1/4 times, Performer vs. Performer RPM

[zenboy99]

I raced True Street at the Fun Ford Weekend in Illinois this weekend. I spent all day Friday at the test and tune trying different shift points with my new RPM intake. All I can say is my SOTP meter is probably broken, I thought I gained more power with the RPM intake but it doesn't look like it.

Previous Best ET, same track, similar conditions.
1/4: 13.10 @ 107.10
1/8: 8.47 @ 86.23
60ft: 2.047
Shifting at 6100rpm, 5900rpm 3-4 shift

ET with RPM intake and no other changes
1/4: 13.09 @ 107.31
1/8: 8.53 @ 83.03
60ft: 2.036
Shifting at 6100rpm, 5900rpm 3-4 shift

Other ET's with different shift points
Shifting @ 6400rpm
1/4: 13.26 @ 105.94
60ft: 2.044

Shifting @ 6250rpm
1/4: 13.25 @ 106.30
60ft: 2.050

Shifting @ 6200rpm
1/4: 13.31 @ 106.55

My traction loc is toast so I couldn't really launch it hard or do a burnout. Every pass I launched at 1500rpm and eased out the clutch.

 

[wytstang]

Do you think the traction loc could have affected your times?

 

[zenboy99]

The traction loc has been gone all summer, my previous best ET was with the same launch technique. I didn't spin hardly at all off the line or on the 1-2 shift so I don't think it had any effect.

 

[Grn92LX]

Hmm, I was hoping to see a decent gain. Its very possibly that your lean up stairs. Try adding more fuel. You should have tried another 3-4psi just to see what happened. You lost a touch mph, but nothing huge. My guess is your lean up top OR you need a 410 gear to get you across the traps higher. Although, my friends 89 trapped 110.xx with 373's and an RPM with his afr/fti car.

 

[wytstang]

Maybe the RPM is to big

 

[5spd GT]

You mean that bigger isn't always better ...I rest my case...again...

You got a cam setup for your previous mods...not a higher breathing intake...even as little as it gives...

Keep practicing with it...

 

[zenboy99]

Hmm, I was hoping to see a decent gain. Its very possibly that your lean up stairs. Try adding more fuel. You should have tried another 3-4psi just to see what happened. You lost a touch mph, but nothing huge. My guess is your lean up top OR you need a 410 gear to get you across the traps higher. Although, my friends 89 trapped 110.xx with 373's and an RPM with his afr/fti car.

Thats true, I still would like to dyno this set up to make sure I'm not running lean up top.

 

[Grn92LX]

Yeah definatly throw it on the dyno and see how the a/f is. I can almost garantee its off. The rpm was a good choice, now you gotta dial it in. If you step back and think about it, the car isnt 100% tuned with the new intake and you didnt even lose a full mph. The ET is lost from your driving and bad trac lock, NOT the intake.

When will you redyno? When are you gonna get longtubes and a 75mm TB like you NEED

 

[zenboy99]

I should be able to re-dyno within the next two weeks. I have a 75mm throttle body, but I need to modify it to get it to fit. Long tubes will come after I buy a house with my wife, or hit the lottery.

 

[onebad95]

These results should get posted in the other post where the rpm is being made to look like a huge gain over the performer. You won't see a big gain unless your shifting at higher rpm's with the performer rpm intake. Although, you have to have the lower end to accomodate those high revs.

I still think the performer is the best intake for our 302 stock shortblocks.

 

[zenboy99]

I couldn't believe that the optimal shift points for the Performer and RPM where the same for my car.

 

[wytstang]

I would guess the shift pionts would have to do more with the cam then the intake.

 

[tmoss]

Shift points have more do do with the cam's torque/power curve and the transmission gearing. The rear end gears are a constant multiplier and don't play into shift points - they just get you there faster.

 

[nmcgrawj]

These results should get posted in the other post where the rpm is being made to look like a huge gain over the performer. You won't see a big gain unless your shifting at higher rpm's with the performer rpm intake. Although, you have to have the lower end to accomodate those high revs.

I still think the performer is the best intake for our 302 stock shortblocks.

I would wait on that one. His car is not tuned or dialed into the new intake. That cam isn't even made for the intake. Let him get it tuned and make those small adjustments before you say that the performer is better. Just like in the other thread, Killercanary took a lot of adjustments and such to get where he is at. If we had this discussion after his first run, then we would be totally off.

I think it leans towards the side of the RPM for him to throw it on there and run it and still get basically the same times. Get that tb, get it on the dyno and look at the a/f ratio, and run it again. Then we will see.....

 

[GTJake]

To everyone that says this is evidence that the RPM is "too big" for a 302...

You can't just swap parts out like that and excpect to see results without tuning. For example, I changed my CAI setup and added a 75mm TB and the best I could do was a 12.8@108. That is compared to a previous CAI setup and 70mm TB with a best of 12.7@110. When I changed that setup the car started to run real fat and would even backfire when I shifted hard and when I left off after the traps. The point is, big changes in air flow affect the A/F ratio and need to be tuned.

I don't know whether the RPM is better for Chad's setup as far as 1/4 mile times, but I'm sure it has more in it than this preliminary test. Tuning is needed to show what it can really do.

Jake

 

[nmcgrawj]

To everyone that says this is evidence that the RPM is "too big" for a 302...

You can't just swap parts out like that and excpect to see results without tuning. For example, I changed my CAI setup and added a 75mm TB and the best I could do was a 12.8@108. That is compared to a previous CAI setup and 70mm TB with a best of 12.7@110. When I changed that setup the car started to run real fat and would even backfire when I shifted hard and when I left off after the traps. The point is, big changes in air flow affect the A/F ratio and need to be tuned.

I don't know whether the RPM is better for Chad's setup as far as 1/4 mile times, but I'm sure it has more in it than this preliminary test. Tuning is needed to show what it can really do.

Jake

Exactly what i was saying. To call this a test for the RPM vs. Performer is . Grn92LX started it and i will back him up, too many people like to run the same thing as everyone else just "because" and are scared to branch out and try something new or "bigger". Its pretty weak to take a crummy comparison like this and try to make it so called proof of something. It just goes to show that you gotta build the motor around its parts. When you do, whether you build with big parts or small, you get performance as long as things are matched. Try to compare when things are not matched and you see what seems to be no difference in performance. But there MIGHT be if you tune the motor for the new setup....leave the throwing crap together and expecting results up to the chevy guys! (i just know a kid who's done that for the past year and says he's building a stroked 350 thats supposed to fly....well the 350 before was DEAD slow and im sure this one will be )

 

[onebad95]

what I'm saying is that the performer is better for our stock shortblock. Sure, the rpm will be better if you rev it to 6,500 to 7,000. That is not the case here, nor is it in most of our situations.

 

[GTJake]

He said that the optimum shift points DID NOT change for the Performer vs. RPM comparison.

I couldn't believe that the optimal shift points for the Performer and RPM where the same for my car.

I think he needs to tune the car to see what it really has in it.



Jake

 

[tmoss]

Lots of variables in comparing track data in some cases - there may be fewer variables (maybe smaller too) in comparing one dyno to another on the SAME car with one change. The trac-loc alone could be the poison pill in this case.

You can get too big with an intake. Peak numbers should not be the standard - average area under the curves is where it's at.

 

[nmcgrawj]

what I'm saying is that the performer is better for our stock shortblock. Sure, the rpm will be better if you rev it to 6,500 to 7,000. That is not the case here, nor is it in most of our situations.

I agree with most of us not revving that high....but what we are trying to get across but obviously are failing is that if the Performer is "better", then why in an untuned state did the Performer RPM do just what the Performer did? The RPM has more in it as he tunes and changes a couple other things.

You dont have to rev it that high to see it. I hate being like the crowd, whats the point of that? If i can run something different and still make ATLEAST what the other guys make,then im going to be different. I mean come on, the performer is better? The RPM did what the performer did and wasn't even tuned.

Anyway, lets keep the discussion going. Im sure we all will stick to our guns and our opinions.