Turbo charging a LT1 C4
 

Before you guys get the wrong idea about me thinking that I just want to put a turbo on my Vette because its sounds cool or whatever, I want to let you guys know that I am very familiar with forced induction applications. I restore Buick Grand Nationals as a hobby. Along with my GNs I have a SBC twin turbo setup in a 3rd gen Trans Am, I also have a GMC Typhoon and few other forced induction cars as well.

I love my Vette but it’s the way too slow compared to all my other toys. I know the factory LT1 is in the 10.5 to 1 compression ratio or there about. So we maybe looking about running 4-6 psi boost and may be spraying methanol until it gives out.

My question is;

How realistic is it to turbo charge a 1993 LT1 and maintain all the accessories like AC and things, well at least I have to have AC( for the wife) I really don’t care about the emission accessories. Has anyone done this with any success. Does anyone make custom headers or any pictures I can take a look at so I can get some ideas. I did do a search but not much there. Any information on this matter is greatly appreciated .

Thanks
Prasad

Try this link.

http://www.turbochargedpower.com/

Does anyone actually have this turbo kit for a C4? All I have seen is negative feedback about this company.

check with sts in orem utah, they have a rear mounted turbo systom i think. they were on the cover of the last vette magazine with a 700hp c6 they call z07. i have heard good and bad about them but they just keep getting better. and with all the pipe to put the turbo in back instead of mufflers you get a built in air cooler for the intake air.
www.STSturbo.com

just checked the site and they dont have one listed but i think they can make one. i saw it in a vette mag that they were building one. id just call them and ask.

You could check the Forced Induction C4 forum on this site, lol.

There are no turbo kits available. Raptor is close to releasing their version of the rear mount turbo, and the under hood one from the guys in NM can't actually be bought.

There are a couple guys in the FI section that have built their own. lcvette just made a 940 RWHP with his 96, and there is another guy who is working on selling his LTX turbo car.

If you can build the hot side, I think it's doable. Building the headers would be the most difficult part of the labor. The engineering aspect of making the kit fit would be challenging, but as long as you are fabbing your own parts it's doable.

Good luck, keep us posted!

i think the sts shop is working with raptor to build the rear mount setup

same here, all bad. :lurk::bigears

dude, Raptor is working with STS, they HAVE NOT come out with their c4 kit yet (it's been some time).

EVery turbo kit currently for the Lt-x based cars are DIY.

the FI forum is a much better source for refined information about this topic.

the AC can be retained. if you take a look at some supercharged c4's (Lt-x's), you'll see that the kits COME with new AC lines to "re-route" the lines out of the way of the head unit. the head unit (for supercharged applications) sits on the passenger side cylinder head.

The LT-x community has much more experience with superchargered setups rather than turbocharged combinations. the Supercharger route has been done several times, and for the most part is a relatively well thought out kit.

I would suggest Greg at blowerworks.net

no-one (to my knowledge) has run the "turbochargedpower.com" kit. There has literally been one car (that was in development for along time) that also required quite a bit of "modification" to the existing kit to get it to fit properly and work correctly in the c4.

the 1993 engine (and older) had the "less capable" engine computer. The newer (94'-96') c4's have a computer that is MUCH more flexable to tune for boost.

the interesting part is that I've "heard" of a few vendor that use to use the syclone/typhoon computer in the corvette (killing some dash functions) in order to run a computer that could recognize boost, and be tuned accordingly.

the other options are standalone, LS-x computer swap (this one is new to the market), piggy-back systems (auxilary injectors, etc).

with the centrifugal (since the power delivery is linear) there isn't a real need to have a computer that recognizes boost (you cannot use a 2-bar/3-bar map sensor on these older computers). Greg @ blowerworks, Alvin @ pcmforless.com both offer mail order tunes, but i would suggest finding a local shop with a dyno that is capable of tuning for your geographic location. They (the tuners) essentially inrich the fuel mixture in relation to rpm and engine load... the computer is actually "blind" to the boost generated. not a very accurate way of tuning, but sufficent.


******edit*****

thick wall tubing in a log style manifold will be more than acceptable in a good, compact, turbo package. Log style manifolds have proven themselves several times! there is a 402ci Ls-x swapped c4 in the FI forum putting down nearly 1000rwhp with log manifolds!

I looked into twin turbo's a year or so ago and got a lot of help from the forum. There are several people who have done this 2 C4's, do a search and you will find tons of info, I remember one or 2 that put the turbo's in the backend of the car.

According to this the kit is out for the LT1 and LT5.

http://forums.corvetteforum.com/c4-f...date-pics.html

What's wrong with supercharging? A procharger will give you plenty of boost and the install seems much easier.

Thanks for the link and thanks for all the reply guys. I called and talked to the guys at Turbo charged power. I think their kit is about $4500 with everything. Well all I need is the headers. They want about $1200 for that and about 8 weeks wait on it which is not a big deal. I do like their setup. With their kit, you would relocate the battery to the trunk and mount the turbo where the battery goes. I think this can be done without too many complications. This by far makes the more sense from what I have seen so far. I am looking for other options as well. I am not much fan of rear turbo set up even though it works well. Something about sitting 3" to 4" from the ground scares me and I also think it can get pretty expensive.

Thanks again
Prasad

This not the first time I am making the mistake of posting in the wrong forum. My dumb ass can't get used to all the dedicated sections here.:D

Sorry guys!

There is nothing wrong with super charging, I know people always argue about what's better. Well in my opinion Turbo charging is more efficient than supercharging. A super charger is belt driven and takes power from the motor to turn for example it may take 20 hp from the motor so it can spin and make 100 horse power. Now the turbo charger is driven by the velocity of the exhaust however, it creates back pressure in the system so it also robs horse power. it would be more like giving up 10 horse power to gain a 100 HP. So in my book the turbo charger is more efficient beside when it come to tuning it much easier to turn down or up the boost. I know the turbo chargers and Super chargers have come a long way but back in the days I read an article that someone took two identical motors and bolted a supercharger on one and a turbo charger on the other. The motor with the supercharger took around 570 horse power worth of fuel to make 500HP where the turbo charged one only to 530 HP worth of fuel to make 500HP. This was over 20 years ago so don't quote me on my numbers.
I also have enough turbos and waste gates laying around so I can go this route. I guess it’s all personal preference.

Just my $.02

Prasad

It can be done, there's plenty in the FI section.

A supercharger it a lot easier, which is the route I'm going.

Here's a good example
http://forums.corvetteforum.com/c4s-...te-12k-mi.html
http://i229.photobucket.com/albums/e...e/P5040300.jpg

http://forums.corvetteforum.com/c4-f...-progress.html

http://forums.corvetteforum.com/c4-f...installed.html

http://forums.corvetteforum.com/c4-f...-mm-turbo.html

http://forums.corvetteforum.com/c4-f...nterested.html

I'd like to know how he changes spark plugs. :crazy:

I'm with you wicked, I prefer turbo to supercharging. I used to work at a small shop doing some turbo work on smaller engines. Might build a turbo system on mine somewhere down the road.

Here's something you can find in the FI section.

http://www.forcedairtech.com/vette_kit_after.jpg

Company that did it was actually a Subaru shop, but they took the additional pictures down from their site. http://www.forcedairtech.us/

this is one that I posted several months back. they are local to me (AZ). I called them to figure out pricing, they can do the "package" for about $10,000-ish. they re-located the AC unit with a smaller one. that's an authentic grand-sport BTW. The owner of that car also had a CObra-R getting Turboed!

that looks like an lt1 to me, how do you swap out the optie for that dist.??? i want to do that.

One easy way is take the rotor out of the opti so it just works at an opti sensor, and run the coil wire from the coil to a regular distributor to distribute the spark. You (obviously) need a hole in the intake.

you also need an aftermarket computer

Not for the method I described. The opti is still providing the signal to the computer, and the computer is still firing the coil when it wants. All this mod does is move the cap and rotor from the opti to a regular distributor. This won't fix problems with the opti half of the opti, but it will prevent moisture build up from causing problems with the cap and rotor.

Id like to see one put together. If you can control the boost I think it would be fun. Neat when it hits and pins you to the seat back. :smash:

Think my next build will be t.charged.

You know guys after looking into all the options; the rear mount turbo setup seems by far the easiest. Initially, I forgot about the Independent rear suspension where the center section remains idle. The link you guys posted with rear mounted turbo setup, there are other things that hangs lower than the rear mounted turbo. This way you can leave everything up front almost the way it is. I have to get the Vette back up on the lift and actually check everything out. Maybe I have to lose the spare tire. If you can weld and do a little fabrication you can do this fairly cheap.
You can buy a brand new 60 series P trim turbo with a decent size exhaust housing for about $450, decent waste gate for $150 to $200 bucks, several feet of 3" and 2" stainless or mild steel tubing ( which you can get it ceramic coated) and have them bend at a local muffler shop for a good fit. An air regulator (the one that they use for spray guns or air compressor) forms your local hardware store to control the waste gate along with several feet of vacuum hose. Turbo oil and feed lines, I am thinking braded lines or hydraulic lines that can handle some heat. Now the most important piece, the oil pump to return the oil back to the oil pan. I have made few calls but I haven’t gotten any prices yet. I have a felling it wouldn’t be cheap. You can also add an IC or spray methanol to cool the air inlet temp which brings me to my next question. I was told that the 94-96 computer system is far superior and you can change the tune fairly easy. How hard is this to accomplish on a 93 vette? Can I just change the computer or do I have change the harness as well? I don’t want to go to an XFI or BS3 and loose all my dash functions.

I have all he pieces on hand except the oil return pump so it makes more sense for me to go this route.

I also want let you guys know that this is something that I will do for sure but I don’t have set time frame. I have way too many projects going on at this point and this project maybe 3rd in line. I would also like to run this car at the track and see what she does before the turbo installation.

As always, thank you guys for all the great replies.

Prasad

I don't think it will be problem, the key is a large enough exhaust housing, minimum of .96 a/r and a large enough wastegate 42mm or bigger with maybe a 4 psi spring.

HTH

Prasad

As simple as it sounds why no copy what callaway did on a C4 and call it a day..... They seem to work just fine. I thought they were right off the manifolds stuffed down where the pre cats live now on a 91 at least... Those elctric oil pumps are on the web though have to say i am not a big fan of them. If you use one you will need a sump of sorts so it is pumping oil and not foam.

I put together a collection of photos from the forums I've collected over the years

http://s242.photobucket.com/albums/f...orvette/turbo/
http://i242.photobucket.com/albums/f...rbo/cotms4.jpg
http://i242.photobucket.com/albums/f...igassturbo.jpg
http://i242.photobucket.com/albums/f...o/DSC00841.jpg

I found similar scavenging pumps on eBay for $229, I also want to run a bigger single turbo for simplicity. Trust me, my twin turbo Trans Am was a single turbo to begin with then I went to twin turbo setup. After that I told my self, it not worth the time or the money, you practically need two of everything. Unless you are going all out for the fastest time slip, I will take the few tenth slower and keep my sanity and money in my valet.
Hmmmm, there is always some sort of compromise. Those pics are great thanks for posting them.

I am off guys on a little vacation, I will check back on 07/10/09. Have a great 4th guys and be safe!

Thanks again
Prasad

I'd be interested to know how long the spark plug wires last under that much underhood and header heat.:eek:

But that mofo looks wicked as hell.

Not real crazy about those turbos that close to the floorboard, like the idea of the rear mount. :cool:

Anyone have this kit on an LT1?


http://www.turbochargedpower.com/C4%...t%20Mockup.jpg

http://www.turbochargedpower.com/85-96%20Corvette.htm

I'm not a fan of the rear set up. There will be some time needed to pressurize the charge pipe, that you won't have if you keep the turbo(s) in the engine bay. I like a linear feel to the power, With a lot of power and boost that just hits you out of nowhere you could get yourself into some interesting situations when driving.

If you are going single, the space where the battery is would make a good home. Could probably locate it on the passenger side front of the engine if you relocate a couple things (trying to remember what's up there, PS reservoir I think). You can get electric or belt driven scavange pump like used in the Callaway if you need them. You could go with additional injectors on a separate controller and just reprogram your timing map, off boost driveability shouldn't be effected, and the additional injectors fuel the added boost.

Drop a set of aftermarket heads on that LT1 with 64cc chambers or more, and it will drop compression down abit more... about 3/4 point so you'll be at a better 9.8 to 1 or so which is alittle better for some low boost on aluminum heads. Plus the better head flow will make more power with less boost so the compressed air will be at a lower temp which is good. Add meth injection and you should be ok.

try swapping out the gas pedal for a cool metalic one, that will give you the performance you need. Don't wast $ on the turbo, its not necessary. a corvette is too fast as it is. I am trying to slow mine down. LOL

Naw for real, Turbo is the way to go, I have a 93 and pushing over 500hp, did tuning work, new ignition (its key) upgraded exhaust, long tube headers, and added a turbo (a remote turbo on rear) so I have AC etc... it moves baby