Black LS1 T/A

I'm asking this in the Boosted Section because, well, duh ... I'm boosted. I need FI opinions.

BEFORE:
Seeing peek 11 PSI in 1st and 2nd, but boost would drop 2 or 3 PSI above 6000 RPMs because of belt slip.

My best power was 549 RWHP, 757 RWTQ.

But, at the dyno, or on the track, because of belt slip at the time, in 3rd gear I'd see about 9 or 10 PS peak when I hit it. By the time I hit 6000 RPMs, I would be DOWN to about 7 PSI.

My best run was 10.84 at 124 MPH, 1.57 60'.
It slams ***** to walls out the box, thru 1st and 2nd, but feels like it lays down in 3rd.

My top dyno sheet I don't have on the web, but this one is consistent with the best one, except I only had 42# injectors and the old fuel and pulley setup and was running about 7 PSI.

Notice how torque slams initially, and then drops off. I know the converter stall has something to do with this, but not all. Part of it is I was losing power as the belt slipped.



AFTER:
Now, with the 8-rib and Superdamper, I'm seeing 12 ~ 13 PS consistent, at least in 1st and 2nd. (I haven't been to the track yet to see what happens in 3rd.) I hope to go tomorrow if it doesn't rain.

But, I think, seeing as how, even with MT 11.5x28 ET Streets I spin like glass in the street, and can only get good traction at one of four tracks around here, I could stand to lose some torque if I gain some top-end power.

Instead of 550 HP/750 TQ, I'd like something like 650 HP/700 TQ or even 650/650.
Of course, with my boost up, I may be nearing 600 RWHP now, anyway.

With my current cam grind (approx. #'s), 236/246 @ .050, .585/.575 lift, 116 LSA, I idle at 750 rpms no problem.

I talked to the original engine builder and comp cams. Do you think this grind would give me more of what I want:

242/250 @ .050, .592/.595, 114 LSA?

Opinions?

sr71

iTrader: (17)

I don't think your cam is the problem, unless it is 3-4 teeth off at the chain. you may be asking too much of that D1. to put this in perspective, I made 650rwhp/600rwtq with a 347, D1, 222/228 cam and home ported heads with stock valves. my car went 10.38 @ 135mph still on the stock irs. it sounds like you have a bottleneck somewhere or are pushing the D1 outside of it's useful flow range.

frcefed98

iTrader: (16)

F1 upgrade for the big ol 422 Mike...poor ol D1 just can't hang.

Black LS1 T/A

Thanks for the advice, guys ... I'll see what it does at the dyno and track now that the belt doesn't seem to be slipping.

2001WS6Vert

If your seeing 12-13 lbs. on a 422 I would say you have to be over 600rwhp. Maybe you'll get a nice suprise when you go to the track.

NA$TY-TA

iTrader: (21)

Id agree with the other guys... the cam you have in there is working and as you said belt slip was your problem....... if you want more out of it... its time to upgrade head units.......


Kyle

engineermike

This is a VERY interesting thread to me.

My last combo was a Vortech T-trim at 13 psi on a 383 LT1, AFR 210 Race Ready heads, and a Comp 224/236-114 cam. I ran a Vigilante 2800 "0" pump converter and a TH350.

Here's the interesting part: I made right at 550 rwhp and my curve looked almost identical to yours.

However, my car ran 10.40 at 132.5 mph on a 1.52 60' at full street weight. That tells me that you've got the power to run the same number if you have your belt slip problems solved.

I've seen others run over 140 mph with the T-trim and the D1, so it is possible for you to go faster than even I did.

Before I decided to go turbo, my plans were to optimize some other aspects of the combo such as:
- Remove all restrictions upstream of the compressor.
- Install skinnies up front.
- Larger throttle body and ported intake.
- Ice down the intercooler.
- Race gas with more aggressive timing.

Mike

BlkHwk

iTrader: (8)

Not sure how I remember this but when you had originally dynoed the car and posted the results (If I remember correctly) the tuner had thought the exhaust system might be limiting the HP levels. Have you opened up the exhaust? Do You have anything left on the table as far as impeller speed (interested because I will be using my D1 on my new combo)? I like the new cam specs you have posted (it is similar to the cam that is going in my new engine) but it sounds like eliminating the belt slip will help considerably.

There is no doubt that 422 would get along very well with an F series.

Looking forward to seeing your new ET's & MPH.

Black LS1 T/A

Thanks, guys.

I haven't done any more exhaust work yet.

Also, I have some more work to do on the fuel system. I have rails and RRR, but the Y from my pumps and the outlet of the fuel sender needs to be bigger, going to my supply line. I'm still a heavy car .. almost 4000 lbs. with me in it. That's the one thing I don't like about the Iron Block. The front is heavier AND the car is more difficult to hook.

Also, I could probably use some adjustible shocks to get a better launch. And, the ET Streets may not be enough. But, I'm afraid I'll trash the 4L60E again and have to deal with the issues of making another tranny work.

I know ... I'm such a wimp ...