cv67

Looks real strong. Get to work on that base/runners sometimes theres power to be had there.

TA

Unfortunately I'm gonna be away that weekend.

TA

Both are untouched, other then a little radius work on the upper end of the runners. I know there's plenty of room to hog out the base, but can anything really be done to the runners? I mean, short of scrapping them and going to a set of mega-ported SLPs or a First system.

I came real close to buying someone's old First set-up here on the forum, but I ended up passing. I'm kinda regretting it at this point.

I'll probably run this set-up for awhile and see what I can wring out of it (hopefully high 11s) and then consider an intake change down the road (SR or MR).

cv67

Good question didnt notice you had ASM runners

Probably not worth your while cost wise to go crazy on the base, buy SLPs then all the work involved. eventually youll tire of it and want more so skip all that

LT4BUD

The dyno curve is actually motor torque and horsepower as measured at the rear wheels.......so you are seeing what is left of motor power after drivetrain losses, etc.

RWTQ would be the torque shown on the dyno curve multiplied by the overall gear ratio (transmission & rear axle)....

Point is you really want to stay at the highest horsepower possible, since this will result in the highest rear wheel torque!!!

The horsepower curve being so flat does mean that "precise" shift points are not going to be that critical with this incredible engine build..

Hope this help, but don't want to get to far off topic..

Beach Bum

I am not a big fan of that HP curve.... you want a flat torque curve, hence a rising HP curve, versus a flat HP curve that you have. That motor will make a lot of noise as it makes its journey from 5000 to 6000 rpm, but will accelerate slowly and without much drama.

Your motor is a perfect candidate for a Superram if you can find one.... the torque curve will drop off at a slower rate, hence that HP curve will continue to rise. You won't lose any torque and might even gain some. On an initial dyno with my old 383, I had 540 ftlbs at the wheels. Bear in mind, this isn't necessarily reflective of what your motor truly has, its converter flash distorting the dyno.... but its good never the less.

You shift where the window provides the most average HP through that window. Hence, if you have an average 1600 rpm slap back rpm, then mathematically figure out what 1600 rpm window gives you the most average HP and you shift at that top of that. As LT4Bud said, your motor will not be real sensitive to shift changes because its all about the same, hence I'd shift your motor somewhere around 5200 rpm to get yourself in the next gear quicker, but this could be argued.

Here is an old dyno from years back of my 383 with the Superram/219.... at the time of this dyno, the car ran 115-116 mph traps and mid 11's with some below par Dart heads.....with better heads, it got another 3 mph on average, but I didn't dyno with the improved power, but believe it would have been in that 380-390 rwhp when I was running 118-119 mph traps. Take note, the torque graph scale is on the right... HP scale is on the left. Take that curve, lay it over your current curve and thats what you could have and then some....with just an intake change. (Ignore the little graph showing a 4700 rpm HP peak.... that was a pencilled in graph from another vehicle)

TA

I agree with what you're saying completely and I knew, going in, the pitfalls of keeping an LTR set-up on the car. The build really ended up the way it did because I was trying to complete it with a relatively low budget in mind and I had all the LTR stuff already. I probably have under 4k in the engine and that's including gaskets and misc small parts. So I definitely understand the limitations. That being said I still think the car will be a pretty strong runner. Hell, it can't be any more of a dog up top then the old engine was (stock cubes/heads/cam) and that still turned mid to high 12s.

Another concern for me is that I don't want to put a cage in the car. It's not a dedicated race car and I drive it and enjoy it too much to have to deal with a cage. I think the car will turn high 11s to low 12s even with the LTRs (obviously only track time will tell) so flirting with a different intake will having me right around that 11.50 barrier.

All that being said I'll still likely consider a SR or a MR once I wring what I can out of this set-up. It'll be fun trying though.

Beach Bum

Sounds like you know what you're doing.

No matter what you do, you're going to have fun.... 383's tend to do that.

GREGGPENN

Didn't notice this question the first time around. It's a good one too. But there are at least three reasons that should make the answer obvious....

1) My sidepipe system is more restrictive. Estimates are anywhere from 20-40HP gain just by converting to true duals.
2) I installed my cam 4-deg advance -- for maximum torque.
3) My cam is actually 10-deg total duration less than a SR cam. It also has a smidge less lift.

I didn't think about it until after I started typing but I don't recall if Tom has CATs on his either. I do.

Lots of power-cloggers on my setup. Seeing this thread makes me want to drop the sidepipes, throw on an HSR, and change cam orientation.

I still think Tom's build turned out great! It does say A LOT for porting the 113's for a TPI setup -- and not telling everyone that just HAVE to have AFRs for a successful build.

cypher85

cv67

its so hard to compare dyno#s
They can all read different

Gear ratio stall size even tire pressure and type can change the readings noticeably.

Put simply a 380rwhp car can run 10s right along with a 450rwhp car depending on what parts are on it.

Chevyguy168

If you don't mine me asking what was the peak hp rpm on this setup and you used as&m long tube runners?