Best 408 + TT build (another build thread pt.2)

[blake-b]

Originally Posted by RupertPupkin

I have 14 1le, so 3.91. I like the taller gears. :/ Not looking to swap that out either. What options are there to have a happy median?

Agreed, Kevin’s been great throughout the process. Even got an email at midnight. Granted there’s a time zone difference, but still.

Guys at the shop ran the comp turbos on 7/8 builds that they did. Maxed out at 1500+, but I’m not about that life. I’d be happy @ 1001whp w/ a good set of twins.

You have the S60, a couple of 9" options, or a ZL1 rearend for something stronger than OE 1LE. Where are you going to use it the most? At a track on in Mexico? If the track, 3.91s will be good. If in Mexico, you'll like lower numerically gears.

[RupertPupkin]

Well not entirely Mexico…. Just your weekend fun you to drive around.

[HOJO]

Rupert, I just changed over to ZL1 rear unit with 373’s. More for strength than anything. I am not noticing much of a change from the 391’s. I can run the gears out a bit further which has it’s benefits. I’ll see how these perform once I turn up the boost, I just need some tires. Think I am going to do a 15 inch conversion next year, it’s just looks wicked. Good luck with your choice.

[RupertPupkin]

From Kevin..



I like the 3.91’s too for a 1LE you want to be just violently fast up to 160-170mph. 3.91’s are fine because the 1LE transmission gear ratios in 1st and 2nd

are taller than the regular SS. It actually works out to the same as a regular SS with 3.45’s. BUT it will become obvious to you real quick once driving it that you want the two or three stages of boost control.



You WANT (any really fast car has) too much power availible at all times. Then you can adjust it back to be the exact right amount of power for any given condition/mph/traction situation.



All these things are totally different with an auto trans and a high stall. Or a regular SS. Or a ZL1. But with the details you gave and asked for, this is the way I would go. It’s not exactly how I would build a 1/2mile car and certainly not a mile car. Each car has to be looked at with it’s exact combination of parts and what the customer wants out of the car. For a 1LE with a 6L truck block, I would dial it in for the most violent 1100whp you can and then tweak all the little details to make it all work together perfectly. 1100whp is a good stopping point because it can be good and reliable and uses small enough turbos to have no lag. I’ve built this exact combo you are doing several times, and raced them and beat up on 1300awhp GT-R with $150k in mods and walked it.


I guess I’ll try out for now… different strokes for different folks.

[blake-b]

Originally Posted by RupertPupkin

From Kevin..



I like the 3.91’s too for a 1LE you want to be just violently fast up to 160-170mph. 3.91’s are fine because the 1LE transmission gear ratios in 1st and 2nd

are taller than the regular SS. It actually works out to the same as a regular SS with 3.45’s. BUT it will become obvious to you real quick once driving it that you want the two or three stages of boost control.



You WANT (any really fast car has) too much power availible at all times. Then you can adjust it back to be the exact right amount of power for any given condition/mph/traction situation.



All these things are totally different with an auto trans and a high stall. Or a regular SS. Or a ZL1. But with the details you gave and asked for, this is the way I would go. It’s not exactly how I would build a 1/2mile car and certainly not a mile car. Each car has to be looked at with it’s exact combination of parts and what the customer wants out of the car. For a 1LE with a 6L truck block, I would dial it in for the most violent 1100whp you can and then tweak all the little details to make it all work together perfectly. 1100whp is a good stopping point because it can be good and reliable and uses small enough turbos to have no lag. I’ve built this exact combo you are doing several times, and raced them and beat up on 1300awhp GT-R with $150k in mods and walked it.


I guess I’ll try out for now… different strokes for different folks.

I completely forgot about the 1LE trans gear ratios! Good call on Kevin's part.

I hope you own a pickup. You're going to need it to carry you smile around after slapping on turbos.

[RupertPupkin]

Combos out here are endless! My eyes are killing me from reading. You guys got some pretty stout builds. Still waiting for the shop that going to do a custom turbo setup, but from the looks of it I’m going AGP route. Kevin’s been a pleasure talking to throughout this whole process.

I’m torn between the 62/62 and the 65/65 agp kit. Who needs another 100-300 on the street? Lol. With the 2 turbos having the same a/r, I’m assuming the 65/65 will push out more trq/pwr in the lower RPMs.

[C@mero]

From the conversation I had with Kevin he said 62/62 would be more streetable, and the 65/65 would generate a little lag. I guess it would come down to your tolerance. I’m mostly likely going to do a 65/65 option since it’s mostly track duty. You can always run more boost to squeeze out more power.

[RupertPupkin]

Finally got a quote from the shop. Very similar build from TMS. Only difference I see is that they’re using ported ls9 heads, instead of the Frankenstein M311 heads. Saves me about 600$, which is always nice.

Any disadvantages of doing the LS9 Heads?

[RupertPupkin]

NVM. Same price. Didn’t see the cam package…

So for the same price….. 408 with LS9 heads OR 408 with FED m311 heads?

[blake-b]

Originally Posted by RupertPupkin

Finally got a quote from the shop. Very similar build from TMS. Only difference I see is that they’re using ported ls9 heads, instead of the Frankenstein M311 heads. Saves me about 600$, which is always nice.

Any disadvantages of doing the LS9 Heads?

None unless you need 6 bolt heads (maybe they are using the 6 bolt version of the LS9 head called the LSX-LS9 head).

FACT: Myself and many others put aftermarket heads on our LS9s in our ZR1s. People who kept the LS9 heads but had them ported are making the same power.

The only advantages of an aftermarket head are thicker decks, 6 bolt options, and better valve angles vs OEM LS9 heads.

Just saw your update. If you are starting from scratch and there is no price difference, go with the M311 heads due to the thicker decks, valve angles and 6 bolts. If the LS9 heads are the LSX version, still go with the M311 heads as the M311s have .750 decks and the LSX-LS9s have .625 decks.

[RupertPupkin]

Just your regular CNCd ls9 heads.

[Bluto 2010]

A pair of 6766 with a high ram on that 408 would haul ass. I think it would stick better on the street with those as well because they'd come on a little later and would rev further with lower iats and lower backpressure. Its a turbo car, doesn't need whipple torque off idle.