Well, I dyno'ed the car again today after installing the Vortex Airbox, 160* t-stat, and having the PCM remapped by Fastchip. I'm disappointed, and feel like I wasted the dyno charge. Two weeks ago with only the mufflers the car had 296.6hp and 302.2 torque at the wheels. Today I got 303.3 and 307.1 respectively. For the money I spent I expected more....

The worst part is, technically the hp only really hit ~300, there was a spike that happened from 5800rpm to 5900rpm that bumped it up to the 303 mark, I intend to call them next week and ask what that's all about. Seems like a joke to get the largest difference at the very end of the power range, it literally only jumps for that 100rpm's (will scan and post soon)

I know that it's next to impossible to really dyno a ram air system, so hopefully I'm getting some benefit from it, but if you care about my impression of the Breathless Performance Vortex intake take a look here: http://www.corvetteforum.cc/reviews/...=161&TopicID=5

Sorry to seem so negative, I just wanted my new baby to be the baddest one on the road, and I'm feeling like the upgrades are letting me down.

On a more positive note, I completely shamed a couple 5.0 guys the other night, one of them I didn't even get on it until he was 1 length ahead of me, then I was able to gap him by 1+.

Thanks for listening, and let me know what you think of Fastchip programming,
Sam

 

I have his chip. I bought it for the cooler temperatures. My car never breaks 182* in 100* weather. It does this task well. I'm not sure what it did performance wise though.

 

Oh and another thing. I have a ram air too but the gains can't really be seen on a dyno unless they have a hi powered fan. Maybe if you go to a dyno with a fan you can see the results with the ram air and chip working properly.

 

I think you'd have been more happy w/ the results if you did before and after testing at the track because I don't think your vortex is gonna show much on a dyno as there is no air moving through it.

 

I agree. I'm running the forced air kit and I'm sure that if I dyno'ed with a turbine blower forcing the correct MPH winds in there ... or if I took it to the track and calculated out the HP from there, that it woud be higher than my dyno showed as well.

 

Sorry to hear that. I would deffinately take it to the dragstrip and get some numbers on it. I've got a fastchip on order and it is supposed to straighten my car out. The tech seemed to know exactly what my car's problems were after my mods on my 90. I guess I'll find out next week... I sure hope I get more than just a few extra horses.

 

Ditto with what the others said. I had my LT4 dyno'd back in July and put down 305/313 with similar mods.



My AFR was running a bit "factory fat" at the time. From what I've seen, you really won't pick up much if anything on the dyno with the airbox. The reprogramming job also won't give you much with a stock motor. I think a 7HP pickup sounds about right.

Scott

 

Anyone wanting my OPINION on this one E-MAIL me.
I'll don't want to get into anymore trouble on this topic. :blueangel:

 

Thanks for the e-mail. I hope I was some help. :blueangel:

 

Stick and LT4 hot cam in the motor. Then get it reprogrammed. I had my first reprogram done by Ed Wright. Overall its work well.

 

I dont know about the dyno difference, but after I removed the Hyper junk PPP, and had Ed flash my ecm I ran .3-.4 quicker and picked up 4 mph in just the 1/8 mile. I am installing the LT4 hotcam and longtube headers soon, so Ed will reflash the ecm and I will post the results in my signature. :cool:

 

Not sure what you expected. If you really thought you were going to pick up a whole bunch of free HP from just that Breathless Vortex, then you are another victim of highly exaggerated advertising claims.

I have one too, and expect it probably does help in the top end (a little) but probably not that much more as compared to an open filter lid with K&N. Its OK, but overpriced for the quality of materials used.

In regards to Ed Wright, I've been fairly pleased with Fastchips in the past. My PCM was reprogrammed and turned around quickly and the car ran great. Had lots of other mods done at the same time so can't compare what his reprogram did, performance wise, although it was certainly a lot better than the Hyperslop tuning I had in there before! He also took care of my 4.10 gear speedo adjustment and 160 stat fan timing, too.

I'm about ready to ship the PCM off for a retune as soon as I complete the next round of mods. Fortunately he only charges 1/2 price for retunes!

To be fair, I think he does an admirable job getting a very *close* program for you via mail order. Just wish he was closer to me so I could have him dyno tune the car on site.

 

I had said that I would post the dyno sheet once I got it scanned in. My main issue with the reprogramming is what happens at 5800rpm, take a look and tell me what you think happened here.
http://photos.yahoo.com/bc/silver_fd...iew=t&.hires=t
Thanks,
Sam


[Modified by LT4Sam, 6:58 PM 9/20/2001]

 

You've got mail. I converted your Dyno chart into a .gif for ya.

Tim

 

Sam, looking at your dyno chart, that is a very small bump, not even a spike, that occurred on only one run at about 5800 RPM. If you look at the line below it (the sedond run) that bump isn't there. This is most likely due to the car just bouncing around on the dyno a bit. Happens all the time.

I wouldn't worry about any small anomalies such as this. If you had a big spike or dip that occurred in the same range on every test, then you would have reason to investigate. I had a much bigger dip in my power curve in the same RPM area that we finally attributed to injectors being over taxed beyond their rated duty cycle.

And again, your power output *is* in the range for a stock or very lighted modifed LT4 such as yours. It still equates to 356.8 HP at the flywheel which ain't shabby. I also note that this was done on a Mustang dynamometer. The Mustang units around here typically show less HP than the Dynojet brands, but it can vary a lot from one facility to another.

 

A little clarification is necessary.

The two lines you see are pre-mods and post-mods, the bump isn't on the lower line because that was done before the mods went in. The bump was there on the three post-mods runs I did, this is the only printout I have though. The guy who ran the dyno didn't update the text for "Sam 004" to show that there was more than just the mufflers at that time.

For the record the post-mods were the ECM, Intake, 160* T-stat, and the tb bypass. Like I originally stated I'm sure the intake wouldn't really show an increase, but I was hoping for more from the ECM. To see only a 3rwhp gain from the ECM is depressing, they told me to expect at least 11fwhp, I didn't even get that with the spike.

The dyno is a Dynojet, the test was performed at a shop called "The Mustang Ranch" which specializes in Mustang restoration and parts.

Thanks for the reply, but I'm still not sure what happened at 5800.

Sam

 

I just got off the phone with Ed Wright from Fastchip (the man). We discussed my car and he says that his programming should have been good for 10-12rwhp, but without seeing readouts the dyno sheet won't tell him anything. During the course of our conversation and trying to determine what happened we hit on the issue of gas...I can only get 91 octane here in Northern CA. Bingo. I was probably seeing some pretty heavy knock retard up until the 5800 point so as to prevent detonation. I love the gas in CA.

Sam