Big port head swap for 500whp?

[Tadope]

Hi. I've been reading that small port is actually better.
But I'm about to do an engine build on my car
Current setup is AMU small port. K04 turbo.

I have an AEB large port head ready to go on.
But I'm having second thoughts.
I read a lot about modern opinion switching from large to small port. And this is due to the velocity benefit of small.

Now my ultimate power goal will be 500whp. I have not decided which turbo yet. But I'm looking at gt30 series.
Also I would like a linear power band.
And not super lag then only high rpm power.

What do you think? Small or large port for my goals? Thanks

 

[S3AMJ]

I’d go with large port….. turbo wise depending on your budget, GT3076r, GTX3076r Gen 2, G30-660/770. Those are in price order from less to more.

I’m going Large Port with G30-770 on my build which is currently being built by Badger5.

If you look at the differences between small port and large port they are like night and day, big turbo needs the flow.


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[Tadope]

I’d go with large port….. turbo wise depending on your budget, GT3076r, GTX3076r Gen 2, G30-660/770. Those are in price order from less to more.

I’m going Large Port with G30-770 on my build which is currently being built by Badger5.

If you look at the differences between small port and large port they are like night and day, big turbo needs the flow.


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Yeah the big ports are giant. But i dont want a super laggy turbo

 

[S3AMJ]

Go large port with a G25-660 turbo then bud, these turbos have proven to spool like a K03s on a stroker engine with anything up to 580bhp! That’s what a 2.1 Stroker TT achieved recently. Built and tuned at Badger5


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[Tadope]

Go large port with a G25-660 turbo then bud, these turbos have proven to spool like a K03s on a stroker engine with anything up to 580bhp! That’s what a 2.1 Stroker TT achieved recently. Built and tuned at Badger5


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Wow those turbos sound amazing . out of my budget though. I'm stuck with gt series.
If spool is only 1k higher then a k04 I'm happy though

 

[<tuffty/>]

Ye olde 'lag' discussion... love it lol... fitting a large frame turbo to a small capacity engine will always result in what could be deemed to be 'lag' however if the engine is built right and the right parts are used then lag is largely irrelevant... also... don't get hung up on boost as boost is just the result of flow restriction...

So... as an example... my stroker 1.8t (2ltr crank) with a GT3582r...

As you can see the 'spool' is much later boost wise than a K04 but given the power and expectation this is actually one of the better setups I have had any experience in (of which I have a fair bit)

Point being trying to get 500 'whp' from a small capacity engine is an ask and the closest I have seen to getting the holy grail of early spool and 500+hp is from the G25 series turbos

<tuffty/>

 

[<tuffty/>]

...and should say that you have to learn to drive the car differently as in be in the right gear when you have a bigger turbo and lag will not be an issue at all

<tuffty/>

 

[Tadope]

Ye olde 'lag' discussion... love it lol... fitting a large frame turbo to a small capacity engine will always result in what could be deemed to be 'lag' however if the engine is built right and the right parts are used then lag is largely irrelevant... also... don't get hung up on boost as boost is just the result of flow restriction...

So... as an example... my stroker 1.8t (2ltr crank) with a GT3582r...
View attachment 238920

View attachment 238921

As you can see the 'spool' is much later boost wise than a K04 but given the power and expectation this is actually one of the better setups I have had any experience in (of which I have a fair bit)

Point being trying to get 500 'whp' from a small capacity engine is an ask and the closest I have seen to getting the holy grail of early spool and 500+hp is from the G25 series turbos

<tuffty/>

Yep. The g25 series would be perfect. But out of my budget. I think I'm limited to gt or t3/t4 turbos.

Your spool is not bad actually! My k04 spikes at 4k. Looks like yours is only 5k.
That's not a bad tradeoff for the power.
I thought gt35 would be way laggier.

I'm looking at gt30 series. Gt28 would probably have a great powerband. But I'm doubtful it would hit my hp target.

Your tempting me with the gt35 now though. Whats your comp/turbo sizes

 

[<tuffty/>]

GT3582r details

GT3582R – Garrett Motion

GT3582R ORIGINAL GT SERIES AERODYNAMICS INTERNALLY WASTEGATED TURBINE HOUSING NON WASTEGATED TURBINE HOUSINGS AVAILABLE BALL BEARING CONFIGURATION WITH WATER COOLED CHRA V-BAND TURBINE HOUSING OPTIONS

www.garrettmotion.com

I am using a 0.63AR Tial vband hotside too... makes a big difference to spool... anything larger would be a lag monster

<tuffty/>

 

[Tadope]

GT3582r details

GT3582R – Garrett Motion

GT3582R ORIGINAL GT SERIES AERODYNAMICS INTERNALLY WASTEGATED TURBINE HOUSING NON WASTEGATED TURBINE HOUSINGS AVAILABLE BALL BEARING CONFIGURATION WITH WATER COOLED CHRA V-BAND TURBINE HOUSING OPTIONS

www.garrettmotion.com

I am using a 0.63AR Tial vband hotside too... makes a big difference to spool... anything larger would be a lag monster

<tuffty/>

What would be good comp/turbine sizes for my 1.8 500who goal? I was thinking .6x comp. .5x turbine?

 

[<tuffty/>]

3076 tends to be decent... just bare in mind that you won't get 500hp on std cams.... on mine I hit 470 ish hp on std cams... fitted a set of Badger 5 spec cat cams and gained about 100hp

<tuffty/>

 

[Tadope]

3076 tends to be decent... just bare in mind that you won't get 500hp on std cams.... on mine I hit 470 ish hp on std cams... fitted a set of Badger 5 spec cat cams and gained about 100hp

<tuffty/>

100hp just from cams! Wtf. Any performance cam? Or you had some special thing? What supporting mods do cams need?

 

[<tuffty/>]

Its more that the std cams are restrictive at flow levels nearing 500hp... a GT3582r is a 600hp capable turbo and its flow was restricted... fitting cams allowed the turbo to reach its potential is all...

Prob best you have a read of my build thread from here for more details of whats needed

My minor modding thread

S6 towing the S3 looks awesome lol. Didnt realise how much power this thing was running, oh dayum! Bet you surprise a fair few porschers etc in that!! Looks really clean too, good work! What an S3! Thanks... she is a bit of a sleeper... (exactly what I set out to do)... Saturday wasn't a...

www.audi-sport.net

<tuffty/>

 

[S.Pellegrino]

Its more that the std cams are restrictive at flow levels nearing 500hp... a GT3582r is a 600hp capable turbo and its flow was restricted... fitting cams allowed the turbo to reach its potential is all...

Prob best you have a read of my build thread from here for more details of whats needed

My minor modding thread

S6 towing the S3 looks awesome lol. Didnt realise how much power this thing was running, oh dayum! Bet you surprise a fair few porschers etc in that!! Looks really clean too, good work! What an S3! Thanks... she is a bit of a sleeper... (exactly what I set out to do)... Saturday wasn't a...

www.audi-sport.net

<tuffty/>

Ha! 100 pages of goodiness