Engine upgrade help

[boomdart]

I need to know about fuel and air ratio. If I get larger fuel injectors, I would need forced induction correct? I will be doing this to a turbo engine, so perhaps I could increase the boost to get more airflow and make sure the car isn't running with a crappy distribution of air/fuel. I am also getting a high flow fuel pump, ignition system, cams, oversized valves, gapless piston rings, copper head gasket, boost controller, 75mm throttle body, cold air induction, higher flow intake manifold, exhaust manifold, downpipe, cat, and cat-back/muffler, and suspension stuff. I want to make sure everything works with everything else as best it can, so sizing is important.

By the way, it's an '89 Ford Probe GT 2.2L Turbo. Personally I love the '89 models for the paint scheme and stock "body kit" for lack of better words.

Note, I want more performance but I am not looking for 10 second car. 240hp is my goal.

And no appearence mods will be made to the car, except *maybe* new wheels.

 

[Howard]

<<If I get larger fuel injectors, I would need forced induction correct>>
No.
<<so perhaps I could increase the boost to get more airflow and make sure the car isn't running with a crappy distribution of air/fuel>>
How would increasing boost improve the A/F ratio?

BTW, that's a lot of stuff to change to make a measly 240HP...

 

[NutBucket]

Your best bet is just to start upping the boost. Get a manual boost controller and a piggy-back fuel computer to adjust the fuel curve. Something like an APEXi SAFC is what I had in mind. Tho, I'm not sure how advanced the electronics are in this car.
The most important tuning tool you should get yourself is a wideband O2 sensor, period. The stock O2 sensor doesn't provide precise enough information for tuning.

 

[Evadman]

If you change to larger injecters (higher lb/hr) what changes is the dwell time. This is the time (usually a %) that an injector is "open" alowing fuel to flow. Changing injectors will usually require a reprogramed computer.

How high are you going with the boost? 20+ lbs? why do you believe you need a copper head gasket? (not that it would hurt)

I would suggest you get a baseline a/f mix by reading your o2 sensor (or installing another) upstream of your cat. After instlling your performace mods, check it again. You should still be in the same range.

Remember, O2 sensors are for removing fuel, not adding it. never run lean.

 

[boomdart]

I'm probably only going to run the boost at around 12psi, that's almost doubling it from the stock 7.3 (peak of 9.x psi) but the engine can handle it.

So if I get the 850cc injectors, and boost the turbo, the o2 sensor will sense how much fuel/air ratio is and cut out the fuel injectors to match that of the air coming in, correct?

Yeah, it does sound like a lot to get a 'measly' 240hp, but this car with 240hp can make low 14's and high 13's. I'm fine with that speed. The ~240hp is with the stock 7.3 boost, if that means anything.

 

[NutBucket]

Not necessarily. The stock ECU only has a limited operating range. I doubt it will handle that large of an increase in fuel/boost flawlessly. You need to reprogram the computer. How much power does this engine make stock and what's the compression? Do you know if the bottom end is any good for that much more power?

 

[TechnoKid]

Copper head gaskets require (last i've read unless the design has been updated) grooves to be machined for the o-ring that is generally required. Traditional head gaskets usually don't need the groove for a o-ring. I would suggest going with a 3-layer gasket if going turbo, unless you don't mind the additional milling and machining expense or a copper gasket, go with that.

If you're gonna have the pistons out for new rings, may want to think about getting stronger rods, or having them shot-peened(sp). I would think that the rods would go out before the pistons would under boost, but you may want to get the piston skirts coated as well.

Also think about upgrading your clutch and getting a new flywheel, perhaps a chromoly one. Aluminum ones may be lighter, but chromoly is supposedly stronger. A lighter flywheel will get you better throttle response, especially with the turbo.

 

[KokomoGST]

Well, you also have to consider that the engine in boosted applications is going to be more turbo-limited rather than engine-limited at a certain point. That point being the estimated hp limit based on airflow the turbo is capable of.

I know that Probe's turbo is WAY puny. Doing all the fuel, exhaust, and intake modifications is just good groundwork for making the most out of a bigger turbo. With 240hp for your car won't require nearly as much as you think if your turbo wasn't so sucky (pun NOT intended). At 12psi your turbo will prolly do nothing more except blow lots of hot air instead of the denser and colder air at the stock 7.3psi so the extra volume will end up with nearly no gain in oxygen to burn. Similar thing happens the majority of smaller turbos... the Probe turbo just happens to be REALLY small. It runs up to 12psi but is gasping and wheezing out the 7.3psi at upper rpm ranges due to inefficency.

Don't try to tune the car's fuel curve by changing the injector size, that won't do any good. A basic fuel computer like the S-AFC should be fine for your goals. I think I'm going advise against what Nutbucket suggested even though his way is the "correct" way... to reach your goals you don't need nearly the amount of money and effort it seems you're willing to put into it. Just get an Exhaust Gas Temperature gauge to make sure you're not running too lean since your goals are nothing to radical that a dyno session couldn't set up.

The thick copper head gasket is a trick that some people use to lower compression on higher compression motors. Generally there's no need for that on most factory turbos since they are low compression and tend to have decently stout bottom ends to take boost. You don't need a big sheetmetal intake manifold... porting your factory one should be enough. No need for cams, piston rings, ignition upgrade, etcetc...

My suggestions in no particular order to have a 14second turbo Probe...
1) get a cheap but slightly larger turbo
2) add upgraded fuel pump and 550cc injectors and fuel pressure regulator if your stock regulator can't handle any higher flow fuel pumps
3) a basic fuel control piggyback like the SAFC
4) a manual boost controller set to an efficent boost level for your bigger turbo
5) large turboback exhaust piping and hard pipe to/from intercooler (larger TB is optional)
6) motor mounts, tires, etc for more traction

EDIT: you may need an upgraded clutch but 240bhp doesn't need a very heavy clutch to hold.

 

[TechnoKid]

Originally posted by: KokomoGST

No need for cams, piston rings, ignition upgrade, etcetc...

I would tend to disagree with the ignition....I would reccomend an igntiion upgrade even on a non boosted motor. More spark, more complete burn. Also under boost, better ignition could help prevent detonation. Im not sure how the stock ignition on the probe performs. I'm not saying an all out ignition like a MSD digital 7, but something like a SCI, or 6A. Wires and plugs; well, wires, I'd go with 7mm-8mm for road application, larger (10mm) if you are going into a lot of racing on the track. Plugs, copper conducts electricity better than platinum, but are not as heat resistant and do not last as long. Perhaps iridium if they have it for your app.

 

[NutBucket]

Originally posted by: KokomoGSTI think I'm going advise against what Nutbucket suggested even though his way is the "correct" way...

😕

The only thing different then what you suggested was the wideband O2. Course, I had no clue the stock turbo was so tiny either. Am I wrong in thinking its a T25? (had this idea in my head from somewhere or other)

 

[KokomoGST]

Originally posted by: TechnoKid

Originally posted by: KokomoGST

No need for cams, piston rings, ignition upgrade, etcetc...

I would tend to disagree with the ignition....I would reccomend an igntiion upgrade even on a non boosted motor. More spark, more complete burn. Also under boost, better ignition could help prevent detonation. Im not sure how the stock ignition on the probe performs. I'm not saying an all out ignition like a MSD digital 7, but something like a SCI, or 6A. Wires and plugs; well, wires, I'd go with 7mm-8mm for road application, larger (10mm) if you are going into a lot of racing on the track. Plugs, copper conducts electricity better than platinum, but are not as heat resistant and do not last as long. Perhaps iridium if they have it for your app.

More spark more burn? That's just doesn't make sense. Any spark and if the fuel is properly atomized and timed... it will burn regardless of the strength of the spark as long as you have an ignition system that is capable of enough voltage to jump the air gap. Sure, denser air adds more resistance to spark, but if the factory system provides more than enough voltage... there is NO reason to change it. I know many people deep into the 12s & 11s with factory ignition systems.

All this iridium, thick wire crap is nothing but riceboy marketing. If your application doesn't require big current/voltage, you have no reason to use thick wires other than for durability. High quality silicone wires and a set of properly gapped fresh copper plugs is just proper care of the car and all that's neccessary. Iridium is just extra $$ and platinum electrodes aren't durable enough for forced induction apps.

 

[KokomoGST]

Originally posted by: NutBucket

Originally posted by: KokomoGSTI think I'm going advise against what Nutbucket suggested even though his way is the "correct" way...

😕

The only thing different then what you suggested was the wideband O2. Course, I had no clue the stock turbo was so tiny either. Am I wrong in thinking its a T25? (had this idea in my head from somewhere or other)

Nope... it's even smaller... it makes my T2small look big. My T25 runs out of puff at 12psi at upper rpm ranges but can readily push 17psi efficently.

I agreed with you basically but he'd prolly never really get/need a fuel computer with enough adjustment to really take advantage of a full wideband. A real wideband is a fairly big chunk of $$ in comparison to an EGT.

 

[NutBucket]

Eh hell. I guess I need to educate myself more about turbo stuff if I plan on getting a new Legacy🙂

 

[TechnoKid]

Originally posted by: KokomoGST

Originally posted by: TechnoKid

Originally posted by: KokomoGST

No need for cams, piston rings, ignition upgrade, etcetc...

I would tend to disagree with the ignition....I would reccomend an igntiion upgrade even on a non boosted motor. More spark, more complete burn. Also under boost, better ignition could help prevent detonation. Im not sure how the stock ignition on the probe performs. I'm not saying an all out ignition like a MSD digital 7, but something like a SCI, or 6A. Wires and plugs; well, wires, I'd go with 7mm-8mm for road application, larger (10mm) if you are going into a lot of racing on the track. Plugs, copper conducts electricity better than platinum, but are not as heat resistant and do not last as long. Perhaps iridium if they have it for your app.

More spark more burn? That's just doesn't make sense. Any spark and if the fuel is properly atomized and timed... it will burn regardless of the strength of the spark as long as you have an ignition system that is capable of enough voltage to jump the air gap. Sure, denser air adds more resistance to spark, but if the factory system provides more than enough voltage... there is NO reason to change it. I know many people deep into the 12s & 11s with factory ignition systems.

All this iridium, thick wire crap is nothing but riceboy marketing. If your application doesn't require big current/voltage, you have no reason to use thick wires other than for durability. High quality silicone wires and a set of properly gapped fresh copper plugs is just proper care of the car and all that's neccessary. Iridium is just extra $$ and platinum electrodes aren't durable enough for forced induction apps.

I agree with you on many points. The reason i would use thicker wires is for durability. In harsh racing conditions, like say road racing at Buttonwillow, constant high underhood heat can take a toll on stock wires.

I was going by what I have read in a sport compact article a while back, where they tested and said using an MSD SCI gave them what seemed to be a smoother revving engine, and slightlly better fuel economy (though fuel economy shouldn't be your top concern if you are worried about perforamce) (I take sport compact mag to be more of the 'performance' oriented magazine and not the "rice" stuff, though every mag seems to slowly turn into the "rice" stuff). When i said more spark more burn, i meant that the better (more voltage) the spark is, the less chance that the air/fuel mixture wouldn't ignite.

I personally don't like platinum plugs; copper conducts electricity better than platinum from what I understand. On all the hondas I sevice (my mothers's accord and bro's civic), i use copper plugs, and change them about once a year. They cost about $1.99 per plug, so it not that much of a maintentence expense.

 

[NutBucket]

Originally posted by: TechnoKid

Originally posted by: KokomoGST

Originally posted by: TechnoKid

Originally posted by: KokomoGST

No need for cams, piston rings, ignition upgrade, etcetc...

I would tend to disagree with the ignition....I would reccomend an igntiion upgrade even on a non boosted motor. More spark, more complete burn. Also under boost, better ignition could help prevent detonation. Im not sure how the stock ignition on the probe performs. I'm not saying an all out ignition like a MSD digital 7, but something like a SCI, or 6A. Wires and plugs; well, wires, I'd go with 7mm-8mm for road application, larger (10mm) if you are going into a lot of racing on the track. Plugs, copper conducts electricity better than platinum, but are not as heat resistant and do not last as long. Perhaps iridium if they have it for your app.

More spark more burn? That's just doesn't make sense. Any spark and if the fuel is properly atomized and timed... it will burn regardless of the strength of the spark as long as you have an ignition system that is capable of enough voltage to jump the air gap. Sure, denser air adds more resistance to spark, but if the factory system provides more than enough voltage... there is NO reason to change it. I know many people deep into the 12s & 11s with factory ignition systems.

All this iridium, thick wire crap is nothing but riceboy marketing. If your application doesn't require big current/voltage, you have no reason to use thick wires other than for durability. High quality silicone wires and a set of properly gapped fresh copper plugs is just proper care of the car and all that's neccessary. Iridium is just extra $$ and platinum electrodes aren't durable enough for forced induction apps.

I agree with you on many points. The reason i would use thicker wires is for durability. In harsh racing conditions, like say road racing at Buttonwillow, constant high underhood heat can take a toll on stock wires.

I was going by what I have read in a sport compact article a while back, where they tested and said using an MSD SCI gave them what seemed to be a smoother revving engine, and slightlly better fuel economy (though fuel economy shouldn't be your top concern if you are worried about perforamce) (I take sport compact mag to be more of the 'performance' oriented magazine and not the "rice" stuff, though every mag seems to slowly turn into the "rice" stuff). When i said more spark more burn, i meant that the better (more voltage) the spark is, the less chance that the air/fuel mixture wouldn't ignite.

I personally don't like platinum plugs; copper conducts electricity better than platinum from what I understand. On all the hondas I sevice (my mothers's accord and bro's civic), i use copper plugs, and change them about once a year. They cost about $1.99 per plug, so it not that much of a maintentence expense.

But many cars already have 8 or 8.8mm wires standard. I know mine does. As far as plugs, I've found that OEM works best. Current engine specs NGK Platinums so that's what I'm running🙂 I think a good set of OEM wires should be fine for the OP's intentions🙂