Finally dyno'd with the D1
 

Best I could get was 548 rwhp 563 rwtq on 10#. Blew the plenum twice on the dyno. Then starting blowing the hose off the TB.

I didn't gain anymore boost. But under the curve I gained quite a bit.

Blue line is the P1. Red line is the D1

http://www.ls1.com/ed/d1/dyno.jpg

http://www.ls1.com/ed/d1/plenum.jpg

Looks like you need to find a better tranistion piece and get rid of the worm clamps and invest in some T-bolt clamps. Good results though.

At least you got a small power gain. But I feel your pain. I was making 13 psi last year with my D1 with a damaged impeller. I had that replaced & now all I can make is 10 with all the same parts. Haven't dynoed it yet but I lost 1/10th & 4 mph. WTF?!

Where is the D1 pulley'd compared to the P1SC? I remember you had the P1 maxed out but if you have the D1 maxed out and seen that little gain there are some other issues.

Yep. T-Bolt will be next.

I don't know why I didn't gain any peak HP. Peak boost was the same.

Peak HP is still 5500 rwhp. I really thought I would have gain more with the D1.

I moved the pulley from the P1 to the D1.

area under the curve gain is nice. but damn what a p.o.s plenum box. looks like you'll have to get a custom one made with heavier gauge stainless steel.

And what size pulleys are they?

No shit. I had that area welded and it blew on the side on the next run. So I had them weld the whole box and put in two supports in the center.


If I remember correctly 3.2

I wonder if I could be getting belt slip??

what size crank pulley, sdce, ATI 8 rib, MMS 6 rib, stock 6 rib? I dont remember what you are using.

Interesting that you are blowing the plenum apart and hoses off with only 10psi. Either way I would think that D1 should be making more then 25hp peak more with the same pulleys, something just doesnt sound right.

bypass valve not working right? what do i know.

Yeah I bet the surge valve or something related is not likeing all the new found air. And another thing is the blower has nothing to do with where peak power is that would be your camshaft mostly there are some small variables, but my experience has shown if the same motor peaks at 5500 with one blower it will with the next also. I was thinking the same thing about the plenum box blowing apart on 10 psi but then there is a lot of surface area so 10 pound per square inch means there was a lot of presure on it really.

I am running the SDCE.

Ya, I was really disappointed with the numbers. I really thought the D1 would have put me real close to 600. I really don't know what to check next.

I was thinking the same thing. Getting a larger valve.
I guess the cam might be an issue, its not a real hot cam. But I would have thought it would peak @ 6000.

10# isn't that much, but isn't it more as you close the throttle? I think both times is blew as I either hit peak boost or as soon as I let up.

I did have them weld the whole plenum and add two center supports. It held on the next two runs, but the hoses didn't ;)

http://www.ls1.com/ed/d1/plenum1.jpg

I didnt say anyting about where the peak was rpm-wise, just it should make more power there compared to the P1. *edit, thought you were referring to what I said about the 25 peak since I wasnt real clear when I typed that, sorry ;)

The lower rpm numbers look right between the two but it seems to dying out up top, I have done the P1 to D1 swap and picked up 60rwhp, 476 to 535 peak on a stock engine, pretty much across the whole rpm range using the same pulleys. Someting is hurting the airflow up top it appears. Could be the air filter, intercoolers, or the belt could be slipping, I never ran a 3.2 pulley and thats gettng pretty small.

But does seem to peak early, my '01 z06 cam peaked at 6400rpm or so, the 222/228 115 XE about 6600 and didn start really falling off until 7000rpm. A 4" stroke will peak earlier but 5500 and dropping off quick seems kinda short but thats another issue.

If you are using the stock ATI bypass you will most likely keep blowing things off when you let off the throttle quick. It just cant move enough air, if you have a mondo or something make sure the spring tension isnt cranked up.

I just changed the air filter to the larger one EPP sells. I guess it could be the intercoolers. But some have hit over 600 with them. :dunno: Now I can believe the belt could be slipping, I will check for dust tomorrow.

My cam is very similar to yours, 222/226 115 XE with .595 lift.
The only variable I am unsure about are the heads. Maybe I should get rid of them and go back to a set of 5.7L. That will bring up my CR to 9.5:1

I will look into a larger valve. I currently run the Pro version.

jesus ed! stop breaking things!!! :lol:





so you want more power? sounds like its time for some TTs :devil:

Yeah anything under a 3.4" pulley some have had belt issues. The heads still aren't going to affect your peak power issue I would ask did you advance the cam any when installed that can affect where peak power comes in, but it is usually a few hundres RPM's I'd guess around 4-500 rpms so you could always retart it a little to raise the RPM it peaks at etc. And on another note if you want to keep it from blowing off after a pull don't just release the throttle all the way at once just lift a little slower so that that the valve has time to catch up etc... until you get a new BOV.
Yeah I gotcha KP. Didn't think you were. Just trying to give him a little more info that he may or maynot know just so he thinks it through etc...

Who doesn't? ;) Regardless of peak power. It does pull pretty darn good with all that torque under the curve. So that should make me a bit faster. But it is disappointing to spend all these $$$ and not hit your goal. Guess I could spray!

I think my builder installed it straight up. Thanks for all the info.