i dyno tuned the new motor yesterday.

dissappointed to say the least, but the open cutout gained 21 rwhp, no bullshit.

the motor only made around 365 rwhp, and around 385 tq... i was expecting ALOT more, but there are a few problems i need to sort out i guess.

power was peaking around 5600, a bit lower than i was hoping.. i am sure my stock truck intake is choking it a bit up top... i still havent found out the exact cam specs, and these are supposed to be patriot stage 3 heads, and 11:1 pistons.. you would think it would do 400+ rwhp... but it didnt

motor is a 6.0 bored .030" over, with the afore mentioned heads/ cam is "supposed" to be around 230/236 580/585 on a 112 ... it sounds lopey and good, and i love the sound, but DAMN. my 4.8 made over 300 rwhp with just a cam/headers.. WTF?? granted this was a conservative tune to keep me a little rich for the juice, and not alot of timing ( 26-28* ) but the 4.8 was tuned just the same, for nitrous.. and made over 300..

i was so dissappointed i didnt even save a file of the pulls.. a member on here was around for the first pull or two, and made a video of it. ( ntmd8r )

i need to upgrade the fuel pump before the juice hits it, but it WILL get juiced for sure.

 

I would guess that the problem is in the tune... IMO that motor combo should pull way into the 6k area... Hard to say without seeing the logs and tune...

 

WOW. applying your results to my 5.3 NA #'s I would be putting down 376 RWHP. I was fixing to go test it myself, lol. maybe I will and see if we get like results.

 

nah, that is the only thing i do trust about these results..

he is the best tuner for miles and miles... seriously.. AFR was dead on, timing was where i wanted it for the juice.. he spent 4+ hours messing with it, this is all he does for a living is tune..

i am dumbfounded though, it should have made more. a friend of mine questioned the pushrod length, i will be getting a PR lenght checker and measuring... but i cant see a PR accounting for the missing 60 hp it should have had?

i used the 7.400" manleys from my other setup, since this new motor didnt come with any. stock 1.7 rockers and 7.400 manley PR's...

 

A quick way to find out is ask him if he adjusted your cylinder volume parameter in the tune... Or if he just used a 6.0 segement and adjusted the cylinder volume parameter for the over bore... Just cause your AFR is dead on doesn't mean the tune is setup correctly...

Also there are a couple of TM tables/parameters that will do the exact thing your describing, I have read of several Corvette guys that get into modding having the same problem...

 

fixing to call him and see.. i know the tune is a bit conservative for the nitrous... but i just feel it should make much more than that on motor.

maybe i expect too much?

 

Are you comparing the 4.8 and this engine combo on the same dyno? I would think it'd keep pulling to 6k also. Run it and see how it does in the 1/4, do you have times from the 4.8 for comparison

 

i am, and was. it will be run at the same track as well. the 4.8 only had a high peak power of 305, but the line on the graph was a steady climb..

this new motor is making an avg of 90 ft lbs over the 4.8 in every area except where it peaks.. and about 70-80 more hp the same way.

the track will tell me what i need to know... i was just hoping for some high 7 second 1/8th miles n/a. probably not gonna happen

 

Sounds like tuning, Again that combo, should do 400whp, the truck intake should let it pull past that mark, to the 6k mark atleast before it fizzles out... Post some vids damn it

John

 

How is it 377ci? I thought .30 over was 370?

Also, maybe you just ran on a conservative dyno? My stock tuned LQ9 put down 267 in 2nd gear. Even if you factor in the converter being unlocked, it's still well under what is "normal" here for a 6.0.....the dyno is just known for being low