My basic setup was: 8.3/1 383 LT1, AFR210 heads, 224/236-114, +0 cam, T-76 GTS turbo at 19 psi, Vortech aftercooler with torturous miter 90's, 52 mm throttle body, 3 speed auto and Vigilante 2800.

This combo made 680 rwhp.

Then, I made a few upgrades. I switched to an intercooler 2.5x the size of the Vortech (still water/air), used all long-radius 90's, 58 mm throttle body, raised the runner roofes in the intake manifold (helps LT1's alot), fixed a 1/4" boost leak, added ice to the intercooler water, raised the boost 1 psi, and switched to a cam very similar to the F-cam since people make so much power with it. It's a custom grind from Crane that's 226/226-114, +5.

This made 675 rwhp today.

I'm pretty disgusted that, with all those new parts, it lost power. Everything except the camshaft can only help power. Bigger intercooler with ice, bigger throttle body, more boost can't hurt horsepower. I was counting on at least 40 more rwhp, but it LOST. The only thing I can figure is that the cam hurt the power.

Any other ideas???

 

maybe a leak somewhere? Sucks to go through all that work and end up with that.

 

can you post the graphs of each?

 

I don't have them scanned, but they wouldn't do you much good anyway. Due to the "loose" converter (a 2800 vigilante will stall pretty high with alot of torque), the dyno runs are only from 5400 - 6200 rpm. You can't tell if it gained low-end.

 

you could also be eating through the converter that would give a lower dyno #.

 

Mike,

what happened with the torque? and what did the graphs look lke? was it just peak powerthat fell off or was it consistently lower across the curve?

do you have an adjustable cam timing set? you may try degreeing that +5 cam in back a few degrees, maybe something like +2 or +3.. advanced cam might be hurting it a little but its just a thought. if you don't mind me asking, why did you decide on a +5* advance ground in? I think that cam is likely why your power fell off, can you get some pictures of the setup online to look at? and did you change any tuning with this new cam intercooler upgrade? perhaps the new cam likes a little more timing and with a more efficient intercooler, you may be running a little ultra safe compard to what the new combo would like to have.. just thoughts trying to toss ideas out to find a solution!

Chris

 

Yupo the cam moved power down too much and it seems as though you blew through the converter.

 

What does the converter flash to? 5400?

 

I'll do my best to interpret the graphs:

-rpm- old new
5400 612 600
5500 643 622
5600 663 645
5700 675 655
5800 680 670
5900 675 675
6000 651 650
6100 640 625

LT1 doesn't have adjustable timing set. I had it ground 5 adv because I was trying to match the Ford Motorsports F-303 spec's as closely as possible since the turbo mustang guys have made sick power with it.

I don't have any good pic's, but I can describe it. My homemade kit is similar in layout to the TTi LT1 kit. The turbo is in the same place as a Vortech supercharger except the compressor is facing forward. I'm using an SLP 1 3/4" shorty header on the passenger's side with a 2 1/2" crossover pipe under the motor. Driver's side is a 3" log, but I made the tubes "merge" into the log rather than "tee" into it (except #1 tee's for lack of room). The downpipe is 3" until it doglegs to get under the car, where it goes to 3 1/2". For the cold side, I'm using a 5" inlet pipe and air filter. Cold side piping is all 3" long-radius mandrel bent piping, with the 20" x 4.5" x 4.5" water/air intercooler mounted just behind the air dam.

For consistency's sake, I left the timing along. The A/F ratio was 11/1 on the dyno pulls.

Mike

 

It seems on the street to flash to 5200, but on the dyno it looks like 5400, so somewhere in that range. Amazing how high a 2800 Viglante will go when you apply alot of torque to it.

 

Sounds like you're blowing through the converter.

 

What does it mean to blow through the converter????

 

Some believe that you can actually increase power too much for a specific torque converter, so added power just causes the converter to slip more.

Though this premise is incorrect, you can actually have too much converter. For instance, if you install a Vigilante 7 pump (3600) in on a Duramax diesel, you're probably not going to make much rwhp. Likewise, if you make a change to the engine that lowers the rpm where your hp peak occurs, and the converter is loose such that it stalls just below peak hp, then you could lose rwhp.