Air intake Question?

[chris92svxlsl]

I have owned my svx for a few months now and there seems to be nothing you can do to increase hp, except buy a NOS kit or pay 4,500 for a turbo. Are there any other options?? GROUP BUY Vortec superchargers greddy turbos

[SubaSteevo]

Possible hp increases:
Remove intake silencer (no increase really, just sounds like it )
Remove resistor behind battery (no hp increase, search to find out what it really does)
Aluminum foil intake insulation (5hp max)
Switch to Mobil 1 Full Synthetic Oil (5hp max)
New exhaust (5-10hp max)

Besides that there's not much you can do. I dunno if you'd notice 5hp but if you did all 3 you'd definately notice 15hp. You're welcome to try a "Tornado" type device

[chris92svxlsl]

forgot to mention, what about boring out the pistons?? just a thought.

[Phil Hill]

Here are a few things you can do for virtually nothing to increase your performance :

1. Check you tire pressures are correct.
2. Ensure your brakes are in peak condition, not dragging or rubbing.
3. Ensure your transmission is in peak condition, not slipping or binding.
4. Always use premium fuel.
5. Keep the car clean and polished.
6. Turn off the A/C.
7. Keep the windows closed (might be uncomfortable if you follow the above and it's hot out).

After that its' the usual suspects like intake, exhaust, headers/manifolds, gas flowed heads, cams and cam timing, ecu etc. It's an engine the same as any other, all the same rules apply. What seems to be lacking is an experience base to call on to know what works and what doesn't. The Imprezza turbo has the cake when it comes to modified Subaru motors, I'm not sure how much read across there is but the principles should be the same.

[mbtoloczko]

Originally posted by BurgundyBeast
Possible hp increases:
Remove intake silencer (no increase really, just sounds like it )
Remove resistor behind battery (no hp increase, search to find out what it really does)
Aluminum foil intake insulation (5hp max)
Switch to Mobil 1 Full Synthetic Oil (5hp max)
New exhaust (5-10hp max)

Hyperground wires have been shown to work on several different cars. 5 hp on the dyno has been shown on WRXes. I think SVXes have a pretty anemic ground path for spark discharge. I made a set of "hyperground" wires from some big speaker cable. I think it cost a total of about $40. I grounded to the battery the bolts holding the coils onto the cylinder heads. I used 4 cables, 2 on each side.

Also, along the lines of maintenance, I suggest cleaning the throttle body to get back some lost hp. Several people have mentioned that their car runs much better after they have cleaned the throttle body on their SVX.

Another item to look at is the throttle position sensor. If its not working properly, your ecu is not getting accurate info about the throttle position.

[Trevor]

Originally posted by mbtoloczko


Hyperground wires have been shown to work on several different cars. 5 hp on the dyno has been shown on WRXes. I think SVXes have a pretty anemic ground path for spark discharge. I made a set of "hyperground" wires from some big speaker cable. I think it cost a total of about $40. I grounded to the battery the bolts holding the coils onto the cylinder heads. I used 4 cables, 2 on each side.

.

Just where and how these fairy stories originate is hard to imagine. All appear to suggest that the original designers and manufacturers were complete and utter idiots devoid of any technical understanding or knowledge and exceeded in wisdom by some no body with something to sell. If five extra horsepower were on tap at the cost of improved wiring is it seriously suggested this would be left untapped in respect of the original equipment ? What is more before accepting this BS talk to Mr. Ohm about his laws.

In the case of our car the idea is completely absurd. Ignition is provided by a separate coil for each cylinder and all are earthed directly back to the MPFI control unit via the wiring loom.

N.B. The mounting bolt does NOT provide the earth connection for the coil.

[Chicane]

Bhahhaha. Trevor busts through a wall, guns in each hand blazing, and takes no prisoners. Muha. Another myth dispelled.

What I'm QUASI interested in is a JACOBS IGNITION SYSTEM. They supposedly offer REALLY good spark, and will make your engine run a little better. >shrug< Worth a shot if you have the $ laying around.

Here's my plan for more power:

1. Buy used SVX engine
2. Take apart
3. Bore it out (hopefully), and find some pistons that'll work
4. Extrude hone intake
5. Headers (jet hot coated)
6. HEAD WORK!!!!!!!!!!!!!!!!!EVERYTHING I"VE READ SAYS YOU CAN ALWAYS GAIN POWER IN THE HEADS!!!!!!!!!
7. 5 ANGLE VALVE JOB!!!!! AND SWIRLED VALVES! ANYTHING TO INCREASE FLOW!
8. Portmatch EVERYTHING. Lot of work, but worth it!
9. Lightened flywheel
10. 6spd transmission.

That should pretty much take care of any power problems, I'm guessing.

- Rob

[Landshark]

Originally posted by Chicane
Bhahhaha. Trevor busts through a wall, guns in each hand blazing, and takes no prisoners. Muha. Another myth dispelled.

What I'm QUASI interested in is a JACOBS IGNITION SYSTEM. They supposedly offer REALLY good spark, and will make your engine run a little better. >shrug< Worth a shot if you have the $ laying around.

Here's my plan for more power:

1. Buy used SVX engine
2. Take apart
3. Bore it out (hopefully), and find some pistons that'll work
4. Extrude hone intake
5. Headers (jet hot coated)
6. HEAD WORK!!!!!!!!!!!!!!!!!EVERYTHING I"VE READ SAYS YOU CAN ALWAYS GAIN POWER IN THE HEADS!!!!!!!!!
7. 5 ANGLE VALVE JOB!!!!! AND SWIRLED VALVES! ANYTHING TO INCREASE FLOW!
8. Portmatch EVERYTHING. Lot of work, but worth it!
9. Lightened flywheel
10. 6spd transmission.

That should pretty much take care of any power problems, I'm guessing.

- Rob

how much do you expect to gain vs. cost? seems like it might be a lot of $$$ for not a whole lotta extra hp. i hope i'm wrong. i had an old performance catalog with before and after dyno runs with Extrude-Honing done, but i think i threw it away. i do kinda remember thinking it was too much loot for what you get, though.

[Chicane]

Total? Beats me. Extrude honing isn't worth much... but..heh... I think I might ghetto rig it and do it myself somehow... think high speed air running through the intake.... and then adding some abrasive sand. >shrug<

As for the HEADWORK and VALVE work, and INCREASING DISPLACEMENT, yeah, that would definitely give this engine more kick. The H6 is just like any engine... with one exception: It's basically already 'tuned'.

This is a good thread to read again:

http://www.subaru-svx.net/forum/show...&threadid=9389

"Now, with a naturally aspirated engine, you can only get a MEP so high. You can port and polish, put on new manifolds, raise the compression ratio, tune the fuel system, but there is definitely an upper limit to how much pressure (or effective pressure) you can get. What is this limit? Well, no one really knows, but you CAN look at some of the best engines in the world (namely, Formula One) and compare what their teams of 100's of world-class engineers are getting to what you want, and see if it's reasonable. The MEP's in high performance racing engines are typically around 20% greater than in passenger car engines.

Moto GP - 14.55
McLaren F1 - 13.70
Honda S2000 - 13.33
Suzuki GSX-R600 - 13.22
BMW M3 - 13.01
Porsche 911 - 12.70


Rob wanted me to stress the fact that the power efficiency of the stock engine, 10.72, can be improved. "

So yeah, there's room for improvement, but the Subie nerds have done a pretty good job already... which means 'bolting on an intake' isn't going to do much for us.

- Rob

you guys are going to kill me but here it goes. toss the 3.3 its to heavy any way. drop in a 2.0/ 2.5 turbo out of a wrx and your performance problems are solved. and there are a lot more performance parts for them.

ED

[Chicane]

Originally posted by SUBIE TECH
you guys are going to kill me but here it goes. toss the 3.3 its to heavy any way. drop in a 2.0/ 2.5 turbo out of a wrx and your performance problems are solved. and there are a lot more performance parts for them.

ED

Problems with that:

1. Engine mounts
2. Integrating the wiring harness to the SVX
3. No more smooth idle
4. No more low center of gravity
5. Would the hood close? Doubtful
6. Handling would be weird with a different

That would suck. The H6 is a good engine.... and it makes good power, for its size. Think of NA supras, 300zxs, and 3000Gts. The SVX is right on. The only thing we don't have is a turbo SVX to compete with the big boys.

- Rob

[mbtoloczko]

Originally posted by Trevor


Just where and how these fairy stories originate is hard to imagine. All appear to suggest that the original designers and manufacturers were complete and utter idiots devoid of any technical understanding or knowledge and exceeded in wisdom by some no body with something to sell. If five extra horsepower were on tap at the cost of improved wiring is it seriously suggested this would be left untapped in respect of the original equipment ? What is more before accepting this BS talk to Mr. Ohm about his laws.

In the case of our car the idea is completely absurd. Ignition is provided by a separate coil for each cylinder and all are earthed directly back to the MPFI control unit via the wiring loom.

N.B. The mounting bolt does NOT provide the earth connection for the coil.

Its no BS. Several of the magazines have done tests on these wires complete with dyno charts. You can choose not to believe it if you want.

N.B. I know that the coil bolts do not provide earth ground for the coil. That's not the point of the wires. The coil bolts are however screwed to the cylinder head, so they provide a convenient path for grounding the spark plugs more directly to the battery which is the whole point of the hyperground wires.

[Trevor]

The magazines depend on advertising for revenue and will print anything that is to the advantage of their advertisers be it fact or fiction.

The secondary high tension circuit involves very low current and lots and lots of volts. Therefore a few ohms of resistance means nothing. The deep technology can be quite involved and can be quoted by way of confusion by those peddling snake oil but I know something of it having developed high tension equipment for industrial purposes. You are being conned.

[mbtoloczko]

Originally posted by Trevor
The magazines depend on advertising for revenue and will print anything that is to the advantage of their advertisers be it fact or fiction.

The secondary high tension circuit involves very low current and lots and lots of volts. Therefore a few ohms of resistance means nothing. The deep technology can be quite involved and can be quoted by way of confusion by those peddling snake oil but I know something of it having developed high tension equipment for industrial purposes. You are being conned.

ok. I think the dyno charts are real, and you are in denial. Shall we call it even?

[Phil Hill]

But I'd be interested in seeing the magazine test results. Any chance you could scan them in ??

The only "hi-tech" plug leads I've seen any actual test results which made a difference with were the Nology leads (www.nology.com).

These leads incorporate a capacitor at the plug end, which sort of applies the principle of capacitive discharge for each plug. The idea is the the capacitor charges up with the output voltage of the coil, then releases the stored energy in a very sort time period. As power is work done per unit time, if the stored energy is the same but the time period is much reduced, the power of the spark is much greater. This allows a much leaner mixture to be ignited and the burn process is apparently much more complete. Therefore more power for less fuel, the holy grail !!

The down side appears to be the cost, at almost $200 for a 4 cylinder you have really got to want these leads !! The overall timing figure had to be adjusted to optimise the gains, which is something else people don't mention when doing so called "bolt on " mods.

In terms of the SVX all this is academic as the coil is connected directly to the plug, so the HT lead length must be all of 1/4". As the plug is grounded though the engine block, which is connected to the body by a dirty great big earth strap additional earthing should also be irrelevant.