First of All Fellas,
I missed the hell out of this board. I caught a computer virus or something that put me out of commission for almost 2 months.
Anyway, during that time...I purchased a set of coated Jett hott LTs w/emmissions. I purchased a 3" noncoated custom y-pipe off a member of this board. The Y-pipe has 2 built in highflow cats. I'm trying to figure out how much of a gain should I expect. I called many speedshops around town and in the GM High-tech magazines and noone could give a definate answer. Either way, I'll tell all once I get them in and redyno the car later this year.
Current Mods are in the Siq.

Thanks

Tim

 

25 views and not one single reply.....Hmmmmmmmmm

 

Should help, I would think they will compliment your mods well. I would be guessing but I'd say 15-20hp. Make sure you match the flanges on the headers to the heads or you will loose some power. I took .125" off in places on mine to match them to the 1406 gasket that the heads were ported to.

 

Did you have SLP dual cat headers or single cats? Not sure what you meant by shorties since you have a 96.

 

I highly doubt they'll make more top-end HP, since the primary tube size is the same, but the long tubes will make more low end torque and that's about it.

 

I disagree, I think you will free up about 15 high rpm hp

 

11rwhp/15rwtq. Bank on it

 

Hey,
Just getting in from work...
Thanks for the replies.
I have the SLP dual cat headers.

Only 11 rwhp/15rwtq. I would not have gotten them for that gain, but I've come too far to turn back

Nonetheless, I'll keep you all posted

Tim.

 

You may pick up more. I had the single cat headers, and they are the best shorties on the market.

 

I would expect some big gains in tq and hp going from SLP d/c's to LT's, probably biggest gain will be in tq. I had the d/c's for a while (never installed them) they were not a well designed header to say the least. It's hard to say exactly how much you will pick up, I'll guess 15rwhp 20rwtq.

 

By the way, my numbers were peak numbers that I was guessing. You'll pickup more torque at lower rpms, but I think the peak will be where I said.

 

So the gains you listed where going from SLP single cats to LT's? I'm curious cause I have the single cat SLP's and thought about going to LT's eventually. This guy should pick up a lot from SLP dc's over to LT's, there's no comparing the design of the two.

 

The way I figure it is this, Lloyd is pretty consistent and his heads with XE230/236 usually net in the mid 380's rwhp with mid 350's rwtq. Thats how I came up with his numbers Its all a guess. There is more to gain when going from dual cat headers to LT's versus the single cats to LT's.