HELP! Wanna Build Twin Turbo

calereeves · Post by **calereeves** » Sat Sep 01, 2001 12:09 am

Here's my story: I am resto-customizing a '68 bug for my daily driver (I'm 16). I want a monster engine, and I was thinking about a 2110 with my corvair spyder turbo. BUT, would it be plausible to run this engine on the street, OR could I opt for a smaller engine, say 1914, and run twin turbos from a motorcycle, or other small turbo? To do this, I dont want to run progressive turbos, I want two independant turbos. To run that, I was thinking that I could have a custom header built by a friend of my dad's who's a machinist for pretty cheap, and have the 1&3 cylinder going to one turbo and the 2&4 going to another. Then, I would have the turbos forcing air through an x-pipe to even out the pressure differential, if there is any and run dual dells., blow through style. How does that sound? Perfectly IMPOSSIBLE, or attainable goal? Thanks for your help. -Cale Reeves

P.S. I'm very good in math and science, so I actually know a little bit about the mechanics of turbocharging, I'm not just some speedfreak teen who sees turbocharged cars running 9's at the strip and decides he wants one. Thanks again. -Cale

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Fight 'til hell freezes over, then fight on the ice!

[This message has been edited by calereeves (edited 09-01-2001).]

GodofAtheism · Post by **GodofAtheism** » Sat Sep 01, 2001 12:21 am

The correct answer here is....

noone really knows. I started a discussion about this a while back. There was a guy running TT in a bug in france or something, but it apparantly worked like crap. So as soon as I get the money together, im going to try and get a working setup with dual motorcycle turbos. So basically, you'll jsut have to try it

Peter

Cam · Post by **Cam** » Sat Sep 01, 2001 2:54 am

I'd say in theory it will definately work. You'd without a doubt have to make it a blow-through system though.
Ultimately you'd want a proffesionally built 2007 or the like with forged EVERYTHING from a supplier like the bergs, (they'll sell you a 2007/2110 in kit form, and are the best on the market) a near stock cam, heltech EFI system (available in the berg kits, from memory) and I'd suggest doing abit more research into turbos before throwing your cash at random bike ones.
After finding compatible turbos (if you're buying second hand *not reccomended* get turbos off something thats already dual turbo charged i.e audi s series or many jap cars) hook everything... the reccomended way is having a turbo each cylinder bank with equipment to monitor boost on each turbo (every factory dual turbo set-up is done this way)
Then take it off to a 'rolling road' dyno and get someone with the knowledge and equipment to dial it all in and tune it all up electronically.
It would be an AWESOME pakage, and if you do it properly a very reliable one too.
But be prepared to spend big... and break transaxle parts if you drive it hard!

[This message has been edited by Cam (edited 09-01-2001).]

vw505 · Post by **vw505** » Sat Sep 01, 2001 2:54 pm

is the corvar turbo the one whith the side daft carb if it is and you have it it will work on you 1915 with out a wast gate i have seen it done and it ran in the 8,s 1/8 mile the small carb on it was the restricter but it was just right for the small motor.it also ran on the street with out a problem.

calereeves · Post by **calereeves** » Sat Sep 01, 2001 7:07 pm

thats cool, but I really want the twins

, however, if someone can dissuade me from the twin turbos, i'll just install my turbo and sidedraft and be done with it. Also, I'm a quarter-mile thinker, so what would a 8 in the 1/8 mile translate to in the quarter?

Cam · Post by **Cam** » Sat Sep 01, 2001 10:28 pm

The prob with the 1915 is the 94mm Barrels. They really would be too thin to run a hipo turbo application. Also a pull through turbo system is'nt exactly reccomended on aircooled engines, particularly if you want to go the sort of distance you're talking about without doing a re-build. You're better off spending the money on your drivetrain and saving up for a berg engine kit with haltech EFI (I checked for you and they are available in the kit)
As for the stroke argument. It's hard to find a company who makes forged 69mm. And you won't notice the difference between the 69 vs 78... I can't?!?!?! You can also run a lighter flywheel with a forged 78 more reliably than you could with a 69.

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Cam · Post by **Cam** » Sat Sep 01, 2001 10:30 pm

oh... by the way.
check out this link for good info on building air-cooled turbos:- http://clubvw.org.au/illawara.htm

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vw505 · Post by **vw505** » Sat Sep 01, 2001 10:47 pm

if you have the side draft use it and save your money for a motor and trans. yes 90.5 slugs &jugs are thicker and a 74 stroke will work just fine with more low end tq. to make up for turbo lag .build your motor trans. combo solid and use the turbo you have (for now) and school your self on the ins and outs of turbos with the small one (less broken parts)

[This message has been edited by vw505 (edited 09-02-2001).]

vw505 · Post by **vw505** » Sat Sep 01, 2001 10:50 pm

EFI=$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

calereeves · Post by **calereeves** » Sat Sep 01, 2001 11:40 pm

Thanks for your help but I have a few questions now. What are all of these expendatures your talking about, other than the price of the turbos, I estimate about 1700-2000 for the engine, about 200 for the custom headers(once again my dad knows a machinist)a 911 fanshroud(used) about 200 and an msd(also used for about 150). What am I missing here? Now for the questions...QUESTION #1: Couldnt I get a 1915 engine for way cheaper than the 2007, that would wrap up quicker than the 2007, due to the big bore, small stroke, and still get all the forged parts?

QUESTION #2: Would the 1915 engine produce enough exhaust gasses to run the twin turbo application, or is that the main reason for having the larger engine?

QUESTION #3: Would it be (A)cheaper and (B) more powerful run say the 2007 or the 2110 with my corvair spyder turbo, or a garett T03, or something of the like?

QUESTION #4: Would EITHER of these engines be a good daily driver that I can get at least 20K miles out of before I have to do a top end rebuild?
(last)QUESTION #5: (obvious question) Which one has the highest "cool factor"? Obviously, the twin turbo would kick ass on paper, but I want something that looks cool, sounds good, and runs FAST. I want to spank my brother's 92 camaro with an LT1 that only runs 14s every saturday night!

Thanks alot, and I'm sorry the post is so long, I just keep getting Ideas that seem like they're pretty good, and could possibly be done. Thanks again. ---Cale Reeves

Lo Cash John · Post by **Lo Cash John** » Sun Sep 02, 2001 7:38 am

If you realy want to know about twin turbos, contact Ron Lummas Racing. They just had a twin turbo speedster drag car in the shop not to long ago. It had EFI, MD-4 trans, you name it. If you want to see a low budget (less than $300 so far) single turbo system then checkout www.locashracing.org I'm guessing you don't have pockets deep enough for all that wonderfull Berg stuff (Who does??), but the truth is you don't need it. Just remember "Speed cost...How fast can you afford to go?" If you are realistic with your budget, and are resourceful at fabricating you can build a surprisingly cheap VW capable of blowing the doors off of a LOT of cars (V8s included).

Later, John

[This message has been edited by Lo Cash John (edited 09-02-2001).]

Cam · Post by **Cam** » Sun Sep 02, 2001 8:02 am

Turbo's = $$$$$$$$$$$$$$$$$$$$$$$$$$$$
Don't know how it is in the U.S but dual throat carbs down here are starting to cost a FORTUNE!!! And thats before you even get into venturi's, jet's, getting the things all synched up properly etc... So EFI is looking like a very viable option for anyone looking to make big power. And if you've done any research into hppi (aka the haltech style set-up) injection you'll know it has over 500 mixture pick up points, as oposed to a carb which has less than half a dozen.
EFI would also allow you to run with a more agressive cam grind than carbs would.
Personally I'd save up for the next however long until you can afford to get someone with the know-how and reputation to build you a motor. This is the only way to go with hi-po motors particularly turbos, besides you'll get a warranty with it which is an added bonus!
I don't know if you've ever built up an aircooled engine before and I don't want to make assumsions by any means. But if you're hell bent on hi-tech engine building start off with something a little bit smaller. Maybe pick-up a second-hand 1641 or 1776 with carbs and give it a full re-build. This will give you a much better chance to get your head around the workings of a fast spinning air-cooled engine. And the hands on experience, will be invaluable!
If you want your car to run 14's check out the speed and drag racing forum. All those guys are running those times, one of them even has a 1641.

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http://www.geocities.com/campbell_winks/

calereeves · Post by **calereeves** » Sun Sep 02, 2001 11:08 pm

Thanks guys, but I think I might have found a perfect "semi-prebuilt" twin setup. Its off of a 3rd gen. RX7 and has the exhaust inlet and outlet in between the two compressors. The only question I have is are they sequential or not, I've heard yes, I've heard no. I found one on ebay and I have the picture...

Jerry D · Post by **Jerry D** » Mon Sep 03, 2001 7:13 am

I disagree with you about not using 94's. The wall thickness of 94's is every bit as thick as it needs to be for many miles of "spirited driving" so to speak.
We have been running 94's on a turbo EFI street Manx at 18lbs. of boost (300hp) for 3 summers now (more then 10,000 miles) with absolutely no problems.
I am presently assembling a 2332 injected turbo for another Manx for the street.
94's are the only way to FLY.
Jerry...
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Cam:
<B>
The prob with the 1915 is the 94mm Barrels. They really would be too thin to run a hipo turbo application. Also a pull through turbo system is'nt exactly reccomended on aircooled engines, particularly if you want to go the sort of distance you're talking about without doing a re-build. You're better off spending the money on your drivetrain and saving up for a berg engine kit with haltech EFI (I checked for you and they are available in the kit)
As for the stroke argument. It's hard to find a company who makes forged 69mm. And you won't notice the difference between the 69 vs 78... I can't?!?!?! You can also run a lighter flywheel with a forged 78 more reliably than you could with a 69.

</B><HR></BLOCKQUOTE>

[This message has been edited by Jerry D (edited 09-03-2001).]

[This message has been edited by Jerry D (edited 09-03-2001).]

vw505 · Post by **vw505** » Mon Sep 03, 2001 2:35 pm

anyne know what mods need to be done to carbs i have 40 dells and 44webers and i am planning on a blow through supercharger