Help need a tenth or two
 

Hi, I've been comparing my car to others on here. I know all are different and tracks but I think my car maybe off a little compared to others.

My car weighs 4040 with me in it but I do have some heavy 20 inch torque thrust wheels. I have long tubes, no cats, tune and a vararam. I have only had a chance to run eighth mile so far and first time was about three weeks ago. Ran with the street tires first time had a 1.91 60ft 8.15 @ 88.20. Fast forward to Friday night, put a set of 18 inch 26.5 tall Mickey Thompson dr on and ran a 1.86 60ft 8.14 @ 88.09.

Now I ran at two different tracks and both nights was nice and cool. Not sure what da was but it was in the negative on both nights. I checked the da but forgot them. My thing is I lost about 40 or so lbs by going to the drag radials and really thought the 26.5 tall tire would net me some better ets. Can't figure out why I slowed down in the mph too. Rest of the night was 87 mph.

I had a 98 z28 m6 z28 with bolt ons that would run 8.0s at 89mph and really like to see that out of my 5th gen. Also the guy that tuned it is kinda local and has been tuning for awhile but unsure how many 5th gen autos he has tuned. It seems real lazy when it shifts 3rd. It's never been on a dyno either just a wideband street tune. Just like to see if you guys have any ideas on why it slowed down on the drag radials and how can I get that 8.0

Not sure if this is your problem but if my car spins any at all leaving it will mile per hour faster.If it hooks hard then i'll have a lower et but the mile per hour will be lower.

Car was hooking every pass. My concerns are more in the trans tune. Just seems like its lazy in 3rd. Not sure if the shorter tire messed my shift points up or not.

Different tire height will alter shift points.

That short tire is why you slowed you mph down... but at 87-88mph is not bad at all with your mods man. I think your 60ft at 1.86 is soft and thats whats holding you back. Personally I think you should get a taller tire, at lest a 28" and work on that tune more.. possibly that short tire could have a negative effect! You should be in the lower 1.80-1.7s 60fts on drag radials easy and that would get your 8.0s

Here is my best slip so far from last year.

I have a local friend who did cut a 1.83 with 20's up front and stock height 18's on back.

http://i638.photobucket.com/albums/u...psfb1c37f6.jpg

there you go

Thats the slip Im searching for. I need to figure the whole tune stuff out myself and break down and buy hp tuners. I just bought theses rims and like to stick with them. It actually launches pretty good

pm sent

The 18" wheel is not the problem, Its the tires! I just picked up a set of 18s myself and 305/45/18s nto5rs, they are basicly stock hight tires.

I have the same set up, 18's stock height on rear and stock 20's up front. My car consistantly cuts 1.6 60' times.

Karbon I see you have heads and cam too, what does it run? My next move will be H/C or blower. I miss running in the 10's and quicker.

You could be bumping the rev limiter on your shifts due to the shorter size of the tires throwing your shift points off. Those tires should help your 60 ft but seems like the tune is the culprit of your lagging mph and ET. The 26.5 height of the tire itself is not at fault, it's the tune in combination with that height if tire. This tire is on the Fastest Bolt on L99 car with stock internals, and he makes plenty of mph. Fix your tune and you will be fine.