My son and i picked up a 1990 talon tsi as project. The original owner was planning an upgrade so he sold the turbo. We would like to get the car running with plans to mod it a bit in the future. My question is, can we install a big 16g turbo with the stock ecu and injectors if we dont crank up the boost? Will the stock waste gate keep the boost from the bigger turbo at the same level as the stock turbo? We would prefer not to have to buy a small turbo now to get it running and than upgrade again later.
Thanks

The big16g really is a small turbo . Yes, you should be able to switch it out and use the stock injectors. Does it have any other mods?

If it's a manual car you can, but there will be no real advantage to the 16g over the 14b until you start boosting around 20 psi. The auto cars have a smaller turbo and injectors and different fpr than the manual cars.

It is a manual awd car. No other upgrades other than a boost gauge. We just want to get the car running for now. We may upgrade to a stand alone later so we can upgrade the fuel system. i,m used to working on older cars and this my first venture into turbo chargers. It seemed logical to me that if the 14b wastegate keeps the boost at a set level with the stock turbo, it should with the 16g as well.

You should be ok. Just make sure you're running wastegate pressure until supporting mods are done

You can adjust wastegate pressure up or down. I would also rewire fuel pump too. It's good to do even on a stock pump and injector set up. Go to the resources section and lookup fuel pump rewire.

Schneider said:

It is a manual awd car. No other upgrades other than a boost gauge. We just want to get the car running for now. We may upgrade to a stand alone later so we can upgrade the fuel system. i,m used to working on older cars and this my first venture into turbo chargers. It seemed logical to me that if the 14b wastegate keeps the boost at a set level with the stock turbo, it should with the 16g as well.

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You should be fine but i think your statement merits some discussion. Stock boost (pressure level) does not determine the amount of airflow. There is more to it. Your statement sounds like the stock boost is stock boost no matter which turbo. Not true. Airflow will increase (mass of air) at the same boost on larger turbos. Even so i would run wastegate pressure and not even run the solenoid. This will limit your boost to as low as it can go on that actuator. Don't buy an ebay 16g

pauleyman said:

You should be fine but i think your statement merits some discussion. Stock boost (pressure level) does not determine the amount of airflow. There is more to it. Your statement sounds like the stock boost is stock boost no matter which turbo. Not true. Airflow will increase (mass of air) at the same boost on larger turbos. Even so i would run wastegate pressure and not even run the solenoid. This will limit your boost to as low as it can go on that actuator. Don't buy an ebay 16g

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You are correct @pauleyman. I forgot to mention that. Thank you for not allowing half of the info to mentioned. My bad

Thanks for your replies. I think i've got it figured out. The waste gate doesn't completely negate the effects of a bigger turbo. But probably enough in this case to not confuse the computer too much. I will avoid ebay 16g's

If you run a direct vacuum line to the wastegate actuator you will only have the sppring pressure of the actuator at 8 or 9 psi. Factory setup includes the boost solenoid that adds a few psi and allows ecu to cut to spring pressure if need be.

Hey guys just wondering if i can run the evo 3 turbo with a 2g maf 560cc injectors....i have no wide band, link or safc. That will be my next and final buy. Dont plan on any more mods. Im looking for a safe efficient psi of 16-18 if its ok? Searched a little bit and ended up seeing running it at 13-15 is ideal with my mods and no tune or data logger.

I've held 15psi safely on a stock engine setup where the only upgrade was a boost controller.

15psi on stock set up maybe just the evo 3. Your gunna have a hard time driving the car with out a tune on bigger injectors

My spyder ran perfectly fine on 15psi with absolutely no tune and had oem injectors.

Yep, difficult especially with no wideband. I would say you could maybe get away with it with a little bit of E85 mixed with 93 to lean out the stock tune but know that you are playing with fire. Otherwise you'll just run pig rich. Get some stock 450's.

Hard to say without keeping your afrs in check. I wouldn't go over 14psi. Few years back I had he same setup as u but I did have a wide band and safc. The safc needed minor adjustments. Hold off on increasing boost until you have more tuning tools.

So with my setup i could run the evo3 turbo just fine as long as my boost is below 15? Would adding just a wide band benifent me any? And i would assume the evo3 at 15psi is way different than my maxed out 13g at 15psi. Cars is a manual previous owner put that in, dont know why.

Sachsline said:

So with my setup i could run the evo3 turbo just fine as long as my boost is below 15? Would adding just a wide band benifent me any? And i would assume the evo3 at 15psi is way different than my maxed out 13g at 15psi. Cars is a manual previous owner put that in, dont know why.

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E316G is a big difference over a 13G, you need a wideband MINIMUM. A way to log knock would also be a good idea.

The 2g MAF and 560s in a 1g is a GREAT combination. I ran it in my 90 Laser and the car performed like stock. I had an SAFC, a PLX wide band and a pocket logger, but the fuel trims weren't so off the chart that the car needed dialed in to run. Above 3k on a frankenstein 20g setup, I was dead solid with 12.0 AFRs with zero SAFC compensation. I had it to a dyno day and had the operators scratching their head how solidly the fueling was with no adjustments to the SAFC. Now, that's not to say it was dialed in perfectly for cruising- it was a little rich, but the fuel trims weren't maxed out by any means. The SAFC was just there to help get the injectors along and get the fuel trims a little bit tighter. On the dyno, the runs were made at 12 psi. Later I dialed it up to 17 psi and it ran fantastically with no further modifications or tuning.

15 psi is 15 psi, fuel won't be your issue at WOT the Maf and O2 sensor can probabyl handle that. As far as idle is concerned, the 560's need something to help them out. i would imagine that your low airflow fuel trims are maxed out right now.

Also ran the 2g maf and 550 combo in my gvr4 when I first got it, before link. Was running 17psi on my 14b with no problems at all. Even managed to hit mid 13's that way haha.

Link is a necessity if you have goals that include a big turbo and what not. If you're not going to tune the car, you will definitely want to toss in a wideband to monitor AFR's. otherwise you'll never know when to stop increasing boost and keep afr's safe.

Probably wouldn't go over 14psi without a wideband. It's worth investing in.

I'm new to the scene as well and have just done some minor tweaks on my otherwise stock rebuilt 2g, and haven't gotten a wideband as of yet. Thus why I'm not going crazy at the moment, but I'm running the stock t25 with a new cartridge in it and a plugged bypass on my stock BOV with headers and 3" catback running boost at around 16-17lbs at 2500-3000 rpm, falling to about 10-11 by 7000 (about all the little huffer can do at high RPM,) and been pulling plugs with good results. They're a nice brown/tan. But I would still agree with the above in getting a wideband at minimum just to check that A/F. It will be my next purchase as a matter of fact. Then, tune away!

You should have no fuel issues with the T25, almost like they designed it that way....

Sean Denny said:

I but I'm running the stock t25 with a new cartridge in it and a plugged bypass on my stock BOV with headers and 3" catback....... Then, tune away!

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What do you mean "plugged bypass"? I hope you aren't quite sure what you are talking about because that is a bad thing if it is what you did.

Also, you don't have headers. You have an exhaust manifold.

Lastly, what do you intend to tune with and what do you expect to gain? That t-25 is giving you all it's got. Other then minor HP gains from leaning out the overly rich stock fuel map and possibly advancing timing, you won't be able to do much more. Do you have future upgrade plans?