Building a forged motor

[drxlcarfreak]

I am getting ready to start researching and sourcing parts to build up an engine for some high horsepower. Right now I have a 95 Talon TSI AWD and have been slowly picking up supporting mods for the TD06-20G that I will be getting in a couple weeks, but I know maxing this turbo out wont be enough for me for too long.

I plan on building a motor to withstand 8-900HP (only planning on around 6-700, but would like extra headroom for tuning mistakes and just to help with the longevity of the engine), via twincharging.

My first in probably a long series of questions that I cannot seem to easily find via the search function is if I am building a forged engine is there any difference in reliability/price between a 6 bolt and a 98-99 7 bolt? Because I already have a 7 bolt trans, would I need to get a different trans if I went with a 6 bolt block? I was kind of leaning towards a 6 bolt originally because they have lower compression options, which would help me out with getting higher boost levels without detonation, but if the difference is negligable like 7.8:1 vs 8.0:1 and I would need to fit a new trans then maybe a built 99 7 bolt it is.

I apologize if there have been threads on this, but in my searches, it really only related to the durability of stock 6 bolts vs 7 bolts.

 

[BogusSVO]

from what I have seen, either can be built to that hp level with enough cash.

some say the 7 bolt has crankrod issues

the 6 bolt has the stronger rods

but for your HP goal you should be replacing the crank/rods/pistons in either block

from what I know the trans is the same for the 6bolt or 7 bolt... you just need the proper flywheel

 

[DOHCeclipse]

I don't know much about the price difference between 6bolts and 7 bolts, but I do know that you can use your 7 bolt transmission on the 6 bolt. You will need a 6 bolt flywheel though of course.

 

[Awdspyderman]

Hey man can i ask how many DSM motors you've built? Don't get hurt, I'm asking becuase what you want from a 6 bolt or 7 bolt is a big order! Also what are your goals for this car? DRAG,AUTOX, or just a street car? I'm not trying to insult you I'm trying to help by figuring out what you really want=)

To swap a 6bolt into your 2g you just need a 6bolt flywheel.


Price on a 6bolt to 7bolt may vary depending on who you know or were you go to get it i.e your friend or the local junkyard hell you may get your motor off the classifieds on here but the 99 7 bolt your talking bout is just as good as any 6 bolt to build so the choice is yours (I'm building my 7 bolt =)) GOODLUCK!

BOGUSSVO<< YOUR THE MAN!! l

 

[drxlcarfreak]

I will definitely be replacing the entire rotating assembly with forged internals. That is a definite.

Oh, I thought that I could bolt a trans up, but I had seen a few classifieds selling AWD trans and transfer cases that would only fit 1Gs and some that would only fit 2Gs... Something about the number of splines on the output shaft if I remember correctly.

If the price and "reliability" of each is the same when using forged internals, maybe it comes down to the compression ratios available to each engine then...

I appreciate the help, anyone else have any insight?

 

[rollover-tsi]

a 7 bolt would be easier to put into your vehicle. there are various sensors and mounts that need to be changed in the 2g to run a 6 bolt. However, just talking about the tranny, all you need is a 6 bolt flywheel, which im guessing that you would be buying a flywheel anyways.

In my experience neither the 6 bolt or 7 bolt present any type of disadvantage/advantage over the other in high horsepower builds, as all the things that make them different are being replaced anyway.

In summation-> more work for 6 bolt, no advantages over 7 bolt.

I am curious about your twincharging. did you mean a twin scroll turbo, or a compound setup, or 2 seperate turbos?

Hope this helps

 

[drxlcarfreak]

I definitely do know the difference between a 6 bolt and 7 bolt. What I haven't been able to find is the difference between 6 bolts and 7 bolts when forged internals goes away. I would think with a forged crank, rods and pistons it kind of evens the playing field out, I just wanted to check with people who know more than I. I am sure it is somewhere probably about 50 times on this site, but I just haven't come across it yet.

Even though I have a very low post count, it doesnt mean that I haven't researched the hell out of this site, dsmtalk and the ecmlink forums. I can understand where you are coming from, there are a bunch of people asking how to make 10s or 800hp on a stock block. I assure you that is not me. I am at stock right now... well I have a bunch of supporting mods to max out the 20g, but I am still at stock HP and do plan on taking things one at a time. I have already done all of the maintenance on the car... actually it was barely running when I got it. I fixed all of the running/overheating issues and then started with the upgrade path.

 

[wdawson4]

if your stock you need to start here cause there is alot to learn before u start ranting and raving about 800hp this 10 second that.
Tech Guide: 1G 4G63t Upgrades - DSMtuners

 

[91stocker]

if your stock you need to start here cause there is alot to learn before u start ranting and raving about 800hp this 10 second that.
Tech Guide: 1G 4G63t Upgrades - DSMtuners

This.

A healthy stock block will handle whatever that 20g can throw at it.

Start with link v3 and speed density bundle. Then injectors and fuel pump. Max your stock turbo. Intake,exhaust, mbc.

That should run ya $1000+ or so, but it will bring that car alive. Then see where you want to go from there.

 

[ed1380]

I am getting ready to start researching and sourcing parts to build up an engine for some high horsepower. Right now I have a 95 Talon TSI AWD and have been slowly picking up supporting mods for the TD06-20G that I will be getting in a couple weeks, but I know maxing this turbo out wont be enough for me for too long.

I plan on building a motor to withstand 8-900HP (only planning on around 6-700, but would like extra headroom for tuning mistakes and just to help with the longevity of the engine), via twincharging.

My first in probably a long series of questions that I cannot seem to easily find via the search function is if I am building a forged engine is there any difference in reliability/price between a 6 bolt and a 98-99 7 bolt? Because I already have a 7 bolt trans, would I need to get a different trans if I went with a 6 bolt block? I was kind of leaning towards a 6 bolt originally because they have lower compression options, which would help me out with getting higher boost levels without detonation, but if the difference is negligable like 7.8:1 vs 8.0:1 and I would need to fit a new trans then maybe a built 99 7 bolt it is.

I apologize if there have been threads on this, but in my searches, it really only related to the durability of stock 6 bolts vs 7 bolts.

if you're going with forged internals then compression ratio can be easily changed by ordering different pistons. no need to worry about weaker rods because you're getting forged rods anyways. the 7 bolt block is stronger overall.

 

[drxlcarfreak]

RolloverTSI: Wow, I have never been on a site so busy that I get responses WHILE responding! I like that!

Awesome, that is kind of what I was thinking and hoping for. Sounds like I will be going with a 7 bolt! I did slightly read into the wiring that I had to change in order to fit a 6 bolt and wasnt looking forward to that.

As for my twincharging, I am planning on doing a compound setup. I have really read into Paul Volk's and Ray Peter's setups and really liked the outcomes from both of them and want to try something similar. My ultimate end goal is probably going to make me look like an immature 16 year old that thought if 1 turbo is good, 2 turbos are better then 3 turbos must be the best! But here goes...

Basically, I am thinking of a triple compound system with 2 turbos and 1 positive displacement supercharger. The end goal being:
- Much quicker boost response than a compound system
- Allows for a larger low pressure turbo for more HP
- Lower IATs as the supercharger isnt creating a ton of the boost
- Less parasitic drag from the supercharger (more whp)
- Less back pressures due to SC, which leads to scavenging and cleaner air charge so pressure can be upped higher resulting in more WHP
- More stages for cooling so IATs are even lower than compound

I am sure I am missing a few of my reasonings here.

The intake side is what I am still debating. Keep in mind this is waaaay down the line as I have to do a lot of testing of different chargers and their interactions between each other before I can properly size everything, but I have already done a bunch of preliminary calculations with assumed interactions between the chargers. In the end, the gains in the powerband be not worth the effort and complexity, but I will never know if I dont try. Ten years ago everyone I spoke to thought that twincharging wasnt worth the effort and people like Ray Peters proved them wrong. I can send you the excel file that plots the boost responses if you like.





Take a look at my mods list guys... I already have everything on the upgrade list.

Walbro 255HP, Aeromotive AFPR, 880cc Injectors, FMIC, Greddy BOV, 3" Megan Racing Downpipe, 3" Turbo-back Exhaust, Ported O2 housing, ECMLink V3, Innovate MTX-L Wideband

I have a second exhaust manifold that I am planning to port and install with the 20G. I also have a MBC sitting in the garage, but haven't taken the time to install it because the T25 is already hitting 17psi, which from what I have read is pretty close to its max.

I am will be going with speed density here soon, but wanted to play around in tuning more with the MAF on so I can understand it better.

ed1380: Awesome, thanks for confirming that!

 

[300hpbound]

RolloverTSI: Wow, I have never been on a site so busy that I get responses WHILE responding! I like that!

Awesome, that is kind of what I was thinking and hoping for. Sounds like I will be going with a 7 bolt! I did slightly read into the wiring that I had to change in order to fit a 6 bolt and wasnt looking forward to that.

As for my twincharging, I am planning on doing a compound setup. I have really read into Paul Volk's and Ray Peter's setups and really liked the outcomes from both of them and want to try something similar. My ultimate end goal is probably going to make me look like an immature 16 year old that thought if 1 turbo is good, 2 turbos are better then 3 turbos must be the best! But here goes...

Basically, I am thinking of a triple compound system with 2 turbos and 1 positive displacement supercharger. The end goal being:
- Much quicker boost response than a compound system
- Allows for a larger low pressure turbo for more HP
- Lower IATs as the supercharger isnt creating a ton of the boost
- Less parasitic drag from the supercharger (more whp)
- Less back pressures due to SC, which leads to scavenging and cleaner air charge so pressure can be upped higher resulting in more WHP
- More stages for cooling so IATs are even lower than compound

I am sure I am missing a few of my reasonings here.

The intake side is what I am still debating. Keep in mind this is waaaay down the line as I have to do a lot of testing of different chargers and their interactions between each other before I can properly size everything, but I have already done a bunch of preliminary calculations with assumed interactions between the chargers. In the end, the gains in the powerband be not worth the effort and complexity, but I will never know if I dont try. Ten years ago everyone I spoke to thought that twincharging wasnt worth the effort and people like Ray Peters proved them wrong. I can send you the excel file that plots the boost responses if you like.





Take a look at my mods list guys... I already have everything on the upgrade list.

Walbro 255HP, Aeromotive AFPR, 880cc Injectors, FMIC, Greddy BOV, 3" Megan Racing Downpipe, 3" Turbo-back Exhaust, Ported O2 housing, ECMLink V3, Innovate MTX-L Wideband

I have a second exhaust manifold that I am planning to port and install with the 20G. I also have a MBC sitting in the garage, but haven't taken the time to install it because the T25 is already hitting 17psi, which from what I have read is pretty close to its max.

I am will be going with speed density here soon, but wanted to play around in tuning more with the MAF on so I can understand it better.

ed1380: Awesome, thanks for confirming that!

I can't say I agree with your statement of lower IAT's and more stages for cooling. With the research you have done you may have seen the sizes of turbos that Paul and Ray have used... Those turbos are creating some high temperatures through the compression process, although one intercooler can be used (as in pauls build) You would need two completely seperate intercoolers to get your cold air that your thinking of to the supercharger. Anybody know the average temperature change from pre and post turbo?

exhaust--> turbo--> intercooler--> turbo--> intercooler--> supercharger--> aftercooler--> into engine? Even if you could get all this to work in unison, there is just no way that's fitting into the 2g engine bay.

I'm no mechanical engineer but i'm not forseeing this happening my man. I understand your effort to be innovative and original but the only way your using two turbos and a supercharger is if you use a v6 or v8

I kept up pretty well with Pauls build and although he's only using one intercooler he's probably somewhat limited due to that fact, (If he could chime in and give his opinion that would be great as I'm not a genius with his setup.) But to top it all off, tuning would be an absolute nightmare if you ask me. Just my opinion though. if you can pull it off I will give you a congrats but I think that you might be getting in a little over your head.

 

[Gus@RRE]

Your compound setup idea is new i guess, but too much busy stuff going on. Why not go with a single turbo that can hit full boost at 4k and still make upwards of 600whp? You do realize if you make 400ft/tq at 2k rpm i don't care what forged internals you have you WILL snap a rod right? If you're that concerned about partial throttle response you can always go with a twin scroll setup. I say install your 20g, see what differences you can physically discern between your current setup and that and take one step at a time.

 

[drxlcarfreak]

I can't say I agree with your statement of lower IAT's and more stages for cooling. With the research you have done you may have seen the sizes of turbos that Paul and Ray have used... Those turbos are creating some high temperatures through the compression process, although one intercooler can be used (as in pauls build) You would need two completely seperate intercoolers to get your cold air that your thinking of to the supercharger. Anybody know the average temperature change from pre and post turbo?

exhaust--> turbo--> intercooler--> turbo--> intercooler--> supercharger--> aftercooler--> into engine? Even if you could get all this to work in unison, there is just no way that's fitting into the 2g engine bay.

I'm no mechanical engineer but i'm not forseeing this happening my man. I understand your effort to be innovative and original but the only way your using two turbos and a supercharger is if you use a v6 or v8

I kept up pretty well with Pauls build and although he's only using one intercooler he's probably somewhat limited due to that fact, (If he could chime in and give his opinion that would be great as I'm not a genius with his setup.) But to top it all off, tuning would be an absolute nightmare if you ask me. Just my opinion though. if you can pull it off I will give you a congrats but I think that you might be getting in a little over your head.

They are creating high temperatures at the 40+ psi pressure levels, but overall it is actually cooler than forcing a single turbo to do the 40psi by itself. I am actually thinking of 3 separate intercoolers. The temperature change post compression is a function of inlet temperature, inlet pressure, outlet pressure and turbocharger efficiency at that pressure ratio. A GT35R at 29psig runs at about 77% efficiency, say there is 1 psi of vacuum and the inlet temperature is 70 degrees. The compressor outlet would be about 310 degrees F.

That is about right for the intake side of things. I am planning on using W2A coolers which take a fair bit less space. The AC compressor is also leaving and the supercharger will take its place. It will definitely be extremely tight, but I think I could make it fit. Not sure why I would need a Vee engine to run 2 turbos and a SC?

Other than boost control, I do not see tuning being much worse than a single turbo at that HP level.

Your compound setup idea is new i guess, but too much busy stuff going on. Why not go with a single turbo that can hit full boost at 4k and still make upwards of 600whp? You do realize if you make 400ft/tq at 2k rpm i don't care what forged internals you have you WILL snap a rod right? If you're that concerned about partial throttle response you can always go with a twin scroll setup. I say install your 20g, see what differences you can physically discern between your current setup and that and take one step at a time.

I will definitely be taking the steps one at a time and the end all plan is a ways away, which is why I was a bit leary of mentioning it in the first place due to the responses I knew I would get.

I realize that massive torque at low RPMs is harder on an engine that wasnt designed for it, but I dont see why I would snap a forged rod when modified 4 cyl diesels can do much more torque regularly and still be reliable. I am not really aiming for 400ft/lb at 2k, but I am aiming for a very flat and high torque band from <3k to redline.

 

[99gst_racer]

The idea sounds neat, but I'll be the first to say it's overkill for a small displacement engine trying to make less than 1200 HP. I love the turbo + supercharger idea, but you can easily make 6-700 WHP with room to grow with one turbo instead of the two. plus, two power adders will fit under the hood a little easier than three.

I've seen the 2 turbos + SC combo a few times, but they were always on larger displacement engines in the 1200-2000+ HP range. Amazing powerband though. Eye candy incoming!

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[drxlcarfreak]

Well honestly, I would like more power than 700, but dont think that even forged internals would hold up very well for very long at 900-1000HP much less 1200.

Those are some sexy twin charged setups there. I remember the second one I think from your thread or a thread on the yellowbullet forums? Both of those are parallel turbos compounded into a supercharger or vice-versa right? I am sure that you guys are right that the benefits are not worth the complexity, I just wanted to see if I could get a better response/higher top end power than the already great twincharge/compound turbo setups.

Paul, with twincharging in mind, would you still build an engine with 9:1 pistons or would you go with a lower compression ratio piston? I was thinking on a twincharged setup, because of the instant boost I think that something like the stock 1G 7.8:1 would work pretty well. It shouldnt have the noticable offboost lag and allow me to safely run higher boost.

 

[99gst_racer]

Well honestly, I would like more power than 700, but dont think that even forged internals would hold up very well for very long at 900-1000HP much less 1200.

Even if I were shooting for 1000 WHP, I'd still only use one turbo and one supercharger.

But at that level, I'd recommend a better rotating assembly than your average Wiseco piston and Eagle rod.

Those are some sexy twin charged setups there. I remember the second one I think from your thread or a thread on the yellowbullet forums? Both of those are parallel turbos compounded into a supercharger or vice-versa right? I am sure that you guys are right that the benefits are not worth the complexity, I just wanted to see if I could get a better response/higher top end power than the already great twincharge/compound turbo setups.

They're both from the compound thread on YB. The second one is the GM 4.2L I6 that they use in the Trailblazers and Envoys. IIRC, the guy kept having issues with snapping crankshafts on the dyno at around 1800 WHP.

Paul, with twincharging in mind, would you still build an engine with 9:1 pistons or would you go with a lower compression ratio piston? I was thinking on a twincharged setup, because of the instant boost I think that something like the stock 1G 7.8:1 would work pretty well. It shouldnt have the noticable offboost lag and allow me to safely run higher boost.

I honestly don't think CR will matter near as much, so it should probably be matched to whichever fuel will be used. I'd keep it in the 8:1-9:1 range. I know I never had issues with 9:1 pistons and 45 PSI boost, but I'm not sure how much boost pressure you plan to run (or will need to run) to hit your target HP.

 

[95AWD6Bolt]

More power to you if you actually achieve this setup in the future but imho, a 16 year old kid does not have the driving experience or maturity to handle 600+ hp. Plus, you probably dont have the coin to do so. With that being said, good luck my friend.

 

[99gst_racer]

I'm pretty sure the OP isn't 16 years old.

 

[phunny]

Well honestly, I would like more power than 700, but dont think that even forged internals would hold up very well for very long at 900-1000HP much less 1200.

Those are some sexy twin charged setups there. I remember the second one I think from your thread or a thread on the yellowbullet forums? Both of those are parallel turbos compounded into a supercharger or vice-versa right? I am sure that you guys are right that the benefits are not worth the complexity, I just wanted to see if I could get a better response/higher top end power than the already great twincharge/compound turbo setups.

Paul, with twincharging in mind, would you still build an engine with 9:1 pistons or would you go with a lower compression ratio piston? I was thinking on a twincharged setup, because of the instant boost I think that something like the stock 1G 7.8:1 would work pretty well. It shouldnt have the noticable offboost lag and allow me to safely run higher boost.

Have you every had the chance to ride in a 700hp vehicle? At those hp numbers you can take the price of what you'll have in the engine and multiply it it by 3 or 4 times. You'll need a transmission, drive shaft, axles, suspension, brakes, rims and tires that will at least try and get some traction and then your safety equipment. And all this if you just had a single turbo 700hp car, you through another power adder and you are just multiplying your cost and complexity.

 

[drxlcarfreak]

Even if I were shooting for 1000 WHP, I'd still only use one turbo and one supercharger.

Man, I just did a quick calculation on a 2.0L and 1000HP is around 85psig! That is a good bit of pressure...

But at that level, I'd recommend a better rotating assembly than your average Wiseco piston and Eagle rod.

What exactly would you go with at that point? I would rather do things once rather than buy them twice just to get where I want. Even if I "just" stay with 700hp, I figure with internals built to support 1000+ will make the engine more reliable/last longer. Something with a forged crank, rods and pistons
like this: EXTREME PSI : Your #1 Source for In Stock Performance Parts

They're both from the compound thread on YB. The second one is the GM 4.2L I6 that they use in the Trailblazers and Envoys. IIRC, the guy kept having issues with snapping crankshafts on the dyno at around 1800 WHP.

I remember reading about that. They abandoned the setup because it was too powerful for the engine!

I honestly don't think CR will matter near as much, so it should probably be matched to whichever fuel will be used. I'd keep it in the 8:1-9:1 range. I know I never had issues with 9:1 pistons and 45 PSI boost, but I'm not sure how much boost pressure you plan to run (or will need to run) to hit your target HP.

Right now I want to go as far as I can with 93 plus meth injection and maybe some octane boosters. It is my temporary DD right now until my Jetta is back on the road, so I dont want to be throwing money at my gas tank with race gas... at 18mpg on 93 its already expensive. Once I max out with that and get tired of playing with the tuning, I would probably begin garaging it more often and start using race gas, or E85 if I can find a station within 60 miles.

More power to you if you actually achieve this setup in the future but imho, a 16 year old kid does not have the driving experience or maturity to handle 600+ hp. Plus, you probably dont have the coin to do so. With that being said, good luck my friend.

Have you every had the chance to ride in a 700hp vehicle? At those hp numbers you can take the price of what you'll have in the engine and multiply it it by 3 or 4 times. You'll need a transmission, drive shaft, axles, suspension, brakes, rims and tires that will at least try and get some traction and then your safety equipment. And all this if you just had a single turbo 700hp car, you through another power adder and you are just multiplying your cost and complexity.

Yeah, definitely not a 16 yr old. I actually have saved up for awhile to begin this build and will be taking things slow, doing them step by step but hopefully only once. Not quite 700hp, but was in a 680hp Civic. It is what made me get an AWD car, as soon as boost hit he just spun through all of the gears. I do know price wise what I am getting into. I haven't really put it all down on paper yet, but I know what a stage 4 shep trans costs, forged internals etc. cost on their own.

 

[dsmornothing]

but I know what a stage 4 shep trans costs, forged internals etc. cost on their own.

I think with this setup you may want to look into going auto. Just sayin, Its going to be hell trying to drive this thing otherwise.

 

[bryanwheat]

How did you calculate 80+ psi being needed? Pressure doesn't make power, airflow does. Also i would first build a 400 horse setup before even attempting to go for anything more than that. You are way over complicating this. A good single turbo will be plenty.

 

[ed1380]

There are formulas using the ve of an engine to give you necessary numbers. I don't know them off the top of my head

 

[turboglenn]

a quick note.. the reason there's AWD trans for a 1g or 2g only is the mounting into the body(trans body/shell fits the corresponding year of car's mounting points, BUT a 2g FWD trans can be put into a 1g FWD car,, but that's the only compatibility there is between generations trans), 6 or 7 bolt engine only depends on your flywheel and modifying the front motor mount of the 7bolt to work on the 6 bolt engine since that's different between the 2 styles of bodies also

I won't run a 7 bolt, but the head design from the 2g 7 bolt is better for making a wider power band and just flows nicer even with smaller ports

The MAIN difference in reliability (even with swapped parts) is teh 7 bolts are known to kill thrust bearings and crank walk, there's many theories as to why but no one has pinned down a solid explanation or cure for that matter in all the years they've been out (15 years now and no one can take a crank walked 7 bolt and fix it to be worth building again, they are paperweights, and with the knowledge that some of the people have put into this and still no cure, well that makes me so NO THANK YOU)

Now a 6 bolt engine has a standard size main berings (as well as oversize for turned cranks) where a 7 bolt you have to read an ID from the block, then mic out that main journal on the crank and pick EACH main bearing individually this way, making a 6 bolt IMO much simpler, and easier to just "throw some bearings in" and be done with, picking each main by a journal ID and journal measurement, and THEN doing the standard clearance checking is more of a PITA than i want to put up with from an engine that may just spit the whole damn crank out the front of the engine by .080 -.100" (the worst case fo crankwalk i've measured was owned by V12killa on this forum and it was .087" out of spec (i mean you didn't even have to measure it it was so bad, you could push/pull the crank in and out by hand