Standard Engine Management

[Guest piran21]

What's the most whp anyone has got out of the Xu9J4 on stock engine management. Chip tuning permitted. I don't mean carbs and TBs. Just wondering what the limits of the stock setup is.

[Guest DesMi16]

The most i've ever heard of is 177bhp running standard setup with Catcams 274 inlet cam which is taking you towards carb / tb territory. Any more on the cams and carbs / tb's start becoming a necessity.

[Guest piran21]

The most i've ever heard of is 177bhp running standard setup with Catcams 274 inlet cam which is taking you towards carb / tb territory. Any more on the cams and carbs / tb's start becoming a necessity.

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Was that brake horsepower (at engine) or WHEEL horsepower?

[Rippthrough 98]

The most i've ever heard of is 177bhp running standard setup with Catcams 274 inlet cam which is taking you towards carb / tb territory. Any more on the cams and carbs / tb's start becoming a necessity.

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Was that brake horsepower (at engine) or WHEEL horsepower?

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bhp.

[Guest piran21]

That's uninspiring.

[Rippthrough 98]

That's uninspiring.

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Well, considering the injectors start to max out a little way after that it's not bad.

Especially as that's only with an inlet cam.

[Guest piran21]

I wonder if the original management could handle larger injectors. I guess you're right if it's just an inlet cam. Was the motor stock otherwise?

[Rippthrough 98]

I wonder if the original management could handle larger injectors. I guess you're right if it's just an inlet cam. Was the motor stock otherwise?

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That and 3 angle seats as far as I remember.

Edited March 17, 2006 by Rippthrough

[Guest piran21]

So can the stock management handle slightly larger injectors?

[Hilgie 16 2 Cars]

yes, as long as they are the same impedance

[KRISKARRERA 2 1 Cars]

Is it all a bit hit and miss though? You improve airflow so you increase the amount of fuel injected but you can't be sure you've got the air:fuel ratio perfect. Some say you can get a bhp increase on a standard mi just be using a mappable ecu.

[petert1345402284 0]

Some say you can get a bhp increase on a standard mi just be using a mappable ecu.

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I doubt it. You can definitely improve the low-mid range however.

 

The limitation of the std. setup is the injectors. There's enough fuel in the standard setup to get up to 180hp. With that sort of power the std. injectors run to approx. 13:1 AFR, about as high as you want to go. When you fit bigger injectors you obviously have to remap the whole RPM/load ranges. This is quite achieveable if you have the resources to rewrite the code. It's just time consuming.

[KRISKARRERA 2 1 Cars]

Sounds bloody complicated too.

[RobMGti 0]

Not complicated if you have the skill to do it. As peter said its been proven before the limiting factor of a standard Mi is the injectors. A decent cam and a remap i would expect to net you over 170bhp but anymore and you are getting to the maximum load of the standard squirts.

 

On a totally standard Mi i would doubt you would even see an increase of 5bhp after a full remap.

 

Personally i cant see the point of services like Wayne at Chipwizards offer unless you have a number of Mods that are not catered for by existing pre-made maps. £450 fora 4 hours :s scary.

[KRISKARRERA 2 1 Cars]

I've got the skill. But not the knowledge.

[Guest DesMi16]

Other limiting factor of P1 Mi is the ignition map. Nothing as simple as a dizzy to change here. The ignition map on a modified engine is far from ideal for a modified engine

[petert1345402284 0]

That's for sure. I've been lucky enough to have spent quite a bit of time on the dyno massaging ignition maps and now have good collection and an understanding of how much torque can be gained in this area.

[Guest danzmi16x4]

i got a 1991 mi16x4 and its got aftermarket extractors and a freeflow exhaust but standard filter would a pod filter make much differance??

[KRISKARRERA 2 1 Cars]

They look good and sound good but as for a bhp gain....

 

The standard intake and exhaust systems on these engines are supposed to be pretty good unlike some other cars which seem to gain alot with a freer flowing exhaust and air filter.

[Guest DesMi16]

From my experience, cone filters give you nothing over the standard air box but do sound good. Did dome experimenting on a rallycross car and found that a good airbox and panel filter can give better results than a cone filter as you can control the factors such as heat soak from the engine bay far better.

[Guest Eric Josefsson]

The original exhaust manifold sucks though. No tuning at all, all the pipes have diffrent lenghts and the collector is to tight.

[Stuey 2]

From my experience, cone filters give you nothing over the standard air box but do sound good. Did dome experimenting on a rallycross car and found that a good airbox and panel filter can give better results than a cone filter as you can control the factors such as heat soak from the engine bay far better.

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Yep, I think you're right Des. I bought mine with a cone K&N and have put it back to stock, and it feels the same everywhere except low/mid torque, which seems better. I'm not sure if this is because of design or temperature, but there you go. It has quite an effect as we get 40+ degrees in summer.

 

(Incidentally, I lived in Erdington before emigrating when I was only 4 and still have relatives in Walsall).

 

Cheers

 

Stuey

[Guest DesMi16]

From my experience, cone filters give you nothing over the standard air box but do sound good. Did dome experimenting on a rallycross car and found that a good airbox and panel filter can give better results than a cone filter as you can control the factors such as heat soak from the engine bay far better.

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Yep, I think you're right Des. I bought mine with a cone K&N and have put it back to stock, and it feels the same everywhere except low/mid torque, which seems better. I'm not sure if this is because of design or temperature, but there you go. It has quite an effect as we get 40+ degrees in summer.

 

(Incidentally, I lived in Erdington before emigrating when I was only 4 and still have relatives in Walsall).

 

Cheers

 

Stuey

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Small world!!

[Bozi 0]

A friend of mine tested that on standard mi16 (phase 1) he gained 7hp just by taking out the airflow meter and turning it by hand on dyno. So I suppose that would be enough to tell that you should not even try to improve power with the motronic.. Anyway, you can build a megasquirt system with the price of custom chip for motronic so it should not be a problem?

 

Also the low/midrange power is so much better with mappable ecu, idle a lot smoother etc. I have lowered compression rate, three times larger injectors than standard and the idle quality is now about the same. Though with standard setup and mappable ecu the idle was soooo much better. I really, really recommend to replace the original ecu with somethin better.

[Guest piran21]

how much would a MegaSquirt system be?