Timing map?


Hello, I just picked up an 89 Turbo TA with a Holley HP EFI in it. It "looks" to have a pretty good timing map (pic attached) based on my experience with other turbo motors, but I was wondering if anyone has anything to share based on turbo Buick experience? The motor is about 9.5-1 (GN pistons with the TTA heads). I am currently running 18 psi but want to verify timing and such before I start turning it up any.

It does have an upgraded turbo- but I don't know which one. I was going to post asking for id help later on.


  • Screenshot (12).png
    Screenshot (12).png
    215.3 KB · Views: 160
That timing table looks very weak imo. Plenty of feathering could be done. If you have 9.5:1 with the FWD heads you will need to keep timing way back to keep cylinder pressure down.

Sent from my iPhone using Tapatalk
So should I cap it at 15* under boost up top to be safe? When you say weak, do you mean out of boost? That would explain why it feels so sluggish out of boost.

This is my first turbo buick without a chip that someone else burned, so I've never even seen a map for one before. I ran 20* at 21 psi with my 9.4;1 blowthrough 351 turbo stang without issue, so that's why I figured the 17 this is at was safe up top.

Thanks, I appreciate any insight :).
As for compression, I was told "about 9.5:1". It has 160 cranking, so I figured that sounds about right not taking camshaft and other variables into consideration.

Thats another thing, It is supposed to have a "small cam" and definitely has ported heads with ss valves. That's the problem with buying something from someone who bought it this way...
92. No meth yet. Has one of Julio's kits on it but not working currently. Have to go over it and see what's up. Probably not wired up. Once it's working, I'll tune it a little more aggressively and up the boost.
I'm no expert but that looks pretty good for a pump gas tune. Does the Holley system detect knock and will it pull timing?
I'm no expert but that looks pretty good for a pump gas tune. Does the Holley system detect knock and will it pull timing?
That was my thoughts as well based on other cars I've set up but figured you guys here have more experience than I with the turbo buicks :). No knock sensor. It can be added and I'm going to, don't know why the guy didn't put one in. It's on the long list of things I still need to do. Got the car needing a quarter, paint and interior work. Hung the quarter last week and am working on the rest of the body currently, so I'm trying to juggle it all at once lol.
If it was me I would prioritize get the knock sensor working even if it was just to log and it didn't have the ability to pull timing that way you know your tune is safe.
I agree. I guess I'm just curious what a typical curve looks like for these. Especially curious what idle and cruise timing would be without going out and building a map from scratch (if this one was way out). The car feels sluggish and lazy off boost so I was wondering if the map was just too soft in that area or if I need to look elsewhere. Always fun trying to clean up someone else's mess lol. That said, it was done by a shop that is supposedly reputable. However, of course there are a bunch of things I'm going to change because I'm not impressed with how they did the install..
Oh lord, ''about''. That means they didn't measure and there's really no idea what the static compression is.
My thoughts exactly... However, it was supposedly built by a GN shop down in the miami area and "done right"- but it was for the owner prior to the guy I bought it from. The guy I bought it from *claims* the other owner spent a ton and he saw the receipts but the guy wouldn't give them to him. Looking the car over, it was definitely in good hands at one point and I don't doubt that it was built "right" then. Not from the guy I got it from though. If he touched it, it needs correcting lol. The guy I got it from only knows "stock bottom end with forged GN pistons, ported heads with stainless valves (verified by pulling the manifolds after I got it ), "mild cam", small stall, 50# injectors and Holley HP" oh- and "alky kit but I disconnected it because I turned the boost down and never used it"..cough bs cough...
To be honest, I have not checked the Holley forums. I haven't been to them in over 10 years probably and last time I checked them out, it was mostly just a bunch of small block stuff so I honestly didn't even consider checking there again. I'm sure things have changed over the last decade though lol. I'll look there later on. Thanks for the link, checking it out now.