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-   -   Impul Throttle Bodies (http://www.the370z.com/engine-drivetrain/4758-impul-throttle-bodies.html)

370Ztune 05-21-2009 01:38 PM

Impul Throttle Bodies
 
Since JDM engines vary from USDM engines we suggest against purchasing JDM ECU reflashes. I considered this unfortunate because I really enjoy the Impul throttle bodies which until recently, we only offered with the Impul ECU; not any more. These beautiful throttle bodies can now be purchased seperately.

Impul Throttle Bodies

http://www.the370z.com/members/370zt...6-capture1.jpg

-Hunter

semtex 05-21-2009 01:51 PM

So . . . what does running these do to our USDM reflashes (when they become available)? Anything?

wstar 05-21-2009 02:01 PM

Quote:

Originally Posted by semtex (Post 76075)
So . . . what does running these do to our USDM reflashes (when they become available)? Anything?

I'm sure a good dyno tune shop can account for these with good software. What I recall from my LS1 days is that an oversized (vs stock) throttle body will tend to lean out the engine without the ECU knowing about it, so it can be potentially dangerous without a retune.

The MAF on the LS1 was calibrated for a given TB diameter. If you oversize without adjusting the ECU (or somehow adjusting the MAF output), the MAF output is actually wrong, and it's giving bad data to the ECU. I don't know if the ECU's data from the header-mounted wideband O2's can help it adapt or not, but I wouldn't want to be the first to try without knowing more.

Edit: Actually I'm pretty sure it would be a bad idea without a tune. The widebands might tune for it at idle or cruising throttle, but IIRC at WOT the ECU is going to ignore those inputs and use a preconfigured map, which will run the car too lean given the bad MAF input.

370Ztune 05-21-2009 02:15 PM

Quote:

Originally Posted by wstar (Post 76082)
I'm sure a good dyno tune shop can account for these with good software. What I recall from my LS1 days is that an oversized (vs stock) throttle body will tend to lean out the engine without the ECU knowing about it, so it can be potentially dangerous without a retune.

The MAF on the LS1 was calibrated for a given TB diameter. If you oversize without adjusting the ECU (or somehow adjusting the MAF output), the MAF output is actually wrong, and it's giving bad data to the ECU. I don't know if the ECU's data from the header-mounted wideband O2's can help it adapt or not, but I wouldn't want to be the first to try without knowing more.

Edit: Actually I'm pretty sure it would be a bad idea without a tune. The widebands might tune for it at idle or cruising throttle, but IIRC at WOT the ECU is going to ignore those inputs and use a preconfigured map, which will run the car too lean given the bad MAF input.

Great feedback :tup:. This is one of the main reasons why until recently, Impul was only offering these throttle bodies with the ECU.

-Hunter

t-ray 05-22-2009 09:10 AM

I just can't see any need for larger TB's, not unless you are pushing some major air through the system. And if you're doing that, you're force inducted, and the entire intake tract is pressurized, so I don't think the TB's would really have any benefit.

Can someone please explain this to me?

JCZ 05-24-2009 10:11 AM

Quote:

Originally Posted by 370Ztune (Post 76062)
Since JDM engines vary from USDM engines we suggest against purchasing JDM ECU reflashes. I considered this unfortunate because I really enjoy the Impul throttle bodies which until recently, we only offered with the Impul ECU; not any more. These beautiful throttle bodies can now be purchased seperately.

Impul Throttle Bodies

http://www.the370z.com/members/370zt...6-capture1.jpg

-Hunter

Do they come with the coollant line bungs?

Phimosis 05-25-2009 03:33 AM

Oh. 3 grand? Ouch. I would buy if there is real benefit. Please show me some dyno tests with the abient temp, elevation and barometric pressure listed, please. I just don't see the value-to-performance ratio working out on these.


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