Tuned IDI vs VR6.

[jaed_43725]

My IDI has a worked pump and a smaller turbo (no lag, and pushes 22 lbs). I did a 2.5" straight exhaust and opened up the intake a bit plus a lightweight flywheel and South Bend Stage II clutch. And I got a bunch of newer parts on it like a complete 16V brake setup. But anyway the thing that irritates me is that I really cant go past 70 mph with it. Additionally it is pretty crappy when trying to pass people. Off the line its ok. But as we all know that it runs out of steam about 3,500 rpm and up. So I was thinking about selling and moving to a VR6. I know I can get about 25 mpg highway (30+ with a TDI 5th gear which I plan on doing if I do go this direction). So between the 2 (my built IDI and a stockish VR6) what is the driving experience difference? Is the VR6 considerably bit quicker both off the line and passing (say 55 mph zone)? And what is a VR6 like on the highway (can you easily cruise at 75 mph uphill without the engine sounding like its going to fly apart)?

I have considered other cars like an Integra. But lets be honest here. If you are gonna get a FWD gasser it might as well be a VR6. And my first love is another WRX, but they are pretty expensive still (never should have sold mine) and will have to wait until I get a better job (and I will get another one no matter what one day (you just cant mess with the REX)).

[745 turbogreasel]

if you found a smaller than stock turbo, it's no wonder you top out at 65 or 70....

[jaed_43725]

if you found a smaller than stock turbo, it's no wonder you top out at 65 or 70....

Its not the turbo. Its just running out of engine at above 70. I can go to 75 for a bit but the revs are so high it sounds like its gonna explode. Its about 4K at 70.

[vanbcguy]

Sounds like you've got the wrong transmission...  Or you've got the crappy Ecodiesel trans.

My 1.6TD had absolutely no problem cruising along at 80 with my utility trailer loaded up.  Plenty of power left...  I'd be looking for a transmission with more appropriate gear ratios.  You should be around 3K RPM at 70.  I had a CHD, it was stock for the AAZ in the Mk3s.

[745 turbogreasel]

I'd say my IDI only really starts to pull at 3200 ???Which is about 73 MPH in 5th

[RabbitJockey]

if you can't go over 70 in a turbo diesel there is something terribly wrong with your car

[jaed_43725]

I thought I had the ACH but I am thinking I have the AVX. Although my car is not an eco-diesel, it must have had a swap then. And this would explain why my speedometer is constantly showing 9-10 mph slow. I guess I could need a ACN or CHD.

But back to the VR6. Anybody have some answers on those?

[EcoTX]

What is the "worked" pump you have, also what transmission do you actually have?  Look on the bottom of the bellhousing for us, it takes 5 seconds.

I have a ECOdiesel (8mm pump, K14 turbo @ 10 psi) and it will do every bit of 100MPH on the highway before it is RPM (and EGT) limited, but I keep it around 70-80 mostly because that's fast enough for me and I don't want any tickets.
It can hold 75MPH and even gain some speed if I floor it going up some slight rolling hills we have around here.
Mine also has no exhaust, just cut right after the downpipe.

Mine definitely has the MOST power above 2500-3000 RPM range.
When I drug it out of the barn about 4 years ago, in completely stock form it was very anemic and would struggle to do 70-75, and lose speed on hills big time.

Only thing I did to it was screw in the fuel a little bit, hammered on the pressure regulator a few taps to increase the internal pressure a bit to bring on more advance, and adjusted the timing.
It felt like I was driving a Corvette compared to a Taurus after that, it was completely different car.

Seems more and more people just read stuff on forums and don't actually know or want to learn to do stuff themselves and have their own opinion and way of things, they just blindly jump on the bandwagon.

You want a "fast" turbodiesel, here are the responses you'll get 90% of the time...

You MUST NEED a Giles pump if you want to go over 70, you MUST NEED 30 PSI of boost to get over 70, you MUST get rid of that "crappy" transmission, you MUST need to spend thousands of dollars in mods to go over 70
ANYTHING LESS AND YOU ARE NOT COOL AND SLOW AND STUPID AND NOT SCENE GTFO
 

Sounds like you've got the wrong transmission...  Or you've got the crappy Ecodiesel trans.

My 1.6TD had absolutely no problem cruising along at 80 with my utility trailer loaded up.  Plenty of power left...  I'd be looking for a transmission with more appropriate gear ratios.  You should be around 3K RPM at 70.  I had a CHD, it was stock for the AAZ in the Mk3s.

That "crappy Ecodiesel trans" is actually GREAT at making top end cruising power, with 185/60/14 stock tires you are at 3300 RPM at 70 MPH, and about 3800 RPM at 80.

A CHD with the same tires is 2800 @ 70 MPH and 3250 @ 80, I don't know how being higher in the power band at cruising speed is crappy, especially if you are wanting more top end passing power.

I think there is some "groupthink" left over from some very outspoken members of this forum that bashed on the AVX a lot, so everyone just started bashing on it because people saw "they" didn't like it for some reason, so it must just be a shi*ty transmission because "they" didn't approve of it.  I highly doubt any of them ever rowed the gears on one.

[TylerDurden]

I figure a poorly tuned vr6 can perform just as badly as a poorly tuned idi.

[RabbitJockey]

im curious what turbo is on it?  and whats the history of the engine?  does it start well?  have you checked timing

[RabbitJockey]

im curious what turbo is on it?  and whats the history of the engine?  does it start well?  have you checked timing

and yeah vr6's run great, it would have almost 3 times the power of a stock 1.6td, and a much wider powerband

[vwroadkill]

comparably, the vr6 is going to have more torque of the line and will pull and pull and pull, I think you get what I mean..
I have owned 5 vr6s... a well maintained vr6...regular oil changes , they effect the life of the chains for the valves. and cooling system kept up,ie crack pipe and water housing changed, expensive no.. just a pain in the ass to change when the go bad.
you can rev a stock vr6 to about 5800 after that things fall off. power wise
a built tdi is comparable, except for fuel mileage, fuel cost is nominal, premium fuel cost about what diesel costs today .
I just recently finished a build on a vr6 that put down 435 hp and 455 tq.. at the wheels... using stand alone fuel and ignition
factory ecu can handle maybe 255 before a tune is required, and all this with 19 in town and maybe 23 on the highway...
hope this helps on the vr6 side of the conversation... I recent found out for myself I don't know *** about diesels so good luck

[745 turbogreasel]

The last  two posts lead me to wonder why the VR6  isn't substantialy better power or MPG Vs my fullsize Dodge

[vwroadkill]

because inline engines don't get the fuel mileage.. and these engines love to be rev'd... and they sound sooo good
but anyways I understand the fuel mileage. versus a full size  truck. gearing could be the reason...

[Jaceb-GLI]

My ECO has 220k miles on it.

It has a K14 still, TD pump, boost controller, and a 2.25" TT with a Borla. Also has the AVX still. I bust off 45-50 average and it does NOT struggle to hit 100mph. Not sure what the problem with yours is.

I also have a 90k mile 92 Corrado VR..You're kind of comparing apples to oranges. They're both very fun to drive but I'm happier in the econobox everyday than I would be the "sports" car. (Even if it is sexier :-P)

Also, the VRad pulls strong past 6k in bone-stock configuration. Hardest pulling stock VR I have ever driven or been in.