TheSamba.com :: View topic - Light weight flywheel for turbo 2110 VW Sand Rail.

Thu Jun 14, 2012 5:12 pm

Just reaching out to see what people in the know say about running a light weight flywheel in a light somewhat underpowered turbo (2110 cc 6lbs. boost) Sand Rail that tends to bog at lower RPM's. What I'm saying is when I go riding with others in the dunes and they slow down at a sharp turn or dangerous obsticle I normally have to "catch" a lower gear to keep up with them especially when we are climbing hills. Just trying to eliminate the bogs (turbo lag) and unwanted shifting. It runs just fine on fast runs or climbing hills. It's just under loads in the lower RPM range.

Thanks,
Pat

Thu Jun 14, 2012 5:27 pm

What static compression ratio are you running?
Engine specs would also be helpful.

Thu Jun 14, 2012 7:32 pm

lostinbaja wrote: What static compression ratio are you running?
Engine specs would also be helpful.

7.36-1, max boost is 6 lbs. 82mm roller crank, stock rods, new 90.5 cylinders w/ new mahle pistons and 2 nd ring total seal. Bigger than stock heads and 1.25 rockers
and the good push rods. Holley 350 cfm 2 bbl carb with enrichment circuit to push more fuel under boost. Timing is locked at 20 degrees so I don't detonate under high rpm boost. Rairly go over 4K RPM. k runs best at 3500 to 4000 Rpm. Stock flywheel and HD pressure plate and HD disc. That's about it for the motor.

Thu Jun 14, 2012 7:39 pm

What cam?
Which power valve in that Holley, 35? 45?
Blow threw or draw?

Thu Jun 14, 2012 8:16 pm

SRP1 wrote: What cam?
Which power valve in that Holley, 35? 45?
Blow threw or draw?

Draw thru, engle turbo ts10 and I dont know the power valve. Based on what I have said witch one should I have for my app?

Thu Jun 14, 2012 9:13 pm

sandawg wrote: SRP1 wrote: What cam?
Which power valve in that Holley, 35? 45?
Blow threw or draw?

Draw thru, engle turbo ts10 and I dont know the power valve. Based on what I have said witch one should I have for my app?

That's just a W-110 on 112 centers, not to bad but still ok, I would not go bigger though if you do change it, smaller if anything.
Have you done any dyno work yet? In effort to tune in the combo you have.
Lag can also have a ton to do with the turbo your using.
How about running a wide band to see what your AFR is doing? The power valve will depend on your vacuum level, but a 45 should be about right, again depends on your vacuum level and jetting.

To answer your original question, yes a lightened flywheel will help with low speed throttle response and help RPM to pick up quicker and smoother.

Thu Jun 14, 2012 9:39 pm

SRP1 wrote: sandawg wrote: SRP1 wrote: What cam?
Which power valve in that Holley, 35? 45?
Blow threw or draw?

Draw thru, engle turbo ts10 and I dont know the power valve. Based on what I have said witch one should I have for my app?

That's just a W-110 on 112 centers, not to bad but still ok, I would not go bigger though if you do change it, smaller if anything.
Have you done any dyno work yet? In effort to tune in the combo you have.
Lag can also have a ton to do with the turbo your using.
How about running a wide band to see what your AFR is doing? The power valve will depend on your vacuum level, but a 45 should be about right, again depends on your vacuum level and jetting.

To answer your original question, yes a lightened flywheel will help with low speed throttle response and help RPM to pick up quicker and smoother.

I am through changing anything in this rig except the flywheel and possibly the power valve now. I'm done with changes! Just want the flywheel thing answered since the motor is on the stand and ready for the change if it's the right thing to do. I do run a wide band and AF meter and monitor i t pretty close and tend to run it on the rich side.
Thanks

Thu Jun 14, 2012 9:44 pm

Then put the lightened flywheel on it, yes it makes perfect sense.
Just don't expect it to make magic, all it will do is help by increasing throttle response.

To get to where you want to be, you need to put a wide band on it, and tune that sucker in.
Make the most of what you have, a dyno is best, but tuning in the car can work too if you now how to do it. Just take allot more effort.

Fri Jun 15, 2012 7:20 am

"I do run a wide band and AF meter and monitor i t pretty close and tend to run it on the rich side. "

He has one it seems! Also I see your locked out at 20 degrees, mechanically locked with a distributor? If you haven't played with timing already, I'd advance your timing a few degrees and see what that does. The best gains you could get from your set up I think would be in tuning, not just adding a lighter flywheel!

Fri Jun 15, 2012 8:54 am

74Superveedub wrote: "I do run a wide band and AF meter and monitor i t pretty close and tend to run it on the rich side. "

He has one it seems! Also I see your locked out at 20 degrees, mechanically locked with a distributor? If you haven't played with timing already, I'd advance your timing a few degrees and see what that does. The best gains you could get from your set up I think would be in tuning, not just adding a lighter flywheel!

From my constant research it says that timing that is to high leads to deetonation under boost and the timing should be retarded under boost. Ideallly I should have a retard ignition system b;ut that is about $1K and I'd have to get rid of the locked dist. and my compufire set up. That's not feasable for me.

Fri Jun 15, 2012 10:04 am

sandawg wrote: 74Superveedub wrote: "I do run a wide band and AF meter and monitor i t pretty close and tend to run it on the rich side. "

He has one it seems! Also I see your locked out at 20 degrees, mechanically locked with a distributor? If you haven't played with timing already, I'd advance your timing a few degrees and see what that does. The best gains you could get from your set up I think would be in tuning, not just adding a lighter flywheel!

From my constant research it says that timing that is to high leads to deetonation under boost and the timing should be retarded under boost. Ideallly I should have a retard ignition system b;ut that is about $1K and I'd have to get rid of the locked dist. and my compufire set up. That's not feasable for me.

The reason detonation happens is due to improper fueling, it sounds like you have fueling enough to handle a few more degrees. I'm not talking like 30 degrees, I'm talking literally a few more, 24 is a very common number that turbo guys run locked out. I've had mine Locked at 27-28 before without issue just running a regular Holley 350cfm with no enrichment (just ran a bit rich off boost).

I understand not wanting to change you ignition set up, but there are a few less expensive options out there. Here are some links just in case you'd like to look at them.

http://www.cbperformance.com/catalog.asp?ProductID=1855

http://www.autosportlabs.com/megajolte-p-41.html
(I personally run this, it's worlds away from a locked Dizzy)

But as I said earlier, you don't have to change your ignition, just bump it up a few degrees, if you don't like it you can always move it back.

Fri Jun 15, 2012 10:12 am

Running a lightened Flywheel will definitely wake up that engine but the real culpret whether you really want to hear it or not (You sound a little frustrated) is your static compression is too low for tooling around and the distributor needs to be unlocked.
Running anything in the 7's is more ideal for, in my opinion, drag racing.
The typical choices are:
low compresion/High boost (Drag racing)
medium compression/ medium boost (Street and all around)
high compression/ low boost (Pointless)

You have chosen the first scenario so your bottom end suffers when not on boost. This also makes your buggy a pain to drive when just tooling around off-boost.

If it were mine I would install a 12Lb flywheel, raise the CR up to 8-8.5:1, Run the boost to about 10 Lb's. unlock the distributor, limit it to 24 degrees, run High test pump gas and definitely find out where the afr is so you can tune it properlywhich does not mean rich.
Rich is just as bad as lean.

Fri Jun 15, 2012 10:16 am

I would lock the timing at 24*. Also running to aggressive of a paddle tire and tall or stock gearing will have a big affect on your low end bogging.

Fri Jun 15, 2012 11:19 am

yamaducci wrote: Running a lightened Flywheel will definitely wake up that engine but the real culpret whether you really want to hear it or not (You sound a little frustrated) is your static compression is too low for tooling around and the distributor needs to be unlocked.
Running anything in the 7's is more ideal for, in my opinion, drag racing.
The typical choices are:
low compresion/High boost (Drag racing)
medium compression/ medium boost (Street and all around)
high compression/ low boost (Pointless)

You have chosen the first scenario so your bottom end suffers when not on boost. This also makes your buggy a pain to drive when just tooling around off-boost.

If it were mine I would install a 12Lb flywheel, raise the CR up to 8-8.5:1, Run the boost to about 10 Lb's. unlock the distributor, limit it to 24 degrees, run High test pump gas and definitely find out where the afr is so you can tune it properlywhich does not mean rich.
Rich is just as bad as lean.

^^^^ I AGREE
I gave up going further because the poster was dead set on leaving the internals alone, but in reality the engine sounds a bit like a bastard combo.......ssssort of, it just does not fit the bill for dunning that's all, not all bad.
Me; 8.0:1, Engle VZ-14 cam on 110 centers, timing 12* idle 24* max, 10-12 psi boost, t3/4 turbo, 12lbs flywheel, 40 x 37.5 valve combo with a stage 1 P&P job on the ports (just good fluff and buff on 040 heads) Slap it on the dyno, dial it in, 275ish HP is an easy target yet very drivable in the dunes, blend in a little race fuel just for insurance purposes.

Fri Jun 15, 2012 11:45 am

TURBOEDVW wrote: I would lock the timing at 24*. .

Stop the madness! That is flat out bad advice so I am sorry I have to call that one out.

Fri Jun 15, 2012 12:00 pm

yamaducci wrote: TURBOEDVW wrote: I would lock the timing at 24*. .

Stop the madness! That is flat out bad advice so I am sorry I have to call that one out.

Locked timing does suck, back before I changed my ignition set up around, I was locked at 24-28 degrees. Such a pain in the ass to start the car, low rpm response was terrible as well. The best thing I ever did for my turbo was adding a worthy ignition system, it's 100% a different animal with correct timing.

Fri Jun 15, 2012 2:53 pm

I'm getting some good info but I need to clarify something. I am very pleased on how the rail runs in general. I have already assembled the motor less the flywheel.
I have blown the ring lands out on the first trip when I had 113 octane fuel in the motor on a hill under boost and at 4000 to 5000 RPMl and 5 or 6 lbs of boost.
The second problem occured when nuimber one cyclinder deformed and let the plug foul with oil getting by the stock rings. That's when I decided to drop the cc's to 2110 s o I could use the heavier walled 90.5's and install the total seal ring on the second groove.
In the first instance the builder misfigured the comp ratio and it was 9.3 to 1. I will be 70 next year and go to the dunes about 10 times a year. I just want to have a motor combo that will last and run on 100 octane fuel. I am ordering the lightened flywheel because it sounds like it might help some with quicker rev build and that sounds good to me.
Last chance to talk me out of the lightened flywheel for dune crusing and some semi fast hill climbs at sea lever and at 5k altitude. I have to stick to the locked timing but may turn it back up to 20-22 from the 18 I had backed it down from to help with detonation.
Great advice and a good thread in my humble opinion.

thanks to all

Pat.......The "Sandawg"

Fri Jun 15, 2012 3:12 pm

yamaducci wrote: TURBOEDVW wrote: I would lock the timing at 24*. .

Stop the madness! That is flat out bad advice so I am sorry I have to call that one out.

It is was it is. The owner said his timing is already locked which in most cases the distributor is unlockable or unsalvagable. So in his case he might as well lock it at 24* instead if 20*.I agree a limited advance distributor would be better but not enough to justify swapping. Unless he has another distributor available. I've ran a locked 009 in a buggy before and if anything the drive ability was more aggressive when locked then a limited distributor.

As far as running the lighter flywheel, I would say yes. Also run light aluminum rims and even playing with the tire air pressure can have an effect on things.

Fri Jun 15, 2012 3:14 pm

Go for the flywheel!

Fri Jun 15, 2012 3:47 pm

The reason I have to run the compufire ignition is that when the turbo set up was built there wan not enough clearance for a stock cap. The plug wires 90 degree connections were burning off from the heat off the headers. I talked to MSD about their set up but it needed a distributor that was to big or tall to work........"Oh woe is me" :-) I really appreciate the feed back folks........It's off to another season of duning before I drop! :lol: