Ported GT350 intake

[4V Mayhem]

Back on topic (rascally thread pirates):threadjacked:

Is there a way to definitely tell if porting is worth it? From an engineering perspective, if someone supplied a before and after flow curve, would someone be able to translate that into a difference on a tune (ie, since this part changed, I would make this adjustment compensate/take advantage of that change).

• At some point, I would think you would say "that's it, we crammed as much air as we possibly can into the otherwise stock NA engine as we are going to get" in which case more flow is irrelevant, now it is all about flow velocity I would think.
• Unless you now put a different camshaft in the car in which case you may need the extra volume of air if the engine is keeping the valves open longer or if they are opening further.
• If you are going forced induction, I would think any increase in flow is going to translate to power... that is until you reach the limit of what your power adder can cram into the engine.

Am I off base on this here? Engine builders and tuners out there?

At a certain point then yea a larger TB won't add any more. But judging by other cars out there I think there is still a way to go before reaching that point. For example, my 10 Camaro SS has a stock TB size of 90mm. I have a ported one which increased the size to 93mm. And it is widely known that the ported TB on those cars add a bit of HP. And those LS3 engines start off with 426 hp. Of course different engine types have different characteristics and don't often respond the same way. But to add to that, BBK was making a 95mm TB that was still seeing gains. I mean, at some point th you won't make any more power because the opening of the IM would be smaller than the TB, lol! But I'd bet that you could probably have gains up to about 90-95mm. Also remember that the older SN95 CObras had a dual blade TB and those engines gained hp from opening up the TB as well. People were even porting out the plenum. So I don't think you can just keep increasing the size and making more hp on a NA engine. But I do think these engines are nowhere near their max. That is just my opinion. I could be off...

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[Terminator2]

Back on topic (rascally thread pirates):threadjacked:

Is there a way to definitely tell if porting is worth it? From an engineering perspective, if someone supplied a before and after flow curve, would someone be able to translate that into a difference on a tune (ie, since this part changed, I would make this adjustment compensate/take advantage of that change).

• At some point, I would think you would say "that's it, we crammed as much air as we possibly can into the otherwise stock NA engine as we are going to get" in which case more flow is irrelevant, now it is all about flow velocity I would think.
• Unless you now put a different camshaft in the car in which case you may need the extra volume of air if the engine is keeping the valves open longer or if they are opening further.
• If you are going forced induction, I would think any increase in flow is going to translate to power... that is until you reach the limit of what your power adder can cram into the engine.

Am I off base on this here? Engine builders and tuners out there?

Being that the head ports on the coyote are already smaller than the ports on the GT350 and that it seems like almost zero power gains with the 88mm GT350 throttle body aside from throttle response I doubt this will be worth it unless ported heads and cams are introduced.

 

[4V Mayhem]

Being that the head ports on the coyote are already smaller than the ports on the GT350 and that it seems like almost zero power gains with the 88mm GT350 throttle body aside from throttle response I doubt this will be worth it unless ported heads and cams are introduced.

I wonder if the gains reported on the GT350 TB vs the stock TB are a bit skewered by the fact that most tuners didn't have it properly dialed in at the time the testing was done. It seems like up until recently not many people had it down. And even now it seems that results are a bit varied between different cars. So I wonder if the GT350 TB would be much better than the stock TB when tuned properly. On a stock manifold I wouldn't know if there would be much of a difference. But on the GT350 IM I for sure would bet there'd be a difference especially in the higher RPMs. I have the stock TB sitting but I have the GT350 TB on my car. I was gonna swap in the stock TB but I figured it would be better to just hold out until definite answers are provided. It might be a while before anyone has a definitive answer on the subject. But I'm gonna guess the larger TB is gonna outshine the stock TB.

 

[Terminator2]

I wonder if the gains reported on the GT350 TB vs the stock TB are a bit skewered by the fact that most tuners didn't have it properly dialed in at the time the testing was done. It seems like up until recently not many people had it down. And even now it seems that results are a bit varied between different cars. So I wonder if the GT350 TB would be much better than the stock TB when tuned properly. On a stock manifold I wouldn't know if there would be much of a difference. But on the GT350 IM I for sure would bet there'd be a difference especially in the higher RPMs. I have the stock TB sitting but I have the GT350 TB on my car. I was gonna swap in the stock TB but I figured it would be better to just hold out until definite answers are provided. It might be a while before anyone has a definitive answer on the subject. But I'm gonna guess the larger TB is gonna outshine the stock TB.

It is possible due to the drive by wire and torque control based nature of this ECM. Honestly though I think most of the issues are with part throttle surging not wide open throttle. It's easy to data log and see if the ECM is allowing wide open throttle with the new throttle body. I bought new injectors rather than spending $200 on the GT350 throttle body and blowfish adapter. I was going to try it on the stock manifold just to see if throttle response and top end flow was better but decided against it for now.

 

[SleeperGT]

Get on fb and contact the guy at airflowsolutions. He will prob tell you to call him and it will be an hour convo lol. He does the port work for most of the fastest coyotes in the world btw. I found all this out from a little searching.

Is a re-tune required after the porting?

 

[09jsw]

Is a re-tune required after the porting?

For the intake no I doubt it, for the gt350 tb the guy said yes because it's similar to a cj mono blade. Lots of air at once.

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