Pick-a-part Turbo? Which car?

yupididit said:

I doubt the 2.7 Audi used vgt turbos. They're normally used in big diesel applications. Earlier someone suggested k03 and k04 turbos. They can be found cheap. As well as dsm t25's from turbo second generation mitsu eclipse/talon. The 14b are also small and cheap and can be found in first generation manual turbo eclipse/talon/laser, they're good for almost 300hp each on e85. I've personally sold 14b turbos for less than $100 bucks. 

OK I guess I’m confused.  I was led to believe that KO3’s were a VGT. If they aren’t then what the heck that’s my answer!   Grab  them from someplace that does the upgrades to KO4’s 

A pair should provide enough boost on 5.3. Liters Much better than a pair off Saab’s 

Here’s a question. If I run the exhaust from those and instead of dumping it outward ahead of the rear wheels dump it back underneath. Do you think the turbulence under the car would muffle it enough to get safely past the sound meter without any additional muffling? 

I know Turbos do quiet down the exhaust but it would be nice to skip the mufflers 

In reply to frenchyd :

Ha! My initial post about vgt was just a caveat on what to avoid. Go with those k03's if you can @

Do you mean rerouting the exhaust to dump out the back of the car instead of ahead of rear wheels? 

I'd look for a wrecked Subaru because almost every Subaru owner I've known who's upgraded their turbo has then totalled their car afterwards. So you'll probably find a GT35 hanging off of a wrecked EJ2507. 

In reply to yupididit :

Well the rules say it has to exit behind the driver 

so running the exhaust  along side the rocker panel and  turning under the chassis just in front of the rear wheel 

dumped under the car like that I want to believe  that the turbulence would in effect muffle the exhaust 

In reply to frenchyd :

Can't help you there buddy lol

In reply to yupididit :

I’m going to try it.  If it works I save the weight, bulk, cost, and restriction of mufflers.  If it doesn’t  I’ll just have to buy and deal with mufflers. 

Trouble is the only way to find out is go to the track and see.   I suppose I could have a back up plan of tailpipes and mufflers fabricated. Ready to install. 

I guess I could go to one of those SCCA track nights   and see.  Well, except if they don’t let me run I’ll have wasted the cost of getting to the track and the entry fee.   

Gee, my frugal nature cause a lot of problems. 

MazdaFace said:

I'd suggest ko4's preferably from a cobalt ss (off the lnf engine)

That really sounds promising. Exactly the information I was looking for. 

In reply to yupididit : 

while it would be possible to actually fit a single turbo in the engine compartment. I’m not afraid of cutting things open and then going back and reinforcing things to return the  strength back to the chassis . That’s just cut and fit work  

the problem is airflow. Air has to go someplace after it gets through the radiator or it stalls out.  The result is overheating.  

Using a tiny Alternator and one of those small power steering pumps with the remote fluid reservoir will improve that problem. 

That’s why I stuck the Turbo’s in the front fender getting them out of the way of airflow in my first version of this. 

I looked at those KO 3’s that’s a pair for a V6 .  To feed the V12 I’d need 4 of them. If I’m going to use 4 then the Saab is bigger. 4 would effectively feed 8 liters  

If you're not afraid to cut, don't be afraid to build an extractor (Mustang GT500 style) into the hood to help get air out from behind the radiator. 

For air to air vs air/water intercooling, the air/water setup can make your piping easier.  It means the intercooler (and associated large pipes) doesn't have to go up front, it can go wherever it fits best (with smaller water lines run to a radiator up front). 

rslifkin said:

If you're not afraid to cut, don't be afraid to build an extractor (Mustang GT500 style) into the hood to help get air out from behind the radiator. 

For air to air vs air/water intercooling, the air/water setup can make your piping easier.  It means the intercooler (and associated large pipes) doesn't have to go up front, it can go wherever it fits best (with smaller water lines run to a radiator up front). 

I think cutting the hood would detract from the Jaguars looks.  I think what I might do is when I flair the front fenders on the back side of the flair duct engine air out. 

Ducting out the back of the bay works.  The hood vents could be done neatly, but it would take a little planning to come up with something that looks good. 

In reply to rslifkin :

Plus if the duct is too far back the high pressure in front of the windshield might prevent air from escaping. 

On the XKE the rear two louvers allow air in only the fronts really help air exit. The drag on the Ferrari GTO was significantly higher than the XKE because of exactly that reason.  

I bring no specific knowledge to this discussion, but do have one question. If the engine bay is so crowded as to cause problems with heat and space for the turbos, how about a large truck Turbo in a rear mount set up?

From what I've read, rear mounts don't require an intercooler and it totally eliminates both the Heat and room under the hood issues.

The overall weight would probably be about the same, due to being able to eliminate the intercooler. The weight distribution would be superior to a conventional setup.

In reply to Floating Doc :

good idea.. don't eliminate the intercooler, but you'll have to worry about oil pumps and lines....  Oil starvation kills turbos...

In reply to Fueled by Caffeine :

It's been a few years since I read up on rear mount turbos, but I think I recall a dedicated oil system with it's own pump and the oil tank in the trunk of the car. 

In reply to Floating Doc :

A big single tends to take more time to spool up than smaller pairs. Thus turbo lag becomes serious. 

The trouble with rear mount turbos is the loss of heat. Heat is energy. Lose it at your peril. 

That’s  why I put the turbo’s  in the front fenders  out of the engine compartment but right next to it. 

frenchyd said:

In reply to Floating Doc :

A big single tends to take more time to spool up than smaller pairs. Thus turbo lag becomes serious. 

The trouble with rear mount turbos is the loss of heat. Heat is energy. Lose it at your peril. 

Thats why I put the turbo’s  in the front fenders 

Use a smaller, cheaper and easier to find turbo mounted in the rear.  Lag is less of an issue and heat is also your enemy as is the front heavy nature of a front engined car, especially one with a V12 stuffed in the nose.

Keep in mind:  Modern turbos are much more efficient and lag isn't as problematic as it used to be. 

In reply to Stefan : That’s why I put the turbo’s  in the front fenders.  Out of the engine compartment but right next to it so loss of heat won’t be an issue  

Floating Doc said:

I bring no specific knowledge to this discussion, but do have one question. If the engine bay is so crowded as to cause problems with heat and space for the turbos, how about a large truck Turbo in a rear mount set up?

From what I've read, rear mounts don't require an intercooler and it totally eliminates both the Heat and room under the hood issues.

The overall weight would probably be about the same, due to being able to eliminate the intercooler. The weight distribution would be superior to a conventional setup.

GRM tested airflow not long ago. A couple of things I learned is bends are the enemy of air flow and the longer the tube the greater the loss.  

Weight distribution would be slightly improved, but smaller turbo’s don’t weigh very much.  I’m guessing about 5 pounds each? Maybe 7?  

But total weight will be up. Exhaust tubing to go 12-15 feet times two plus intake tubing to go even further?   

However when I put them in the front fenders it was a simple U bend up to the turbo and a S bend back into the intake.  

I’m gamboling here.  When I built my first twin turbo’d Jag I just used gas, racing gas. To control detonation. I didn’t have a lot of boost 6-7 pounds.  And the compression was only 7.8-1 

I’m shooting for 15 pounds. But the compression will still be 7.8-1.  Now however I’ll be using E85!!

As you know Alcohol really cools an engine.   So much so that on cold days it can frost up so much the intake valve is blocked.  That’s right!  It’s actually been known to freeze up the intake on a running engine.  

So, all that tubing and bends plus getting through a intercooler.  Or a short shot right into the intake with alcohol to cool the charge?  

See the last time I bought E 85 it only cost $1.79.9 a gallon when 87 octane sells for between $2.43-$2.49.9 a gallon.   Race gas is over $7.00 a gallons!  

Fueled by Caffeine said:

In reply to Floating Doc :

good idea.. don't eliminate the intercooler, but you'll have to worry about oil pumps and lines....  Oil starvation kills turbos...

Really?  Is an intercooler really needed if alcohol is used? 

Sounds like the fender well and e85 plan is well thought out. Love to see track video when it's done. 

Floating Doc said:

Sounds like the fender well and e85 plan is well thought out. Love to see track video when it's done. 

Yep.  No changing his mind, he just wanted confirmation.

I really don't think turbo lag is gonna be a big issue on a v12.

In reply to simplecat :

I agree as long as I don’t try for too big a turbo.  However using cheap used turbo’s off small cars should be a safe move. 

frenchyd said:

Fueled by Caffeine said:

In reply to Floating Doc :

good idea.. don't eliminate the intercooler, but you'll have to worry about oil pumps and lines....  Oil starvation kills turbos...

Really?  Is an intercooler really needed if alcohol is used? 

I'd like to see an answer for this.  Yes the compression of the turbo will increase the heat but will the phase state change of the ethanol lower the  intake temperature that much?