currently have whats listed below(pump tweaks are very minor as i hate messing with these things and i just got it back from the shop for a pump rebuild.

what woul dyou buy next?

im leaning towards the turbo cuz i have the 21 right now.

thanks all, jiMMy

 

4" straight "PIMP" exhaust? Is that new?

 

lol, didnt even catch that, pimp pipe what ever, you guys know what i ment sorry for a typing error, get over it! jiMMy

 

Luv those Pimp exhaust systems......the horse power gains are unlimited from a Pimp exhaust

 

It's a typo!?! I thought you were going to go with some of these Pimpin' gold stacks!

Still, my great knolwedge on these matters would say to go with the exhaust, turbo then injectors.

 

Fixed a couple of typo's for ya.


phox

 

please vote, geesh its not hard to do. im leaning towards exhaust though

 

I think maybe you need one of them pimp 10" tachs on your dash to go with it.
Just don't hook it up, wouldn't want the ricers to get too jealous....

 

Jeez, I had to drive all the way back from Maine to get this thread back on topic. Definitely swap turbine housings, with your auto trans you could go all the way down to a 12cm without flutter issues. Even a 16 cm will make the truck more fun to drive and lower the EGT at the same time. Big exhaust won't do anything much for you power-wise, and you don't have enough air for POD's because the turbine housing's too big.

 

Jimmy, I say go exhaust... Im gonna be doing gauges on my 04 first...
Scott

 

but its still al ong bed ! lol.

i ordered up the exhaust already, next saturday, turbo on order as well. the crap is adictive.

hell i dont even drive the thing but once a week if that. lol.

all thsi trying to get my FOR DDDD to teh trail faster. thank to all for teh comments and suggestions.

jiMMy

 

I was under the impression that a smaller turbine would equal a faster spool-up, but less maximum boost, right? Following this logic, would a small 12 CM housing provide enough air for the POD's? How much boost would it generate, versus the 16 or 21?

 

BWAHAHA.. I know.. you don't like long beds... Well crap.. I still have warranty.. what to do... LOL
Scott

 

The 21 cm housing is so big that the turbo does not spin fast enough to generate the boost needed to keep the EGT down. You can get a truck with a 21 cm housing dangerously hot with stock injectors, it just won't make enough boost. A smaller housing always provides more boost, but you have to consider the backpressure that it causes while making the boost. You can easily get to the point where you have way more backpressure than boost, and this causes the EGT's to shoot up even though the boost gauge says you have plenty of air. This is why wastegated housings are nice, you can relieve some of the backpressure at high RPM but keep the quick spoolup. A 12 cm housing is a little small for POD's even with a wastegate, for Jimmy's application I would suggest going to a 16 cm if he gets POD's. The 12 cm is a really nice package with the stock injectors, I love the way mine drives in traffic.

 

Let me get this right;
A a richer fuel-air mixture results in more heat.
A smaller housing makes exhaust harder to escape, which leads to higher EGT's.
However, a smaller housing also causes higher turbine RPM, which equates to more boost.
So you always want to run as small a housing as possible. To avoid overspooling of the turbine, and to decrease backpressure and EGT's, you have a wastegate.
Wastegates allow you to tune the speed of the turbine, and thus control the amount of boost that the turbo will put out. However, they can't put out too much boost without grenading.
But there is a limit to the amount of air a wastegate can shunt off. This is where you loose me. Even those giant external wastegates you see can't blow off enough air for a 12 CM housing?
Also, if you have enough exhaust, as in enough air and fuel, wouldn't it still fill the larger housing enough to provide the same RPM, and thus boost, as the smaller housing with a smaller amount of exhaust?

SO, on twin setups, you have a small housing first, with a big wastegate.
Once it spools up to max, it is providing a lot of air. This air going in provides more exhaust going out, which is enough to spool a larger secondary turbo.
The secondary turbo has a larger turbine than the primary though, so it can utilize the greater exhaust flow better, and provide more air at the same RPM as the smaller turbo.

Am I right in this?