[fleadh]

I noticed last weekend at willowsprings that my car was kinda weak... coming out of corners, and down the straights.. i figured it may have been tcs retarding timing or doing some other stupid crap. So, for this weekend at buttonwillow, i popped the trac fuse and tested it.

At buttonwillow, the car felt even weaker... the midrange was just awefull, and the topend was marginal. On the street it feels ok (i can feel the second turbo come on at 3200 solidly)... but on the track it just feels slow.

Here is some info, if anyone has an idea what it could be:


Stock boost, exhaust, intake.
Trac fuse removed.

I have seen it smoke for a split second on startup 2 or 3 times... i think it was after i turned it off without letting it idle, and restarted when it was cold. Maybe valve seals?

Also at buttonwillow (and willowsprings), i was running the suck ass southern california 91 octane gas.. combined with the heat (100+ degrees) at both tracks, could that have been causing the knock sensor to retard the timing enough to cause loss of power? I was thinking about pumping in 100 octane at BW, but i didnt remember what exactly you had to do with the mkiv when switching to (unleaded) race gas.

At BW, it actually felt like the second turbo wasnt coming online... thats how slow it felt... altho i went back and forth from the street and the track multiple times throughout the day and i know the second turbo was working.

Also, i ended up using nearly 1/2 a tank of gas per 30 minute run session.. that seems way abnormal..


Any thoughts/opinions would be appreciated..


I havent had a compression test done, but im planning to. If anyone can recommend a good tuning shop that can look at and work on my car in so cal let me know...

-mike <-- still no overheating problems.. yet

 

[Eric]

Originally posted by fleadh:
<STRONG>
Also at buttonwillow (and willowsprings), i was running the suck ass southern california 91 octane gas.. combined with the heat (100+ degrees) at both tracks, could that have been causing the knock sensor to retard the timing enough to cause loss of power? I was thinking about pumping in 100 octane at BW, but i didnt remember what exactly you had to do with the mkiv when switching to (unleaded) race gas.

</STRONG>

I doubt that's the cause. I was expecting the worst when I went to Thunderhill last Monday with 91, but it worked about as well as the 92 used to. EGTs stayed under control as long as I stayed at 15 psi or less. You don't have to do anything to use 100 octane. Just dump it in and go. You will get less timing retard with it, and your EGTs will be lower with the same boost (and fuel if you have a fuel computer) settings.

<STRONG>
Also, i ended up using nearly 1/2 a tank of gas per 30 minute run session.. that seems way abnormal..

</STRONG>

Nope, that's about normal. I get less than 5 mpg on track, so I have to fill up after 70-80 track miles. One thing the mkiv does amazingly well is not fuel starve as the tank gets low on fuel. I've run mine down to having the fuel light on at the end of the day without any hiccups. My previous car needed a minimum of 2/3rds, and sometimes 3/4 of a tank to prevent fuel starvation in the corners.

 

[fleadh]

Woot! Just got the car back from the shop. Had the 90k mile service + timing belt done. They checked the compression and 3 of the cyls were less then 80psi!

They had it for 2 days, and cleaned the heads and valves and removed some of the carbon buildup ontop of the pistons and now the compression is back within spec. It feels like a totally different car.. cant wait for willowsprings this weekend.

I need to buy a hotlap timer to see if i can get below 1:35 on real street tires (daily driven on same tires) with stock boost/suspension...

-mike http://www.blazen.com/mike/nsx/