I dynoed 263 rwHP & 297 rwTQ yesterday. The technician noticed a lag at 5500rpm. When he showed me the graph, you can see nice lines up to 5500rpm and then she poops out? He said it could be anything which didn't help me sleep at night. Car seems to run good, I'm lost.

 

Was the air/fuel ratio taken during the run? My car (stock) was starved for fuel after 5200 RPM. Can you scan and post your chart?

 

If possible a pic of the dyno sheet....

Chris

 

I've yet to post a pick in this forum....hhhmmm I'll take a photo of it and try to figure out how to post it asap.

 

E-mail it to Mattashaffer@hotmail.com and I can host it and post it for you.

 

If your engine is stock, your power is dropping off at around 5,200 rpm anyway.

 

don't always take dyno numbers as gospel. run it at the track and see what your time is. thats actually a cheaper way to dyno it

 

Weak stock valve springs will cause valve float which could be it. Ignition breakdown (Opti) could be another cause.

 

I'm not saying it's gospel. What I'm saying is, I've seen plenty of LT1's dyno in my day, and, by nature of how the motor's built, stock cam and all, power drops starts to drop off ~5,200 rpm.

 

Yeah LT1's are known for low end, not top end. So it makes sense. If you want top end than get a cam or an LS1

 

Thanks a lot. I sent you the pic, let me know if it went thru OK. Whoever said the LT1 power starts to drop at 5200rpm was right, I had a closer look. I put my stock MAF back on now and I'm getting that "PCM recalibrating" power. We'll see once it settles. Can Ion fix this 5200rpm crapper in a tune? What would a LT4 knock sensor do? My car was loud as hell !!!!

 

Here is the dyno sheet.

I'll try to get mine posted, as a comparision.

 

Ok here is my dyno sheet, if anyone is interested.

 

Hey patrick, was it a dynojet or a mustang dyno?? If it was a mustang dyno then your numbers are fine and it would make sense... If it was a dynojet then you are in fact making less power than you should because 260 is around stock for an LT1 on a dynojet.


Chris

 

She was a dynojet and I was looking for 270-285rwhp, that's making this so frustrating?! Can anyone narrow down where I should start looking for the missing power. Just want to know what steps I should try next.

my thoughts.....
I have bought an aftermarket granatelli MAF and used it for this dyno test. Stupid me I did not bring my stock MAF to do a quick switch and see any differences. Will a tune help this out, maybe the OBD2 is still not recognizing mods? Is my timing being pulled by the PCM....ie LT4 KM? I hope ION at MADZ28 can prescribe a cure.

Thanks for the get an LS1 jab. This car is for life!!