166 replies to this topic

[Bench Racer]

Sorry guys. Referring to Bolanos not Buras.

Aw, come on, ya threw the bait twice before I responded.

[Tom Sager]

Here is very recent dyno comparison of my NA1.8 at 47mm vs my VVT.  Note that this is a realy stingy Dyno Dynamics dyno. Reads 20HP less than some SAE Dynojets, so for comparison my '95 at 47mm showed 126-127HP on a Dynojet and the VVT showed 128-129HP on same type. Sorry for the rainbow of colors.  Wanted to clean that up but it was past closing time at dyno shop and they wanted to close.

 

This is moot since the rule change but it's interesting to see where we were.  Will post unrestricted comparison also.  Better numbers on this graph are the VVT. Click the image 2 or 3 times and it will get bigger.

 

[Tom Sager]

Here is unrestricted NA1.8 vs VVT.  Both cars with fairly fresh pro built engines by very good builders.  NA1.8 makes more peak and has some HP advantage up top.  VVT has advantage down low.  We're at about 5250RPM at bottom of 3rd gear so not that often do we race below that.  Torque gap is larger.  Clearly though the horsepower through the racing range is now similar. 

 

[Rob Burgoon]

 Clearly though the horsepower through the racing range is now similar. 

 

 

 

I don't think so.  Consider the rpm after a shift.  Higher gears have closer ratios so it gets worse in lower gears.

 

Looks like 5th gear favors the VVT a lot on tracks that you don't get near the limiter in 5th, 4th favors the VVT, and 3rd favors the VVT a lot.

 

And that's just power.  Not considering heat soak or suspension.

[Brandon]

VVT is also 25# heavier than 94-00.

Is a 15-ft/lb increase at 4500RPM enough to overcome a 25# higher weight?

 

SMAC has my dyno plots from my 2015 build with comparisons to other 99-00 builds my guy did.

 

I'll be sure to capture & share 2016 current state and then 2017 current state once I make it up to my guy's place.

[Bench Racer]

Is a 15-ft/lb increase at 4500RPM enough to overcome a 25# higher weight?

One way to answer your question would be, I'll take the 15 ft. lb. at 4,500 rpm and the 25 pounds ever day of the week for my 1.6 and you'll never be able to wipe the      off my face

[Jamz14]

25 lbs heavier is in the noise. No impact.