Sales@Tick

iTrader: (3)

This car belongs to another one of our local NC customers, and initially he had brought it to us to tune some readiness codes out of it so it would pass inspection. When it first arrived, it was making 490rwhp and 477rwtq. We didn't expect to gain any power with the car as the visit was for him to be able to pass inspection. We were able to pick the car up to 499rwhp and 492rwtq which will be the first pull you see in the graph I am going to show you.

The owner was very pleased with the gains and how much better the car drove after having us tune it that he decided another round up upgrades were in order. He had another very reputable tuner in the area tune it before, but since he no longer does tuning it was hard for him to trust someone to tune his car after his tuner "retiring".

Fast forward a few weeks and he had installed a new Duspeed OTR style intake and port matched his Fast 102. Excited to see the results we chucked it on the dyno and Jonathan dialed it in. When the smoke cleared these were the results:



522rwhp/501rwtq!!! This was a very nice surprise to see these gains after the tuning was done. I believe this is the highest dyno number I've ever seen from a 4" stroke LS motor with 243's. While I'm sure there are probably a few that have made more than this, I personally haven't seen one this strong. His heads have 2.08" intake valves and 1.60 exhaust valves and have been CNC ported by a local guy to 230cc's. I think he did a pretty good job!

The cam isn't one I did, but I am also very impressed by it. It is a Bullet racing grind and is 242/249 112+4. I am unsure on the lift figures, but I believe them to be in the .63x"/.64x" area.

We currently have tentative plans to swap his 243's out for a set of TEA CNC TFS 235's or possibly 245's and a set of Kooks stepped 1x7/8"-2" primary headers from the 1x3/4" headers the car currently has. We're hoping that with these modifications it can crack the 560-570rwhp/525rwtq area and not lose the awesome power curve the car currently has. This is a heavy GTO so it needs all the available average power it possibly can make.

Thanks for looking, and if anyone would like a package similar to this we can do it! We're just a call, pm or e-mail away.

JakeFusion

iTrader: (7)

So he had the 102 before? New intake and port matching netted ~20rwhp? That's awesome.

Sales@Tick

iTrader: (3)

Yes he did, he had the 102 since he did the stroker engine if not before. All of the tuning prior to the tuning we did was done by another shop after Mike(the customer) picked out all of his parts. I just found the results very impressive. I think most if not all the gains here can be attributed to the parts, but on Monday when I get back to the shop I'll pull up his original dyno run from before we tuned it the first time, to after where it picked up 10rwhp and some torque. This would be before he installed the new Duspeed cold air intake and port matched his Fast.

The camshaft events would be nearly identical to what I would do for a set-up like this and I really like what Mark@Bullet did with the camshaft to match the heads and intake.

KCS

iTrader: (20)

If the FAST is port matched to the 243's, how will it be affected when the new heads are swapped on?

bozzhawg

I had the same question as well?

6PntHo

iTrader: (2)

That's awesome. Nice gaines.

Sales@Tick

iTrader: (3)

With the new heads being larger in CSA and the intake runners being slightly larger in volume, it will only be another port match away from the way it sits now with the stock castings. The customer won't mind doing it I'm sure. He is very proactive to fixing his own car and planning his modifications with my insight.

I certainly wouldn't think that even if he didn't port match the intake to the new heads, that the new ports being larger in size would hamper power production. In comparison it wouldn't be anything different than an out of the box Fast 102 on the same sets of heads in this application.

Thank you! The main thing I found so bad *** was that the gains were all the way across the entire board and not just peak to peak. That is truly 20rwhp/10rwtq you will feel in the seat of your pants every day.

Sales1@Texas-speed

Very solid setup! Interested to see what it picks up when he swaps to an aftermarket casting.

Sales@Tick

iTrader: (3)

Aaron I would like to see what it would do with a set of your small bore 250cc LS3 heads, but with the customer already having the cathedral port Fast it kind of makes it impractical. This engine set-up would be perfect though IMO for that head.

Sales1@Texas-speed

I agree for sure! Yea too bad he already has the FAST for the cathedrals lol. Regardless this has got to be one fun running car!

Sales@Tick

iTrader: (3)

I would do a little tweaking to the camshaft events, but other than that I think it would make very good power.

I'm really curious to see how much of a difference an aftermarket casting that has a steeper valve angle than stock can pick up in this situation. The guy that ported his heads is very reputable locally and I think he did a great job with them. The 2.08 intake valve really helps open up the pathway into the cylinder to allow this thing to breathe deep.

It is a very fun car to ride in. It doesn't need to be wrung out to 7000rpm to make it move out very quickly, and shift points are kept at 6600rpm.

Do you think 560-570rwhp is achievable with a 245cc cylinder head or a 235cc head even?

weldermike27408

What's up Martin:
GTO came to you at 490RWHP/477RWTQ on your first pull...after a TUNE ONLY by Jonathan you guys gained me +9RWHP/+15RWTQ and came out to 499RWHP/492RWTQ.The torque increase blew me away.
After I matchported the out of-the-box FAST102 I had been running a while,added the NW 102mm TB,DuSpeed OTR you guys re-tuned it and got me another +23RWHP/+9 on the torque for current number of 522RWHP/501RWTQ.
As far as the heads they are fully CNC'd castings,not hand ported but I do think he did some hand blending on the bowls. Greg scanned the as-cast 243's I brought him years ago and digitized his own program and CNC'd them.They came out to 233cc and use a 2.08" intake but the smaller 1.575" exhaust.WHY 1.575" you may ask,thats because they were originally on my stock cube 364" LS2 and when it blew and I went to the 416" he enlarged intake port and installed the 2.08" intake valves but kept the 1.575" exhaust valves to save me some $ but enlarged the exhaust port.

weldermike27408

cam is .650"/.650" but you got the rest right...drove it a bunch today...sunny and cold...that dog did some talking in this cold air !!!

weldermike27408

Id like to see what it runs before I swap heads...got some new street tires for it this week 'cause the BFG's just light up if you mat the gas in 3rd at 55 mph.
Either way I think those 243's did pretty damn good and 500 RWTQ is impressive to me on motor.

weldermike27408

I had been running the unported FAST 102 for a while and I decided to matchport it when I enlarged the 102 TB. The TB,OTR and matchporting got +23RWHP

JakeFusion

iTrader: (7)

What tires do you have that'll hold that power? lol

Sales@Tick

iTrader: (3)

Mike! Glad you dropped in after giving you that link to the thread. I knew I probably got some of it a little wrong, but still these numbers are far beyond over inflated and are VERY solid. If it made 499/492 after we tuned it it would have picked up 9rwtq to make 501rwtq with the TB, Porting and OTR intake correct? I think one of the reasons the torque is so solid with this set-up even with the small headers is the exhaust valve size. It's helping to really keep exhaust velocity up and scavenge the spent exhaust gasses out of the primaries into the collectors.

If we do the bigger aftermarket castings whatever they may be with their 1.60" exhaust valves, we can similarly mimic this with a stepped header and try to extract some more power along with the new casting cylinder heads.

Greg really knows heads and I almost would like to see if he could improve upon anything we get cylinder head wise.
I bet it felt like it had 15rwhp more than usual didn't it!?!?! I knew the cam was pretty high in lift, but if it's not hurting anything valve guide or valve stem tip wise we'll continue to run it. Since you put such a minute amount of miles on it each year it will probably continue to be OK, but we'll keep an eye on it.
Yes, 500rwtq is very impressive for those heads!
I forgot about the throttle body, woops!

Also guys, I will admit, I am not much on GTO's(no offense Mike, you're A OK in my book). Mike's GTO changed all of that for me. It's a gorgeous silver with all black leather interior and it still smells BRAND NEW inside, seriously it smells brand new. He keeps it meticulously detailed and even more so under the hood. It's amazing how clean his car is and it has really changed my outlook on GTO's.

weldermike27408

we'll see...got a little stickier summer only tire and we'll see how they do...400UTQG BFG's can't hold

weldermike27408

as far as what you were saying about LS3 style head Im not opposed to it cause i could sell 243's with the matchported intake as well..Id like to get a few times in my fat *** GTO first...
my cam may not be optimal for the LS3 heads though but thats way above my paygrade

weldermike27408

Greg does good work and stays under the radar because he's not into the internet "I'm God's gift to racing" sh*t...If he can make a set of 243's work like this it would be intersting to see what you guys could come up with on an aftermarket pro-porter/as-cast head...