Bring it over to Dez Racing in Seekonk MA, it's pro;;y under 2 hours from you. Let Don dyno tune it for you and you'll see real results.

My 2004 Whip'd 5.3 jumped from 332rwhp to 370ish with custom tuning.

.02

 

Actually, SOTP is awesome for me in the lower-mid to upper rpm ranges, the low TPS stuff is slightly less responsive which added timing should take care of.

 

hell...i already called allen...he's sending me a new tune to compensate for the upgrades

 

yep...only thing diffrent is im running a 3.1 pulley and cam but other than that it's what it is dyno tuned by allen nelson...i trust him to send me a tune for the lt's for the added bolt on's power!!! he say 30-35 more hp...we will see whenever i get back up there and dyno again
he's done alot of av's...hell he owns one too!!!have him send you a tune...if you dont like it...send it back...you will love it thou...he will get you everything outta it you will want

 

Nelson was one of the first mods I did, but frankly custom was better route. Only costs slightly more. R/

 

Where's BlownChevy? He must have some insight on this...R/

 

I'm betting it's your tune and not the LT's....I've never seen an application where a set of long tubes was outperformed below 3500rpms by stock manifolds.

I'd look at getting a dyno-tune done and then have it cleaned up with some street tuning....there's no way a canned tune will outperform that combo

 

Agreed, and I've had that done and plan to do more. However its worth noting that nobody at Mag had any different experience, or any experience at all frankly with the set up. Once I spoke to another tech over there he mentioned that LT's weren't the best choice for blown apps. Nobody seems to have an exact answer why so far, and the lack of exact answers on this thread are only reinforcing that point...I'll just keep working on it. R/

 

I just can't see that adding LT's to the Radix would hurt performance.
The LT's are a big compliment for the Ford Lightnings and factory supercharged Cobras. I know they are a Ford product and not A GM one, but it's still a decent example. IMO

Jim

 

Definitely felt a significant SOTP/tire spinning difference when I added the longtubes/catless Y. You are better off with them than stock. Don't think you need backpressure with a blower.