850 N/a Throttle Body on a T-5 manifold for performance

[charlyW]

I'm going to fit an N/A Throttle Body on my T-5 manifold because the N/A body has a wider throat than the T-5 one.

Question: Once I fit the N/A Throttle Body is on do I need to widen the throat of the manifold openning to match or will it be ok fitting straight on?

Have I been given correct information on the N/A Throttle Body being 54-56mm and the T-5 being 52mm ?

Charlotte

[JDS60R]

I am unaware of the intake sizing but have had many come and pay me to do a similar mod. The result is always dissapointing for them.

Keep in mind that many of the N/A tricks do not apply as the turbo pressurizes the air and this offsets most intake restrictions.

The main thing that occurs is that the trottle body now gives higher air flow for a given throttle plate angle. This will cause the car to relearn the fueling curve which in our cars makes it seem slightly more powerful for about 1 day. After that you will be back to normal.

I would bring the motor up to top operating condition and then give it a tune. You normally get more from a proper crankcase, injector, valve and piston cleaning than the throttle body will provide (always do an oil and filter service after chemical cleaning). This is true of most cars as the added contaminants lead to earlier detonation and the car pulls back its timing to compensate. If you have a clean combustion chamber and let the car relearn its adaptations you will have increased power.

On the other hand the worst that could happen from installing a slightly larger throttle body is the need to port match the two and an engine light.

[charlyW]

I am unaware of the intake sizing but have had many come and pay me to do a similar mod. The result is always dissapointing for them.

Keep in mind that many of the N/A tricks do not apply as the turbo pressurizes the air and this offsets most intake restrictions.

The main thing that occurs is that the trottle body now gives higher air flow for a given throttle plate angle. This will cause the car to relearn the fueling curve which in our cars makes it seem slightly more powerful for about 1 day. After that you will be back to normal.

I would bring the motor up to top operating condition and then give it a tune. You normally get more from a proper crankcase, injector, valve and piston cleaning than the throttle body will provide (always do an oil and filter service after chemical cleaning). This is true of most cars as the added contaminants lead to earlier detonation and the car pulls back its timing to compensate. If you have a clean combustion chamber and let the car relearn its adaptations you will have increased power.

On the other hand the worst that could happen from installing a slightly larger throttle body is the need to port match the two and an engine light.

I will be porting the manifold to match the size of the throttle body throat as a matter of course and will over time be cleaning the entire engine along with the piston crowns and valve heads. PCV is going to be done tomorrow [saturday] followed by an oil and filter change. I am thinking about new injectors going from the Orange ones to the maybe Blue or White ones that have a larger volume.

[JDS60R]

Best Wishes on the PCV . The larger injectors will change your ability to control the fuel output. They are sized specifically for a reason. larger injectors without a need or new map to control them leads to less accurate air/fuel mixtures and resulting lower power.

For maximum performance on a budget I would suggest a Stage Zero with a downpipe ,exhaust and a Stage one tune.

A larger throttle body and ported intake with new injectors will not yield increased power without a tune. The turbo will provide the same pressure and any extra fuel provided by the injectors will raise internal temps and lower performance.

New injectors will be needed if you have surpassed the normal turbo and the new one raises boost so quckly you need to raise the enrichment levels over that of the stock injectors. You will be in the upper 400hp levels to need them. A specific tune will also be needed along with cams and some porting to compensate.

[charlyW]

Best Wishes on the PCV . The larger injectors will change your ability to control the fuel output. They are sized specifically for a reason. larger injectors without a need or new map to control them leads to less accurate air/fuel mixtures and resulting lower power.

For maximum performance on a budget I would suggest a Stage Zero with a downpipe ,exhaust and a Stage one tune.

A larger throttle body and ported intake with new injectors will not yield increased power without a tune. The turbo will provide the same pressure and any extra fuel provided by the injectors will raise internal temps and lower performance.

New injectors will be needed if you have surpassed the normal turbo and the new one raises boost so quckly you need to raise the enrichment levels over that of the stock injectors. You will be in the upper 400hp levels to need them. A specific tune will also be needed along with cams and some porting to compensate.

I am having a remap on the 13th along with the oil service [stage 0 in the usa] let me stress I'm not just bolting things to the engine willy nilly I'm doing research and then having the necessary retune after/during each stage. After extensive research its not the BHP which kills the Autoboxes its the sudden peak torque that a lot of cheaper remaps and aggressive parts give which I'm not doing. I'm trying to get the smoothest power curve along with the smoothest torque curve and not just a "Bang" 300bhp.

Currently I'm having problems locating larger injectors here in the UK as Bosch are not very helpful, though I have found a larger set in the UK at volvomotorsports.com so might leave the injectors out of the plans for now and compensate my mapping/tuning plans for now.