Why would a V8 swap be slower than a 3.8

Dahoopd

Registered User
I was searching to find the answer and couldnt find any truth other than maybe weight being the answer. But weight can be reduced. Why would a V8 in an SC be slower than building the 3.8.

I understand there is more torque in our little 6, but when you compare the cost of a 3.8 and V8 for horse power. I would think that it would be somewhat cheaper to build an 8 with the same horsepower output. This is taking into consideration that the parts for a swap from a 6 to an 8 are already available.

Can someone take the time and help me understand. The 6 just seems so much more complicated to build.
 
Who said it would be slower? A 5.0L Ford V8 is one of the lightest production cast iron American V8 engines. With a regular EFI system or a carb, it would be very close to the weight of a 3.8 SC engine, if you include the supercharger, intercooler, tubes, etc.


cheers
Ed N.
 
Best bet is just buy a LX that already has the V8 in it. Then build on that.

It's probably more of a question that the V8 is gonna need a little help to beat the Supercharged 3.8 that's already had some help.
 
I think a modded SC against a SC with a 5.0L thats stroked, AFR headed, cam, intake manifold, all the other goodies that I dont need to list out, would have a really hard time keeping pace especially if the 5.0L SC had nitrous under the hood. Plus the overall cost to mod the 5.0L engine is nothing compared to the V6. I am not hating on the 3.8L here at all because I do like the motor and it does have potenial in its own respect, it just takes more to get it there.

Shane
 
Just as a reference, here are some times from my bird.

Its a 95, originaly, it had the 4.6/4R70W in it.
Stock, it ran a best of:
15.8 @ 86 mph. 2.2 60'.
After a 75 shot was installed, I had a best of:
14.15 @ 95 mph, 1.99 60'.

Now, the car is completley gutted, I went from 3940 w/ me in the car, to 3110 w/ me out of the car.
Also, I swapped the 4.6/4R70W for a 351W/C6.
The 351W is bone stock, and it has ran a best of:
14.18 @ 95 mph, 1.98 60'.

Hope this helps any.
 
95badbird,

Have you considerd a C4 tranny instead of the C6? You should be able to go faster with your current setup with a C4 than the C6.

Shane
 
Mike8675309 said:
Best bet is just buy a LX that already has the V8 in it. Then build on that.

It's probably more of a question that the V8 is gonna need a little help to beat the Supercharged 3.8 that's already had some help.


Why would that be the case if a basic 5.0 puts out 210hp and the 3.8SC puts out 210hp. All things being equal and doing the exact same upgrades to each. Wouldnt the 8 be quicker with less money and tuning?


With the amount of parts that are obsolete, and the resale issues. Think about how many HP parts go unsold for the SC because of expense. But there are many in line looking for 5.0 parts.

I have 3 5.0 mustangs and I would not trade my SC for one. But the 5.0 is much easier to tune and build than the SC. So the question is, why would it not be cheaper and better to build the 8 in an SC.
 
quick35th said:
95badbird,

Have you considerd a C4 tranny instead of the C6? You should be able to go faster with your current setup with a C4 than the C6.

Shane
yes I have.

But at the time of the swap(I was very limited on my budget), it was all I had. I basically got the motor and tranny for free, so I couldn't complain.
But yes, their will be a C4 in my future, or the cars future.

I think a C4 and a 3000 stall, and some 4.30's would put me close to a mid 13.
 
Dahoopd said:
Why would that be the case if a basic 5.0 puts out 210hp and the 3.8SC puts out 210hp. All things being equal and doing the exact same upgrades to each. Wouldnt the 8 be quicker with less money and tuning?


With the amount of parts that are obsolete, and the resale issues. Think about how many HP parts go unsold for the SC because of expense. But there are many in line looking for 5.0 parts.

I have 3 5.0 mustangs and I would not trade my SC for one. But the 5.0 is much easier to tune and build than the SC. So the question is, why would it not be cheaper and better to build the 8 in an SC.

Stock for stock the 5.0 will be slower. Even though they both have the same HP, the 3.8 SC has considerably more torque (because of the supercharger).

If your going to mod both motors, the 5.0 has more potential because of the larger displacement.

David
 
95badbird said:
Just as a reference, here are some times from my bird.

Its a 95, originaly, it had the 4.6/4R70W in it.
Stock, it ran a best of:
15.8 @ 86 mph. 2.2 60'.
After a 75 shot was installed, I had a best of:
14.15 @ 95 mph, 1.99 60'.

Now, the car is completley gutted, I went from 3940 w/ me in the car, to 3110 w/ me out of the car.
Also, I swapped the 4.6/4R70W for a 351W/C6.
The 351W is bone stock, and it has ran a best of:
14.18 @ 95 mph, 1.98 60'.

Hope this helps any.


Your comparing an LX with NOS. I am looking for an SC 3.8 and SC V8 comparison. Budget wise and HP.
 
Dahoopd said:
Your comparing an LX with NOS. I am looking for an SC 3.8 and SC V8 comparison. Budget wise and HP.

Budget wise, you should be able to pick up a stroker kit, cam, heads, intake manifold and probably headers for the 5.0L for probably the price of an AR kit for example or less. Its even cheaper if you pick up some of the parts used which is not at all hard to do. You could even pick up a nitrous kit used as well and be at more of an advantage with the 5.0L. Then of course there is weight reduction options that you could take on either car.

Shane
 
David Neibert said:
Stock for stock the 5.0 will be slower. Even though they both have the same HP, the 3.8 SC has considerably more torque (because of the supercharger).

If your going to mod both motors, the 5.0 has more potential because of the larger displacement.

David


Dave,

So given that information, if you spent the same amount on both (hypathetically $3000). Would the the 3.8 end up being faster in the exact same car?
 
Dahoopd said:
Dave,

So given that information, if you spent the same amount on both (hypathetically $3000). Would the the 3.8 end up being faster in the exact same car?

Depends....if you did all the stuff Shane mentioned above excluding the nitrous, and you added an AR to a stock SC...I think the SC would still be faster.

But if you were to take that same money and instead of doing the stuff Shane listed, build a turbo system using the stock longblock the 5.0 motor would probably make more power.

I think it really depends on your power goals and intended use of the car. If your going for anything less than 400 rwhp without nitrous, I think the SC motor is probably a better choice. If your going for 500+ rwhp I think the 5.0 would be a better choice.

When installed in a T-bird (MN12), aside from certian engine parts like pistons, heads and intake manifolds, the 5.0 isn't really any cheaper to mod than a 3.8 SC.

David
 
The 5.0 without a doubt was slower after I did my swap. stock for stock.
If any of you gluttens are actually looking to do the swap I have everything from my 93 SC.
 
lets look at this another way..

Dollor for dollor, I put my $$ on the V8... Now for my side of it. You can drop a big block 514 from Ford "crate" people that gives you 500 horse stock... Now you add a 300 shot fogger setup and you jump to a cool 800...Total cost is less than $8,000 even with all the parts to do the swap...
Now for the best part...weight...If you take every part out of the car and hit the scale with it you will find that a big block with alumium heads and intake will be LESS weight than ALL the parts that it will replace.....
This may be hard to understand, but if you start to weight each part that comes off you will start to see the difference....More power, less weight makes for one fast V8 S.C. in my book..........Rich
 
pro street rich said:
Dollor for dollor, I put my $$ on the V8... Now for my side of it. You can drop a big block 514 from Ford "crate" people that gives you 500 horse stock... Now you add a 300 shot fogger setup and you jump to a cool 800...

and id put my $$ on a SC with nothing more then a pulley swap against that sprayed bigblock SC. Car wouldnt make it 5ft without breaking something in the drivetrain with a 514bbf with a 300shot.
 
Thats a bet I will take...

Blown 91 Bird said:
and id put my $$ on a SC with nothing more then a pulley swap against that sprayed bigblock SC. Car wouldnt make it 5ft without breaking something in the drivetrain with a 514bbf with a 300shot.
I have run that setup for three years and guess what?? It has been VERY good to me... If you nail the bottle AFTER you nail the gas it has stayed together....
Now I have gone even bigger in another car and still the rear has been holding up to the beatting.....Sure now there are some aftermarket parts back there, but the stocker's will do just fine IF you watch how you launch the car..............Rich
 
pro street rich said:
I have run that setup for three years and guess what?? It has been VERY good to me... If you nail the bottle AFTER you nail the gas it has stayed together....
Now I have gone even bigger in another car and still the rear has been holding up to the beatting.....Sure now there are some aftermarket parts back there, but the stocker's will do just fine IF you watch how you launch the car..............Rich


514bbf with a 300shot with stock IRS? Must be a slug... :p I could see if you are waiting a few tenths (which in drag racing, is a long time...) it not hurting anything cause its not really shocking the tires... but theres possibly a few tenths not being picked up that you could there. 'Round these neck of the woods' is all 1/8 racing, and if you only got one kit and dont have everything in within a 2-3 tenths dont bother turning it on

A well built 514bbf should make 800+tq (at least the one my buddy had in his 91 LX did) on nuts alone. With a 300shot you could leave off 60% or so with a progressive, but if you got a good converter you'd still be putting them halfshafts through some serious shock stress.

Id love to watch your car leave off a t-brake with a 300shot with the bottle pressure jacked up around 1100 with some stock halfshafts..that is, if you dont have a lemon of a 514 :p j/k
 
no lemon's here............

As I had stated before, some of what you say is true..You have to come out soft or you will have trouble. I know this as when I first tested it there were some broken parts...But if you are a true drag racer you know that if it breaks you find better parts or have them made for your car....Like I said before not everything is stock back there.
Now as far as the trans brake and the stall, well lets just say that it is a very soft convertor. I am well into the power band when it locks up. Sure if you come out hard it will tear up parts, but that's racing.... There is sooooooooooo much power that it is not hard to catch up after you leave the tree. Sure my 60 ft time's suck, but my 440 and up are killers...
I took a few of the people who post around here for a ride, maybe one of them would like to add what it feels like when I nail it from a roll???.....Rich
 
makes me wanna put this SCJ headed 460 in my SC. be about 850+ on 200 shot, but then i think i would just fly away into the unknown in the supercoupe.. leaving a trail of flames


what kind of hp/tq numbers are you making anyways rich ? you can PM me if its a secret lol

I almost built a 520 for my 88 tbird. you use chevy rods, and i believe it makes it a little better ratio
 
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