N9T modification

[V-M]

I have asked price for these (local store),

ARP-200-8428
ARP-300-8396
ARP-AU7700-1B

There was allready discution about these bolts and I would use those on opposite way so no need to change block treath. And for fast look from summitracing that set would be around 150$ (imported here price would be ~220e (postage and taxes))

V-M

[V-M]

I orderd set from england, cost 240e.

V-M

[keebs]

How about these wheels?

[Bean]

I like them - reminds me of stock Subaru STI wheels. Not to blingy and they suit the car nicely...

So what your plan to fit them? Adapters? (They look high / FWD offset so should have room for them)

Rabin

[keebs]

They are sti wheels:). They're 17x8et53 as opposed to stock 15x6et25. Adapters will have to do for now, later I want an sti strut assembly for parts availability and big brembos.

[keebs]

Here it is, the adapters ended up being 45mm thick front and rear for an effective wheel offset of 8.

[Bean]

Very nice! What kind of clearance to you have to the strut tubes up front?

Rabin

[keebs]

There's about 5mm between the tube and rim. The fronts fit without issue, the rears needed the lip rolled and some hammering on the inner fenders for clearance. Not too bad considering the front/rear track width grew 85mm.

[Bean]

I still have hopes of getting my bmw wheel and brake fitment done this fall, so I'm hoping to see what I'll need to fit the 17x8.5's. I was hoping to run 255-40-17's all round. I've also got 17x8's should it need too many mods to fit the 89.

What size tires are you running? (Conti DWS?)

Rabin

[keebs]

17x8.5 with a 255 is one hell of a stretch from where I'm sitting. With a stock angled strut the front wheel offset would need to be 0 or negative, and the fender would need to be widened an inch or so. To keep track with ratio the same as stock (4 identical wheels) the rears would need the same widening which might look funny unless you widen the door too. If you want it super easy get some 17x7.5s and you wont even have to worry.

Yes those are conti dws in 225/45, they came with the wheels. I haven't had any rubbing issues yet, even after some more than rigorous offroad (cornfield) testing. I'll test some more and let you know where the issues are if they come up.

[Bean]

Arun is running 245-45-17's so I was hoping the 255's worked as I like how the tires fit the rim as well as the wheel to sidewall ratio looks perfect.

I don't really want to mod the 89' much, so if I have to use the 17x8's and narrower tires so be it - I'll mod a different car to run the 8.5" rims.

Rabin

[keebs]

Spent the past few months making an intake manifold. Pretty straight forward dual plenum. Some specs.

-ford 65mm throttle body with extra shaft seals

-around 5l plenum volume 

-tapered velocity stacks 

-1.61" i.d. 9" long runners.

-alum fuel rail

I have more pics, but the data seems to be corrupted. Any questions just ask.

[Bean]

Very cool Keebs - it's very Audi Quattro rally intake inspired. 

I did a ton of research on intake design as well and this was my ideal design - but so cool to see it already done.  I never considered packaging - so very interesting to see how you ran the TB and piping to get it all to fit.

Anything I can do to help with pics just let me know - I NEED to see more details - especially the runners and stack designs if possible.  Any trumpets internally?

Completely forgot to ask how you would describe the changes so far with the new header and now intake on the car?  Did you have to alter your tune very much with the intake?  Very curious to hear what you think so far and what future plan is. 

Rabin

[keebs]

I built it based on the fact that the engine will never produce over 350whp, so this style mani fits the bill.

Initially the cone was supposed to mount the other direction, but space constraints with the tb and iac made it a no go. It was a small compromise to make the p/s reservoir accessible.

Not much to say about the plenum, its a box. The transition slots are 105-110% the tb size. 

Like I mentioned above there are velocity stacks about 4" tall and tapered from 2" down to 1.61" which is as big of a taper that would fit. The top of the stacks are about .75" off the plenum floor. From there I welded on another 4" of tube to make the length. Straight pipe, not much to it.

We milled the flange bolted to a scrap head to match the port roof angle which we didn't measure, but a guess would be 25°-30° whereas the stock mani is about 5°. That being said the air now flows into the back of the valve instead of the port wall. 

Injector bungs were installed very close to the head at the best reasonable angle to hit the back of the valves. The stock injectors aren't placed on center so we had to make a new fuel rail to match the new spacing.

The thermostat housing also needed to be angled to make runner clearance which luckily I did last spring when I made the new rad. The dipstick also needed a few new bends, and the coolant bottle relocated. I think the mani invades the battery tray too, so thats something to consider.

Haven't done much testing as I'm still breaking in a new clutch that had to be put in during all of this. However I'm most happy with the 65mm tb tip in response. It was chosen for this reason alone not as a power adder.

[Bean]

If you get a chance to post any build pictures, or even just more pictures that would be great.  You're description tells me all the details - but the pictures are what I like to pour over.  Just looking at the welded segmented intake pipe is a work of art - so many hours into it, and all the details the words just don't do it justice.  Did you do all the welding yourself?  Hopefully your photo 'corruption' comment doesn't mean their lost at all - that'd be a damn shame.  I really really want to see anything you have - even if you were to just bulk upload into member gallery with no details. 

As for specs - I took a chance on a 75mm TB knowing that throttle tip in could suffer.  There was a TB shoot out that 034 did and the had the best power delivery from a 75mm TB, so I took a chance that it should work as well on the N9T**.  Up until now I was thinking of modifying the stock intake, but after reading your description it sounds like scratch built is the much better option.  Still a long way off - but it's fun to plan it out. 

Rabin

[keebs]

Managed to get a few pics out. I'll have to see if my buddy took any while it was strapped to the mill.

Yep did all the welds myself which is good and bad since I don't do it enough anymore.

I think you may have misinterpreted my throttle body comment. I prefer the 65mm to the stocker because it feels like less of a dog at low openings. Personally I would put that 75mm on the shelf or in the trash can (whichevers closer). Something that size belongs nowhere near something so low output. 60mm would be best, but the way things worked out 65 was what I landed on.

Stock manifold isn't really worth playing with since the entry angle is so poor. You could match the ports since they're not even close to the same size or shape. As I recall the head is 41.xxmm wide oval and the intake is a 35mm circle.

[Bean]

Thanks for posting those - very cool indeed.

As for the 75mm - this was the post I read that sealed the deal after finding a few other references on going with a bigger TB:  http://forums.vwvortex.com/showthread.php?4690902

It's a Wilson Billet TB so not exactly trash worthy - but if the gamble doesn't work and it's shite then I'll sell it and go smaller.    Got it for a great deal so figured what the heck.

Odd question - but there's no chance that plenum is a DIY kit of some sort is there?  Plenum and trumpets look manufactured and you were able to assemble them which is awesome - but if you fabricated everything then I'm even more blown away.

Rabin

[Bean]

Dual plenum DIY kit

Looks like this must be the kit you used maybe? 

Rabin

[keebs]

If it's a wilson by all means skip the can and get some coin for it. Don't let yourself be clouded by dyno numbers, think about the driveability. Also fyi wilsons and most other ford tb's leak like crazy through the throttle shaft so they need extra seals.

Yep thats the one. Send Juha an email if you're interested, his english is very understandable. I had the stacks custom made by racerxfabrication. 

I could've made the whole thing, but you can't beat a cnc for repeatability and the pressed box saved me lots of cutting and bending. Not to mention trying to make a cone out of 3mm alum without it looking junky.

[V-M]

Looks good keebs . Used AMW services and products for years, I can recomend them.

V-M

 

[Bean]

Not just peak dyno numbers - there's gains across the entire curve on SRT4 and Evo engines, with great reviews on street drivability - even on those 1.8T plots you can see gains all over.  So it wasn't just that post that led me down the path - there was a raft of info and it all looked promising.

Tip in throttle response will be the issue, but I can play with the cam profile on the throttle shaft to tune how the cable open the throttle at tip in to tune response.  That's the plan anyway - if it's shit, it's an easy change to something smaller. 

Can you post a close up of how you did the extra shaft seals? 

Rabin

[keebs]

Thanks VM. I guess they are in your neck of the woods.

With all due respect Rabin you're headed down the wrong (long) path. My point is you will probably reach max flow before 50% throttle. Some simple area calcs.

60mm + 19% 

65mm + 40%

75mm + 86%

I'm not arguing nor telling you what to do just stating the truth.

To take pics of the seals I would need to disassemble the unit so... no. They're just generic skf 3/4x3/8 double lip oil seals that I pressed in from the outside. The wilson may not be so easy.  

[Bean]

I appreciate the heads up, and I'm well aware that by the numbers / calculations it's too big, but there is also an awful lot of empirical evidence on just how good a 75mm TB can be on 1.8T VW's, 2.4L SRT4's, and all manor of Mitsu 2 - 2.3L evo engines.

I'm curious enough to risk the effort just to know for myself - but the discussion might be moot as Nick Cota has been unreachable these last few weeks.   (I lent him my VEMS set up on condition that I'd get the dyno tune off his car as my base map on mine.)

If the TB is lost, then I'll probably listen to reason and go with a 60 - 65mm one.

Rabin

[keebs]

Well I sure hope you manage to get your stuff back so you can get started.

[keebs]

So far the manifold test results are positive. Some fuel had to be taken out in the idle-cruise parts, but I attribute that to raised efficiency not power loss. At a constant throttle opening during cruise higher vacuum is being maintained with 1-2% less fuel. In boost 2-5% fuel was added to maintain the same afr and power falls off less after 5500rpm. The boost solenoid duty cycle also had to be increased 8% to reach the same target of 1.15 bar.