caci

Sorry, never had that one - only Horsepower Overlay. I’ve checked all of our email & PM.

Chimera96

Valve float typically shows up on a dyno graph as jagged and falling line often above 5k rpm. The car, while driving, when this happens feels like it "noses over" meaning just not gaining any power and can break up. If this is not happening than your valve springs are keeping up with whatever cam you have.

Freds comment referencing a B body cam which would give lower RPM TQ vs the F or Y body LT1 cams as the B body weighed more. The F & Y body cams made more HP respectively than the B body LT1

Cam aside, without knowing what quench is, that can considerably affect engine HP/TQ

caci

Yes, I understand the “more low-end torque” of the B &D bodies LT1 engines vs. the Camaro/Corvette versions.

I also understand Fred’s point regarding I may have a “B-body” cam (perhaps my “truck cam” remark was taken out of context?).

I like the theory of wrong/wrong-timed cam (UNLESS, this all is due to engine management).

I’m not sure if my latest Scan, (included in original post) has yet been blessed.

caci

My mechanic spoke with Jasper guy today. NOW, we are being told that the camshaft IS new, NOT reground. He said they installed Melling MC1335, which seems to be a stock grind for 93/94 LT1 Camaro/Corvette.
So now, if they are to be believed, then the cam must be mistimed or defective. I’m still waiting to hear if my scan shows any signs of another issue.

TubbyFormy

looks like a b-body cam, looks like valve float (fred sent me the scan9495 data), looks like whoever "tuned" this before did NOT know what they are doing (blm's are not even locked at 128 wot, pe enrichment table appears stock).

that 336 hp green line is definitely fudged based on correction factors and weather. i am sorry, but theres NO way. even a hotcam full bolt on lt1 will barely touch that to the wheels. a stock cam definitely will not

many years of doing lt1's now, stock lt1 auto original plugs original exhaust 248whp on a dynojet, bone stock T56 94 camaro stock plugs etc (around 80k miles) on a GOOD day std correction 270whp.

get rid of the bbk 58mm tb, probably vac leaking around the throttle shaft causing some of the lean o2 readings. i really really think it is valve floating based on the maf and map values above 5300rpm, its hopping all over the place once you get there. also your maf g/sec data from the dyno would suggest around 270ish whp.

A final edit: just got home from work and looked at a "Jasper reman" LT1 i have in the garage (pulled from a 96 Trans-am), if its any indication of Jaspers reman quality, it was 1 0.030 over piston, and 7 0.020 over pistons....................................now i want to measure the cam against a good known stock f-cam. will get back with results tomorrow

if you would like help (free help, not charged for) and you have a aldl cable and a laptop with your tune, fred can give you my email address, or you can find me on fb shaun townsend. be happy to help. i am fairly active on LTXTech still too (SSlowBoat).

fyi stock throttle body on a 381 solid roller lt1 stroker is good for high 9's lol and for the record it went 9.90 @ 134mph with an opti and original 94 pcm tuned by myself. fred can vouch for that (its his old car))

Injuneer

My Holley TB sure looked good, all polished up. But it had issues. BBK may be similar. The Scan9495 data log shows a solid 0.63 volts closed throttle. But just on the two WOT pulls I looked at in detail one showed 100% at less than 4 volts, and the other 100% at more than 4 volts. But neither reached the ~4.5 volts I typically see. Could be a combo of the slop in the cable??, plus the blades simply aren’t opening all the way, causing a loss of almost 9 kPa MAP above 5,400 RPM.

Many people have complained about the aftermarket TB's having inadequate idle air flow, or split BLM's from the idle air flow. The Scan9495 log shows idle IAC counts near 60. That would appear to indicate the BBK TB has the typical problem. It was not an issue on my setup because I was only using the factory PCM for idle control. The MoTeC ECU could not control a stepper IAC, only a PWM IAC.

Rather than try and solve the BBK problems, listen to Shaun. My 381, making 490 HP on the engine dyno did not need the 58mm TB. The dyno cell was measuring air flow, and the engine got all the air it needed at about 75% open. Opening the blades further did not increase air flow (or HP) significantly. The guys that built and tuned my engine laughed at my 58mm TB. My mathematical approach showed that normally aspirated (no volume reduction due to auto cooling of the N2O injected before the TB) a 52mm TB would have been more than adequate. Just consider a stock replacement.

I'll send a graphic presentation of the LTFT issues. In closed loop, non PE they are adding less than 5% extra fuel on the right bank, but in the range of 5 to 10% extra on the left bank. In PE mode the LTFT's are adding up to 15% extra fuel. I'll have to see if there's something other than locking the trims at 128 to solve the issue.

I think I forgot to ask Shaun if the loss of MAP and the torque “peak then drop very severely” could also be caused by the cam being installed advanced or retarded from where it is supposed to be.

caci

Sent you a FB Message.
Thanks,
Chris

TubbyFormy

fred i spoke to chris yesterday and went over his log with him. the iac isnt far off from where it should be, but i feel like the tune needs work either way. the split blms didnt look too bad, but i feel like something else may be up sensor-wise. im wondering about the opti signals getting weird. similiar to my msd incident

Injuneer

For anyone following this (anyone?..... anyone?....Bueller?) here is the extracted data for two WOT pulls that I sent to Shaun. Second item is a graphic presentation of the LTFT data.

lt1-xjs

That's in a nice easy to read format.

caci

Thanks everyone for trying to help me. Shaun has suggested that there's an issue with my tune but, I argue that I have a GOOD tune, based on former performance (AND, previous performance at the dyno).
To verify my tune, he recommended that I download Flashhack/EE Flash and copy my tune to a file for his review.
I'm not able to connect for "read calibration" with the following error - "Could not connect or load the kernel" (even after successful Flashhack's "cable test" procedure). This is the same cable I use to connect to Scan9495 (I built it...)
Shaun has been VERY generous with his time, as has been Fred!
Anyone have a suggestion for getting my notebook connected?

Chris

chevykid

check out this video

caci

Been there, done that, have the t-shirt!

Thanks, but I did view that and I've chatted with Shaun about it.
Scott says "do not extract anything from the Application File". However, to get the Application to open, I do have to unzip it (I've downloaded, deleted and re-installed 3 or 4 times.)
It asks to "verify the connection, with the cable in the computer but unplugged from the ALDL" . Have done that every time I try to launch and always shows "OK" .
Then, "cannot...kernel", every time.

When opening the downloaded Program, the file window looks just like the one in Scott's video. Again, I have to un-zip (extract) to get it to run and THAT file window looks different, although it does have the Application File, which can be opened (see photos below).

It will be obvious I'm not too computer-literate...

Thanks!
Chris


"Zipped/Un-Extracted", same screen as Scott Strong's Video



"Un-Zipped / Extracted" - Scott says not to... but can only open App from this window (or via shortcut from this window)

Chimera96

OP, replace the TB with a stock one to get rid of the several "issues" the BBK has. Your motor does not need a 58 and would require a stock intake manifold to be enlarged from 54 to 58mm so hopefully that happened.

While the support you are getting analyzing data, above my pay scale, is extremely helpful regarding your tune....no offense but you are polishing a turd (Jasper engine). Their build quality is simply lacking. With a perfect tune it can run as good as it can but ring gap. quench, valve springs and possibly cylinder bore concerns, a perfect tune won't fix that

caci

Correction.
A member from another forum and some of you have questioned the throttle body as a possible reason for the loss of power.
I’m mistaken, as I have a BBK/Edelbrock 52mm version, NOT THE 58mm one.
As can be seen in the photos, I’m not using an add-on air foil - it’s integral and has the “idle holes”.
I’m having no issues with idle and it is fully opening (solo today- no one to floor the accelerator pedal).

Thanks