tube inside to keep it clean and smooth?

Clould I dump it and shorten the air tube to bring the K&N closer to the TB ?

 

I don't think the guy from the MOT would pick-up the difference with and without a AFM, while they spotted obviously the Turbo #^$!§!

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Yes, megasquirt is MAP sensor based, meaning it doesnt need an AFM nor a MAF. If the guy at the MOT wouldnt notice the difference, just scrap the AFM all together. although, I thought you were concerned about making it look stock.

 

You could also put a cold air intake on it and just have a tube going from your TB to a K&N filter located in front of the radiator. I think that would be best, as it would make it stock appearing.

 

oh and yeah, about the whole european octane, I thought they also had much cleaner (more refined) gasoline than ours. which I would think would make it more detonation resistant. its the reason they can run Direct Injection in thier cars, correct? not as much sulfur content?

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I am more concerned by the apparent mods... The one that can be really obvious like my old BAE turbo kit is !!!!!!

If I dump the AFM I don't think they will notice it... they just don't know this car. But the NA system is notified on the car's paper!

 

As for gas... I run on 98

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oh and yeah, about the whole european octane, I thought they also had much cleaner (more refined) gasoline than ours. which I would think would make it more detonation resistant. its the reason they can run Direct Injection in thier cars, correct? not as much sulfur content?

The elimination of sulphur has to do with emissions IIRC. I'm not a chemist, but that's what I remember reading somewhere.

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98 eqyuates to about 93 stateside and there is at least one person on this board running megasquirt on hot NA engines with compression ratio stretching into the high 11's (maybe low 12's, cant recall) and it runs fine. Ive driven it. this being said, you do have to know how to trune yoru car, or take it to a reputable dyno -tune shop and have them work it out.

 

If all the MOT will be looking for is the addition of a turbo kit, then I would suggest at least buying a better aftermarket intake manifold. the ones on our cars are pretty restrictive, especially when you start chasing upwards of about 175rwhp. I would suggest an aftermarket intake (lonewolfperformance.com), megasquirt, turbo injectors, some more compression than you have now, and a camshaft. nothing too wild or crazy, just somthing a step or 2 from what you have now. maybe a 270*/.460lift. oh, and of course a header witha 2.5" mandrel bent exhaust. Maybe have your head proted. depending on how much you have to spend.

 

 

 

on the octane...

 

well, Im not going to whore this guys thread out anymore, but i will say that sulphur produces more pollution, and more byproducts of combustion. as well as more ash (read:more deposits) a cleaner running engine will be more resistant to detonation. less carbon build up, less chance of detonation. less crap to get in the way of the burn process, is always better for the engine AND performance.

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I am more concerned by the apparent mods... The one that can be really obvious like my old BAE turbo kit is !!!!!!

If I dump the AFM I don't think they will notice it... they just don't know this car. But the NA system is notified on the car's paper!

 

 

so then gut the AFM and leave it in place? some serious thought can hide just about anything.

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Ok now could we be more specific

So I need :

- Megasquirk (wich one)

- Is it coming with all the harness ready to bolt

- I have a spare laptop used presently as a weight paper!

- Injectors (are the one I have good enough to get full usage of MegaS?)

- I have my Cam it's a britt one made for Street/track day and 3 carbs, still good? Or FI ask for an other profile?

- I have my nismo header

- What about sparks??? The ZX dizzy is fine ?

It's like learning all over again... this is fun!

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