Maximum potential of tuning with Stock Exhaust system.

[osama.asr]

Hello Stinger tuners!

I would like know the potential of the car without changing stock exhaust.

This is mainly because of preference of quiet car and avoid legal issues.


Appreciate your feedback all!

 

[Thomby]

A freer flowing exhaust might give you a few extra horsepower, but it's not a bottleneck at any realistic power level. The turbos themselves, and their integrated manifolds/housings, are the ultimate limit.

Rule of thumb is up to around 500bhp/450whp with plugs/tune/octane, then maybe another 60-75hp from a power adder like methanol or charge pipe injection + ethanol. With a full back end flash and the power adders, call it 600bhp/550whp.

 

[osama.asr]

A freer flowing exhaust might give you a few extra horsepower, but it's not a bottleneck at any realistic power level. The turbos themselves, and their integrated manifolds/housings, are the ultimate limit.

Rule of thumb is up to around 500bhp/450whp with plugs/tune/octane, then maybe another 60-75hp from a power adder like methanol or charge pipe injection + ethanol. With a full back end flash and the power adders, call it 600bhp/550whp.

If I understand you correctly, with gas pump 93 octane. I will be missing around 100whp? If going with everything intakes/plugs/tune etc.. (except exhaust system). Not talking about turbo upgrades those are another level.

 

[Thomby]

If I understand you correctly, with gas pump 93 octane. I will be missing around 100whp? If going with everything intakes/plugs/tune etc

I believe the JB4 maps are conservatively designed so that Map 1 works with 91, Map 2 with 93, Map 3 with E30, etc. You really need to check the logs to see how your car performs in your local conditions, but intake + plugs + Map 2 should get you something like 40-50hp over stock, and maybe 50-60 lbs-ft.

So you won't see the gains that more octane/cooling unlocks, but still a very noticeable improvement.

 

[Plakchup]

Can easily get nice power out of the stinger with the stock exhaust. As said the limitation are more the turbos themselves entirely. Exhaust modifications really won't bring much gains with the stock twins. Logs tell a lot about how the car runs so definitely get a few logs going on 2 most common maps. The kinda crappy area of the stock exhaust is the axle back that is crimmed down to a flat surface and pretty narrow but likely it's done for a reason to reduce noise. There are plenty of stingers modded with stock exhaust. Quiet and fast is a good combo! I myself am not entirely sure changing out primary downpipes are really worth the hassle unless you chasing max performance. Secondary downpipe gains are pretty minimal too.

Fuel quality matters too so you need to kind of experiement and see what works. I go to the same gas station pretty much and run map 3 with e30 mix most of the time and go back to map 2 with 91 once every 2 months or so. Something like a fuel it ethanol analyzer is very handy to have to get true ethanol readings and make fill ups very easy for blends which I have. As said the good rule to follow is staying at or below 500 whp to avoid lifting the heads. Bms ran 540ish whp on stock twins and slightly lifted heads but luckily was no damage done.

The power difference between map 3 with e30 and map 2 is very noticable especially if you have good supporting mods. Map 3 is the "oh shit" map on jb4, really throws me back into my seat. I have most bolt ons without cpi and I am about to do backend flash with KJT for his e30 tune which should be around 470ish whp but I probably will be just slightly above that due to my mods (intakes, fmic, cp, secondaries + catback). Should really make a nice difference.

These videos below should give you some good insight: