How much boost are you running with factory headbolts/gasket

[Jason]

Hi folks,
just wanting to get some imput on what kind of boost levels you are running with stock headbolts. Is there anyone out there that has installed a set of ARP studs? I know this is a popular mod on the 1.6 vw diesels (which I have had) and they run pretty good boost 15+lbs with thet stock gasket. You can upgrade the head gasket to the metal TDI one for the 1.6, is there a better gasket than stock for the D24T?

I'm thinking 15lbs with an intercooler and bigger exhaust... Too much?

Thanks,
Jason

[cuaz64]

1. About the headbolt: I don't know if someby has update the stock headbolts.
2. Max boost with stock engine: I remember read about somebodoy runing 15PSI on with stock headgasket and Audi 5000 intercooler
3.The next step in headgaskets is the Volvo Stainless Steel headgasket
4. About intercoolers: I found the following options:
A) Volvo D24TIC intercooler: Was sold only in Europe, is basically the intercooler from a B230FT engine and a special manifold.
B)Saab 900 Intercooler: Small intercooler, ideal for be used with the stock (or NA D24) intake manifold.
C) Audi 5000: Already done (I gonna post the link later)
D) Cheap Ebay intercooler: Already done. (I gonna post the link later).

[Jason]

Where do you go about getting the stainless version of the head gasket? I'm thinking ebay intercooler, though I have a intercooler from a Audi TDI in the garage that I scored of ebay for $30 that I may use if I can fit it somewhere.

I only know of stock replacement headbolts. If you want to upgrade, arp makes a head stud kit for the 1.6 vw diesels, you would just need 1 and a half sets...

Jason

[cuaz64]

Where do you go about getting the stainless version of the head gasket? I'm thinking ebay intercooler, though I have a intercooler from a Audi TDI in the garage that I scored of ebay for $30 that I may use if I can fit it somewhere.

I only know of stock replacement headbolts. If you want to upgrade, arp makes a head stud kit for the 1.6 vw diesels, you would just need 1 and a half sets...

Jason

I think that is only a dealer part, Tom Bryant have the part number y know a few tricks to squeeze more power of the D24T. Also, the non-turbo D24 intake manifold supposedly have a better desing that improves the airflow, and makes easier the intercooler installation.

[Jason]

Interesting, hopefully someone will post up a non ic manifold for sale! Suprising that the dealer can get a stainless head gasket for it.. I didn't think the dealer would have much of anything for the diesel engine.

I have modded a few vw diesels, and rebuilt my 85 jetta turbo diesel... I'm familiar with the pump mods and such for more fuel. Not so sure how the auto trans will handle the power though!

Jason

[Slobodan]

You don't need that N/A manifold. Just reclock the comp housing away from the motor and use two 90 degree angle silicone couplers, and then piping to the IC. Easy. I even used the 240/740 turbo intercooler flipped upside down and way up front behind the grille. perfect on the 240. however, I am using the EGR Non-IC manifold. I like how this manifold is small and compact plus has the over boost valve.
I am run 12psi and when revving out it will overboost and the valve drops the psi down to 8.. hmm.. I need a stiffer spring.

Also not using the stock turbo compressor. I fount a HT182s. I think its .60 A/R... came from the RX-7 turbo II. slapped that on the stock centre and turbine which is .36 A/R. hmm... I have been thinking that I want to get the Turbine housing and wheel from a Mercedes 300TurboDiesel. I believe they have .48 A/R.

My belief is that while cruising at 65 ~ 70mph boost will be lower like 1 - 2 psi rather than 4 - 6psi currently.

i should note that I have stock downpipe that is coupled to a 3" side exit.

[Jason]

Doing the two 90 elbows was what my plan was originally... Why haven't you just blocked off the overboost dump valve? That was one of the first things I did on my jetta TD. That was dumping boost by about 8lbs and leaked just about all the time from what I could tell. Interesting idea on the turbo setup. I wonder what other compressor and turbine housings will swap over. What kind of rpm are you running on the highway? My jetta always ran about 4 or 5lbs of boost cruising around 3000rpm. I'm guessing your boost while cruising was less with the original compressor housing? What kind of difference did you notice with the bigger housing compaired to stock?

Lots of questions i know.. I'm excited that we have a forum starting up here with people that want to talk about and tinker with these cars!

Jason

[Jason]

By the way if you have any videos of your side pipe I would love to see and hear it!


Jason

[Slobodan]

No video yet.
Originally with the stock setup and non intercooled it would cruise ~ 3000 rpms around 68 to 70 mph at 5 psi. when I added the Audi 5000 intercooled (which is now 240 intercooler - which dropped it a little) It dropped by 2 psi then I put on the bigger compressor. then it went back up. but it had so much more power and torque. I noticed that the compressor wheel was bigger by 1/16th an inch in diameter. and the compressor outlet had a bigger inner diameter aswell. The final turbo configuration I am looking to build is a .48 T3 waste gated turbine with a T4 .50 a/r compressor. I have most of that all ready just need a good T4 backing plate for the compressor.

[SuperTurboD24T]

You will incur great losses with one tight radius (I am assuming due to the location) 90 degee bend, and even more with two, especially since the opening for the manifold is not that large. It will get you up and running quickly, however.

The d24t manifold is nice and compact, and I might suggest that if you use it, remove the overboost valve and in its place fit a 2.5 minimum diameter short straight pipe, or a gentle 90 degree pipe if you need it, via welding or another suitable method. It will be far more efficient, and you will gain both power and fuel economy.

Interesting choice with the FC Hitachi turbo. In general, that turbo is designed to deal with a lot of exhaust products, and on the compressor side, move a lot of air, efficiently at low boost pressure. It is sort of at the opposite end of the scale in terms of engine requirements as compared to a diesel which is on the other end of the scale.

It may however, be quite good if you can fit it with a larger, t4 based compressor in the .50 - .60 A/R range, given it's good exhaust flow.

How does it respond/spool up, and if you kept other things equal (boost, pump, etc.) the the power increase, or shift to a higher rpm range?

[SuperTurboD24T]

Head studs are a must, and if you can do it, install the factory metal gasket. It is proven to not leak at manifold pressures of 2.5 Bar and above.

Without those two details, you could be ok with the stock turbo and ~25 psi, provided the stock head gasket is in good shape. The only problem is how do you really know if it is solid. The same would go for the head bolts.

I might suggest you get studs at a minimum, since they are very easy to install, and do not require you to remove much of anything compared to a head gasket install. Just replace them one at a time, making sure there is very little to no oil in the block threads.

[Jason]

I was wondering about changing out the bolts to studs. Its a common practice on the Cummins 5.9 engines, but the head is cast iron, not alum. How would you go about torquing it? I know there is a specific torque procedure, would you remove one at a time, and torque the new stud/nut to the first stage, and then do all the studs to the next amount after they are all installed? Or go all the way to the torque value plus the extra 1/2 turn (or is it 90 degrees, I forget) on each stud before removing the next bolt?

[Jason]

I like the idea of changing the dump valve to the new intake inlet location... The stock inlet does look rather small.

Jason

[SuperTurboD24T]

In general, follow the instructions from the company you buy the studs, paying attention to the type of oil on the threads where the nut is, as it affects the torque value.

Torque the nut to the factory spec or the spec from the stud manufacturer. Since the head gasket should already be compressed (we are writing of a currently used HG) you should not need to stage the tightening procedure.

[Jason]

The arp studs are one of the first things I would like to do. I'm thinking that I should be able to push 15lbs of intercooled boost with the stock bolts and gasket without too much trouble.

Jason

[jbg]

[...] I have been thinking that I want to get the Turbine housing and wheel from a Mercedes 300TurboDiesel. I believe they have .48 A/R.

Slobodan, can you confirm if the turbine housing off a 5-cylinder Mercedes turbo diesel (W123-era) is the same "type" as what we have on the D24T? I had a conversation with Tom Bryant looking for a suitable replacement turbine housing if the funky integrated wastegate were to fail. My idea was to use the turbine housing from the MB because it looked very similar (wastegate, exhaust down pipe mounting (bolts instead of studs/nut)), etc.

This picture was pilfered from eBay auction #320349918326:

http://i9.ebayimg.com/08/i/000/fb/4d/5ae6_1.JPG

Any thoughts on the matter?

Jim

[cuaz64]

Slobodan, can you confirm if the turbine housing off a 5-cylinder Mercedes turbo diesel (W123-era) is the same "type" as what we have on the D24T? I had a conversation with Tom Bryant looking for a suitable replacement turbine housing if the funky integrated wastegate were to fail. My idea was to use the turbine housing from the MB because it looked very similar (wastegate, exhaust down pipe mounting (bolts instead of studs/nut)), etc.

This picture was pilfered from eBay auction #320349918326:

http://i9.ebayimg.com/08/i/000/fb/4d/5ae6_1.JPG

Any thoughts on the matter?

Jim

Why don't use the gasser T3 exhaust housing? use the same flange, or not?

[Slobodan]

The Hitachi turbo is actually just Garrett parts that hitachi threw together. I just used the compressor backing plate, comp wheel and housing. The rest is the stock centre cartridge, turbine unit. I noticed it taking a little longer to build boost up to 6psi then after that it just bolts towards 12psi like no other.

[Jason]

If you can find a T3 of suitable trim, you can just bolt it up. You will probably have to make some kind of down pipe or modify the one you have. T-3 turbos are so common in many different trims, it shouldn't be too hard to find one that is very close to the same A/R as the stocker. Most will have an internal waste gate, which more than likely wont open at more than 8 to 10lbs wich is factory level for the D24T anyway.

Jason

[SuperTurboD24T]

The arp studs are one of the first things I would like to do. I'm thinking that I should be able to push 15lbs of intercooled boost with the stock bolts and gasket without too much trouble.

Jason

25+ psi with the stock turbo (and it's associated BMEP) has been proven on stock engines (both d24 and d24t) with sound head gaskets without studs. It is cheap and easy enough to simply fit the engine with studs, so you would not have problems down the road, and should be considered.

[SuperTurboD24T]

The Hitachi turbo is actually just Garrett parts that hitachi threw together. I just used the compressor backing plate, comp wheel and housing. The rest is the stock centre cartridge, turbine unit. I noticed it taking a little longer to build boost up to 6psi then after that it just bolts towards 12psi like no other.

As is the case with a larger turbo :) It is a trade, but if you have the hardware to support it, a good trade. Turn up the fuel, fit a charge cooler, and you will get back some of the losses you noticed. Of course, a compressor with more suitable pressure characteristics would be best, and it seems you are searching for such a combination (less total flow, greater pressure ability).

This information *should* be true, if Mazda's engineers spec'd the turbo for the 13B properly. Normally, they are very good at this.

I would probably try to increase the boost in stages, with a commensurate increase in fuel, and see how the engine responds, whilst watching the EGT. It might work well for you.

Yes, a T31 style turbine housing will fit the downpipe flange directly.

[Jason]

25+ psi with the stock turbo (and it's associated BMEP) has been proven on stock engines.

Sorry for my ignorence, but what does BMEP stand for? I'm really suprised that the engine can handle 25 lbs of boost with a stock gasket and head bolts. Over on the VW 1.6 side, I have always heard more than 15 or so would blow the gasket. There are guys over on vwdiesel.net that are blowing the stock gasket with studs at 25lbs of boost. When you say stock gasket, do you mean stock like original, or the stock replacement thats stainless?

Jason

[reed]

Running 12-13 psi stock. Im thinking of runnig about 32psi. j/k

[nick]

Sorry for my ignorence, but what does BMEP stand for? I'm really suprised that the engine can handle 25 lbs of boost with a stock gasket and head bolts. Over on the VW 1.6 side, I have always heard more than 15 or so would blow the gasket. There are guys over on vwdiesel.net that are blowing the stock gasket with studs at 25lbs of boost. When you say stock gasket, do you mean stock like original, or the stock replacement thats stainless?

Jason

(BMEP) Brake Mean Effective Pressure

I got a quote from Raceware for studs: $290.

Did you use this part number for the ARP studs?: 204-4706
What about the washers and nuts?

[Jason]

I bought my studs off a guy, they are the ones everyone has been using for the past few years in the vw diesels, its the cosworth kit. I just found out that ARP came out with a vw diesel specific head stud set. They are higher strength studs and are sold for 1.6 and 1.9 TDI applications. I would call ARP directly and buy them, your going to need 1-1/2 sets, and I don't know of any retail places that will break a set. I don't think they normally sell direct, but if you tell them the situation they will sell them to you rather than loose a sale to some other brand. My friend Alex did it and they were happy to help out. The 12pt nuts and washers come with the kit.


Here you go:
http://i1004.photobucket.com/albums/af168/vwjunkie53/volvo/Release34.jpg

Jason

[Jason]

They are slightly stronger than the ford/cosworth kit. The paperwork with my studs said 200,000psi, these are 220,000. Not huge but every little bit helps I suppose. Don't know the price though. If they are way extra expensive I would probably just buy the cosworth kit.

Jason

[EvoStevo]

Jason, do you have any more info on the Cosworth kit? I didn't know there were any other options other than what ARP sells.

[Jason]

Untill they came out with the 1.6/1.9 diesel specific kit, they were the only studs that ARP sold that worked in a VW diesel. They are the 12X1.75mm thread for the block and the correct length. There may be almost no difference in price between the new ones and the ford cosworth ones.. Not sure on that.

Jason

[HetLaeN]

i am running 58psi on stock studs and the thickest stock headgasket :) not blown anything apart yet :P

[Jason]

Nice! My kinda boost... What combo of turbo/pump mods are you running?

Jason

[HetLaeN]

Nice! My kinda boost... What combo of turbo/pump mods are you running?

Jason

i think the turbo is a T3/T4, and with the 12mm pump.

this is an old picture before the overhauling:
http://i933.photobucket.com/albums/ad173/HetLaeN/Pulleren/sort_guld_08.jpg
http://i933.photobucket.com/albums/ad173/HetLaeN/Pulleren/DSC00027.jpg

and here is one after:
http://i933.photobucket.com/albums/ad173/HetLaeN/Pulleren/tractorpuller.jpg

[Jason]

That is easily the coolest thing ever. I love the straight cut stack you've got now.... I have the same thing in my garage wating for my car! You need to put up a new vid of it.

One question? Is that a factory D24T manifold I see? You should really think about running the NA manifold. The flow characteristics are much better and its a 3" inlet. Looks to me like you did the same kinda thing I did at first by boring out the front of the stock turbo manifold and plugging the old inlet. I noticed quite a difference with the NA manifold, you should really think about doing it.

Jason

[HetLaeN]

That is easily the coolest thing ever. I love the straight cut stack you've got now.... I have the same thing in my garage wating for my car! You need to put up a new vid of it.

One question? Is that a factory D24T manifold I see? You should really think about running the NA manifold. The flow characteristics are much better and its a 3" inlet. Looks to me like you did the same kinda thing I did at first by boring out the front of the stock turbo manifold and plugging the old inlet. I noticed quite a difference with the NA manifold, you should really think about doing it.

Jason

the puller is bought from sweden, and those who had it before had it running for 5-6 years without doing any thing to the engine other than oil change, and we drove it for a year before we changed the headgasket just to see how it looked in the cylinders, and it was not bad to have driven so long.

but it is done as you say with the manifold. i can start looking at least for at NA manifold :)

[Jason]

Take a look at some of my engine pictures, you can see the NA manifold pretty clearly... Its pretty large with the intake runners and plenum, it makes a nice setup.

Jason