9N3 GTI Polo 300bhp build

[svensktoppen]

Fantastic

 

[sam_9n]

Have you a phenolic gasket between the head and inlet mani Jack?

 

[HILL9N3GTI]

Have you a phenolic gasket between the head and inlet mani Jack?

I do indeed sam its a large port to small port to allow for the stepdown of the bjx head i want to keep it in ass it keeps the inlet temps way down and i find it helps.
Plus i feel like that would be a large restriction in the system especially being so close to the injectors i feel like it will effect the misting of the fueling.

It does however cause the problem im dealing with and if it was not their i dont think it would be a problem

This is the stepdown im talking about the spacer eradicates that problem

 

[sam_9n]

Yea that’s exactly why I said. Not Gona lie, I never ran one and used a standard gasket and standard intake mani (good upto around 450hp) before becoming super restrictive.

just a thought, fairly sure all the guys who ran the k430 on the Polo too never used phenolic. I’d genuinely think the difference wouldn’t even be noticeable on the road. Worth trying before touching that nice mani

 

[HILL9N3GTI]

@sam_9n unfortunately its already been left to be skimmed. it wont be hard to refine with a file and a little sandpapper to make it look like its still brand new but its the way i think is best to go.

Ill probably regret it later tho. but for now we will see how it turns out, i might even sell it and order a new one depends on how this hole thing turns out and preforms with the tb spacer

 

[sam_9n]

Suppose you need it for a smooth transition from large to small port. Every little helps with flow so may as well keep it, just be interesting to see a difference in dyno figures between your intake and a normal BAM one for example.

maybe not best for you to remove your injectors too often though, can’t have you burning your eyeballs each time

 

[HILL9N3GTI]

Suppose you need it for a smooth transition from large to small port. Every little helps with flow so may as well keep it, just be interesting to see a difference in dyno figures between your intake and a normal BAM one for example.

maybe not best for you to remove your injectors too often though, can’t have you burning your eyeballs each time

Promise i wont make it a regular occasion

 

[veedubnoodle]

View attachment 285580

This is the stepdown im talking about the spacer eradicates that problem

Would you not be better just enlarging the ports on the head and giving them a wee polish while you're there? Not a massive job to do and will improve flow a great amount.

 

[HILL9N3GTI]

Would you not be better just enlarging the ports on the head and giving them a wee polish while you're there? Not a massive job to do and will improve flow a great amount.

I probably should of done but im not sure what it would be like to do on a bjx head. I have heard a few horror stories
and its not really.one of the better heads to start with

 

[veedubnoodle]

You could enlarge them ports no problem at all. Essentially all you're wanting to do is match it to the gasket and manifold to make the flow as smooth as possible. Nothing worse for air flow than hitting a flat surface.

 

[svensktoppen]

But you don't want them too big either, they need to match the actual flow through the engine.

I guess all this tedious flowbench work and actually measuring stuff and doing some actual calculations is overrated these days, just get a dremmel in there and work away

 

[HILL9N3GTI]

You could enlarge them ports no problem at all. Essentially all you're wanting to do is match it to the gasket and manifold to make the flow as smooth as possible. Nothing worse for air flow than hitting a flat surface.

But you don't want them too big either, they need to match the actual flow through the engine.

I guess all this tedious flowbench work and actually measuring stuff and doing some actual calculations is overrated these days, just get a dremmel in there and work away

This is what im saying if i was going that far i may aswell change the head to an agu which are you of the larger ported cylinder heads and @sam_9n correct me if im wrong but is their not some sort of cooling channels near the ports on the bjx.
Thats what iv heard aperntly a few people have broken through and struck gold

 

[sam_9n]

There’s a water jacket that runs around in that area. But you can still port with no issues unless you go crazy. Tbh, for the work you’ll have to do to remove some of the intake mani TB flange is minimal compared to taking the head off, porting and matching it and then refitting the head lol.

only reason I initially suggested running without the phenolic spacer was because I didn’t know your mani was large port. But yes, you’ve went for the easier option by machining the TB flange

 

[HILL9N3GTI]

Little bit of an update of whats been going on today

i have everything striped and the parts that were ready for powder coating were lifted so should be a few days until they are back in my hands.

Majority of pipes cut and cased in the fibreglass surround where needed.

All that i need to do now is wait for the postman for the rest of the parts to finish off tidying up the cluster **** of pipework and electrics.
Its like a spiderweb under their at the moment.

The part designed for the throttle body spacer have been made and i have also got a few extra bends in case i need to make adjustments before they are welded permanently in place

Since im not doing a lot under the bonnet i managed to get back into the job of getting Jayme to draw up the seat brackets and i think they will do the job.

Also PBE stamp of approval was a must

Made from 4mm plate with the logo pop riveted on

cheers @jayme


Thanks for taking a look

Jack

ps I appreciate all the feedback and advice folks it gives me a little more to think about and decide what could be done next our sometime down the line.

 

[HILL9N3GTI]

I have been working away this week with the car on axle stands, trying to do odd jobs while waiting for parts to arrive in the post

so this is what i have been up to

small bit of re wiring as my map sensor decided it wasn't going to play ball

Managed to get the manifold up to walls engineering to get the corners milled of to stop with the clearance issues under the bonnet, and to stop it from damaging the outer skin.

When they get back from powder coating, i will decide weather our not im willing to do without the spacer between the block and the intake mani which was discussed in a previous reply.

whilst that was in the brewing pot i got word back from RJ Smith that the bits me and big brother drew up a few days ago for the new seats were ready for lifting tomorrow (tue), so instead of sitting around i pulled out the interior today hovered and cleaned it up as mush as possible.
safe to say after that im gonna have to take care of it a little bit more as it was a joke with over spray caked into the floor and reminiscence of tobacco from previous times out.

passenger side is nearly done and you can see how bad it is on the driver side

my progress was soon cut short by typical NI weather with rain




Also i finally after 2 years of chasing people to get a boot floor made i just did it myself and got it carpeted.
finishes the back quite well in my opinion but i still have a lot to do in their in terms of something to cover the back shelf.
No doubt when the cage comes it will need cut up to accommodate the proper fitting


I was originally going to push the carpet into the lettering but decided not to, and just to flip it to use the flat side as the top.

Keep it plain, clean and simple

So thats really it apart from all the other boring pipe work for now
Ill do a bigger update at the end of the week hopefully if the postie decides to give me bits it should be back on all four wheels and running again by Thursday.
But knowing my luck nothing goes to plan


Thanks for taking a look
Jack

 

[HILL9N3GTI]

still waiting on parts so here is a little insight into currently what the main drive is

thanks @cauld1 for the shiftier idea turned out well

more to follow at the weekend if all goes to plan

 

[da.murf]

love the shifter!!!!

 

[HILL9N3GTI]

Well here it is for now as it would of been for dubshed.
But things didnt go the way we wanted
Thanks for the help for those that lended a hand


More to follow on sunday

 

[sam_9n]

Looks excellent mate. Wish you were closer and I’d pop down

 

[Blackie]

That is something else!! Beautiful, great work buddy!

 

[svensktoppen]

Outstanding, well done

That colour really pops! Suits the car perfectly.

 

[cauld1]

Looks great! I've it on good authority it sounds good on boost.

Need videos!

 

[HILL9N3GTI]

Looks great! I've it on good authority it sounds good on boost.

Need videos!

Ill get a few sent through tomorrow but
its been a long tim coming

Thanks for the support folks really appreciate it.
Its just nice to have on the road again.

 

[ossy2004]

Looks so good!

 

[HILL9N3GTI]

Honestly guys thanks for all the support really suprised to how much attention its been getting.
From something that no-one looked at to being sudenly something to stop and admire.

its very strange

I was planning on doing a post on what all has been done and completed over the past few days but its been very busy ill put the work pictures up later this week when i figer out a small boosting issue

but heres some more photos for now after probably one of the most in depth cleaning sessions it has ever received in probably its 14 year lifespan

I thought this one was quite a funny picture it just shows you how impractical a polo is for a tall fat bloke

Once again thanks for taking a look.
Jack