Just got my new 408 together at the engine builders and it is scheduled to be on the engine dyno this week. What do you guys think it will make? my goal was 675HP on motor then hit it with maybe 400 shot.

408 cubic inch
6.0L Iron block. 4.030" bore
Dragonslayer 4" stroke crank
Compstar 6.125" rods
Diamond custom pistons with gas porting.
12.5:1 compression on 110 fuel
hydraulic nitrous cam 251/266 .632/.595 112+4
BTR ported Trickflow 245's w 70cc blended and polished chambers,nitrous exhaust ports, 2.10 and 1.6 valves.
BTR ported super victor intake
1" spacer and nitrous plate
accufab 4150 throttlebody
2" kooks long tube headers

If all goes well I will post up numbers next week.

 

So you thinking about 580 or so at the wheel? If so I think that's very possible. Awesome build!

 

I have a th400 and 12 bolt, so drive train loss might be big. I bet its more like 550 to the wheels from 675HP. I'm not sure how to calculate it.

 

No reason that shouldn't make 550.

 

Anyone else with this setup care to guess? I haven't seen many 408's on here with ported TFS heads and a super victor intake. I'm hoping for the best in the next few days when I got some numbers.

 

655fwhp, 510ftlbs
if it goes to 7500rpm.
Based on math.


But I think it can make 675fwhp

 

I'm thinking 7,500rpm is prolly the max because of hydraulic roller cam.
What kind of math equation did you use? is there any calculators out there that take cubic inch and compression and so on to figure horsepower?

 

Last min decided not to pull my wire harness out of the car and bring the PCM to the dyno. Kind of a hassle. So, I put a 750 carb on it because that's all we had laying around. Broke in the motor that way and made a pull for the hell of it with the small carb. 662hp/551tq with 33 degrees of timing on 110 fuel.

I have found a 950 carb which will be closer to my 4150 throttlebody that will actually be on the car. Slapping it on now to see what it gains. I should have numbers with that on there later today or tomorrow. Hoping for 680+HP.

 

Nice results!! It will be interesting to see the difference once you strap it on a dyno to see the drivetrain and added exhaust loss.

 

No exhaust loss. It has dynatech splitflow straight thru 3.5" mufflers clamped on the headers when its in the car. maybe 1 hp. lol. Ill be happy with anything over 560RWHP on the chassis dyno.

 

Engine builder called this morning said the 950 carb we found wasn't a high end carb like the 750 we had on it was, so it didn't gain what it could have. although he didn't mess with jetting as we are running out of time for the deadline I gave him to pick it up. He said it made around 670HP with that carb. peaks 7,400rpm. I guess its not bad for slapping some old carb on it and not messing with anything on the carb.

Any Idea if the motor would have made more power if I had my 4150 TB on it with my fuel injection? He thinks it would have done a few HP more, maybe hit that 680HP mark I was looking for. I'll slap it in the car, wire it up and bring it to the chassis dyno with my tuner and see what we can put down at the wheels next.

 

I used:
CUINx1.25 = Peak TQ
Peak TQ x.90 =
90%ofPeakTQxMaxRPM/5252

408x1.25 = 510
510x0.90 = 459
459x7500/5252 = 655HP

510TQ @ 7500RPM

With the correct valve train parts it shouldn't have a problem going to 7500rpm.

Too bad you couldn't try a good bigger carb 950cfm+, I think you can go past 680fwhp.

What are you expecting it to run on motor and on spray?
how heavy is the car?

 

car weighs 3,315 with driver and full bottle. Should run mid 10's on motor I'd think. I'm going to start out at 200 shot and work my way up to 350 shot. The goal is 8.99 this season. Next season I will take the plate off and put a fogger on it and spray 4-500. get it going mid 8's hopefully. The plan for the car is an 8 sec car with leather interior and radio that I can drive to work.

 

What rear gear do you have in it?

I think it could be closer to bottom 10s N/A.
250 shot should put it in the 8.80 range, if the suspension is doing what it needs to and the tune up is good.

 

3.73 gear, 28x10.50 tire. Stock trans gearing for a TH400. Suspension is madman custom valved double adjustable AFCO shocks with wolfe racecraft weld in adj spring perches with 150lb rear springs. All UMI adjustable rear control arms, TQ arm ect. with anti roll bar. Front is racecraft K member, A-arms and qa1 coil overs.

 

That thing will fly!

What spark plugs did you have in it to dyno?

 

I am liking the build! Good numbers really

 

NGK TR6 plugs.

I cant wait to spray it. I still need a stand alone fuel system for it. The engine builder said I can spray this thing 5-600 if I want. The block will be the weakest link since it is not filled. Maybe one day I will get that brave lol.

 

Also a bit of added info. pulling timing down to 29 degrees it is able to make full out pulls on 93 octane and it only lost 24hp. I could theoretically drive it around town on 93 all day if I ever decide 110 is too expensive for my wallet.

 

Catherdal port heads right?