Hey Guys, I wanted to see if anyone was willing to lend me a hand in planning to turbo a giant 493 CI big block Mopar. It's my buddies Charger. Here's a few pics of his car. Not very good pics but all I have on this laptop.







Anyhow I know this is Honda Tech but the turbo knowledge on this forum is bar none. Without all the collective knowledge on here my turbo Honda project would never have been such a success. I don't know where else to find such insightful turbo info.

So about the Charger. It started out a few years ago as a 440 big block and my buddy put in a stroker kit and now it's a 493 CI. Forged rotating assembly with 23 CC dished pistons. I would assume the dished pistons gave it low compression but the engine builder told him its probably 10 ~ 10.5:1 which sounds really high?
The heads are custom ported, the dual plane intake manifold is custom ported and it has long tube headers with a free flowing custom exhaust. No cats or anything like that. Just mufflers with electric cutouts.

This car was never tuned right. It ran pig rich. When he had it at the dyno it was gassing us all out from the exhaust, people were covering their faces and running out the dyno room and that's no exaggeration. On the dyno it showed 11.5 AF at idle. Ugg. Timing was also just a guess. Someone told him to set the distributor at 36 degrees and that's where it sat. Never tried anything different.

Well with the cutouts open it made a whopping 378 hp to the rear tires through an auto trans. How sad. I have to admit the car up an moves surprisingly fast but that's just because of the ft/lbs of torque from shear cubic inches. So much untapped HP laying on the table with this beast.

He had a miss hap in the beginning of summer while doing a highway roll race he got to the top of third and then tapped it down to neutral but accidentally tapped it down to 1st (it has a reverse manual valve body) and wrapped the motor to unreal RPMs and bend and broke pushrods, a couple rockers etc. It was never fixed right and clearly has something wrong, bent valves or something because every few weeks it throws a pushrod on cold start up.

So he finally got tired of all that and is bringing me the car next fall and wants me to tear the motor down and rebuild it and fix the head and valve train issue and get it tuned right and make more power. He's looking at either doing a 200+ shot of nitrous or a mild turbo setup on it.

He's leaning towards nitrous because of cost and I'm leaning towards turbo because of power potential and not having to fill bottles all the time. Money aside he loves the turbo idea especially after going for rides in my Honda.

A properly done nitrous setup is not cheap. Electric bottle opener, heater, safety equipement such as window switch, spray by gear, detonation prevention etc. It gets pricey too.

So here's where I'd like some info. Is putting a turbo on this car for approximately $2500 or less feasible? Remember it's already a forged motor, no electronics to tune as it would be a blow through carb and fab work would be done by me. So basically it's just buying components. The single most expensive item is going to be a turbo. I was leaning towards Precision because it's not ebay junk and their prices seem to be the most value for the dollar.
We could leave his existing long tube headers and just make a 180 bend off of them and run straight up to the front of the engine bay to the turbo. We'd need a waste gate and BOV of name brand but could use ebay intercooler and generic IC piping which I could fab up for him.
We'd need an oil feed and drain fabbed in and be good to go.

It almost seems to easy. Once again I know it's sorta off topic of Hondas but figured as much as you guys are into turbos maybe someone has played with bigger motors and has some feed back.

Oh and here's one of my Civic's pistons next to his original 440 pistons lol. And he has 8 of them vs my 4. wow.

 

One thing about this forum is that most of us aren't biased towards Hondas and own other makes of cars as well. I'm sure there will be more then a few people posting here soon to help you out!

That piston is ridiculous! haha I thought 85 mm pistons were big.

 

Nope, I just got done shedding blood working on our c6 z06 track **** lol

 

As a matter of fact I have never seen such an American looking car before.... Let me guess it does 7MPG, weighs over 5 tons and can only go fast in a straight line ?? haha.

I'm in..... looks interesting...

 

Not to far off lol. It's less than 5 mpg the way it runs now but hopefully when it's tuned right we can get it to 7 haha. Weight surprised me, came in around 3800 some change (I forget the exact number) on the scales. It does have full interior mostly but no sound deadening, a/c and p/s etc. are all removed and a ton of other stuff. It's border line "gutted".
Straight line only, you bet.

Glad to hear there's some diversity. I love almost anything with an engine in it myself

 

Is this wonderful thing going to be a blow-through setup, or was it converted for fuel injection ?

 

check out yellowbullet, there's a bunch of people over there with multi thousand horsepower turbo v8s to share knowledgablilities with.

 

Blow through carb.

I'll look that up. Thanks.

 

You can't tune the car N/A and you want to TRY your hand at forced induction? There are actually a couple different style carbs/top hat systems to contend with. I can assure you that playing with Hondas is 10x easier than a domestic setup. The engine had better have aluminum heads and be running race gas/E85 with that compression. The piston only does so much, it depends on how much machine work was done on the mating surfaces. Its nothing to machine 0.040" on those, in a Honda you might be looking for Piston to Head Contact... Either way, if your friend is going to play "Mr. Hot Rod" with a pointless manual valve body in a street car, he should get the properly gated shifter.

A proper nitrous setup would be more in the realm of where that car will want to be. A 200 shot plate system, window switch/WOT switch, a bottle heater (I guess), and maybe a couple other components would be MUCH cheaper and easier than TRYING to turbo the car. It would also work better with the engine setuo from the sounds of it. You are heading the wrong direction and have A LOT to learn.

 

I've never worked on his car or attempted to tune it. So far it's been all him.
Yes I'm familiar with blow through carbs to a certain extent. Our buddy Tony just built a 540 CI big block chevy with an F2 procharger on it. He's on E85 though. I've seen his carb and tube setup.

Yes he has aluminum heads. The compression we are not entirely sure of. We're going to have to pull the heads and CC the chambers and do some math and figure it out. With a 23 cc dished piston I would think his CR is low but we need to work it out for sure.

Correct on the gated shifter. Our buddy Nick has one on his 71 Camaro and it's pretty slick how it works. It's on the todo list.

You say trying to turbo this car is heading in the wrong direction but you don't elaborate? Why? because you don't like it? or some technical reason?

I would think a low boost setup on this motor would be safer and put less stress on the motor than a 200 shot of nitrous. Plus he wouldn't be filling bottles all the time.

 

Don't like it? I have a couple of twin turbo F-body's that are ABUSED on the track. Safe is a relative term. Given, nitrous IS more of a PITA for continous fun, but there are MANY more "safety" factors built in if the setup is done properly. Also, you haven't given us anything to go off of as far as performance increases. How much? The type of carb hat used is determined by type of carb. Where is the internal vacuum source pulled from?

It is headed in the wrong direction because you speak of using exhaust headers for turbo manifolds. TheyWill crack. Comoression is too high. Tuning capabilities are too low for you guys to be playing around. This in addition to other things... Nitrous is easily calculated and a good start for a beginner.

 

Well sounds like you should be very knowledgeable on the subject and should have a lot to offer.

Like I said he only saw 378 on the dyno. We're hoping that would be closer to 400 maybe even 450 tuned properly. Then with the aid of either nitrous or turbo 600+ to the tires is the goal. Now thinking long term by the following year he'll want more and probably be wanting 800 to the tires and if we'd gone the nitrous route that gets hard to achieve. You can't just keep spraying HUGE amounts of nitrous. It only gets you so far.

We don't have a new blow through carb yet. Once we get the carb picked out we'd get the correct hat for it.

Yes true we are considering that. I have seen many a mustang using shorty headers flipped upside down and swapped to the other side of the motor so they point forward and used that way. Did those eventually crack down the road? I suppose they may have but then again how many cracked manifolds have you seen on this forum? plenty.
The main reason we got that idea was recently we saw a turbo build on HP TV and they did exactly that. They left the stock long tubes and routed the exhaust from there to feed the turbos.
If this will just absolutely not work we could come up with something different. Or if we start running into cracking problems we could come up with different manifolds.

That's a possibility. Like I said we need to figure that out when we tear the motor down. The motor will be stripped to a bare block since we need to re-gap the rings for nitrous anyways if we go that route. At that time if compression is to high we will put lower compression pistons in or what ever we need to do to get it lower.

I assume blow through carbs don't offer enough options for you? I've seen many a turbo'd car using carbs so clearly it works.

I appreciate the beginner comment
By your logic no one should ever try anything. Either do the easiest thing or do nothing. Where would mankind be if no one ever took some initiative and tried new things.

 

Well said. He's H-Ts resident jerk, I don't think anybody will dispute that BUT he does know what he's talking about, again, I don't think anybody will dispute that either.

 

I would suggest getting the car running right before anything. If the tune is off that much where he's making 378whp, it may eat up a large portion of money just to fix it. Not only that, but once it is all corrected, the car will probably make closer to 500whp and a more torque as well, so he may find the next weak link in the drivetrain, which again, will eat up the budget.

However, in the event you guys do push forward with a power adder, either route will be fun. This guy's tuning abilities are scary, and since nitrous can have a small margin of error in that department, I'd lean towards a turbo setup. I wouldn't use long tube headers since they're usually made from gauge steel and will certainly fail. You may be able to find OEM cast manifolds to use instead. Us "V8 guys" do it all the time with the LS stuff. If you can't find OEM manifolds, typically aftermarket companies will make cast shorty style headers that will work too.

Oh, and don't ever take any tips from Horsepower TV.

 

Well regardless of what one may know there's no need for such negativity and no need to converse so demeaningly. I have no time for such negative energy. He just tries to bring everyone down.

Yes not only will we get the car running right but we will be tearing it down to a bare block and going through the whole thing.
From what he's told me he spent some money and has a high dollar built transmission in there. Still gathering details on all that.
Yes my buddy knows nothing about tuning carbs but rest assured he won't be tuning it once we put it back together. I'm going to put a wideband in there and tune it for him.
I agree nitrous has little tolerance on the tune and could be very risky in that nature.
Good idea on cast manifolds. I'll see if there are any aftermarket ones that flow more than the stock ones.

Like any TV show I'm sure take it with a grain of salt but they do have some good info from time to time.

 

That compression sounds right... -23cc on pistons that big is a small dish. Flat tops would be in the 12:1+ range

 

Would like to see pictures of this when its done

 

378whp from 493ci...?

 

something was wayyyy wrong

we make 600rwhp out of a 427

 

I'm thinking along the same lines. However still gathering info on the stroker kit he used, heads etc. and going to work out CR for sure.

Yup like I said his tune sucked horribly. He didn't have a clue what he was doing with the carb or timing. I'm assuming it's the ft/lbs of torque that made it move the way it did. For comparison another buddy of ours has a 2011 GT500 which at the time was bone stock with a factory rated 550 HP. He also has the SVT package which added 3:73 gears. Well when the charger and him would do rolls anywhere from 20 to 50 or so they would be dead nuts even till about 100 if I remember right and then the GT500 would start to walk him.

 

It had to of been the sheer torque... which while only making that power wasn't very high or near where it should have been but it was still enough to make the car feel quicker than it ww

 

What was done when the stroker kit was installed? Was the bore sonic checked for thin spots? Was the block checked for cracks? Main caps upgraded?

Production v8 stuff (especially in the muscle car era) is a whole different ball game when compared to Honda quality control and design. The RB block should be fine at 600 HP if its a good block but that's a big if.

 

He found his invoice from the machine shop and from what I can make out on it, it says assemble crank with rods and pistons, bore per cylinder and hone, clean R&R cam bearings and freeze plugs, and grinding for clearance, deburring or tapping of holes by the hour.

Doesn't give me a whole lot of info to go on. I asked my buddy and he said after the short block was assembled they found the block wasn't even clearanced enough for the rods because it was lightly making contact with the block when turned over by hand. wow. So that's when he took it to much more expensive engine builder who tore it down, fixed the machine work and assembled it. This engine builder also is the one who ported his new heads, intake and did the final assembly. He also had a custom grind cam made for the motor. From what I understand this builder is from a larger well known shop and did a great job. He has lost a lot of the paper work though unfortunately from this second job so no details on it including the custom cam specs. We will be getting a new cam anyways because this one has a grove worn in it from the push rod incident explained in the first post.

This is the stroker kit he went with

http://www.hughesengines.com/Index/p...r&partid=24497

I don't have a link to heads yet but from paper work he dug up

INDY 440-EZ Heads.

270cc intake ports, 2.19 x 1.810 valves, 75cc closed chambers (80cc open chamber optional), stock pushrod location and rocker shaft oiling. It's either one or the other on the CC's.

He's almost 100% certain he has the 75cc version of the heads. He also recalls having 35 thousands piston to wall clearance so going on a limb here and ball parking on what I have to work with so far looks like his static compression ratio is 10.47:1

Bore 4.385
Stroke 4.150
Head gasket bore unknown
Head gasket thickness 0.039
Combustion chamber CCs 75
Piston dome or dish -23.7
Piston to deck clearance 0
CR 10.47

So if we pick the turbo route new lower compression pistons are in order for sure.

 

A little playing with numbers shows all else been equal he'd need -43cc pistons to get the CR down around 9:1. They just don't make that. Looks like instead he'd need new heads with the 86 or 88cc chambers. These heads though were over $2200 if I remember right plus machine costs for custom porting them and port matching to the intake. Replacing them may just be out of budget.... we'll see.

 

Sprayyyy