I sold my other car so I finally have the money to do my KA-T setup . I'm goin for a modest setup for the time being. shooting for 205-215whp. I already have a free set of 370cc injectors and would like to use them (better gas mileage than 550's). I plan to run 5-6 lbs of boost. I originally was going to run a t3/t4 60ish trim, but ive heard of people going lean and blowing they're motor with that setup.
Would I be better off with a smaller turbo (t25), or does it matter as long as I only run 5-6 lbs of boost? If it does matter what is the largest trim you can safely run on 370cc's. Thanks
Turbo/Injector setup
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hannibal
- Posts: 9680
- Joined: Wed Sep 11, 2002 2:38 am
- Car: Red Line to Glenmont
- Location: Washington DC
370cc injectors can supply enough fuel to make up to 240-250whp safely. So that would be your limit if you stick with those injectors. Good choice if you plan to stop at 215whp.
A certain amount of fuel will need a certain amount of airflow to maintain a good A/F (air/fuel) ratio. Having too much airflow and not enough fuel is a condition called 'lean'. On the other hand, having too much fuel and not enough airflow is called 'rich'. For turboed cars, running lean is the devil and WILL destroy your motor due to detonation.
Different sized turbos will provide different amounts of airflow. A T25 at 5-6psi will not flow as much as a T3/T4 60 trim at the same 5-6psi. You want to find a turbo AND boost level that will work for 240-250whp worth of airflow. This will be a good match for your injectors.
A T3/T4 50 trim (a bit more efficient than the 60 trim for lower boost levels) can make 250whp at 7-8psi. A smaller T25/T28 will need more boost (12psi or so) to flow enough air for 250whp.
My first piece of advice is to check out the links listed in Turbo Tech section of the sticky.zerothread/99647That will help you understand more of the things I started to describe.
Next, I'd say you could definitely use a smaller turbo like a T25 or T28 from a SR20. They have less lag and theyre cheaper than a new T3/T4 turbo.
Let us know if you have any questions once youve done a bit more research.
A certain amount of fuel will need a certain amount of airflow to maintain a good A/F (air/fuel) ratio. Having too much airflow and not enough fuel is a condition called 'lean'. On the other hand, having too much fuel and not enough airflow is called 'rich'. For turboed cars, running lean is the devil and WILL destroy your motor due to detonation.
Different sized turbos will provide different amounts of airflow. A T25 at 5-6psi will not flow as much as a T3/T4 60 trim at the same 5-6psi. You want to find a turbo AND boost level that will work for 240-250whp worth of airflow. This will be a good match for your injectors.
A T3/T4 50 trim (a bit more efficient than the 60 trim for lower boost levels) can make 250whp at 7-8psi. A smaller T25/T28 will need more boost (12psi or so) to flow enough air for 250whp.
My first piece of advice is to check out the links listed in Turbo Tech section of the sticky.zerothread/99647That will help you understand more of the things I started to describe.
Next, I'd say you could definitely use a smaller turbo like a T25 or T28 from a SR20. They have less lag and theyre cheaper than a new T3/T4 turbo.
Let us know if you have any questions once youve done a bit more research.
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hannibal
- Posts: 9680
- Joined: Wed Sep 11, 2002 2:38 am
- Car: Red Line to Glenmont
- Location: Washington DC
No problem.5psi is just the pressure the air is under. A turbo's airflow involves both pressure and its size. Generally speaking, a smaller turbo is more efficient at lower boost levels. For a T25, I'd guess thats around 7-8psi. 7psi is where is the stock setting for an SR20 (I think). A bigger T3/T4 hybrid is more efficient at higher boost (I'm guessing around 12 psi).
If youre looking for a used OEM T3 turbo, check out one from a 84-88? 300ZX (Z31 chassis code).Specs:comp 0.60A/R housing, 60 trim wheelturbine: 0.63A/R housing, stg 1 wheel
Learn how to read and plot a compressor map. It will make so many other concepts seem much easier.zerothread?id=59168http://www.turbobyga ... m/....html
If youre looking for a used OEM T3 turbo, check out one from a 84-88? 300ZX (Z31 chassis code).Specs:comp 0.60A/R housing, 60 trim wheelturbine: 0.63A/R housing, stg 1 wheel
Learn how to read and plot a compressor map. It will make so many other concepts seem much easier.zerothread?id=59168http://www.turbobyga ... m/....html