dlandsvZ28

Sorry about long post - but to get some good analysis thought I need to show history of upgrades.

In short - can't figure why would loose so much rwhp on same dyno, same tuner, same operator.

1998 Camaro Z28 -85K -A4
History on Dyno
Essentlally stock 2002
LS1 mods with K& N Filter, Whisper intake, Borla Catback Exhaust
DYNO: Dynojet 301 RWHP
************************************************** ***************************
Mods – 2003

LS6 Intake
42 lb injectors
Ported throttle body
LS6 oil pump
Ported heads 99 heads
Comp Cam 224/228 114 LSA
Comp Cams Type R lifters
Yella Terra 1.7 roller rockers
JetHot long tubes, Jet Hot j pipe, Magnaflow Exhaust – no cats
Meziere Elect water pump
Stock rear end 3.23 gears
Precision Industries 3000 stall converter
Rebuilt stock A4
Racetronix 1998 fuel pump kit with wire upgrade
RWHP Results
Dynojet – 377 RWP 373 Torque - increase in rwhp - 76

************************************************** ****

Mods – 2005

Same mods as 2003 with following changes
60 lb injectors
Patriot LQ9 low compression heads
Magnaflow Exhaust – no cats
ATI D1SC 8 rib kit with ATI twin 3.5 intercoolers with 7.65 crank pulley and 4.5 blower pulley, small ATI filter
Didn’t document but think between 6 and 8 lbs of boost.
Moser 12 bolt rear end 3.73 gears
Racetronix 1998 fuel pump kit with wire upgrade
RWHP Results
Mustang – 493 RWP 578 Torque - increase in rwhp 116

************************************************** ********

Mods – 2009

Same mods as 2005 with following changes
Stock throttle body
American Racing 1 7/8 inch long tubes , American Racing y pipe with cats - Magnaflow catback exhaust
ATI D1SC kit with 7.65 crank pulley and 4.38 blower pulley
Custom aluminum 3 inch intercooler pipe with EPP 4 inch bar and plate FMIC.
K & N 5 X 8 inch filter essentially same size as what Bob recommends but it is not cone shaped. It is round.
Didn’t document but think between 8 and 10 lbs of boost.
Moser 12 bolt rear end 3.42 gears
Performabilt Level 3 A4
Yank blower converter 3450
RWHP Results
Mustang – 563 RWP 578 Torque increase in rwhp 70

**************************************************

Mods – 2017

Same mods as 2009 with following changes
Refreshed Patriot LQ9 low compression heads
Comp Cam Epp blower cam 232/240 115 LSA
New Comp Cams Type R lifters
Comp Cams trunion kit
Stock LS6 rockers
Stock water pump
Custom aluminum 3 inch intercooler pipe with OCX 3.5 tube and fin intercooler with K & N 5 X 8 inch filter.
Chevy Chad additional idler pulley on J bracket – no belt slip
Modified stock rear end with 3.23 gears
Alky control kit with one nozzle with a mix of 50/50 methanol. IAT’s were in the hight 70’s or low 80’s

RWHP Results
Mustang – 418 RWP 387 Torque lost 150 rwhp but only showing 5 lbs of boost max.

Was dumbfounded – I thought I would stay the same or gain rwhp, but perhaps loose a lb or two in boost because of cam change.

Second and third pull gave us an increase in of 37 rwhp with an increase in timing that got it 455 rwhp and 386 lbs of torque but still shy of rwhp at EPP (Brute Force and results in 2009).

Anybody have any ideas why the drastic decrease in HP. Same chassis dyno, same operator as in 09.

The significant changes were cam, and different intercooler, and the loss of 3 - 4 lbs if boost. Couldn't find any boost leaks, no belt slippage, Proflow was holding, diaphragm was good.

Note:

Why significant difference in dates? I had overheating issues that I couldn’t resolve so literally parked the car from about 07 up to 2017. Only 1950 miles during that periods of time. Over heating was solved by moving AC condenser off of the radiator and into the bumper cover. So decided to make some upgrades and finally drive the car.

transam69230

iTrader: (49)

Plug wires on? Running out of fuel? What is AFR during pull ? Rockers loose?

Coupler could be cocked ( but still on the pipe ) allowing air to get out.

Did you degree the cam in? O2 sensors plugged in? All the sensors plugged in?

It could literally be anything.

dlandsvZ28

Before running on the dyno to test everything, I only got 5 lbs of boost. Explanation by the cam installer was that because the cam is more blower friendly that would reduce boost - less restriction. But 4-5 lbs less - don't know.

Or that my Ultra lite boost guage was off.

But IMO the results on the dyno I think confirm that it is only making 5 lbs of boost. And if I was actually producing more boost, the 5 lbs difference from previous would makeup for the difference in loss of rwhp.

The first pull tuner used essentially the same tune as 09 tune. On the second pull he added some timing raising rwhp to 455.

Plugs are all new, wires are good, no misfires.

AFR was between 12-13 and that's what my AEM guage was reading as well. When we compared to the dyno Innovative AFR it was a tad leaner than mine. He said that is because the tailpipe will be leaner than my o2 senser installed just after where the pipes merge. Tuner won't tune lean, so basically afr was reading about the same.

All slicone hoses are clamped and tight. The PRO Flow bypass was locked closed. I was watching it as it closed. No holes in the diaphragm.

Tune is SD, so no maf. Map sensor is 2 bar since my PCM is a 98.
No knock - new knock sensors.

Can't find any vacuum leaks.

Does the injection of methanol reduce hp? Perhaps we running too methanol rich. We left the settings as they are dialed in received from Julio (10-2 and 12-2)- it's an Alky Control kit. IAT's were real low. Below ambient - high 70's low 80's. It's one thing we did not consider as a cause of lost power.

How much methanol will it use on a pull? The washer tank dropped from full down to the level where the level can be seen across entire tank- visualize a Camaro tank 7/8 full.

Personnally I think the rockers make a lot of noise, but all I hear is they all sound like that. The sound resonates more into the cabin than when standing next to the car with the hood open. The hood is an SLP Ultra Z hood. No insulation.

It certainly doesn't sound like a sewing machine.

I'll log some data tomorrow. Have a 4.25 pulley I haven't installed yet. If it raises the boost a lb or two going from a 4.38 pulley to a 4.25 pulley, then perhaps will know that I have no leaks and that my guage is correct. If boost doesn't raise then I have a pressure loss somewhere - hole in intercooler maybe.

If intercooler is bad, I still have the 4 inch bar and plate. I changed it out because room it takes and much heavier than the tube and fin installed now.

ta02zx10r

iTrader: (19)

Belt slip?

dlandsvZ28

I installed a second tensioner pulley so don't think that belt slip is the issue.


If I tighten any more both 2 1/2 inch tensioner pullies will be touching.

If if try to go down to a shorter belt it won't go on. Next size shorter is the belt I was using with just one tensioner pulley. Gates green K080415 which is 41.5 inches long - one tensioner pulley with a 7.65 crank pulley and 4.38 blower pulley.

Gates green K080427 is installed now and it 1 1/2 inches longer with same size pullies and with one additional idler pulley.

The ATI damper is pinned.

jordoza777

iTrader: (2)

Honestly i recommend a boost leak test. I'll bet you it's a boost leak. It sure sounds that way to me. It's fairly easy to weld a cap to a piece of pipe the size of your blower outlet with a fitting to inject shop air with a regulator. Don't do straight shop air or you could blow the intercooler even if it isn't bad. Either make a plug like that for pipe to the throttle body or remove the rockers if that would be easier. If you remove rockers then you test intake seal too. It will answer the boost leak idea certainty. Just my two cents but I work with turn is everyday. One of the first tests we run for low power complaint.

SStressin

iTrader: (5)

Just curious as to why did you ever go back to the 10 bolt with having a procharger and 12 bolt already

LLLosingit

iTrader: (4)

I would also do a compression and leak down test for two reasons, (1) previous over heating issues (2) new cam/heads . There is always a chance the cam was ground wrong or that the Valves aren't sealing after having the work done on them or that the pushrods aren't holding the valves open.
It would at least eliminate that possibility anyway.

gametech

iTrader: (1)

Did you pin the crank pulley as part of the blower install?

LLLosingit

iTrader: (4)

He answered it earlier but you could have easily missed it.

gametech

iTrader: (1)

My apologies for merely skimming a detailed post. Feel free to laugh at my booze oriented lack of reading skills while helping him find what must be a boost leak or major intake restriction. That is really the only thing that makes sense if their is no blower drive slippage. Now I am wondering about that new ocx intercooler.

transam69230

iTrader: (49)

We used a smoke machine to test for leaks all way from the compressor inlet to the intake, worked soo awesome!

jordoza777

iTrader: (2)

The smoke machine is awesome but I've found it doesn't make enough pressure sometimes to show a leak in the rubber boots. Maybe you have a better smoke machine that makes higher pressure then my Cornwell blue smoke.

dlandsvZ28

Got tired of the noisey rearend - whined all of the time - from day one. Torque arm bracket about to punch a hole in the floor pan.

Since i don't drag race or street race I'm more interested in city and highway driving. Cruises nice now at 2100 rpm at 70 miles per hour with 3.23 gears.

My ten bolt was completely refreshed with all new parts - only thing original is the housing. Installed a solid pinion spacer, it has a upgraded Torsen diff along with the LPW up-grades. I regret that I didn't weld the tubes too - maybe later. See link.


The way I drive I don't think I will be breaking it any time soon.

dlandsvZ28

Heads were completely taken apart and checked. Tech that installed them is a GM technician with 35 years of experience and 25 years of drag racing. His turbo Camaro is an 8 second car.

I still think the problem is the boost level. 5 lbs is nothing. 10 lbs would have put it right back where it was in 09.

I don't know if he locked the converter this time, or if it was locked the first time. I understand that can make a diff too.

There's only 5 k on the Yank PY3400 blower converter and the Performabilt level 3 4L60.

dlandsvZ28

I'm thinking the same. It was somewhat of a test (tube and fin vs bar and plate) as was the movement of the ac condenser to correct the overheating issue when running the ac in temps over 100 degrees here in KS. Not a lot of space inside the bumper cover. I rebuilt it three times. I will be moving the trans cooler to front of the radiator which will give me more room for the 4 inch EPP intercooler.


So I am going to pull the tube and fin cheap OCX intercooler off and reinstall the EPP intercooler which is bar and plate. I'll pressure test Epp cooler first, though.

Now that all of my intercooler pipe lengths are nailed down, there are a couple of pipes I can weld together eliminating the silicone connectors and restriction. Also one less place to leak.

LLLosingit

iTrader: (4)

I'm sure it is but if nothing changed other than a the cam and heads there is an issue somewhere keeping boost down. Changing the cam alone isn't likely the cause so either the boost is leaking somewhere or it's just not being produced by the supercharger. I went from making 6 to 10 and could tell right away I was making a lot more power.

dlandsvZ28

I also installed all new piping along with an OCX 3.5 tube and fin intercooler which makes me think as soon the pressure reaches 5 lbs the intercooler starts to leak. The old intercooler was a 4 inch bar and plate intercooler. I think it is an OCX but not sure. I got it from Bob at Brute Speed.

I also moved the bypass outlet to between the charger and the intercooler inlet. Both piping systems before this one had the bypass between the discharge outlet on the intercooler and throttle body. For 09 pulls I had professionally built aluminum pipes because the steel ones were rusting on the inside. I couldn't use the 09 custom aluminum same set this time because I had to move the intercooler up and forward so I could keep everything above the fender splash shields and the front bumper cover.

The bypass is an ATI ProFlow vented to atmosphere. The diaphragm was good when I opened it up and installed a new diaphragm Bob sent me. I watched it close and hold tight during the last pulls thinking it might not be closing properly.

So - still think HP down is because of only 5 lbs of boost.

And since I am only getting 5 lbs of boost I think it is because of the intercooler or I have a leak in one or more of the silicone joints.

BTW - the gauge hits 5 lbs very fast and then stops and doesn't go anywhere after the 2-3 shift.

Or if I still have belt slip - one way to test again is to go back to one tensioner pulley like 09 and test to see if boost goes back to 8-10 lbs.

Or try install the 09 41.5 belt if the longer current belt is still slipping even with the additional tensioner pulley.

RealQuick

iTrader: (14)

How old are the valvesprings?

dlandsvZ28

Bob at Epp (Brute Speed) installed the Patriot LQ9 low compression heads - April of 05.

The car has been parked since 09 - lost enthusiasm - driven about 1500 miles during that time period since the last dyno pulls in Oct of 09.

Mileage on heads is less than 9k.

Heads were inspected when the Comp Cams trunion kit was installed along with Bob' blower cam, new lifters, etc. Less than 500 miles on cam, etc.

I specifically requested that if anything needed to replaced to do it. He didn't find anything wrong except to suggest the trunion kit and ARP head bolts which he did. Installer is a perfectionist. If he could have found something to replace he would have.