Last Ride

Hey all. I have been toying with different ideas for adding power to my LT1. I want it to be a fairly aggressive street machine, but not too overboard. I keep coming back to the idea of twin turbos. I like them because of the ability to tune down the horsepower when someone else, my wife for example, is driving the car. I would also never have to refill a bottle. Could a twin turbo LT1 be built for say, less than $10,000? I am looking for somewhere in the neighborhood of 600 hp at its highest stage, so the numbers are not astronomical. I know I could also build a sout stroker or a supercharged motor, but I like the tunability of the turbos. I have heard that the reverse cooled heads make the LT1 a good choice for turbocharging. Is this true? I have also talked to Tom Nelson at http://www.nelsonracingengines.com and he said that they could build me a twin turbo LT1 no problem. We never got into the cost of that, but $16,000 for their twin turbo 350 "crate motor" was out of my range. I also figured that if I had to change to forged internals anyway, I may as well stroke the motor to 383 or 396 as they would cost roughly the same as a forged 350 kit. So what say you? Could such a motor be built using my LT1 as the platform, or should I put down the pipe and keep looking at other options? TIA,

zturbo

Sounds nice on paper to me but....
I just come to the thinking that will it fit?
Second thing if it was a race motor that would be fine having the turbos up top like that but what happens with all that heat next to the valve covers will it weaken your springs from the heat (remember temps of the exhaust get up to 1600 degrees :eek: )

The other thing is fitment with the downpipes where they are will they fit in your car? I dont know cause I am not sure what the engine bay looks like.

Do I think that it can be done on a lt1 sure why not. For that price gets a little close but prob.

Cost wise if done on a lt1...
5k rotating assembly.
for 304 tubing made up for headers like that prob 2-3k welded up etc..
heads another 2k (for above 300cfm)
computer 3k (with injectors)
turbos and (the deltagates) wastegates 2k

So you can see the price is right in there and if you throw in a block another 800 or so you are right about there.

Steven

DeenHylton

I haven't played with turbos since the seventies so don't take my opinion as gospel...you may be able to get the engine built with the twin turbo'sfor the 10K but to equip your car to handle the 600 HP or so will take thousands more. Your also going to need a modified tranny and converter, HD parts for the rear-end, half-shafts and drive-shaft, probably up-grade your cooling system, roll-bar/cage if your going to race, bigger wheels/tires etc.
My street-strip Vette which originaly started out as a $13,000-$15,000 project (purchase price plus original up-grades) is currently somewhere in the $25,000 plus range.

Last Ride

Deen--
I know what you mean about expensive projects. My biggest problem so far is paying for something twice: once where the guy screws it up and then again to have it put right! Yeah, the $10K number I threw out was for the motor alone. I plan on upgrading the transmission and rear end before this. I am also starting to research an unobtrusive roll bar that will allow me access to tracks once the hp goes up. I know I could build a nice supercharged motor for the above-mentioned price, but I think the twin turbo would be more trick! Thanks for the reply!

Last Ride

I think it would fit just eyeballing it, but I am not sure. It looks like there is a lot more room than the engine bay of either a C4 or Camaro.

What about mounting the turbos under the engine and using scavenge pumps to return the oild such as in the Lingenfelter setup?
Like I said, eyeballing the thing suggests it will fit, and I know there are a couple of custom C3 twin turbo cars out there (such as Monty's 427 SBC), but I can't say for sure. I have some crappy pictures of the engine bay on my website:
http://www.geocities.com/silvershark.geo/page2.html

I am trying to update the site with better pics, etc. By the way, the computer in no longer in the engine bay as displayed in the pics. Thanks for the reply!

zturbo

The scavenge pumps would work good i believe. One of the twin turbo cars out of the shop which is doing mine has the turbos way low and is using a scavenge pump/ dry sump pump.

Monty's setup is set more in front/to the side of the engine that on top of the motor (turbos)

I personally would look at building my own though with 2 t4 turbos they should be hitting numbers way higher than they are.

This car has the turbos set way low uses a scavenge pump and makes 900 hp if he wants (turbos are way too small for the motor)
[/URL] http://groups.msn.com/Zturbo/esrcars...to&PhotoID=229[/URL]
After seeing this car i have no doubt that you can twin turbo anything :D
Steven

dsagers

If you are looking for some pics of a Callaway TT, there is one on ebay at
http://cgi.ebay.com/ebaymotors/ws/eB...tem=1848526470

On his car, Callaway hung the turbos off of a shorty style header, used an external sump and pump to pull the oil out of the turbos and put the intercoolers above the valve covers.

I once measured the RayJay turbo that Gale Banks used on his TT SBC kits, and they will easily fit between the frame and the side of the engine. Use some good heat shield for the starter, and ceramic coating your headers.

Looks really tight under the hood, but if I were building a TT, this is the pattern I'd follow. Callaway must have invested mega bucks for the R&D, so why re-invent the wheel?

BTW, Callaway doesn't support the aftermarket, unless you have one of his cars, and you have a lot of $$$ to spend. I once called on an intake manifold he used for one of his speciality cars and was quoted $3200!!!!

redvetracr

Lastride,
I think if you were to ask Monty and possibly Merlin they would tell you the words "twin turbo" and "budget" do NOT go together!! EVER
..redvetracr

Monty

Ztrubo,

What do you means by this:
I personally would look at building my own though with 2 t4 turbos they should be hitting numbers way higher than they are.


I was wondering if you were referring to my TT setup, because I am only using 60-1 compressors, rated by PTE for 600hp each. Since I'm making 1200hp, I felt pretty good about the fact that I got their full potential on pumpgas, a non o-ringed block and headgaskets, and only 18psi of boost. Of course, since they are T04's, I could swap out the compressor wheels and housing for something bigger and make more power but I don't see the need.



[Modified by Monty, 1:33 PM 8/6/2002]

bill mcdonald

I just wanted to add some info to this.
Most headers shaped like that are called log style manifolds. I believe a shorty header would flow better then the callaway manifolds.
The scaveging pump was built right into the idler arm pulley.
The starter was actually rocked down in towards the engine to provide extra clearnece for the turbos. This is the tightest spot on the callaway car.

zturbo

monty
No was meaning nelson engine. I didnt mean your system. I think your system is making pretty damn good numbers for the 60-1's and i amagin can take a bunch more turbo on there.

Last Ride

Red-- I am beginning to agree with this comment. I am simply exploring possibilities for now. Some people have mentioned the use of boost controllers for twin turbo setups to allow drivers of different skills to drive the car at less boost. This may sound like a stupid question, but could a boost controller be used on a supercharged engine? That could be a less expensive alternative.

Last Ride

I used to have a RayJay turbo on the original L48. The manifold was pieced together, and it never ran very well, but it definitely fit.


I would love to keep the shorty-style headers I have now and tuck the turbos away for a stealth effect. I have plenty of room between the radiator and the engine to stash a pretty hefty intercooler. Why is it that this setup would cost so much? It seems simple enough, even though I am sure there is a lot I am not accounting for, but is it all the custom plumbing or what?

Monty

You should check out the "Power Adder" section of the Thirdgen site, http://www.thirdgen.org/techbb2/foru...?s=&forumid=15, there are several guys there that have successfully built budget turbo setups for less than $2000. There's a guy here in the Chicago area that made 983hp on the dyno at Fast Times with a 'junk yard' turbo buildup in a 5.0 Mustang. It might not be the prettiest thing in the world, but the power speaks for itself, it runs on pump gas, and supposedly this is his daily driver, http://members.telocity.com/~89proch...c/mustang.html . When I was building mine up, the guys at Fast Times told me about this car, they said the guy made the headers out of black iron pipe - the kind of sutff you use for plumbing natural gas into your home - it screws together!







[Modified by Monty, 9:01 AM 8/7/2002]

bill mcdonald

whaaa... :lol:
For reals?
Im going to check that out... :lol:

arnold

They are called 'weld els'. And no, they don't screw together. :) They can be a work of art, if fabricated with skill. No different than welding together a set of SS headers. For a street engine, I choose this type of exhaust extractor over SS. #1 choice would be cast iron, but it's tough getting those 'poured' to your specs, without paying a fortune for the limited run of sets. 1? The reason, durabiltiy. Not to take anything away from Monty or anyone else that chooses SS, but they are best suited for very limited street use or for racing purposes. The reason? It is no secret that SS has a high expansion rate, and thus a tendency to crack in durability requirements. Personally, not for me. But with the limited use, they may be ok for Monty. Of course, there is no question, when polished, SS is attractive, flows well, and not overly heavy. But as you can see, with some weld finishing and ceramic coated to a color of your choice, weld els can also be eye appealing. As for my durability scepticism, until Monty reports back at 10,000-15,000 mi. that the headers are still in one piece, ah, actually 2 pcs., I reserve judgement on giving SS my approval for the street. HTH
http://www.sdsefi.com/techheader.htm

Monty

Cast iron exhaust manifolds will also crack in turbo applications, ask any Turbo Buick owner. 321 stainless steel or Inconel is the choice material for turbo headers, and are much more resistant to cracking than the commonly used 304 stainless. A proper design that addresses the heat expansion that you mentioned, using stainless steel bellows and other flexible type joints help alleviate the thermal stress. Back purging the welds reduces weld contamination that would weaken the weld and contribute to cracking. Also, by using braces or brackets to support the turbo will help tremendously - you don't want the weight of the turbo to rest on the header.

Either material is acceptable and they all have their pro's and con's, but you're far more likely to see 321 or Inconel used on prefessionally built or high-end turbo applications, such as European sportscars.

I know of a few custom stainless steel header equipped turbo street cars that have several thousand miles on them with no cracking, not to mention all the 2000hp racing setups I see at Fast Times. I think it's a matter of using a good header layout, good welding process, and using heavy gauge/thick material. 16 gauge tubing and 3/8" flanges will obviously last alot longer than commonly used 18gauge and 1/4" materials. Regardless, even if a crack or two do develop, it ain't nothing I can fix with my TIG welder.

As for my claim the Ronnie rice's turbo headers were built using black iron pipe - that's what I've been told by at least 3 different people. They guy's at Fast Times told me about Rice's setup when I first started designing/building mine, and they told me his headers were made using black iron pipe from Home Depot. I figure they probably know since they are friends with him and helped him build and dyno test the engine. The claim was also repeated to me by another guy who is supposedly a personal friend of Rice's. I don't know for sure as I don't know the guy and have never seen his car firsthand, but the general consensus I've heard from a few people is that it was ultra-low budget, made 980+hp on pump gas, and he drives the thing all over Chicago on a regular basis. TIG-welding the weld-el's as you linked to is certainly an inexpensive, yet effective option, I was just led to beleive that Rice's car was even lower budget (yet highly effective).



[Modified by Monty, 2:02 PM 8/10/2002]