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,

Black'92

Last Ride,
I am also interested on this. If I could come up with a twin turbo setup for around 10K I would do it in a heartbeat. But like you having to beef up the bottom end I would most likely go with a 383 with a 8.5:1 CR. But once again that would also drive the price up even more. Did you talk to Nelson Racing? If they actually worked on your car instead of dropping in a crate motor about how much will this cost? Ball Park?

BubbleHead

To add a little something, Summit has an all forged stroker kit for right around $1800.

I think to keep the price down, you would have to do a majority of the work yourself. I would love to have a TT LT1 with massive amounts of HP and torque on demand.

You maybe better off going with a built and supercharged LT1. I'm thinking of building a bored and stroked LT1 with tons of boost. It's all an idea right now but, when I have the funds, we will see what happens.



[Modified by BubbleHead, 3:31 PM 8/5/2002]

Last Ride

We never got around to talking about the cost of a build-up using my LT1. The crate motor cost $16,000 and came with everything but the plumbing for the intercooler. I want to stick with the LT1 as I have only recently got it running well in my car. Once again, big ups to the VETTEWRENCH for making that a possibility! By the way, Tim, have you guys ever thought about a buildup such as the twin turbo in question? No doubt I will be back up to you guys when the time comes to build my engine no matter what it will be.

Light84vette

Wow ten thousand $$. I was planing on putting a twin turbo setup in my 1984 Corvette then I started to think about it only gives a significant amount of power at higher RPMS. So I just added up the prices that I would have to pay for this setup and it cost me $6,200(plus the fab, myself). Around 2K for heads and forged everything, 1.5K for the turbos, .75K for the wastegates and .5K for intake mods( X-ram) 750 injectors and around 600 or 700 intercooler. Then I planned on using a 700r tranny for $1,500 with converter, going for 800hp. If its Above 10K or 13K and they dont forge all the rotating parts and dont make anything close to this number thier just BS you. :bs

Ken Lanham

600 HP would be a peice of cake for $10,000. I could fabricate full stainless steel headers and downpipes, build a full boogie intercooler, and use very nice ball bearing turbos on the car for that kind of money. What is the HP limit of the stock LT1 bottom end? The compression may be dropped low enough with a simple piston swap. Freshen the bottom end while you are in there. The fact is that turbos make their torque at a low rpm and you don't have to rev the motor to make power. So you don't have to run exotic rotating assembly parts for moderate power cars. Though forged pistons are a good idea. I wouldn't do any work to an LT1 induction tract if you are turbocharging. Use the stock heads, stock cam, stock intake. It is all sufficient for 500+ HP from turbos.

-Ken

Light84vette

at http://www.persicionte.com they have a bunch of turbos that can make your Engine produce up to 1200hp, the only thing holding you back is your tranny and diff. :yesnod:


[Modified by Light84vette, 3:54 AM 9/27/2002]

BubbleHead

YES, I think about it nearly everyday! :D I'm looking around a little right now and have been reading up on turbos when I find the time. Over the winter I'm hoping to dedicate more time to it and will probably contact other engine builders with turbo experience. I want to get some ideas on what would be needed and total cost. That's going to be the deciding fact.

I'll keep you posted with what I figure out. It won't be an overnight thing but, I feel there is some possibility there. Not all of us can afford a brand new Vette then pay LPE $45K for a twin turbo set-up. :( :lol:

Monty

That is not true, turbo's are actually very effective at creating tremendous amounts of power at low to mid-rpm ranges, it just depends on the size of the turbo, the A/R ratio of the turbine, and the size of the engine the turbo is working with. Unfortunately, most people seem to believe that turbo's are high-rpm power adders, probably due to the fact that most people's first impression of a turbocharged car was an import using a small displacment engine that doesn't create enough exhaust energy to spool the turbo up until higher rpms. A properly sized and designed turbo system will produce significant amount of low rpm torque if that's what you want. It's ironic, because centrifugal superchargers are actually more of a higher-rpm power adder, usually producing maximum boost at around 90% of engine redline, but for some reason inexperienced people seem to think turbo's are.

My twin turbo SBC 427 makes 700 ft lbs of torque at just over 3000 rpms. With a 3200 rpm converter, it pulls hard right off the line with no lag. Another benefit of turbo's is that they create a much wider torque cruve, creating more area under the curve (torque). Once the turbo's get spooled up, they can create significant amount of boost and torque over a much wider rpm range than centrifugal superchargers. My setup produces between 700 and 1000 ft lbs from 3000-7000rpm, peaking at 1000 ft lbs at 6100 rpm, and still over 900 ft lbs at 7000 rpm (self-imposed redline).

BTW, while ball-bearing turbo's are nice to have, but not necessary for racing, their benefits on the street are still questionable, and their is concern among many professional turbo builders/shops that they are not as ideal for street use due to reliability issues. I'm using a pair of 60-1's, which only cost $675 each, and a pair of HKS wastegates that are only $250 each. The turbo's, wastegates, and BOV's are not the expensive part, it's the headers and intercooler. I used 16 gauge 321 stainless steel tubing and flanges for my headers, and the materials totalled over $1500. Luckily, I built most of it myself, but if a shop were to do it, they might charge as much as $6000+ in labor, as it isn't unrealistic to assume it would take as long as 100 hours to design, fabricate, and install.

Light84vette

Thanks Monty for the info. I am just torn between putting a supercharger or a Twin turbo setup. Now I'm thinking about using a 468ci Big Block and maybe use the Twin turbo setup. But where is a good place to put the Turbos on a C-4? That would be easy to place in and fabricate the headers and tubing easily.

Monty

I really can't give you experienced advice with regards to a C4 in particular, but I would suggest that you checkout John Meaney's TT '88. Between him and Troy Trepanier, you can't go wrong with cloning his setup.

The choice between whether to go with a turbo or supercharger setup boils down to you personall preference in terms of budget/cost, performance, and simplicity. There's not doubt that a centirfugal supercharger setup offers lower cost and easier installation, while providing amazing performance. However, if your budget, tenacity, and patience allows, a turbocharged setup provides superior performance and unmatched "WOW" appeal.

I forgot to suggest you check out this guys TT C4. I've been helping him since last spring with his setup, and he's almost done - it's going to be an awesome system. http://www.jdhcon.com/vette


[Modified by Monty, 10:02 AM 9/24/2002]

Last Ride

I can't get this link to work! :confused:

Ken Lanham

I think the company being eluded to here is precision turbo. So try spelling precision correctly in that URL and see if it works.

-Ken :seeya

Light84vette

My bad For the typo :flag

Last Ride

Just another thought on this: Could a system be built around a stock LT1 for now just to get plumbing sorted out and get a good power boost, then rebuild the LT1 geared towards the turbos for even more power? Again, I am not looking for astronomical power, but I figure if Lingenfelter can pull 550 hp on a stock LS1 and a pair of hair dryers, what would stop someone from doing something similar on an LT1? What turbos should I be looking at for something like that? Any thoughts or comments? :cheers:

Light84vette

I'm not sure of how much the C/R is on a stock LT1 but you can run 8psi intercooled boost at the max for a while. Then you could put in stronger internal parts later on and lower the C/R and run even more boost if you want to, this way you'll make more power. If Turbos fit in a certien spot in a C-4 then it should fit in the same spot on all C-4 except maybe a ZR-1. What I want to do is run a turbocharged Big Block with only 8 or 10psi just under 800hp so I dont break the Tranny. If I want more I could lower the Compression and forge everything internally and run more boost to make more power later on. ;) :cheers: