[chase206]

Electrical work is not cheap. I doubt a plug n play harness exists for your chassis so it has to be customized regardless. Although a rate of 150/hr for 18 hrs is a bit high, he is diving into an unknown chassis and wants to quote high so there are no surprises.

If you think the hardware costs are too high, try obtaining the parts yourself and install it yourself. That should offset some cost. The tune itself for 1000 is about the going rate.

 

[chase206]

5psi might be safe-ish. Which ECU does your car have? Kefico single connector or two connector? Siemens 2 connector? Is it MAP or MAF based?

The MAF based cars will pickup on the additional airflow and compensate with more fuel to a degree... But the only way it will pull timing is if the ECU sees high IATs. The ECU doesn't know you're feeding it boost if it's a MAF based car. The MAP based cars will need a tune. Any change to the volumetric efficiency will throw the ECU way off base in that scenario.

For reference on the supercharged 2.7L cars we don't push more than 3psi untuned on stock injectors. At 5-6 psi we have to up to injector size to 310-360cc and pull timing back to 24 degrees of advance above a certain airflow threshold otherwise we detonate and melt pistons. If the IAT is moved to the boost side of the blower we see around 5 degrees of timing being pulled over a certain temperature threshold.

Although supercharging is a bit different than turbocharging so a late power band with a little more boost may be safer because your ECU is already in open loop enrichment by the time you are making real power. Typically I see the Siemens OEM tunes start enrichment around 70% throttle. Supercharged and turbocharged reflashes typically start open loop enrichment around 30% throttle. The transitional point just before open loop is trigger would be where you may detonate because the AFR is still targeting 14.7 up to 70% throttle.

 

[chase206]

That is unusual! You seem to have a newer ECU than what that chassis should have. The 1999 Elantra should have a Kefico ECU much like the early 96-00 Tiburon like the following:

I am not familiar with your ECU unfortunately so I can't give you any real insight. But my guess is that WOT enrichment doesn't start until at least 60% throttle and the fact that you've got a MAP sensor means you need to remap the volumetric efficiency table to make it reliable and safe.