Thread: Thinking about More Power/Future Mods

So the transmission on my turbo car is still stock and as such I left have the boost limited to 9 psi to make sure I don't shred the trans. Since my next step is to pull it out and upgrade some hard parts, I figured I'd look at other upgrades to make as well. My current setup is:

L36/stock trans with 69K miles
Cartuning Turbo Kit modified to fit a Precision 6262.
3" Cat & Cat-Back exhaust
Walbro 255lph Pump & L67 Injectors

So my plan for the trans is a 300m input shaft and 7/8" 2.93 Chain along with a Transgo shift kit. Is replacing the torque converter a good idea as well? What are folks using for that. Brandon gave me a few things to replace in the valve body as well. Anything else?

My plan for the motor is a ST1 turbo cam, but I'm not sure what else to run for valvetrain. I'm considering LS6 springs and LS7 Lifters. Looks like I would need Retainers. Would I need new pushrods? What's the best option for timing chain? My goal is to keep it reliable, even if I have to sacrifice a little power to do it.

I'm really thinking I want to run e85, so I'm planning 80lb injectors. Guessing the 255 pump isn't going to be enough. I see folks running fuel logs, do these flow more, are they necessary or can I use the stock rails?

Lastly, I'm planning to install an L26 UIM with an L67 TB and LS1 Maf.

That's all I can think of so far. Thoughts? Anything I'm missing?

I would go with gxp chains versus the 7/8. They are proving to last longer and hold more power. I would also install a converter too. Either zzp or precision would be fine. You should be running a meziere flexplate too.

If it was me, I'd run 130# springs and a double roller timing chain. Ls6's may limit you some on power. You'll need lsx style retainers with any non-factory spring. You may need pushrods. The only way to know is by measuring with a pushrod length checker. 130# springs, you should be running a double roller. Ls6 springs, the stock chain and tensioner is usually fine with maintenance every 50k.

A 255 pump will flow around 375whp on e85. If you want more than that, I would swap in a 450. 80# injectors are good to about 550whp on e85. That'll about max your turbo.

The only thing I see missing is an AFC to scale your maf, or you'll be maxed at less than 350whp.

Thanks for the info!

What's the difference between the 7/8" and GXP chains, I didn't realize that was an option. I meant to ask about the flexplate too, thanks for mentioning that, one more thing to add to the list. For the converter, what's a good stall speed? My turbo is relatively small and comes into boost quickly so I'm thinking a 2500? Thanks!

Gxp chains use stock sprockets. They are literally drop-in from stock gxp's. The 7/8 is a single chain and sprockets from the 4t60e, iirc. They really aren't much stronger than stock.

I wouldn't go less than 3000 on your stall speed. What size is your turbine housing a/r?

Yeah that is pretty small. You could get by with a 2500 stall on that. I'd still go 3000, because you'll probably want to upgrade that.

I read somewhere that the 3000 is similar to an L36, while the 2500 is similar to an L67, does that sound right? What are folks running on the GXP chains? I tried to find some more info on them, but came up empty handed.

NA is about 3000 rpms. S/c is supposed to be around 2200.

I'm running gxp chains on my car. Lots of guys in Canada are using them as well.

FWIW when I get chains from a local supply house, the only chains available for the 4T65E are the V8 aka GXP chains. They superceded the V6 chains and only make the one version.

Originally Posted by BillBoost37

FWIW when I get chains from a local supply house, the only chains available for the 4T65E are the V8 aka GXP chains. They superceded the V6 chains and only make the one version.

Thanks Bill! That's good to know. What are the new dual chains good for HP wise? As much as I'd love the 1" chain, I just don't see it in my future.

I see people use them. Never seen anyone push any significant power through it though.

Can you run 105# springs on a stock timing chain or do you need to run a double roller for them as well? Would they be a better option? I seem to recall folks have lots of issue with the aftermarket chains, but maybe that was only on really stick springs.

Originally Posted by L67Mike

I'm running a JP single with pac 105s, so far so good. In fact, Intense recommended it, but I'm not running a turbo.

That is a terrible combination. It just shows how little experience with these engines Intense has.

You can run 105's with a stock chain. It's easier on the chain than ls6's, but you should still check it every so often.

I might run 105s then, sounds like it will be better all around. Thanks for all the info, it's definitely given me a better idea of where to go next.

Tep's are stronger imo.

What was all required to modify the car tuning kit for the 6262? My pt61 is on its last leg and cartuning won't call me back. Since they don't make on center turbos anymore I've had a hard time deciding what I'm going to do. Also what kind of boost are those turbos rated for?

You would probably be better off just buying a new crossover from zzp or make one yourself if you can.