tire question

[Shimy87]

Here's 2 slips, only picks up 19 MPH from the 1/8. No PL logs, just the ol" SM.

[good2win22]

Do you still have the 37# injectors installed?  I think you may be getting close to their limits

[Shimy87]

yup

[TexasT]

Wow, it sure is movin in the eighth. Lots of mph and a dandy low eight. Easily 7.8 with traction. Sure noses over on the top end. You should be in the 12.20s at 110-111 . How old is the fuel pump? Filter age?

[Shimy87]

Pump and filter are old. Maybe 2 years ago checked FP with a gauge and was coming up on pressure 1 lb for every lb of boost. I have a new filter on the shelf, I could slap this in and check it again. if FP is still good what could the issue be? I thought if the fuelling was a problem it would show up in some lean numbers on the SM at higher MPH but lowest number I recalled was 782 at 104mph....that's kinda rich for an alky car isn't it? maybe I'm too rich on the big end?  Don't know if this matters but the tires I run are only 26 inches tall....would that effect the top end numbers?

[Steve Wood]

You did replace the valve springs, didn't you?  It's about five mph down in the last half of the run so you have a problem and it would be hard to attribute that to richness.

[good2win22]

I'd have to agree with Steve on the valve springs.  Went to comp 981's on the white T and it mad a world of difference at the big end

[Shimy87]

The prior owner had replaced them, should it be done again? How long do they last, I have had the car for 7 years. Looked at some slips for 2014 and it was running 108 then

[good2win22]

I ran the 980 springs on the white T and it would run 7.5 in the 1/8 but couldn't go past a 12.3 on the big end.  TE44 with 25#'s and 60's on the rail and 1.58 in the 60.  Changed the springs to the 981's and 60 foot stayed consistent but the 1\8th dropped to the high 7.2's-7.3's.  Never did get a chance to run the 1/4 before selling the car. 

[Scoobum]

IF you had PL like I've been asking you to get for umpteen months...then we'd be able see if the high gear RPM's are struggling to verify soft valve springs. A 26 inch tire will force the RPM's even higher making the valves float even worse if the springs are soft. If that's a LU convertor...an d it's unlocked...the n your slip rate will likely be higher...lower ing your MPH. I'd try a set of 981's...a 28 inch tire...and try it again. We're taking an educated guess as to what's wrong.

[Shimy87]

Yes I know  Its a LU convertor, don't know if its locked?? Probably cant hurt to put new springs in it anyway so I know for sure what I got, they are less than $100. I see a nice simple compression tool for the job on a Tom's turbo garage video, where the heck can I get that one. Cant find it anywhere in my searching.

[Scoobum]

It's unlocked...unl ess you asked Eric to lock it via his chip. Ask Chris at CK if you can lock it at WOT for racing. Kirbans may still sell the valve spring tool.

[Shimy87]

Looking at that tool, it appears that its just a rocker arm cut out on one end and a bolt and nut welded to the other and a piece of tube to bolt down for it to rock on. I'll make that and I can get 981 springs for about $50.

[good2win22]

Kirban sells the tool if you wanna go that route