About a year and half ago we built one of the 1st 408's with a tvs 1900 on top. Made 727hp and 653 ft/lbs on about 6.5 lbs of boost, which pleasantly surprised us. Engine ran great for about 10k until the evil piece of crap comp valve spring decided to break while crusing down the highway dropping a valve and cratering the motor. Luckily we used the iron block for the 1st build so with a little luck we were able to bore to .065 over and now the new 413 appears. With the help of maggie who nicely took pity on our situation we were able to procure a tvs 2300 that will fit our new ported and polished L92 heads (old P&P 243s needed a lot of work). Small cam change, new pistons and we will put on the dyno tomorrow. Looking for 800+hp with the new setup should post dyno and video by this weekend. Yes went to PAC springs this time!!!! Here is the old dyno will post both when we get it tuned.

 

Subscribed for dyno results...

 

Those are probably the highest #'s I've seen on a 408 with 6.5 psi, especially being up in Colorado.. Interested in the new results.

 

Sounds like a beast. From 3000 R's up, HP just keeps going & going up to 6200. I saw TQ peak @ 3900.

 

Just to clarify are you talking engine dyno here right?

 

That would make more sense.

 

Yes, definitely engine dyno. We hoped to get the new motor on the dyno today but got the wrong fuel rail delivered. Should get some pulls tomorrow afternoon. We got the the L92 heads done and flow tested and we are now thinking 800+hp if we don't have too much belt slip. I should get some video and preliminary numbers tomorrow, hopefully get something posted.

 

Finally got everything together and started tuning on the engine dyno. First thing that is obvious with the 2300 over the 1900 is that a 6 rib belt system has zero chance of working without slip. I see know why the new ZR1 corvette went with an 11 rib belt. If you are trying to make anything over 8 lbs of boost a 8 rib setup is a must. We started with a 2.8 pulley (between 7-7.5 lbs) but went to the 3.0 pulley where we actually made 8.5 lbs of boost from 5500-6500 rpm. We actually ended up with more boost on the high end with the larger pulley.

The good news is the blower is a monster. With 7-7.5 lbs of boost we averaged 728 ft lbs from 2500-6100 rpm. Remind you this is on a very streetable cam, 222-236, 601-603 at 115 LSA.

It is apparrent that the 2300 and the L92 heads need substantially more cam duration if you want to make huge power. We probably could have gone to a 238-255, 650-650, with the right pulley and rib set up but we actually reduced duration from our last motor to make the truck a little more drivable.

So far with this torque pulley we have hit 753 hp at 6400 rpm. This is on a very basic tune and we are hopeful to push this number over 800+ even with the belt slip limitation and the small cam.

Just like the 1st motor, the torque curve on these blowers are unbelievable. If you want power under the curve, or in this case power under the flat plate, the maggie is the answer. Diesels don't have crap on this motor, 705.7 ft/lbs at 2500 rpms says it all. Better start saving for another tranny build.

Will post video and graphs when we get the tune down a little better.

 

good numbers, in what truck is the setup on?

 

Wow Thats a monster there!

Congrats on your new combo,

Glad i bought PAC springs also after reading that.