Bottom End Questions

Ok, I've been lurking mostly since I joined, which was before I bought my TDI. I come from turbobricks.com and turbo volvo gas engines as my background.

I've got some questions about the bottom end of our engines. It seems very few folks here even dare touch the engine internals, so I haven't been able to find much from searches other than kerma's machined lip pistons.

Are there any aftermarket options for stronger pistons/rods/crank?

Are all the stock components forged?

Has anyone looked into custom pistons/rods/crank?

Trying to get a good feel for what the options are for building a properly strong bottom end before moving on. Seems the trend here is to look at shortblock improvements last, where as I think it's the first thing that should be done on the path to a true performance engine.

Thanks for the info.

How much power are you shooting for?

The internals are forged.

There are a few here that have custom rods, but they are spendy, TDIrs has some and I think Diesel des does too, but not sure there.

There are no aftermarket pistons/rods/cranks avalible that I know of but it's sort of irrelevent as I have never read of them failing in a properly tuned engine anyway, except for TDIrs who bent his rods slightly at what, 220 WHP?

Plenty of guys here are around 180 WHP with no bottom end issues, FWIW.

Did you sell your brick for an oil burner? If so, welcome to the dark side, FWD that is

Drivetrain is the first limiting factor, then the turbo, then the drivetrain, and by then you are somewhere around 400 ft-lb and 200 hp. One guy here on these boards is running 250-ish hp with stock internals. More than enough for just about anyone, especially when you consider that 90% of that power is available at ~2000 rpm and throughout the rev band.

Remember people buy HP and drive torque.
Or, as one guy put it,
"My lug nuts have more torque than your honda"

The lower internals as they come from the VW factory are already pretty damn good. The rotating assembly - crank, pistons, and rods -are balanced. Pistons are teflon coated skirts and oil cooled. The crank is forged. TDI-RS is the only one I've heard of breaking a crank, and he's generating crazy peak cylinder pressures with methanol.

Bottom end is not the weak link, at least as it comes from the factory.

What limits these motors making bigger power is the available range of timing advance in the injection pump.

Arn't there some stronger head bolts one can get? Or was it maybe a better head gasket?

Race-ware head bolts can be used , but i'm not shaw what torque/tension should be used.

mojogoes said:

Race-ware head bolts can be used , but i'm not shaw what torque/tension should be used.

Click to expand...

The ARP stuff is cheaper, here is a thread with more info on them.

There's a guy in Chattanooga that has a lot of bottom and top end work done, but I can't tell you his exact gains till he gets it re-dynoed. His last one had a ton of torque for the Hp...

Aluminum connecting rods?
Forged crank? (already have one stock)
Nyrod pushrods?

Interesting.

concave pistons for more displacement?

Verrry interesting.

I supose like Kerma's machined pistons.

The way he explained it to me is they are out of a Rally TDI engine - not sure on any specs or where he got them though... they may be specially made for all I know. I think the concave is to lower the compression ratio considering he's running 39PSI.

Unless I enjoy swapping con rods out every other week, there is no way I'm using (or even sourcing) them made from aluminum in a diesel engine. As The Meister is suggesting, someone may be blowing more smoke than his engine does.

A forged & balanced crank for $350? Where? Why? What's wrong with the OEM forged crank?

And can I see some pictures of those Nyrod pushrods? Are they metric? Are they kept in his glove compartment?

How do concave pistons net you increased displacement? I'd like to see some pics of those, too. Maybe my car is tricker than I thought...

I'm not sure any of his dollar amounts are right - $35 for tuliped valves?

GEMorris: if you're looking into modding the bottom end, why not spend the money on the inline 5 TDI and throw that in there? I'd fit like a glove!

Especially since OEM are about $30 each, IIRC.

Ryan when you suggested the same to your mate what did he say about the 5cylinder motor.

Allright, thanks for the responses guys, looks like the only real reason to tear into the bottom end is to have the lips on the pistons machined down like Kerma did.

Kerma, I'm assuming your first driveline upgrade you listed was for the clutch, what's the second? The diff?

Kerma has a automatic. He did a few things to it to keep it together with all the new power... there is a long post on his auto tranny mod if you care to see it.

I think I'll just find a huge shoehorn and try to wedge this in:

The Audi R10 v12 diesel with 600+HP and 1200+Ft/Lbs.

When did they come out with that beast?

Nevermind...I see that both Champion Racing & Joest are going to be running it. Sweet!

Im new to this forum. Was just looking for some info.

Now if I understand correctly the TDI = Turbo Jetta?

If so, and 220 WHP makes the internals bend, and have problems....And they run 17.9 STOCK! *** ARE YOU WASTING YOUR TIME FOR? These cars are GARBAGE....

knucks3man said:

Im new to this forum. .....These cars are GARBAGE....

Click to expand...

Great first post, good to have you here!

If these cars are Turbo, and only able to put 220 at the wheels MAX....y are you guys even trying? That is honestly SAD.

But if thats not the case let me know. And even worse, a stock 1/4 mile time of 17.9 ?!?!?! Are you joking?


lmao, my stock Acura Legend four door sedan runs 16.1

wow even i know to leave 9 month old posts alone and i'm a complete A$$HLE

Well knucks3man here is a stock jetta that beat you.
http://www.dragtimes.com/Volkswagen-Jetta-Timeslip-6114.html
Send him your pink slip when you get the chance.
But if I recall your Legend has a 3.2 liter V6 engine, ours have a 1.9L 4 cylinder.
200 horsepower out of an engine 59% the displacement of yours aint too shabby by my math.

I think what are numbers most of us like better are the 40 or 50 mpg which according to Consumer Guide is over twice your mileage.
And the number that a 1995 Acura Legend is worth maybe $3,000 based on cars.com
but if you can find a 1996 Passat TDI for sale you are going to have to pay twice as much.

Lets see .. in 10 years driving 15,000 miles a year that would mean my passat used 3400 gallons of fuel. Your Legend used 7500 .
And my fuel comes from a farmer in Kansas or a restaraunt in Kansas. Where does yours come from ?

knucks3man said:

If these cars are Turbo, and only able to put 220 at the wheels MAX....y are you guys even trying? That is honestly SAD.

But if thats not the case let me know. And even worse, a stock 1/4 mile time of 17.9 ?!?!?! Are you joking?


lmao, my stock Acura Legend four door sedan runs 16.1

Click to expand...

knucks3man said:

If these cars are Turbo, and only able to put 220 at the wheels MAX....y are you guys even trying? That is honestly SAD.

But if thats not the case let me know. And even worse, a stock 1/4 mile time of 17.9 ?!?!?! Are you joking?


lmao, my stock Acura Legend four door sedan runs 16.1

Click to expand...

You should try reading up on diesel engines. Turbo on a diesel is not the same as on a gasser, side note I have a buddy with a 2002 ford 7.3L that will eat just about anything on the road, camero ss, mustang GT, cobras, acura rsx(with turbo), they all lost. and to think his truck weights in at 8000 pounds.

Not sure what your red line is but try dropping it to 4800rpm. Then let us ALL know how your Legend is running at 300,000 miles on the clock?

more than likely won't be

Lol at you defending your cars with an economy arguement in a performance thread, and a performance oriented post.

Now thats sad that my 92 Legend will walk on your 00 Jetta. And the blue book on my 92 Legend is roughly 4500.

AND if your PROUD that you spend 10k + for a SLOW turbo car, that can't handle any boost or HP, be my guest lmao.

Ill just spend 3k and walk all over you.


Dont get me wrong, Legends are not FAST, but my point is that the jetta seems to be trash. 220WHP?! Are you serious? They made the car stock Turbo, and the internals are that ****ty? Damn shame you spend 10k for that pile....


They do look good though, I would drive one w/ a nice set of wheels and lowered a lil. But for the price you can suck off

LMFAO @ 300k statement. You have NO idea what you are talking about.

I have personally seen Legends with over 330 thousand miles. Acura's are well built, but this convo is not about my LEGEND.

This is about your ****ty turbo cars...

PERFORMANCE

Not economy and reliablility. Cuz a Legend will last, very well built.

knucks3man.. you should probably realise that the torque on these cars is close to double which mease someone with 160hp is running ~320ft/lbs... so now i ask you
A) how much horsepower and torque does your acura have?
B) while getting spanked on the track, does it bother your that the car doing the spanking is an economy car

oh and you should get you facts straight a little bit tdi= turbo direct injection (diesel) turbo jetta/golf= 1.8T which is even smaller displacement but comes stock with 180hp and can easily reach 400hp+

If you remember I did ASK what TDI was. And getting spanked?

They run 17.9 STOCK, Correct?

Legend = 16.1 STOCK, Fact. I've ran it.

And now onto GTI/Jetta 1.8....400 on stock internals? ??

But even then they are still slow when worked within reasonable spending. Went out with a GTI last year to some races, slow as balls. Sounds cool w/ the BOV though.


Wuts the aftermarket like for them?