[GoneBoy]

Originally Posted by 2out2sea

Isn't 11 stock boost? The 2.3 is supposed to be 9% and increase boost to 13 according to everything I have read. Still trying to figure out why with the 103tb and p&p supercharger it's only making 11psi. I would be more understanding if she showed a weak baseline Dyno, but 566 seems pretty healthy. What else am I missing? I am hoping beyond hope that it was just complete heat soak, but we'll see.

Nah, stock boost on the lt4 is 9.5. I know u ported the blower, but don't think you're gonna realize a lot of gains with the 103tb in conjunction with the 1.7L. You definitely would with a larger blower. I wouldn't focus too much on the Dyno, but how she feels when u get it back, which will be totally different.

[Gunkk]

Originally Posted by 2out2sea

Ok, I got the results and I'm not very happy. Baseline was 566 which isn't bad for an 80* day. Today it was over 90*; the hottest day off the year, but she only made 629. This is with 2" coated kooks, green cats, rotofab big gulp, a super ported stock blower by a shop that will remain nameless, 2.3 underdrive griptec pulley, 103 katech tb, colder plugs, plug wires, catch can and full tune. I haven't seen the dyno graph yet so I am not sure about timing and iat. Car is only making 11psi boost! Shouldn't it be making more like 13-14psi? How is it that complete street performance made more power than this BEFORE adding headers! Not sure what to think at this point. Really not happy.

Headers will drop boost for a given air flow, due to eliminating back-pressure restrictions from the stock tri-Y unit. Since you didn't do heads, cam or fuel, the stock fuel system will probably limit you to max +100 hp no matter what.

The LT4 is a surprisingly well balanced system. No one change gets you all the way there... and you pretty much have to upgrade everything to get much more than +100whp. But you don't have to upgrade everything to get +100ft-lbs.

For a street or track car it's all about the torque, not HP. HP is for egos and the strip and where the ZLE isn't the best choice anyway. The key here is area under the torque curve. I'd much rather have a car that did +100 ft-lbs from 3000 to 5000 (where I have fun with my car) and ZERO extra HP at 6500 (where I don't), than no extra torque and +100 hp at 6500. How often do you really drive the car at peak HP >6000? Be honest with yourself.

You want the tuner to give you back your car that will operate at a safe lambda in all driving conditions. It's easy enough for a bad tuner to make stupid numbers with unsafe conditions... and just as easy to you to drive down the road, blow up the motor, and that same bad tuner to say "sorry you blew up your car, bad luck." Vengeance ain't that.

So reserve judgement a) until you see the torque profile on the dyno sheet and like others have said b) until you drive the car!

[SJFGTO]

Agree with all of the above. I was way off on my guess, I knew it was a little high. I thought your numbers would be well north of mine. Mine was tuned on a very cool spring morning. But dyno numbers are ultimately a by product of a great running car and Mike is an extremely knowledgeable and experienced tuner. I would talk to the guys at Vengeance. I know they want their customers to be happy. I bet your car screams on the street and will be a blast to drive, and reliable day in and day out.

[2out2sea]

Maybe I have missed the posts, so forgive me if that's true. I never saw anyone with numbers as low as mine. Heck, vazl1 is at 640 so I am down even compared to him. Both vengeance and weapon x have stated that 13 psi boost is fairly normal with a heavily ported blower so that's where I was getting that information. I am glad to hear that the stock boost is only 9.5 and I was wrong thinking it was higher.

I guess this thread can serve as a cautionary tale for others. I mistakenly thought that the lt4 was a fairly easy and inexpensive mill to mod up until the fuel ran out. I also mistakenly thought that the fuel system was good until the numbers went beyond 675whp.

I gained 63whp and 74tq. It cost more than 7k to get those gains. I was expecting better return on investment. I am glad I had vengeance do the work. They seem to have a good reputation and I would rather have less power than a temperamental or broken car.

I know that some of you will say that I was unrealistic, etc. But I really went into this with what I thought were reasonable expectations. When you see cars like complete street performance making 630+ while heat soaked and without headers, you start to be overly optimistic.

Fwiw vengeance has sent two other Dyno results to me showing similar builds making roughly the same as mine. Don't know if that's normal, but it is what it is.

Moral of the story- 630-640 is realistic on these cars. Don't expect more for your money.

[TeleZL1]

Agree with all the above as well...you ported and opened things up so boost will be less.
You said it was 90 degrees and perhaps humid with this time of year???......if it was 50 degrees and dry you would probably make 20 more rwhp. Just my .02. Dyno numbers...meh...go see what kind of MPH you pull in the 1/4.

[Markoz28]

I did 2” kooks headers with no cats, TM TB, RF intake (not the big gulp), and 9.17 lower pulley. First tuner (my mistake and will never go back) made 578/638 on Dyno jet. Took it to MS tuning and on Mustang Dyno prior to his tune it made 558/630. After the MS tune 612/648 in 88 degrees and humid. Of course I was hoping for the same as you but once I got the car back DAY HAM! It felt completely different and power is amazing.

Knowing how heat kills these cars I’m planning a trip to the strip within the next 2 weeks. After that the Texas heat is relentless and I will have to wait until October.

[GoneBoy]

Originally Posted by 2out2sea

Maybe I have missed the posts, so forgive me if that's true. I never saw anyone with numbers as low as mine. Heck, vazl1 is at 640 so I am down even compared to him. Both vengeance and weapon x have stated that 13 psi boost is fairly normal with a heavily ported blower so that's where I was getting that information. I am glad to hear that the stock boost is only 9.5 and I was wrong thinking it was higher.

I guess this thread can serve as a cautionary tale for others. I mistakenly thought that the lt4 was a fairly easy and inexpensive mill to mod up until the fuel ran out. I also mistakenly thought that the fuel system was good until the numbers went beyond 675whp.

I gained 63whp and 74tq. It cost more than 7k to get those gains. I was expecting better return on investment. I am glad I had vengeance do the work. They seem to have a good reputation and I would rather have less power than a temperamental or broken car.

I know that some of you will say that I was unrealistic, etc. But I really went into this with what I thought were reasonable expectations. When you see cars like complete street performance making 630+ while heat soaked and without headers, you start to be overly optimistic.

Fwiw vengeance has sent two other Dyno results to me showing similar builds making roughly the same as mine. Don't know if that's normal, but it is what it is.

Moral of the story- 630-640 is realistic on these cars. Don't expect more for your money.

Your fuel system is perfectly fine given your current build, so don't worry about that holding you back at the moment. As others have said, if you're going to focus on anything, focus on the torque if this is just going to be a street car.

Not sure if you plan on adding onto your setup, but what you've done is lay a good foundation for future additions. Throw a cam, meth and/or e85, and you'll easily be north of 770hp/710lb give or take.

Our cars are 'easy' to make power...meaning there are multiple proven paths to safely make 900hp+ without sacrificing the enjoyment of driving it around like a normal vehicle or worrying about cels or the car breaking on you. However, forget about the cheap aspect of that, especially if you're paying someone else to do the work.

I'm spoiled having Vengeance in my backyard, but almost more than anything, they emphasize doing things safely in all aspects of this game. They have a strong core of customers including myself who participate in various race events, and what I've yet to see is one of their cars breaking. Thats not good for business. And given that you're in Alabama, you can pick your car up with the security of knowing that you're probably not gonna have to bring it back to them because they pushed the envelope just to make a few higher numbers on a dyno sheet. You're good man, so enjoy your ride.

[unavailablezl1]

This a UTUBE video that I am sure a lot of people have seen, but it is still worth listening to. VENGEANCE RACING.

Sounds better than the GT350 for sure

https://youtu.be/tzsBv98HGW0

[01pewterz28]

Your vehicle is in excellent hands Ron and his crew are the best in the business IMHO. I know known Ron for 16 years when he was over at GMMG.

[Repman]

I don't think you will be disappointed after you drive it . I made 625 SAE and 647 torque after Vengeance worked their magic I have basically the same mods as you minus the big TB and ported blower. look at my dyno sheet on post 5 of this thread and the torque curve is where you will feel the biggest gain in the seat of your pants . I gave a friend who has a stock ZLE a ride this week and he was amazed how different it was over stock.

I think you will be happy when you get her home as others have said Vengeance makes safe reliable power enjoy your car in good health it will make you smile

[unavailablezl1]

I have followed Vengeance for awhile now. And since I am in Texas, everyone likes to go fast.

Enjoy.

https://youtu.be/FZZaF0O9ah8

[2out2sea]

Just left Ron and his crew at Vengeance. They have an idea of how to find some lost power. Leaving the car for a while. I'll update more when I hear from them. Fwiw their customer service has been exemplary. Very happy with how my car and I have been treated.

[Repman]

Originally Posted by 2out2sea

Just left Ron and his crew at Vengeance. They have an idea of how to find some lost power. Leaving the car for a while. I'll update more when I hear from them. Fwiw their customer service has been exemplary. Very happy with how my car and I have been treated.

Where did they say the lost power was just curious

[Doc_Scott]

Out of curiosity, as I am looking at a similar build, did you ever consider a Whipple prior to finalizing your current build?