Took a trip up to N.Jersey with Chris (distantpulse) yesterday to TVT Design. Got the car tuned (LET v2) and dyno'd. I put down 343 whp, and 360 wtq. It was a Dynapack dyno and the owner claimed it's a 'heart-breaker' (ie reads low) however on other forums I've read the opposite so I'm not sure what to think.

Overall the tune didn't give as much as I expected. According to the graph printouts I gained 17.1 ft/lbs and 18hp. That's pretty conservative for the LET v2 tune w/ these mods correct?

Either way I'm taking it to the track friday to see if I can improve. Unfortunately it's supposed to be another cold day which is somewhat good because it'll be similar to the icy temps I ran it the first time which will make for a better TRUE comparison.

 

I would say it is about right. I gained 15hp/17tq but ran out of fuel on my set-up. Wayne felt if I go larger injectors I will pick up the 7-10hp lost from being lean. What were the AFR's

 

That is a nice garage.

Yes I have always heard that dynapacks read high especially on torque but you can calibrate a dyno to read anything you want. It is just important that if you are tuning to always use the same dyno to be able to compare results.

I have a friend that owns a dyno shop so I get mine at a very nice price

Those are pretty good numbers that you are making though.

 

You are right around the numbers you are putting down with the mods you have. That's a good improvement and you'll see the results at the track.

 

I'm looking forward to your track day. The numbers look good to me but they're only "preliminary indicators" until you verify them at the track. At least thats how I feel about dynos. I'm hoping the best for you.

Les

 

TVT(Anthony)

Did you get a new garage?

In about a month I am going to request some service. I'm getting some eurocharged stuff and NW CAI, can you install that??

Thanks!!

 

I dont see any fans in the pics? Were any used? If so how big and how many?

 

when I dyno'd my car there weren't any fans, does it make a difference especially in cool weather?

 

Indeed- I'm hoping to get out of the high 12's. Plan on hitting the track tomorrow!

 

Hey thanks Les. My concern is the even high torque and existing traction problems. I may have to try and lower the pressure- I think I'm running 36lbs all around. Thanks again.

 

Yeah, they used a single large fan- though I doubt it recreates the wind velocity of driving 80-90 mph.

 

I witnessed a 15-20whp gain from the use of fans. But thats why dynos are only good for tuning tools. One person uses no fans, one has one fan, one has 3, one uses ice on the s/c, one cools the car down and one doesnt. You get the idea, the variables are numerous.

 

i bet you do better than high 12's.

 

36lbs!!! No wonder your so slow! JK. At 36 I have NOOOOO traction. So far the best results are 30ish. I went all the way down to 26 just to see but it was not better than 30. My fastest times are with 28lbs. driver side and 30 passenger. After a few passes give it a try and let me know if it helped or hurt.

Les

 

It is obviously virtually impossible to duplicate all the variables between different dynos or even different operations.

While it is nice to know your true HP at the wheel the best use of Dyno info is the percentage of difference. Using the same dyno for before and after, especially on the same day and ambient conditions, tells that very accurately.

I know I'm stating the obvious but Mrphotoman is right on here.


roadster with a stick

 

I have a dumb question. What is the deal with the rear tires removed and the dyno mounted there. I thought they were all roller type dyno's where you drive onto it.

Steve

 

Apparently the Dynapack dyno works differently- it's supposed to be more accurate avoiding issues with friction and inertia. However there are arguments on both sides. I wasn't vacillating over the numbers but the "changes" in the numbers after the tune. The true test will be at the track.

 

What was the reason for the dip in the gragh reading, the guy said the engine was pulling timing, but why?