How would you build a low 10’s street car

-
1970boy said:
A lot of great information coming from this thread and I think I’ve come to my conclusion of what’s going to happen, it seems regardless of how I want to reach my goals it’s going to take minimum 10-15k to do it, I think I might go for a new engine and pick up a gen 3 hemi down the line and run twins, for now I think making in the ballpark of 450hp with the 340 would be a real fun car, the car is pretty quick as it is it’s kept up with a 2019 camaro with the LT1, plans would be build the 340 have fun with it for a bit then sell the 340 to fund the twin hemi build
Click to expand...
sense you already have the 340 etc you could always build a 416 out of the 340 and add boost to it. Also there is a guy on Mozart's that has a green 62 plymouth 4 door, that built a magnum base 360 with a single turbo that runs in the 9 in the 1/4 and is fully treatable.
 
RustyRatRod said:
3.55s suck. Wapner's on at 4.
Click to expand...
kindof depends on what's ahead of it.
My 3.09 low gear turns 'em into 4.11s off the line, and my 367 takes that to 50/55 no problem. If I short shift, I can split that with my GVod and come out at 65=6900. But now I gotta put it into second.lol
 
Last edited:
mbaird said:
You could build the 340 with a turbo friendly cam and pistons/compression then add the turbo stuff down the line as you can afford it. Much cheaper than building 2 engines.
Click to expand...

I'd be curious to see how much boost you could run on a 340 before it pushes the head gaskets out with it's four head bolts per cylinder.
 
One of our techs turbo’d a 360 for his Duster and blew a few head gaskets. Might want to O-Ring and run studs ...
I dont think you would need torun much boost though to achieve low 10s

justinp61 said:
I'd be curious to see how much boost you could run on a 340 before it pushes the head gaskets out with it's four head bolts per cylinder.
Click to expand...
 
mbaird said:
One of our techs turbo’d a 360 for his Duster and blew a few head gaskets. Might want to O-Ring and run studs ...
I dont think you would need torun much boost though to achieve low 10s
Click to expand...
How would you build the 340 to handle boost? And stay reliable? I feel like if I kept it under 10lbs it would be a sweet combo that would get the job done
 
justinp61 said:
I'd be curious to see how much boost you could run on a 340 before it pushes the head gaskets out with it's four head bolts per cylinder.
Click to expand...


Used to put 30 pounds, sometimes more through 392 Hemis. Same deal. O rings and studs.

Sealing the head gaskets isn't the issue. The block is.
 
Tell me if Im talking out my *** but dont turbos build power slower creating less stress on components ?
No experience with them.
 
mbaird said:
Tell me if Im talking out my *** but dont turbos build power slower creating less stress on components ?
No experience with them.
Click to expand...

Yes they dont have the shock on the rotating assembly like nos and they are easier on the assembly but it's as boost rises on higher psi where the sealing needs to be the best. But it also rely on the tune as well.
 
Power adders is a cheaters recipe. God gave us 1 atmosphere. (About 12 psi) to make power in the N/A world. Everything else? Is devil's brew! (Ok, maybe a little melodramatic?)
 
1970boy said:
How would you build the 340 to handle boost? And stay reliable? I feel like if I kept it under 10lbs it would be a sweet combo that would get the job done
Click to expand...
I have heard that 7psi will about double your power.
10psi therefore would be 1plus 10/7=2.43 times the power, less pumping losses I guess.
Lessee; 2.43 x250 (a lazy 5.9Magnum), =600hp, Badabing
 
AJ/FormS said:
I have heard that 7psi will about double your power.
10psi therefore would be 1plus 10/7=2.43 times the power, less pumping losses I guess.
Lessee; 2.43 x250 (a lazy 5.9Magnum), =600hp, Badabing
Click to expand...

7 pounds of boost wont double your power
Know a couple guys running the torque storm units, which will produce about that much boost( blower)
Gains seem to be more in the range of 125-150 horse.
One guy i know has one on a lightened bracket Duster
With a very mild/ near stock 360 it has run 11.70’s
Headers, gears, convertor, etc
 
B3422w5 said:
7 pounds of boost wont double your power
Know a couple guys running the torque storm units, which will produce about that much boost( blower)
Gains seem to be more in the range of 125-150 horse.
One guy i know has one on a lightened bracket Duster
With a very mild/ near stock 360 it has run 11.70’s
Headers, gears, convertor, etc
Click to expand...
Is the torquestorm a turbo?
 
B3422w5 said:
Blower that makes 7-8 pounds of boost.
A turbo at that level likewise wont double power
It would take more like 15 boost to do so
Click to expand...
And the blower produces boost with rpm. The turbo has to spool. ANybody see a graph between the two?
 
1970boy said:
I’ve got a 68 340 barracuda with a 4 speed and 3.55 rear gear it’s got a cam just a touch above stock and x heads, also got an LD340 intake with carter 1406 afb carb basically a stock rig but also have the hi-po exhaust manifolds, I want to get this car into the 10’s and still be streetable, how would you guys go about this? I eventually may want to turn the car into a daily so if mpgs can be kept in mind with the aforementioned goal that would be a plus. I was thinking something along the line of turbos, overdrive and 2.91’s but I’m just spitballing and have no real knowledge of mechanics behind me
Click to expand...

I'm going to guess by the post that you (OP) do not know what "streetable" means on a 10 second car. It's really not what you think it is, and certainly not like what you may find in terms of modern muscle with boost that can run those numbers with power windows and AC. Again basing the amount of familiarity on the post - you'll have to pay to have it all done. I'd budget $60-70K, with another $10K to fix it after you spend that with some shops and it runs 11s. (being serious here) You need a top quality suspension and brakes, and a driveline that makes 20% more power than a race car of that ET needs. You also need to understand it's going to be loud, hot, uncomfortable, and need regular maintenance.

Or go by a Hellcat. The money's similar...
 
moper said:
I'm going to guess by the post that you (OP) do not know what "streetable" means on a 10 second car. It's really not what you think it is, and certainly not like what you may find in terms of modern muscle with boost that can run those numbers with power windows and AC. Again basing the amount of familiarity on the post - you'll have to pay to have it all done. I'd budget $60-70K, with another $10K to fix it after you spend that with some shops and it runs 11s. (being serious here) You need a top quality suspension and brakes, and a driveline that makes 20% more power than a race car of that ET needs. You also need to understand it's going to be loud, hot, uncomfortable, and need regular maintenance.

Or go by a Hellcat. The money's similar...
Click to expand...
I couldn't have said it any better.
 
@1970boy

My buddy is a dealer for NRE. He can make you a good deal on a set of mirror twins if you decide to go with the hair dryers.

@moper

You said it, i said it. This is the truth of most of the wicked "street cars."

You also need to understand it's going to be loud, hot, uncomfortable, and need regular maintenance.

My car is borderline not even fun to drive but when i drive it i still enjoy it!
I take my girl out to breakfast on Saturdays with it, i take it to the grocery store, i drive it to work some days but i dont want to drive more than about 15-20 min at a time. Then im done and hop in my daily with AC, stereo, power windows, cup holders and all wheel drive.

Last show i went to it started to rain and the guy at the gate didn't want top open the gate for me to leave.
I said, "this aint like the other cars here. Im on slicks with a spool and dont have wipers, open the gate. I NEED TO LEAVE NOW!"
 
moper said:
I'm going to guess by the post that you (OP) do not know what "streetable" means on a 10 second car. It's really not what you think it is, and certainly not like what you may find in terms of modern muscle with boost that can run those numbers with power windows and AC. Again basing the amount of familiarity on the post - you'll have to pay to have it all done. I'd budget $60-70K, with another $10K to fix it after you spend that with some shops and it runs 11s. (being serious here) You need a top quality suspension and brakes, and a driveline that makes 20% more power than a race car of that ET needs. You also need to understand it's going to be loud, hot, uncomfortable, and need regular maintenance.

Or go by a Hellcat. The money's similar...
Click to expand...
^^^^^^^^^^^^^^^^^BINGO You have to have boost of some sort, or rear gearing and big tires, I got the power but street gearing and not much traction.
 
Cope said:
@1970boy

My buddy is a dealer for NRE. He can make you a good deal on a set of mirror twins if you decide to go with the hair dryers.

@moper

You said it, i said it. This is the truth of most of the wicked "street cars."

You also need to understand it's going to be loud, hot, uncomfortable, and need regular maintenance.

My car is borderline not even fun to drive but when i drive it i still enjoy it!
I take my girl out to breakfast on Saturdays with it, i take it to the grocery store, i drive it to work some days but i dont want to drive more than about 15-20 min at a time. Then im done and hop in my daily with AC, stereo, power windows, cup holders and all wheel drive.

Last show i went to it started to rain and the guy at the gate didn't want top open the gate for me to leave.
I said, "this aint like the other cars here. Im on slicks with a spool and dont have wipers, open the gate. I NEED TO LEAVE NOW!"
Click to expand...

Drag radials and a Detroit locker aint a hell of a lot better w/ a 505'' stroker..
garage queen when its raining , monsoon has set in again here-------
 
Although I have only been to the strip a few times recently the Hellcats I have seen run arent hitting 10s much less low 10s.
 
AJ/FormS said:
kindof depends on what's ahead of it.
My 3.09 low gear turns 'em into 4.11s off the line, and my 367 takes that to 50/55 no problem. If I short shift, I can split that with my GVod and come out at 65=6900. But now I gotta put it into second.lol
Click to expand...
How did you mate up to the gear vendors OD to the commando box? I thought they are not compatible with the ball and trunnion design
 
Well a turbo is not a bad idea but this is another way>
Friend of mine here runs a street '72 Demon, mild 416, iron heads, 3.55's, 8.3/4", hyd. cam, 3500stall, 275 d/radials (26" tall), SS/springs, chassis ties, air-gap, 750DP. Car weighs in the region of 3350 all in. Has run a best of 11.6@114, makes around 400fwhp. If you built a similar 416@9.5>10:1 from your 340 but with TF190 heads and a mild solid cam, you could get that up to an easy 450+hp more so near the 500's which would be low 11's@that weight. If you then bolted on an on demand N20 kit and used a good clean tune, a 150hp shot which is quite safe could get you 1 sec off and put you in the low 10's@around 10.1>2's@132 with slicks of course and good shocks. Wouldn't cost a fortune and it would be streetable and still drive ok with a sb with those 3.55's and taller street tyres....my2c's.
 
You must log in or register to reply here.
-

Back
Top