The Official N/A Upgrade FAQ

drjonez

Supramania Contributor
Mar 31, 2005
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GotToyota? said:
I'm mainly doing this to 1) help out people wanting to know how to upgrade their N/A's, and to 2) make it so people do not make the usual "what upgrades should I do to my N/A" threads. Below, I'll state what the reasonable upgrades are, what your routes are, and how you can get these parts. Goes from more simple, to mild, to extreme. Mods can edit this anytime if you'd like to organize/tweak this thread.

excellent work, but i disagree w/some statements.

GotToyota? said:
Intake
First, you need to get that engine breathing better. Start giving it more oxygen by adding an upgraded intake to it. The most restrictive part of the stock intake system is the airbox, so buy something like the K&N FIPK to replace the airbox. You can also just get a filter/adapter on Ebay for pretty cheap, I bought mine for $20, works nearly the same.

don't use ebay filters, they suck. buy a cheapo kit, use the adaptor and throw out the filter. get a k&n sized to fit.

you might as well get rid of the intake resonator too, you get that cool NA honking/growl.

GotToyota? said:
Exhaust
This is somewhat of a controversial subject as far as exhaust systems go for N/A's. One thing you need to realize before upgrading your exhaust is that backpressure on a naturally aspirated engine is your enemy! An increase in backpressure will result in a loss of power, which is what you wanna stay away from. So you people with your 3" exhausts, you've actually lost power. The most reasonable size to use when doing your exhaust is 2.5". You're upgrading to a bigger size thus adding abit more power, and you don't have to worry about backpressure. And as far as sound goes, it's up to you on the muffler you want to use and if you want to use a test pipe/cat. I personally kept the stock cat and added a resonator so the sound was more deep and not very loud, sounds great. You can also look into getting a test pipe, but that is illegal in some states/counties and I will not go into any depth concerning that.

ummm, no.

you will NEVER lose max power on too large of an exhaust. back pressure as most think of it, is a myth. what you will feel with too large of an exhaust is loss of response in the lower RPM ranges, but again, you will NEVER lose max power.

GotToyota? said:
Porting/polishing
This is more of a mild mod, but can be the one of the most expensive mods if you go into more and more detail with the shop you choose to work with. Remember when I said flow was the key? It's the same concept here. The stock y-pipe and the intake manifold are pretty restrictive, take the time to hollow everything out (you can polish it if you want bling, and easy to clean areas), to get the best flow possible from your parts.

don't forget about the head as well....

GotToyota? said:
1-piece driveshaft
Everyone has gotten into the situation at one time or another where their carrier bearing has gone bad. Not only does this affect performance, but the weight of the stock driveshaft is unbearable, at nearly 30+ lbs, you have to give alot of effort at times to get what you want out of your car. Get rid of this problem by going with a 1 piece driveshaft, this will put less stress of your effort to accelerate, making the rotation mass less. You can either choose steel or aluminum, but I recommend steel as it's around 15 lbs, aluminum is around 11 lbs, but I personally think it's too extreme if you're staying N/A. Jawsgear is one company that sells these driveshafts, and they're on the forums as well. You can also go to a local welding shop in your area if you want to save some $.

be ready for some more driveline NVH w/a 1 pc shaft.

GotToyota? said:
Raise the compression/build the head, aftermarket pistons
Again, this is advanced modding. Time to go with an aftermarket MHG to raise the compression. Thickness for the MHG depends on how much you need to mill off the head, then you go from there. I'd suggest a 1.2MM HG if you have a normal head/block. If you have alot of warping however, 2MM might be the way to go. Also, buy aftermarket pistons that are slightly bored over, you might as well if you want to raise the compression and get the full benefit of your motor.

stock HG thickness squished = 1.2mm.

there is a TON of stuff you can do to the engine, most importantly being upping compression ratio. shaving the head to up CR isn't the best idea as the combustion chamber gets all wacky then. unfortunately, with the amount of $$ you'll spend on custom headwork and pistons, you could have turbo'd the car and been making 2X the power (not trying to start a war, just giving facts.).

GotToyota? said:
Fuel and timing
If you have done enough mods, you will know that there is always more that you want. Well, a simple way to benefit more from your mods is to raise the stock timing. The stock timing according to TSRM spec is around 10 degrees. Raise the timing to 12-14, depending on how extreme you wanna go (but be warned, you must go with higher octane fuel if you raise the timing). If you wanted to go the extra mile, you could also get an SAFC to fully tune and take advantage of your powerband.

bumping up the timing does help- makes response better, etc. yup, you need high octane fuel. i ran 16 DBTDC for yrs....

there's little chance the GE will ever need more fuel than the stock 330s.

GotToyota? said:

Ignition

To key is to get better spark. High output capacitive discharge sparks ensure complete combustion of the fuel mixture especially at high rpm. You don't want your system to fail because of your ignition system. MSD along with a few other companies make ignition systems for decent prices.

complete waste of time.

change to new some nice new plugs, try opening the gap as large as possible. might as well get some new wires as well. beware of "racing" wires- some actually hurt perf.

GotToyota? said:
Cams
This is a mod for those going the next step. Since you'll be N/A, it's recommended to go with a mild set of cams, too extreme and you won't be running so good unless you have the supporting mods. There is an online website that regrinds your stock cams to around 244 degrees, which is mild enough for an N/A wanting to go the extra mile. http://www.webcamshafts.com/toyota-auto.html

good idea, but cams should be spec'd to work with the rest of your upgrades. again, the same prev. statements re: cost apply....
 

SupaMan

Want The Boooooossttttttt
Oct 12, 2006
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Cape Coral,Florida
I have a 5spd (if the auto comment was directed toward me) and my car does prolly need a tune up im waiting on 935 for my plugs and wires but its firing on all 6 cly i assure you that my motor is damn near pretty new too was rebuilt about 40k ago even if it was the original motor non rebuilt the car only has 151k miles on it.

Im not sure if i wanna spray it or not i might i might not this is my only car right now so i prolly wont spray it until i have something to fall back on.

I didnt say i was racing it that way it was something i noticed when id be fuckin around and floor it in 3rd doin like 30 mph id never race like that would be retarded. thanks for explaining why it does that tho global.

my car is still pulling hard when i shift around 6300 or so but i didnt buy my car to race it i bought it because i love supras and it was a steal of a deal. :)

it keeps putting my shit here on page 3.........eh fuck it
 

SupaMan

Want The Boooooossttttttt
Oct 12, 2006
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Cape Coral,Florida
my car doesnt have that much low end as it is if you punch it in like 3rd at 2500 it doesnt really start to get a move on until about 3500-4k. Im deff gonna put my car on the bottle later on but its not gonna be a huge shot prolly a 50 or 75 if i get a lil juice happy.
 

Nick M

Black Rifles Matter
Sep 9, 2005
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Dyno would prove me correct the gains are MUCH MORE NOTICABLE than the loss. I still don't see how you people argue this.
Did you ever stop to think that other people actually drive their car on the street, and spend most of the time between 2000-3000 rpm? Probably not.

If you have an engine that you have done up like defiant, then by all means, you can use a bigger diameter exhaust. Something that matches the output of the engine.
 

supramacist

Banned
Apr 8, 2006
1,501
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The Grassy Knole
Oh thank god. I didn't want to say anything because I couldn't tell if I said something or if supaman did it. If your ride doesn't come to life till 4k rpm's...., I would say it either has a 4 cylinder or I would ask when your last tune up was. A full service tune up, not a half ass'd replace part of this and that. I mean plug wires and all kinda tune up. I sure wouldn't hook nos up to anything that was already beyond half of it's life expectancy unless you just want to blow it up.

All of you turbo and nitrous happy heads can keep that shit. You drive a naturally aspirated auto. If you wanted more umph you should have got the mclaren. Or atleast a nissan. Jeeeeeez. Everyone is always bitching about my car isn't fast enough. When you all should be bitching because you didn't do your research, half of you probably impulse bought and found out later it's not what you thought it was. it's like beating a dog because it got to old to play with you or some shit.
 

AGlobalThreat

Acceleration
Apr 4, 2005
991
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Santa Clarita
7MA61 said:
The point is though a 7m with stock cams has no topend so no matter how good the zorst flows the cams pull the power in the top end.

Nope. Advanced ignition timing (I used 14 btdc, Dr. J used 16 btdc) and a free flowing exhaust will have the NA pull hard up to redline. I never upgraded my cams and getting rid of the power drop off up top was one of the first things I did to my NA. It made the car much more enjoyable.

SupaMan said:
my car doesnt have that much low end as it is if you punch it in like 3rd at 2500 it doesnt really start to get a move on until about 3500-4k. Im deff gonna put my car on the bottle later on but its not gonna be a huge shot prolly a 50 or 75 if i get a lil juice happy.

That's your ACIS (air controlled intake system iirc) valve that allows the flow of more air to the intake right around 4k, which is why you feel the boost in power

You guys need to learn how to properly rev match and downshift so you can take advantage of your cars powerband. Just simply cruising in low rpms and punching it will be good for passing cars, but that's not how you win races.

supramacist said:
All of you turbo and nitrous happy heads can keep that shit. You drive a naturally aspirated auto. If you wanted more umph you should have got the mclaren. Or atleast a nissan. Jeeeeeez. Everyone is always bitching about my car isn't fast enough. When you all should be bitching because you didn't do your research, half of you probably impulse bought and found out later it's not what you thought it was. it's like beating a dog because it got to old to play with you or some shit.

Hey now, NA people want to go fast too. If you don't want to upgrade your NA, then plain and simple, stay out of the NA upgrade thread. I bought my NA because it was a good platform to start and was just what I wanted, 2 door, 6 cylinder, and rwd. Did I care that I had less power than the turbos that sell for $2000 more (Got mine for $1400 :))? Heck no, the NA supra is a great place to start and I started building it from day 1. I modded the crap out of it until the point where there was no more weight reduction left to do, the engine bay was cool to touch, and if it weren't for blowing my engine up on a 150 run I would have finished the car with a nice dyno tune and just enjoyed it. I loved my NA engine and the only reason I went with a different engine was because I wanted to go faster, and isn't that what EVERY person who mods a car wants? Nobody is saying to ditch the NA, this thread is for modding it, and there is more than enough information here to make a fast NA
 

Kai

That Limey Bastard
Staff member
Question - i'm at 12' timing (it was at 8' for some reason and barrelled through fuel at an astonishing rate), but it feels like the power is off lower down - is this the case, or is it really old plugs and valve clearances needing doing that causes this?
 

Nick M

Black Rifles Matter
Sep 9, 2005
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It depends on what you consider top end also. The stock 7MGE should pull hard to redline, but redline isn't very high either.
 

7MA61

7MA61
Aug 27, 2006
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Sydney
Nick M said:
It depends on what you consider top end also. The stock 7MGE should pull hard to redline, but redline isn't very high either.
Limiter is set at 7000rpm for me, it'll tag it happily but in 90% of circumstances your better off shifting into the next gear at 6000rpm because torque drops off very quick.

The only instance I've found is useful was on a short hillclimb course, it wasn't long enough and with corners coming up to demand 3rd so I just sat in second gear just before the limiter, then backed off into the corner and jumped back on it again afterwards.

I can rev the car out but the shove in your back when you punch the next gear and the rate of accelration increases dramatically tells me I should be shifting well before the limiter. Remember torque determines how fast a car accelerates and if you look at most graphs it drops off significantly at 5000rpm, hell I have more at 2000rpm then I do above 6000rpm:biglaugh: .
 

supramacist

Banned
Apr 8, 2006
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The Grassy Knole
Right on man..., I agree. It's just if your'e going to want a turbo. Why not do it and get it over with. There's no need to get Dr. Frankenstien on it. No disrespect intended. If what I said doesn't fit you it'll fit someone reading. I bought the na because I knew I didn't want the turbo. Because I know I'll spool it and this will make me want nos. I'll end up picking up trash on the side of the road to work off the tickets. I also think that if they don't want us doing it on the streets, we should be supplied with a place to do it.

Again. These are only opinions and there is a reason they are free.
 

Ma70.Ent

Supramania Contributor
Feb 26, 2006
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NJ
This thread has been stickied. The first post needs some editing though because some of it has been proven slightly false. That, or people can just read the whole thread.
 

Ma70.Ent

Supramania Contributor
Feb 26, 2006
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gnarkill87 said:
hey supaman i have a question for you have you gotten ur spark plugs and wires from 935 yet?

You should PM him or something, because your post has nothing to do with this thread.
 

Boss302

New Member
May 2, 2006
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Mobile, Al
Ma70.Ent said:
There are some people with 3'' exhausts who have felt no power loss at any point. So I don't think you should be saying this unless you really confirm it.

2.5 offers better restriction which is what's needed in our N/A cars ask any mufflershop.

Also... Advanced timing to 14-16 BTDC if you run premium 91-93 (which you should always) always helps.

running premium fuel on our cars yeilds no real performance gains high octane fuel gains only come into play on the higher end of the comp. ratios 9.5 and so. i know this because i saw a demonstration on horsepower tv where they used different comp piston until the reached 9.5 there was NO difference worth chasing after.
 

Ma70.Ent

Supramania Contributor
Feb 26, 2006
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Boss302 said:
running premium fuel on our cars yeilds no real performance gains high octane fuel gains only come into play on the higher end of the comp. ratios 9.5 and so. i know this because i saw a demonstration on horsepower tv where they used different comp piston until the reached 9.5 there was NO difference worth chasing after.

You're late. Read this whole thread about the exhaust.

Also, I never said higher octane made your car faster. I said you needed to run high octane if you ran 14-16 BTDC timing.
 

Tanya

Supramania Contributor
Aug 15, 2005
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high octane makes it so you keep the small amount of HP you "gained" from advancing timing. without the higher octane, spark knock would probably occur under certain conditions and the knock sensor will go off, retarding the timing, and effectively you'd be "losing" the hp from timing advancement
 

drjonez

Supramania Contributor
Mar 31, 2005
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Boss302 said:
2.5 offers better restriction which is what's needed in our N/A cars ask any mufflershop.

heh. no.


Boss302 said:
running premium fuel on our cars yeilds no real performance gains high octane fuel gains only come into play on the higher end of the comp. ratios 9.5 and so. i know this because i saw a demonstration on horsepower tv where they used different comp piston until the reached 9.5 there was NO difference worth chasing after.

you're missing his point- jack up the timing and you DO need higher octane fuel.
 

Nick M

Black Rifles Matter
Sep 9, 2005
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This looks like a nice place to expalin Toyota's air intake control system, or ACIS as it is now called.

First of all, it does not ever "kick in". The default position of the valve is springloaded open, which is high rpm use. Vacuum pulling on the diapragm closes it to boost low RPM torque. The manifold with longer runners aids low end torque, but starve the engine at higher engine speeds. The shorter ones lose velocity, but can fill a cylinder at high RPM.

So the system is set up for high rpm, and closes the valve for low speed torque. If you really feel it kick in, your probably does not work, and the vacuum solenoid is froze. Take a good look at that stock torque curve, and how flat it is.

That is stock and working correctly. Jetjock has posted the parameters for specific opening and closing elsewhere, but now you know why.