Dyno

[Toolman]

Has anyone dynoed their stock Trailblazer, I cant find anything where on it..
Im going to take mine down on saturday for a dyno to see what it puts down should be good..

[02EnvoySLE Guy]

This should be interesting -- what year and powertrain do you have? (Engine, diff. gearing, locker, etc.)

If it's a new truck, just be careful. Even though it's not said so much any more, you still have to be gentile with breaking in the engine and driveline.

[Toolman]

Its a 2005 Trailblazer LS 4.2 engine with the 342 gears..
yeah it doesnt even have 200 miles on it yet, but im not worried.. I like to vary the RPMS while im breaking it in.. so bouncing off the rev limiter on the dyno should be ok..

[02EnvoySLE Guy]

Its a 2005 Trailblazer LS 4.2 engine with the 342 gears..
yeah it doesnt even have 200 miles on it yet, but im not worried.. I like to vary the RPMS while im breaking it in.. so bouncing off the rev limiter on the dyno should be ok..

ouch.... I'd wait for at least 1,000 miles. Remember you have to be sure the rings seat themselves. I seriously wouldn't recommend the dyno just yet.

[Toolman]

From what iv heard the best way to seat the rings is to warm the engine and then give a lot of full throttle..

But im going with the method I have always used, make sure the engine hits every RPM during breakin..


This has always given me great results..

[M Roc]

get some miles under the hood than get dyno...I think you will get better numbers if you wait :m2:

[zrwon]

ouch.... I'd wait for at least 1,000 miles. Remember you have to be sure the rings seat themselves. I seriously wouldn't recommend the dyno just yet.
Charlie, I don't mean to disagree but the best cars I ever owned are the ones I drove the **** out of right off the dealers lot, they always felt stronger than the others and I'm not the only one, there was a discussion on the ZR1net at one time and most guys agreed that when they drive them hard right off the bat, they seem to go better and stronger, plus the deal is you have 3 years warranty, you don't want to break it after the 3 years is up, so go ahead, drive it hard, if it breaks they'll fix it for free, so drive it like you stole it and change your first oil early and it should be fine. Why do you think they put rev limiters?
If it was a fresh rebuilt engine that has never been started yet, then I agree but the new car break-in period I don't worry about them.
Look at rentals, they get abused, did you ever get to a car rental and get a car with less than 50 miles, I have, and I drove the **** out of it, go for a test drive, same thing, brand new car, you drive the hell out of it and someone will buy it and I'm sure it will be fine. Since my first new car back in 1979, my new then Z28 it was the only one I babied for the break-in period, then in 81, I bought a brand new Vette and drove the crap out of it and it ran fine, so all others since never had a break-in period except when I had an engine built for my restored 69 Z/29 6 years ago, that is the only one I broke-in easy but that was for 200 miles, I then change the oil and took it to the drag strip and ran 12.18@118 mph and that car is still running strong today, my buddy has it now and he won't sell it back to me :cry: Back in the 70's they had problems with guys buying LT1's and big block cars and reving them to 8000 + rpm and they would break them, but now with the rev limiter, the cars are made to be driven up to that mark, look at Nascar, they will fry a motor, put a new one in and go back racing, they can't afford to go slow for the first 100 laps and they survive without a rev limiter.
Break-in period to me has been replaced by a rev limiter and if you break it, there was something wrong with it. :m2:
:m2:

[zrwon]

get some miles under the hood than get dyno...I think you will get better numbers if you wait :m2:Hey M Roc, gotta say I like that Aviatar of yours :eek:
It looks like your hand on there, can't be hers from that angle :D

[trk]

I've got a dyno, but need somewhere to host the picture. My usual host is down.

[Toolman]

what were your numbers..

[02EnvoySLE Guy]

I've got a dyno, but need somewhere to host the picture. My usual host is down.

email it to me and I'll host it.... charlie@hahn-on-the.net

[XTREEME]

It will be interesting to see the actual numbers of a new stock I-6. Although, doing one before 1000 miles will not give you the full results.

I'm going to make a guess of 225 rwhp. Now remember, the majority of that will be in around the 5k range, so when you take a 4700 lb vehicle, no wonder its a slug off the line, even with 3.73's.

Also, it is true that how you treat your engine during breakin miles will dictate the full potential afterward. A friend bought his C5 the same spring I did, and he really took it easy on his for the first 3000 miles. Meanwhile, I had mine to BIR twice in that same 3000 miles.

We did stock Dyno's together that summer before I added any mods. His came out to 299 rwhp, while mine came out to 308 rwhp.

[Toolman]

Auto trannies suck about 20 percent of the power before it hits the wheels.. so 225 would be a bit high.. unless they under rated the engine..

I have driven the 255 HP honda pilot and it sucked compared the the trailblazer in power..

[XTREEME]

Auto trannies suck about 20 percent of the power before it hits the wheels.. so 225 would be a bit high..

225 + 20% = 270 No?
(Actually the 05's, and maybe 04's too, are rated at 275 now).


unless they under rated the engine..

GM Under Rate their numbers? http://home.comcast.net/~joelischynski/super-rofl.gif

[Toolman]

275 - 20 % = 220 hehe..