Larger throttle body and injectors in my 94 SL? Help me learn please :)

[opy01]

Ok so I have a somewhat stock SL with 177k miles. Other than the typical smoke when it idles for a few minutes it runs great! I'm starting to do some upgrades and while building is no problem for me the problem is the physics behind it. I ordered a Jesters Chrome ECU from Adam (for the SL) and want to start tuning as soon as possible. I searched a lot and not found much on NAs but tons on turbos so I'm hoping to get more info here and hopefully this will help other wondering the same thing. I know my TB and injectors need cleaning but I was considering buying slightly larger ones instead. I can scale the injectors in the ECU and I assume that will keep it from flooding. Also I know on a stock NA larger injectors will do no good but with a larger TB and exhaust would I see any performance increase at all? My thoughts are if I'm replacing them anyways why not go slightly larger so when I start doing the work on my heads I'll already have good injectors and better TB. Any thoughts, theories and opinions are welcome.

Keep in mind I'm still learning this stuff. Opinions and tips and even long winded lessons are very welcome and encouraged but flaming and or derogatory remarks are frowned upon. Although I was a mechanic for years I never claim to know a lot or want to brag about how awesome my car is (although, even mostly stock, it is awesome to me) lol.

Thanks!

[stealthee]

Stock NA injectors are plenty for a NA. A larger TB and exhaust really aren't going to do much at all for a NA 3s.

[CoopKill]

The largest gain you will get for a NA will be a flashed ecu, and/or more displacement. All else will do very little for the money sans giggle juice.

[opy01]

Thanks for your reply. So I should just buy replacement 210cc injectors?

I've already ordered downpipes and a better cat and while they may not do much I know they help some. I don't want or need a 500HP (just pulled a number out of the air) car so I'm not looking for huge power gains by replacing parts but I do want just a bit more performance as well as efficiency. When you say a larger TB and exhaust aren't going to do much, will the larger TB do anything for me or should I just have mine rebuilt or cleaned? I know I can only suck as much air in as my cylinders will pull but is the TB going to be any bottleneck at all, even if just a little? Consider that I will be having the heads done and getting better cams as well.

I love to tinker and learn so please forgive me if I ask for details.

Coopkill, I have the ECU on the way. More displacement will have to wait till I get a replacement motor . Also keep in mind I will be rebuilding an engine in the future so anything I get now will go on the rebuild.

I know if I want a lot more power a TT is the way to go, but I love my SL. It was the first car I bought my wife after we got married and now she's got another car so the SL is now mine. We've had it for 14 years and it's been the best car ever! I know it will not be worth the money we put into it but as with all my hobbies I'll probably dump a lot into it anyways lol.

[CoopKill]

Rebuild/clean the TB, no gains to be had there. K&N filter is worth the price. A test pipe, or high flow cat is good. The long tube headers have some potential gains. Any other exhaust parts are going to be sound upgrades.

Lighter wheels, and interior are the other options.

[opy01]

Cool! I would gain a smoother idle from a rebuilt/cleaned TB . I tried to keep mine clean but even cleaning periodically it will still have buildup in the ports and places I can't scrub. I have a K&N in the stock housing but plan on getting a cone filter even if only for the coolness factor lol. I thought about headers but the cheep ones on eBay scare me and the 3SX ones are more than I want to pay right now (maybe on the new motor). I've heard good things about the larger downpipes and since the install is way easier than the headers I went that route with the free flow cat. Opening up the exhaust to 2.5" should help a little.

I've seen the stock 210cc injectors on eBay for $100 for a set of 6. Should I avoid those like the plague or would it be worth the money to put them for in for now and send mine of for a good professional cleaning?

Next tax return I'm swapping out the fenders hood and bumpers. While the bumpers are plastic anyways the fenders and hood will reduce weight. I'll probably concentrate on suspension more than the engine then if there isn't much I can do right now.

Just for learning sake, does anyone know the math, or know a site that has it, behind the engine size, injector size, intake size, exhaust size that shows what would work and why? While people doing this longer may know it won't work and I can take them at their word, I like to know why it won't work and/or what will. I'm curious by nature, sorry.

Thanks!

[CoopKill]

There is great info on stealth316.com.
There is a N/A upgrade bible on the other site as well.
http://www.3sgto.org/non-turbo-engin...hp-wheels.html
Look up any of GTWizzard's threads on both sites.

[opy01]

I'll check those out, thanks. I saw the dyno specs for the 3sx exhaust, that's why I ordered the down pipes and cat from them


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[opy01]

I know my injectors are probably pretty nasty since all I've ever done is run Sea Foam through the tank a couple of times a year. 177k on them can probably cause issues and I was going to throw some clean ones in there. Can anyone tell me if these are ok to use or should I avoid the rebuilt ones? I was going to send mine in to have them cleaned by one of the recommended services but still need the car running.

Thanks

[Jesters Deadd]

You can get stock vr4 injectors for cheap/ almost free. And evo 560s super cheap. With a vr4 resistor pack you would be set for inj.
The nice thing about the flash ecu is you can get as big an inj as you want. As long as you understand that low impedence means you need resistors and high impedance means no resistors. You should be good. Match resistance of the new inj to the stock one for easier tuning better running.