Greater than 20psi mods AAZ T3

[mstephenson]

I finally went through my car and had it running and fun. Started every time. 39.3mpg. Fun. It made me happy. Then I started smelling diesel. A constant, fast burble of fuel was coming from the IP. Figures after 35 years something had to dry out. So I pulled it and am now springing in the spring for a Giles pump and injectors.

I now have questions after more reading about boost, boost, boost.

86 mk2 golf
1.9 1Y with T3 & 5-speed

I want the car cross-countryable yet fun. Fun. Not crazy. I know a stronger clutch is in order and am open to recommendations. Also exhaust (2.5" is assumed).

Giles asked if I wanted <=20psi or +20psi. How much more modifications would be needed for the +20psi even if I rarely hit those numbers?

for +20...
APR bolts/studs?
IC?

Thanks.

[RabbitJockey]

an intercooler is always recommended, and make sure giles knows if you are going to be using one or not. The intercooler will help to improve your MPG's, it will improve over all air flow, improved reliability too by keeping the engine cool, and obviously an increase in power assuming you have the fueling to go along with the extra air. you can make more power at 12psi with an intercooler than you can make at 20psi without one.

i wouldn't run more than 20psi with that turbo, especially if you're going to rev it high, with an intercooler 15psi is a good limit assuming you are revving to a max rpm of 5000. otherwise you can overspeed the turbo. those t3's are tough little turbos but it sounds like you're going for reliability more than power.

i think you will be ok with out arp studs, they are a great upgrade but not necessary imo.

[oblique]

Above 20psi requires extra mods to the pump. Like Rabbit says, even at that limit you will be heatstressing the motor. 15psi is safer w/o intercooler but depends on your terrain...if you're climbing a lot, heavy, you may still run into issues.

[mstephenson]

I just don't want to go down the road of upgrading one thing and then living in Upgrade City. it is a vicious, expensive cycle to get caught in.

IC:  The moral of the story is lots of good air in and lots of unrestricted air out. So, I will start that hunt.

and yes, I want Reliability with Fun next to the cherry. I think it can be done.

as far as the clutch, when I talk to the gasser sales people, they speak in terms of HP. I read here clutch matching should be related to Torque. I have looked at South Bend, the Mexican clutch, and the German clutch. and again, I want something that is strong which means infrequent installations (one and done hopefully) and will forgive me for my driving abilities (or lack thereof).
The Bentley A3 (MK3) pg. 3-2 says it is a 210mm clutch.
Any thoughts?

[RabbitJockey]

do you know what clutch you have now? if its a 210mm aaz/1y clutch you're probably fine as is.

[RabbitJockey]

I am a little bit crazy so I made these compressor maps to illustrate

Now i am not 100% certain if this is the correct map for a vw 35 trim t3, it's been floating around this forum as a t3 compressor map for nearly 20 years. It is definitely a 1.6td map, so it might be for the k24 turbo which also came on the 1.6td. This is fine, it's a similar turbo and plotting a compressor map is not an exact science because so many factors like altitude and outside temperature can affect where things land.

First map here is with no intercooler at 15psi and at 20 psi, at either psi the engine flow rates stay well within the safe flow range for this turbo



second map is plotted with an intercooler at 15 and 20 psi. You an see at 15psi the flow rate runs right out to the edge of the efficiency range for this turbo, which i would still consider very safe. At 20psi you flow right past it and you would definitely be overspeeding the turbo if you were running the engine to redline. I dont think the turbo would instantly blow up at 20psi or anything but it would definitely begin to shorten its life span and risk reliability.



i created these in mspaint but i used borgwarners matchbot to get all the numbers
Matchbot can also estimate crank hp and these are the estimated numbers.

non intercooled:
15psi: 123hp @5000
20psi: 136hp @5000

intercooled:
15psi: 144hp @5000
20psi: 168hp @5000

i struck out the last one because i dont think the turbo could flow enough air to make that much, so you'd probably get a max of 150-160hp somewhere between 15-20psi

keep in mind these are estimates many factors can affect your actual results.

[oblique]

Very cool graphs... do we know what engine temps are like at these configs? Are we just simply making more power therefore more heat because we can charge more air @lower temps?

The k24/t3 turbos are huge and definitely better than the small stuff for higher boost applications I am led to believe.

[fatmobile]

 What is a T3?
 Is it a stock 1.6 turbo?

[Dennis Froelich]

T3 is the other K24 turbo. Which my 1.6 TD came with. It's the better turbo of the 2.
I believe the other one is KKK, also K24 1.6 TD turbo.

I'm sure I will be corrected if wrong...

[oblique]

T3's have a much more reliable wastegate in my experience...they are mounted externally and dont get nearly as hot as the k24. They are not common though...I think only early motors came with them and there a few revisions, mostly the wastegate plumbing. All had externally plumbed wastegates but the later ones had rubber lines so can be more easily spliced for boost control. Similar build quality I think but the garretts just seem a little more refined.

[fatmobile]

I don't think you can get 20 psi from one of those.
 Even with the waste gate constantly closed.

[oblique]

Depends on your pump setup I think. These are built pretty solid but obviously longevity becomes an issue.

[RabbitJockey]

k24 or t3 can easily produce 20psi. if you have been on this forum a long time you would remember many people running 30psi regularly.

like oblique said you just need the fueling, with the pump at stock settings you can only produce about 15psi, but once you adjust the pump and add a boost controller you can 20+ easily.

i would also clarify that neither of those turbos is huge, they are physically larger than alot of the newer turbos but they dont flow much more air. they might flow 15-20hp more than a vnt 15 or ahu k03, at most.

they're really not ideal turbos these days but they did leave a lot of performance on the table from the factory.

[oblique]

I think intercooled you can run 30psi for a while...im going to throw 50k km out there as a ballpark but that would be with a fairly fresh motor..also up here ambient temps are pretty low.

I think in terms of size I meant spooling...on a 1.6 the k24/t3 dont reach full boost until 3k rpm...these little IDI's are relatively high revving but it's a long wait in urban conditions and you are making some smoke in the process.

In terms of bolting up factory parts, lots.of guys up here would use the 1.6 units on their 1.9 aaz builds...added volume would make them behave a bit more civilized and 1.6td parts are much more available.

[RabbitJockey]

30psi is outside of its efficiency range no matter what setup you have it on. on a mostly stock engine with out the governor mod it probably would be fine if the egt's are in check although hard on the engine and turbo due to overspeed the turbo and more backpressure in the exhaust. However on an engine with the governor mod or a giles pump, it's giving you full fueling and proper timing all the way into the higher rpm range which will put a lot more stress on the engine and turbo.