Turbos

Hey, let's talk turbos. I have been watching Lowbudget.coms draw through. Thinking in terms of a 1914 with the side draft dell. Yes, I've heard the draw-through = lag stuff, but from what I've read, guys that have it don't complain, they brag! What are other's thoughts?

Jack, @ shoptalkforums.com there is an active turbo crowd that hangs out and exchanges a lot of info. Turbo's sound like a great idea to me.

Jack, I

A recent Vw Trends magazine had a story on these bolt-on turbo kits. Granted the article was lame as are most of their articles (all bun, no meat). I would check with John C.

You can build a turbo engine that has no noticable lag at all. This requires a performance engine build with enough compression to make power without boost, then reducing maximum boost. A compression ratio of 8.5 to 1, 8 to 10 psi max boost, and turbo size and rotors that make 1 psi boost at 2,000 RPM and max boost at 6,000 RPM will have almost imperceptible lag time.

For carburetted engines draw-through is less hassle as you do not have to pressurize everything, but blow-through carb turbo systems work better when properly set up and maintained.

Undeniably the best turbo approach is with EFI which requires variable fuel pressure regulation to offset boost pressure.

Just to state the obvious:

Turbo engines require very careful cam selection. A long duration cam does NOT work well with a turbo setup (you get reverse pumping effect). Talk to people who have the same kind of setup you are going to try and find out what sort of cam they are using.

Since last spring I've run CB performance Ultra Compition FI with the hide out turbo on my 1914 which had approx 25000 miles on it at the time. Now 6000 miles later and tinkering with it, the pros are the grin factor has shot up due to power. Don't know if the double in HP claim is real but it is substancial.

The 1 5/8" merged exhaust and 48mm throttle bodies in them selves will add power to this size engine on the low side, as opposed to the Empi Kadrons and 1 3/8" merged & hide away muffler which was on the eng.

The TO3 turbo seems adequate as I don't feel a lag. I still have it set for 7 psi though believe I can go to 10 or 11 with out damage to my heads. Driving on Colorado high mtn. highways for a couple of hours or driving through Nebraska flat-lands at 75 or 80 for 10 hours I get a respectable 27 mpg.

However, in town I have been getting 13 mpg. The Cons of this set up is the non-programmability of the ECU. There are programable ECU types that are available and compatible with the CB hardware that I am looking into. (they don't come cheap but comparable to CB $ if you start off with and not have to replace it). Varying the fuel pressure and the timing are key to gassing the eng. under reg vac running and when on boost. The 4 knob tune box is seat O'the pants tuning which has not proved user friendly to me. From their sea level vantage point CB Perorm. has been some what helpful and the alt. maybe a factor in the poor in town milage. There is a "forced induction" forum available if any ony is interested. (on shoptalk)
Did not need the new eng. just the power. Next one will be built for the boost. 1hp to 9lb weight ratio is easily attainable.
Victor


(Message Edited 10/31/2002 1:43:52 AM)

Alan, that's not necessarily true. A lot of VW performance people are using normal performance cams (like the Web Cam 86B or 121/125 grinds) very successfully in turbo engines.

Engle has 3 cams that they call turbo grinds. And CB performance lists a couple of more Engle cams that they suggest are turbo...esque.? If I understand the figures correctly, they, in comparison to my 5 yr old #1 grind Engle hydraulic friendly cam, stay open longer and open further. Ergo, for my current 1914cc the turbo system is not optimized.? Wonder if I use a 1.2:1 lifter it would better fit the compressed air? Or would I be chasing the technological nightmare?

I visited Turbo City in Orange, CA and they can fit their turbo into my VS. Look at their detailed photos (www.turbocity.com), the sidedraft Weber with the air cleaner is tight and a squeeze on the right side, but it will fit.
It is an easy kit to install and with the low compression (1776) engine, shoudl make twice the horsepower. Everyone is suggesting a Kennedy clutch to replace the stock one due to the extra torque.
The people claim that turbo lag is negligible and it is validated in the VW Trends article in the November 2002 issue. Worth reading.

They make the turbo kits in batches and I expect to install one in the next month or so. I figure since I have to drop the engine to change the clutch, I'll install the kit at the same time. That's why they invented Saturdays.


(Message Edited 10/31/2002 9:01:24 PM)

By the way, you might want to stay away from wide lobe center cams with a turbo - Pat Downs (of CB Performance) builds lots of turbo engines and he has noticed that exhaust valves and seats generally run much hotter with wide lobe centers which can cause valve/seat failures even with high quality alloy exhaust valves made for turbo applications.

I read with interest the article in VW Trends. I seem to recall that they put the turbo in a MEXICAN crate motor. If they are truly as poor in quality as some have suggested, can it be just a matter of time before they blow it? Ask Jim Ward about his 1776cc that blew at 4500 rpm, right Jim?

Mexican crate motors have good engine case and cylinder head castings, but the crankshaft, connecting rods, and flywheel are cast steel instead of forged. A turbocharged type 1 VW engine that makes any kind of power and uses those components is a recipe for a grenade sooner or later, and very probably sooner.

Most of the VW turbo articles I've seen either have a single carb or some sort of fuel injection system. That's the only way it's done?
Curious two carb upgrades later...
MM

That's right John (H). At a short run of 4500 RPM and winding down for an exit ramp, that Mexican 1776 w/ Hyd Cam, spun the cam gear right off the cast cam and then rapidly came apart as the cam broke and parts started spitting through the case. Less than 3,000 miles, no real abuse, driven correctly, oil changes at 300 miles, 1,000, and 2800. Warrantied and replaced with a new AS41 case, Scat balanced crank and h rods, 8 doweled to 12 lb FW, Mahle Red Box 90,5s, CB Perf 044 Heads 40x37.5 three angeled, P&Pd, Dual Spgs, Engle 110, Straight Cut/Heat Treated Cam/Crank Gear, 009 With CompuFire and 8mm wires, Blue Coil. Remote Oil Cooler with Thermostat and manual bypass, and Fan with manual overide switch if thermo fails. Dual 34 ICTs with CB Perf's unique linkage and Filter base/top system for baby Webers, and intakes. CB 1 1/2" Merged system with 1 1/2" Heater boxes, and Dynomax Muffler. A nice reliable midrange scooter, that I hope to upgrade as soon as all these surgeries are done (maybe March). Pictures on this net and at www.dubudee.com

John, always enjoy your posts.

Jim

(Message Edited 11/1/2002 8:49:06 PM)

Hi Jim. Thanks and ditto. ;)
John H.

We have built two Turbo engines and both times started with a specific built 2110 from CB one has been apart twice due to driver error, read, Warm it up first and when racing a Ferarri at 120MPH if it pings back off a little. I took out a Z05 Corvette on a cool August morning with the boost only at 12 LBS. We have run it at 15 aand as a daily driver at 8. When you want HP start at the beginnig and work to the end, don't patch and hope to get it to work.

OK, you all spooked me for Halloween.

I hate to bring this up, but I am seriously considering the Turbo-City bolt-on kit. Are you all saying it is not a prudent installation unless I install some significant internal performance parts. I thought the 7-9 psi boost with a stock-type low compression engine (VS's 1776) would give me decent horsepower with little trouble. Anyone got thoughts on this conservative approach to turbo-izing?

(Message Edited 11/3/2002 11:44:17 AM)

Joe
I think that my turbo is the best thing that I did to the car sence I got it. Ask on shoptalk if you have not done so already for their input. Or search their archives for related systems and engines combos. Creating more HP & more stress on every thing, caution is good.
If you go turbo plan on getting rear disc brakes as well.
Victor

Jim Ward,
First off, hope you doing well! I was just curious... when your Mex 1776 went south of the border, did Kirk give you any feedback as to if it was a fluke @ 3K miles or was he experiencing a general failure?
Grassy S~R

The feedback on the Mex from VS and also the outfit in AZ that was importing the motors (maybe still are), and also the local gurus, is that the mexi engines run both ends of the spectrum.... they either hold together as advertised or they fall apart in short order. The reason is that there were a few bad castings in the cams, cam gears, and cranks.... those who were unlucky enough to get a bad casting soon found out... I talked to a local that bought a new mexi-bettle that didn't even make it out of AZ.... but the importer made good on the warranty, and a local builder replaced the guts with CB perf crank, hyd perf cam, rods and etc.

Bottom line? If yours has held together this long, then it's probably got the good castings, and will hold together as well as any engine with cast parts, import or domestic built.

Jim

PS. Thanks for the comment on health. I was about to get up to sp[eed on the post transplant health, and was up to a daily 5K, amongst other milestones, but had to have emergency surgery on 10/5 for an ulcerated intestine, because of some post transplant meds and the effect of eating hot peppers for years... anyway, they will do the second part of this in December, maybe early January. It was a bit of a downer, as I was just starting to really feel good, and.... oh, well, I'll be 100% by spring, with no issues to deal with medically. It's been a wild 3 years! But, I still feel lucky.

Jim www.dubudee.com

Jim,
Thank you for the background on the Mex motors! I e-mailed Kirk right after you posted the sad news but he must have been swamped and I've been curious since. I have not had any problems with my motor but then again it only has 600 miles. I'm sure Kirk will back it up as he has done with everything else.
When she does go.... I should have my ducks lined up for a Raby Special.

Hang in there Jim! You're still here 'cause you're a good man. Too bad we don't live closer. We'd have fun with our VS's and of course Medicine Man would make us laugh.
The best to you.
Fraternally,
VSBro

Hi All, I've been collecting[scavenging] parts for my turbo system for a couple of months. The systems [kits] are very easy to replicate using aftermarket/junkyard finds. Just match your displacement with
a mfg turbo car and adapt the exhaust tubing to suit your spdstr
eng. compartment. Not too much trouble considering the bene's. That vw article did not address the timing and air fuel ratio vs boost psi. Once these are addressed even greater reliability and
pleasures would result. Good luck!, Bruce

A good idea might be a dual-vacuum distributor; boost pressure should force retard to about 24 degrees BTDC at full boost. An MSD with all the bells and whistles would probably work well, too. There are several good books available on tubo applications and ignition considerations.

I road in a 3banger four wheeler that does the quarter in the 7's. but you guys don't want to hear about it. It's called cross technology. you could call me NASA Joe, but don't

The vacuum dizzy idea is working out for tubo boost timing. I found a used one off of a '73 type 1 for $20.00, after dismantling and cleaning every thing & adding a vacuum friendly Compufire elec. points unit...First road tests have been 'ping' free & acceleration friendly :) I have the vacuum off the manifold connected to the outside vac canister which seems to pull & push at the right times. (the other hose connection on the cannister is open)
I hope this holds true for the hotter summer months & when the snow tire are off. oldvolkshome.com lists distributors by the year and their specs. On another forum a writer sugests combining the best desired mech advance with the best vac can specs by changing the parts around, if you can find them.

(Message Edited 12/6/2002 1:50:34 AM)

THANKS Victor, you are verrrrry cool. Cool air in hot air out??? Ceramic coating helps to control introatmosperic temperatures, verry helpfull also.