Down the turbo rabbit hole

[allamaabroad]

My current motor is alright, it makes decent power, decent gas mileage, surprises some people here and there...but of course, I want more...

So i was thinking about starting on a project for this winter, something to keep me busy during fall and spring semester, and I stumbled across this thread:
https://www.thesamba.com/vw/forum/viewtopic.php?t=...p;start=60

I think it's about time I build a turbo motor.

Current motor is a pretty mild 1915, 110 cam, ported 041 heads, 1.25 rockers, 40 webers, 1.5" sidewinder exhaust, magnaspark digital w/ vacuum reference.

However, this motor has been plagued with some top end issues (Sinking valve seats, dropped valves, all sorts of nightmares) So I will also be tearing the whole thing down to make some changes.

Here's what I'm thinking:

What I already have:
AS41 case, first align bore, less than first thrust, FF, case savers, cut for 94s
Full set of engine tin
Full weight flywheel
40 IDFs
Magnaspark Digital Dist (Vacuum/Boost reference)
1.5 inch sidewinder header
1.25 ratio rockers
1 quart deep sump

To get:
New Heads (Panchitos or AA 500 casting 40x35)
76 or 82 mm crank
H beam rods
92TW or 94mm piston/cylinders
Engle TC30 w/1.25's or FK-8 w/1.4's
CB turbo intake parts (carb hats and intake piping)
Turbo
Boost reference fuel pressure reg

I'm open to changes or suggestions on anything above. There are a few specific things I'd like to know, however. Keep in mind that I'm trying to use what I have and keep this relatively low budget.
1. I think I already know the answer to this, but is it worth the extra cash to get panchitos for a turbo engine? The cost difference isn't huge, but money

2. I'm wanting to replace my current crankshaft, and as far as I'm concerned, bigger stroke is the same price as smaller stroke. Since I'm planning on sticking with a stock case, blow through 40 idfs, and 92 or 94mm pistons, what stroke would be good to get a nice displacement for this engine?

3. This is a little down the road, but options for a good turbo cam?

4. Target compression ratio for turbo motor?

5. Turbo sizing (depends on displacement) ?

I look forward to getting some advice from all you turbo gurus, and I'm super excited to join the turbo gang and start pissing off some muscle cars
_________________
Dennis - 1973 Super Beetle ('16-'21)
Debbie- 1970 Baywindow Bus ('21 - Present)
Tin top camper/adventure bus

2180 TW: CNC Panchitos, Beehives Done Right, Web 163, Ultralight Lifters, 1.3 Rockers, CSP Python, Custom Speeduino EFI Conversion with 40mm Throttle Bodies

Distributors are lame

I have a really hard time leaving things alone...

Innovative and affordable engine management systems and EFI conversions for your Vintage VW
Visit https://debbiesaircooled.com/

[rayjay]

I eventually would like to go turbo but the first step will be FI probably MS. I will basically build a turbo set up but leave the turbo off until I prove to myself that I can come to grips with MS. Once I have MS mastered then the turbo gets plumbed in and

[BFB]

KISS. like a lot of things these days, i think ppl over complicate things.
i say boost whatcha got for now so you can learn, then build a new engine. 1 you already know the engine you have and will be able to tune it easier.2 you will have a good " pre boost" base feeling so you get an Idea of how much that turbo is actually doing. and 3 if you blow up your current engine no big loss because you planned to build another anyhow
_________________
Forced induction can overcome a lot of obsticles that gets in it's way
"You are the Engineer and the Mechanic.  
Build it your way not the way someone else does it. Their way might not work for you." - clonebug
An interesting thing happens in forums where everyone starts parroting the same thing and "common knowledge" takes over.
“ The monkey see monkey do mentality seems to run deep in VW people. "Gene Berg said it was so 30 years ago so thats the way it is" “ - bdkw1

[Chickensoup]

i say, dont boost whatchagot. you have thin cylinders, tighter ring gaps. failing heads, and a w110. not a good turbo build.

dont waste your time with smaller strokes. i did. not happy. but a turbo will make up for the tourqes. i think with 82mm you can use stock length rods, and b pistons and have a stock width engine, if yours hasnt been decked too much. or you can go shorter stroke, longer rods, which turbos like. get the thicker cylinders. thick wall 92's. cb has a few turbo grinds. look for a cam with a wider lobe separation angle like 112. less overlap. there are other brands as well. run, dont walk away from the empi cams.
_________________
-'85 c10 5.3 LS, 222 cam, long tubes, x pipe, 3 inch spin tech's
-'05 B5.5 TDI Wagon 17in sport rims ;EGR + BSM + ASV Delete, Stage-2 Tune, straight pipe
'65 Tourist Delivery Build
'66 RIP
'69 RIP
Hosea 4:6 "My people are destroyed for lack of knowledge"

[buguy]

I would have no problems boosting those cylinders or the cam. Cam may not be ideal, but it will certainly work.
The heads are a different story. Have to have good heads. Or at least heads that are in good shape. If you have the cash you probably won't do much better than Pachitos. I bought AA heads because it was Xmas time and got them for like $400 for the pair. Panchitos were out of stock and i wasn't willing to wait (they were back in stock 3 days after i ordered my AA's).
Rings can be filed. Although, if you have some miles on them, they may not need it. I would check for sure.
I do agree, i would build as big a stroker as you can. No real difference in cost.
Rockers you will have to match to whatever cam. If you have sold shafts i wouldn't bother with 1.25's if you use the 110. You would have to buy the rockers, lash caps, and pushrods $$. If your going to go through all that i would probably consider the fk43 and 1.4's.FK8 if you go stroker. Maybe something like 8:1 compression if your running pump gas.
A few of us are running the TD04-13t from a WRX with very good results. They are cheap and easy to find. Would work great on a 1915. Any more displacement and you might need something else. All depends on your goals.
Also consider water/meth injection. Gotta keep those intake temps down (plus you can run more boost)

[allamaabroad]

Thanks for all the replies, guys!

Here's what I'm thinking now

2180 (82x92TW)
CB 82mm crank
AA TW 92 Stroker P&C (forged?)
5.4 Unitech rods
Panchitos w/ dual springs, possibly CNC chambers to get 61cc chambers, that would put me at 8.6-8.8:1 CR with a deck height around .055
FK 8 w/ CB 1.4 rockers

.50/.63 trim T3 turbo (probably ebay)
Boosting through 40 idfs, possibly on type 3 manifolds to save space
Ebay water/meth injection kit (Controlled by boost)

Now to start donating plasma so I can afford all this in a few months
_________________
Dennis - 1973 Super Beetle ('16-'21)
Debbie- 1970 Baywindow Bus ('21 - Present)
Tin top camper/adventure bus

2180 TW: CNC Panchitos, Beehives Done Right, Web 163, Ultralight Lifters, 1.3 Rockers, CSP Python, Custom Speeduino EFI Conversion with 40mm Throttle Bodies

Distributors are lame

I have a really hard time leaving things alone...

Innovative and affordable engine management systems and EFI conversions for your Vintage VW
Visit https://debbiesaircooled.com/

[Chickensoup]

forged pistons
_________________
-'85 c10 5.3 LS, 222 cam, long tubes, x pipe, 3 inch spin tech's
-'05 B5.5 TDI Wagon 17in sport rims ;EGR + BSM + ASV Delete, Stage-2 Tune, straight pipe
'65 Tourist Delivery Build
'66 RIP
'69 RIP
Hosea 4:6 "My people are destroyed for lack of knowledge"

[vwracerdave]

I hate to be an ass but you have way too many cheap parts for a boosted engine. several may be good enough for a 140 HP NA engine but not strong enough for a 250 HP boosted engine.

I'm not sure 40 IDF's are gonna be big enough.
_________________
2017 Street Comp Champion - Thunder Valley Raceway Park - Noble, OK
2010 Sportsman ET Champion - Mid-America Dragway - Arkansas City, KS
1997 Sportsman ET Champion - Thunder Valley Raceway Park - Noble ,OK

[Chickensoup]

[allamaabroad]

[UK Luke 72]

78m crank
92mm thickwalls
3/8" ARP road bolts in CB H beams
Wiseco forged pistons

Maybe speak to AJ Sims @Lowbugget about heads/cam and turbo?
_________________
2276 Beetle build https://www.thesamba.com/vw/forum/viewtopic.php?t=670744&highlight=2276+beetle+daily
2276 EFI Conversion https://www.thesamba.com/vw/forum/viewtopic.php?t=689172

[madmike]

my 2 cents,, grab that 82mm bugpack crank Dan has in the classifieds
Porsche jornal has less flex or like Luke said 78mm
FK10 cam or the fk 8 don't fart around with 'turbo cams'
yes on the TW 92 ,I've cracked a few 94's trying to tune
forged pistons are almost a must
good rods too, although my 1915 has 'stock rods' and work fine,deep sump helps !
them 40 idf's will hold you back with only 10-12 lbs. of boost before the throttle shaft's leak, I would slap them on the shelf and find a nice 680 quick fuel Holley and mod it,,I'm getting 28 mpg and runs 11 second 1/4 mile times
as for head's any decent big valve head will work,, I've been using/boosting 044's for about 5 years without any issues, come over to www.shoptalkforums.com and check out forced induction section,lots of info ya their,, cheers madmike
_________________
'Black Ice'Drag Buggy 'Turbo'
Rail Buggy 1915 turbo
76 Drag/Street bug 2180cc 'Turbo' 11:85 @113 mph"If I go any faster I'll burn up the Hamster" ,gets 28 mpg. also 10/09/22 11.90 @115 mph
"If I'm ever on Life Support,UNPLUG Me, Then Plug me back In see if that Works"

[BFB]

im not sure why i even read these type of threads, recon i just love the turbo shit too much. but its always the same thing, you get opinions form one end of the spectrum to the other. ppl like me who put 20lbs to a stock engine and say just go for it and all the way to the other side who will say only use all forged parts and gotta go FI.
as you can see there's a thousand ways to go and doesnt mean anyone is wrong. ive said before it all depends on your tuning capabilities, what one guy can boost thin walls to another guy may destroy forged parts at.
build it how u want to build it and boost it until your scared to boost any more!
_________________
Forced induction can overcome a lot of obsticles that gets in it's way
"You are the Engineer and the Mechanic.  
Build it your way not the way someone else does it. Their way might not work for you." - clonebug
An interesting thing happens in forums where everyone starts parroting the same thing and "common knowledge" takes over.
“ The monkey see monkey do mentality seems to run deep in VW people. "Gene Berg said it was so 30 years ago so thats the way it is" “ - bdkw1

[Ohio Tom]

My additions:

If you run forged pistons, you need to hone the cyls to .005-.006" clearance or you will scuff the skirts.
Also ring gaps have to be bigger, or you will swell the rings and cause interference.
Cast pistons can work up to 18psi with no problem.

Cams with wider LSA's. 112deg. are nice because they bring more vacuum to the low end and they help to spool a turbo. It has more to do with the "un-favoarable" pressure ratio that most VW applications run into.
Unless you have a high dollar (ball bearing) turbo, a wide LSA cam is a good idea.

Don't over-cam a turbo motor. you will just end up with lots of Lag.
FK-10 is not going to make any boost until 3,800rpm.
I like to stay under 300deg advertised duration for street.

Exh valve guides need to be trimmed back flush to the port, or you will melt the guides.

Keep the boost at a reasonable number. Going too high will bend wristpins, hammer rods, destroy rod bearings, melt pistons.
Gotta upgrade those things if you want to put some serious boost to it.

Good idea to sneak up on your boost as you go. You will make mistakes. They can be costly.

Keep it simple. Diving in with EFI,.. and a turbo at the same time is not for the weary. There is a significant learning curve with EFI that you don't want to experiment on your expensive motor with.

I suggest going draw thru for your first system. Simple to work on and troubleshoot.

Go big as you can. With each decision to go bigger, you can run less boost and still make lots of power.
A 2332cc motor at 10psi on pump gas is north of 200hp. It will scare you..
10psi is un-likely to hurt it too..

[vwracerdave]

[buguy]

It's worth it! The first time you feel that turbo pull you will be hooked!

[allamaabroad]

Did some shopping on the classifieds, found a nice set of Wiseco forged 94mm pistons with 5.5 h beam chevy rods with ARP bolts. I should be able to reuse my current 94mm cylinders, probably get them honed to get proper clearance with the wisecos, and throw it together with a 78.4mm crank for a nice 2176cc.
_________________
Dennis - 1973 Super Beetle ('16-'21)
Debbie- 1970 Baywindow Bus ('21 - Present)
Tin top camper/adventure bus

2180 TW: CNC Panchitos, Beehives Done Right, Web 163, Ultralight Lifters, 1.3 Rockers, CSP Python, Custom Speeduino EFI Conversion with 40mm Throttle Bodies

Distributors are lame

I have a really hard time leaving things alone...

Innovative and affordable engine management systems and EFI conversions for your Vintage VW
Visit https://debbiesaircooled.com/

[buguy]

That should work. Be on the lookout for a wideband AFR set up too.

[allamaabroad]

[buguy]

Are you going to buy a turbo header or make one?