Jamie140

Love it.

Thanks doc!

Fabspeed: any progress on a tighter rear end?

Edit: id be interested in a tight 12345 with a longer 6

John@Fabspeed

We don't have a Vbox or a dragstrip around the corner unfortunately

Give me a call, I may have a lead for you on that

Richard.

Looks good, did I miss the before and after Dyno info comparison, no CEL yet ?

John@Fabspeed

Nope, just been trying to get the updated dynojet software to export the graph so we could post it up. What a pain haha.

trebien

What's with all these dynos that only go to 7200 RPM? It's a glaring omission, imo.

And before anybody remarks "the power drops off after 7200 RPM so what's the point?"... well, that exactly IS THE POINT.

We all agree the top RPM ranges are weak on the stock GT4... so it would be nice to compare the full RPM range, and how these products affect the late RPM drop off of the stock vehicle, especially if it opens up the powerband at the top and let's the engine rev a bit more.

Dr. G

Considering the stock vs tuned lines are divergent in that range on the graph, I concur.

There are definitely times I'll run right to redine for a few seconds in sport plus being that it doesn't cut power and you don't get the bouncing effect.

CAlexio

Just sport headers, so perfect.


Sport headers plus exhaust... Race car

Dr. G

As great as your second video sounds, it still doesn't really adequately capture what the setup sounds like - it screams at high RPMs. I really like it, but it's a pretty loud setup.

John@Fabspeed

Hey Guys! We aren't out to bounce cars off of redline on our dyno, it is a bit unneccesary when we all know the last few hundred RPM is going to smoothly fall off and not gain anymore numbers. If you would like to see how how the top of the powerband looks like modified and unmodified. Please see post #22 on the thread below. We no longer have that software issue, but don't rev that high to redline as it is unneccesary stress in our humble opinion.

https://rennlist.com/forums/gt4/9012...c-exhaust.html

trebien

And how do "we all know" this behavior, if it's not in the dyno?

Running a GT4 to 7600 RPM on the dyno is not going to "stress" the engine beyond specs, especially the way most of us drive them on the track.



I for one, DO care what happens over 7000 RPM, as this could affect shift points and other strategies on track.

I am not judging you, but it strongly comes across as a cop-out or excuse or something to hide. Either way, it's a negative connotation related to the presentation of your product.

Just something to consider.

Dr. G

If I get my car back in there I'll let them run it to redline, being that I sometimes do it on the road. Fair enough?

Also, notice that it's 362hp at 6148 RPM and around 358hp at 7150 RPM, where the throttle was let off - and the curve is still on an upward trend and the base line and tuned line are still diverging.

John@Fabspeed

It is our tuner/dyno operator's executive decision to cut the run short of redline, and I can certainly tell you it is not in any way meant to be a cop out as you can see in that post the gains are maintained to red line. Nothing magical is going to happen in that last 400rpm scout's honor (Life Scout not Eagle, sorry) Either way, i'll see what we can accomplish with you the next time we have one in

I spoke with Steve and we would be happy to run your car out to redline and appreciate your willingness to let us accomplish that. You never know nowadays and we always prefer to be on the safe side with our clients' cars especially with low mileage. Would rather be called a cop out than wreckless haha.

trebien

I don't expect magic, but there is so much comparison between the neutered GT4 top end versus the GT3 top end. And rightfully so, for a car marketed to deliver a visceral experience but running out of steam at the top.

In fact, I have a funny feeling that many pundits would back off the complaints about the GT4 engine if the damn thing would just sing in full glory up to redline, and not fall off. Fix that, and you've got something special on your hands.

But I digress, and would love to see dynos run to redline, for the sake of information. Thank you for the offer.

Eagle Scout, 1992

spyderphile

Thanks, CAlexio; those were very helpful. Yes, it sounds awesome! I love how the note increases as the RPM climbs. With header+exhaust, the sound toward redline didn't seem that much different from header+PSE; but, the over-run is much more pronounced. I could be wrong in my perception.

For my taste, just getting the header might be the ticket. And, wonder how the Race Header would sound!! Pretty cool. Thanks again.

p.s. Why the top was up?? Seemed like a beautiful California day!

spyderphile

Thanks, John. Will look them up. Got your PM; will respond in a few days.