L1FRDOG

I have a 2017 Grand Sport. 9K miles, and started Mods just after the new year. A few weeks ago added Borla catless x-pipe, and a Mishimoto 160 Tstat .... ARH Mid length headers are on way, but have NOT arrived yet, and still need to be Jet-Hot'd.

I did not pull a code/engine light with the Xpipe and Tsat, however, today after adding a new Ported Throttle Body from Weapon X, and a Vararam TCR-7 CAI I finally threw a check engine code..

To see if I could get the car to settle, I went out for an hour drive, plus let the car idle for another hour... temps never above 185, and fan is not kicking into overdrive like it did after I first installed the new Tstat.

Even after that I still have the check engine. I currently suspect the culprit is the Throttle body as it is a totally new part (not my original modded) from Weapon-X. If I was worried I'd take the time to swap it back, but I've already made the mental leap that the tune is coming. At this point I will wait for the new headers (ARH Cat'd Mids) and then that will be it.

I will have the car dyno'd with everything minus the tune, and then with. I'll end with 3 effective numbers a base rear wheel dyno number. a dyno with all Bolt-on's but no tune, and then a dyno with all bolt-ons AND a tune.

Looking for thoughts and I have a question...

Q1. I have pretty much addressed all the common bolt-ons for the grand sport. I haven't addressed FI/Nitrous at this point and even if i did that will be 2-3 years down the road. The missing link I see so far is the Axle-back exhaust system. My question is does the axle back really matter from the tuning POV? I suspect it is almost all sound after headers and xpipe.

I ask the above question because I would like to get the tune now and play over the summer. Come end of August at Carlisle I'll make my pick of either the Borla Atak, or Magnaflow Competition. I am just not sure I'd need to tune again after adding only the axle back to this setup.

Thoughts?

Deeds, Not Words!
L1FRDOG

robert miller

You are correct exhaust will be for sound only no need for tune on that piece of the mod list at all. Robert

lakemg

If you're going to tune it, you might as well send the ARH mids back and get the long tubes...

robert miller

L1FRDOG

Absolutely appreciate that thought. However, i am in one of those stricter states. No need to debate, I simply choose to "emulate" a more stock look from the casual observer (inspector) and have "Cats (albeit hi-flow) in the stock locations, as opposed to the long tube headers with cats further down the pipe, (which some states allow... but not mine).

I currently feel the need that Mid-Length are the max headers I can get. So, the long tube options are not there for me. One day maybe, but not now, so suggestions to move that way are not helpful.

ARH Mid-length are a middling solution that is not full length, but an in between... I dont need a solution for MAXIMUM HP... I want to show folks who are trying to gain REAL hp on there limited emissions options what true avenues there are....

Streetrod782

You'll love the sound of the mids. I have the ARH mids, x pipe, weapon x ported throttle body, CAI and never threw a code. I eventually had them put an HP tune on the car mainly to get rid of the V4 crap but it did wake the car up. Debating wether getting a ported intake is worth the money. The Atomic one is expensive but claim like 15 hp.

L1FRDOG

Sweet! sounds like we are on the same page.... Everything I've read on the throttle body seems to come back to throttle response... i never actually saw a Hp Gain.... although I reiterate... I am, not here to debate 1-5 hp here/there.... I am, out right going to stipulate... NONE vs, All Bolt-on, vs All Bolt-on AND Tune. Though I reserve the right to add more... example I may choose to add AFM from Tune.... but not there yet....

Scudz

L1FRDOG

Unfortunately, I don't have the absolute raw numbers for my specific car. I also don't intend on taking car back to stock just to test. What I currently am looking at is a variety of folks who've posted stock Dino results. I am running a M7 and as an average I think we are looking at 410 RWHP /411 TQ as the "baseline". I don't have any preconceived notions about what I have, or where I will be. I just want to see if adding this "stuff" to an already pretty dang awesome car is really worth it. My ultimate goal is to hit about an even 500 rwhp and strictly do road course/ hpde, so I'll look to focus on susp/tires/brakes...

L1FRDOG

Good news, and Better news!

The Good - Took the vette out a nice leisurely highway drive. After 40 miles the Check Engine light is officially off. So that makes 160 Tstat / Vararam CAI / Weapon-X Ported Throttle Body and Borla X-Pipe... No code/no check engine light.

The Better - ARH Headers arrive TODAY on UPS truck "out for delivery!

Internets_Ninja

Did you happen to unplug the MAF sensor with the battery not disconnected? I have seen a Check Engine light happen in this scenario on 2017+ models. I don't think any of the other mods would cause a CEL. The only other possibility that may be happening is the car is running lean with the Intake and throwing a CEL. But you need to find out what the CEL is for.

L1FRDOG

Yes unplugged the MAF and did all mods without disconnecting battery. I had heard that you needed about a 35-40 mile drive on the Highway to reset. Looks like that took care of it.... again, the Headers are in. So I figure 3-4 weeks and install/tune.

Scudz

L1FRDOG

I cannot give a definitive answer. There is a difference but I haven't really gotten on it. For one, the engine light was on and I was trying to get the reset, then when it went off it started snowing ... and yes I was driving... crazy spring weather here in Washington DC...

I'll keep you posted, but I can say the xpipe is awesome . The sound is night day

Scudz

Gary barnes 1098

brettmess24

spinkick

I have the VR Cai, Katech ported tb, debating the edgy vette intake, I'll most likely have diablew tune it. What do you guys think? Is the intake worth the effort?

Southeast Beast

I'm curious as to how this works out for you as I am planning to go a very similiar route,Good luck!!!

kdejac

Another good bolt on would be adding a flex fuel sensor and running E85. Did it on my Z51 and getting ready to do it on my Grand Sport. If you are going to tune the car, its worth the extra $300 for the sensor.