Dilemna: seriously increased power, but not MPH?!

[JekylandHyde]

I am really having a hard time with this.

A year and a half ago, I was making 320 rwhp and trapping in the 115-118 range.

I then upped the power to 351 ..... then again to 377 and now we rocketed up to 440, but my traps are still in the 115-118 range.

I am on the same tracks, car has not changed weight or gearing.
My ETs are great for mph and my 60's are through the roof so I know my driving is right on.

so how can my mph not be increasing with my horsepower??

Other MR2s with the 440-444 range are trapping 121-127 mph at much higher elevqations than I am racing at.

Any thoughts?

Why am I making the power on the dyno, but not the strip?

[chevytrucks92]

You'd think something has to be different though. Have ya changed the suspension or tire sizes any?

[JekylandHyde]

Nope.

[500]

Do you have EGT gauges ? Boost retard ? You may be getting into detonation when in high gear where the motor is under the highest load and the combustion pressures really start to climb. It used to be common to have a 'high gear retard' to avoid this problem. This allows you to have lots of advance in the lower gears where the motor is not as highly loaded and then cut back the timing in high gear to avoid detonation.

Might be time for that next big $ pop. Data logger.

500

[JekylandHyde]

Thanks for the ideas.

I have an aftermarket EMS and I can datalog with it, but I could not use it at this event.

I'm not sure if my EMS retards like that up top.
I am running water injection and 110 race fuel so I am hoping my detonation, if any, is very slight.

[500]

You are going to need :
charge temp
individual egt
O2 sensor
fuel pressure
throttle position sensor
a detonation sensor would be nice
spark advance

I bet you could really learn a lot by going to one of the ECHL meets at Maxton. Would be a great opportunity to do a lot of experimenting and tuning. Just start out real conservative or holes may magically appear in the tops of your pistons.


As I sit typing this somebody is doing dyno pulls within earshot of my desk

[JekylandHyde]

I maybe coming to Maxton in October ... but for the ECTA meet

[500]

Originally Posted by 500

one of the ECHL meets at Maxton

I definitely have hockey on the brain. Can't wait for the season to get started.

[JekylandHyde]

Here is my 351 rwhp dyno vs the 440 rwhp dyno.
I trapped 116/117 in August of last year with the 351 and I am still trapping the same with 90 more rwhp and 65 more rwtorque.

This baffles me:

[chevytrucks92]

Are ya at a different track? Or do ya have a high side chip that you could be hitting? Something has to be causing that, lol.


Has your ET came down?

[JekylandHyde]

My times/mph are staying constant ... at this point, our best guess is that the ignition is breaking up under load.

[chevytrucks92]

So you haven't picked up any? Not even in the 60 ft or 330?? Becuase if you have, you may have too much gear now for the hp (or not enough).

[500]

What's your rpm at the finish line ?

[-The Stig-]

It's the lack of Vtec that's killing him...

Poor Jeff and his Toyota...






Kidding of course, I'm sure it's something simple... get No Shoes on it! He should be able to figure it out.