laughatrice

iTrader: (12)

I'm just finishing up on the dyno with my procharged car. Here's some basics.

LS 427 F1A Procharger FMIC
ETP 245cc heads (valve springs are whatever ETP was sending on them my understanding good to 70 lift)
Cam has a lift that would approach 70 on the exhaust side
TH400 Trans
LS2 intake ported
Lunati link bar hydraulic lifters
Stock rockers!!!

I'm making just over 700hp we ruled out exhaust as restriciton. I think power should be higher.

My graph is on a different computer heres the critical stuff though

@ 6200rpms - 720rwhp- 16psi - PEAK POWER
@ 6800rpms - 670rwhp -18psi - ?????

I ran open headers for a pull it made no change in power at all. I'm thinking valve springs. No noticable break up although there was some speculation if someone heard some breaking up on one of the pulls unconfirmed though.

I may have to much preload in these lifters but I doubt it will be double checked doubt that's my problem.

Suggestions?
I

laughatrice

iTrader: (12)

Here's the graph

2001WS6Vert

What are your cam specs.?

Shawn @ VA Speed

iTrader: (3)

what intercooler is on this? it really doesn't look like valvetrain instability. The tq curve is really low for a sc 427.

laughatrice

iTrader: (12)

The intercooler is the one EPP sent with their procharger FMIC kits I'm not sure the brand name as it was a kit intercooler. I would say the one I got is similar to the ones you would fine on ebay as far as quality. EPP is no longer around but maybe someone can chime in as to more specifics on the cooler.

I do recall on hot days last summer I was seeing IAT close to 150* on WOT pulls.

Shawn @ VA Speed

iTrader: (3)

got any pictures or sizes of it. I would really be curious to see the pressure drop across it.

laughatrice

iTrader: (12)

Yea here it is I'm not sure about the pressure drop I can try and get set up to log that but I don't have the equipment currently.

WS6HUMMER

iTrader: (19)

I think it may be an efficiency thing, I run that same intercooler & have found the limits of my little turbo. I trap the same on 13#'s as I do @ 15#'s, it just cant push anymore air without super heating it. I think this may be your situation, keep in mind I dont have any experience with superchargers though. Thats the ebay intercooler BTW.

Oh yeah, boost leak testing would be a good idea too, I test mine every time I have to pull a charge pipe, I usually always find a tiny leak at one end of whatever piece I removed.

Bob@BruteSpeed

iTrader: (16)

We used this same 12x31x4 intercooler on my Camaro and with an F-1A I was making 19 to 20 psi of boost, and the car ran a 9.12 at only 146 mph due to driving through the converter, which trashed the Powerglide.

We also used this same intercooler on this CTS-V. http://www.exoticperformanceplus.com...Car.php?car=29

What are you using on the inlet side? I'd try a run without anything on the inlet side to see if you pick up a lot of boost. Bob

laughatrice

iTrader: (12)

Bob thanks for weighing in I wasn't sure that you guys used the exact intercooler on those builds. Interesting it worked that well then I honestly haven't been to impressed with the IAT I've seen out of this intercooler they would easily exceed 150* if I ran a 1/4 pass I usually only run the 1/8 though.

We are using the truck inlet we ran it with no filter or inlet just open compressor and the power/tq curves were exactly the same no increase in power. Also tried with open headers same results. The problem is somewhere between the charger and the headers as if that narrows it down.

WS6 and Shawn procharger doesn't have compressor maps available but looking at the vortech ysi which is comparable I think we could be running out of the efficiency range as you mentioned if the intercooler is stopping things up. Anyway to troubleshoot that other than throwing a high $ intercooler would I check boost and temp prior to the cooler and compare with after.

Also keep in mind that boost continues to climb even though power drops off. I don't necessarily understand that.

WS6HUMMER

iTrader: (19)

With this intercooler and small turbo that I'm running, the more boost I put to it the hotter the IAT's get. I see over 150* by the end of the 1/4 running pure C16, & that's with cooling it down completely between passes.

One thing to keep in mind is, if your not tuning your own stuff the tuner that did the tune will almost always setup the IAT spark adder table to start yanking a decent amount of timing for anything over 149*. I experimented with this a little, slowly adding spark back running pure C16 and the car got faster. Didnt have time to remove as much as I wanted to but the car got faster with every degree of spark I added back but still made no more power at 15# than it would on 13#, I would NEVER recommend trying this with pump gas though.

Bob@BruteSpeed

iTrader: (16)

Make sure the intercooler hoses aren't pushed too far onto the intercooler. This has caused a restriction for several customer's front mount kits as it can choke the airflow. Bob

laughatrice

iTrader: (12)

Here's the hp tuners data log wideband data not available here but if you look at the dyno sheet it's on the bottom.

WS6HUMMER

iTrader: (19)

There looks like 2 pulls on the log, which is the first on the graph, the light or dark blue one? Also, I'm guessing you run a 3 bar map?

Gonoma

iTrader: (15)

Im new to tuning but would your spark plugs being gaped too much cause an issue similar to valve float if it is blowing out the spark?

laughatrice

iTrader: (12)

It's the first pull I don't remember what happened on that 2nd pull but the MAP was reading very low the first pull is accurate and reflects the dyno sheet above.


I never really thought much about plug gap I've had that happen before where the spark blows out but usually it pops and breaks up noticeably which it's not doing now. I suppose they could be just barely missing but I thought I would hear it.

WS6HUMMER

iTrader: (19)

I've never had issues with plug gap but I did have someone bring me a LT car with a procharger setup because they couldnt figure out why it stopped making anything over 10psi. I asked about plug gap and they had them gapped @ .055 lol! I told them to close the gap to about .025, after they did they called to say thanks and now it would make the target boost over 20#. They never had the power fall off it just refused to make boost past 10 psi.

Not saying that gap is not your problem but for your 18 psi I'd run my gap @ .025-.02. IMO

laughatrice

iTrader: (12)

Yea right now mine are at .028 I may try 25 tomorrow. It's not missing or anything like it usually does when the spark blows out. Thanks

Gonoma

iTrader: (15)

Sorry like I said Im new to tuning and thought Id throw that out there. wish I could help you more

chevydan

iTrader: (4)

Updates ?