Took my 88 SBC car to the dyno today after work. I wanted to get a baseline for the current setup because I have a few upgrades planned and wanted to know how much they helped (might be next year).
Some details about the setup: 350 4 bolt main, roller cam, 1 piece rear main seal block, bored .060, 10:2:1 compression, Vortec heads machined for higher lift, ZZ4 roller cam, Tru-Ram stainless steel manifolds, mandrel bent exhaust, 2 1/2" off the manifolds into a 3" pipe, 3" in dual 2 1/2" out flowtech afterburner muffler, 2 1/2" to the stock megaphone tips, Ramjet PFI intake, 75mm throttle body, 24lb injectors, 7730 ecm with Moates Ostrich emulator and custom tune. Installed with Archie economy kit. Tranny is a 93 5 speed getrag with a spec stage 3+ clutch.
Dyno was a Dynojet.
Max HP was 283 at about 5200 rpm and 318 lb-ft or torque at about 4000 rpm. 80% of max torque was available from 2500 to 5500 rpm which is really nice.
Elevation is hurting performance since 90-91kpa is WOT (and same value with engine off, key on). The speedway motors Tru-Rams probably flow better than the Rams Horns, but they are still choking this engine... but I have a plan to resolve that. The cold air intake flows well since there was less than 1kpa drop from WOT at 5500 rpm vs. ambient pressure.
Here are the charts from the run:
Video - wish I had taken one at the rear as well to really hear what this sounds like:
Here are a few pics of the setup:
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09:42 PM
PFF
System Bot
AkursedX Member
Posts: 2890 From: Lackawanna NY Registered: Aug 2000
I was on the dyno just under 2 hrs and did 18 runs testing quite a few things. With the Moates Ostrich it was quick to make a change and test it. $100 for the 1st hour and 5 pulls and a flat $75 an hour with unlimited pulls after that. So I spent $175 and about 1/4 tank of gas.
It would have been nice if the dyno computer was at car level so I could see it from the car vs. having to get out and climb down after every run (too much like exercise), but they are 1/2 mile from the house, so it will have to do.
As for as my future upgrades... those are a secret for now!
[This message has been edited by fieroguru (edited 05-22-2008).]
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10:12 PM
AutoTech Member
Posts: 2385 From: St. Charles, Illinois Registered: Aug 2004
The numbers above are rear wheel, so assuming 12-15% driveline loss it is producing between 317 to 325 crank HP. The ZZ4 cam is very mild by todays standards and the Vortec heads flow pretty good for stock castings. This motor probably should make 350-360ish hp at the crank if all parts are properly matched and would be a very mild manner SBC.
I have about 4K in building the engine, complete exhaust, intake and real-time fully programable EFI unit. Compared to the cost of the ZZ4 crate motor fully dressed and ready to run or the Ramjet 350 crate motor, I saved several K on the build. Sure I am not quite to their HP levels yet, but is mainly due to my choice of exhaust manifolds. The performance loss on the engine is flow related, not tune. It most likely is the manifolds so I have some plans on replacing them with something unique.
They are Speedway Motors cast stainless steel - an aftermarket enhancement to the rams horns. When i installed them in early 2007, I knew there could be a potential flow issue, but I wanted to try them anyway (tired of cracking headers).
The overall purpose of my blue car is a test mule. It was originally a 2.5 car and since 2000 it has had a 2.8, 4.5 caddilac, 283 SBC, 350 SBC with carb, and has spent the last 3 years in EFI format with several changes to the exhaust system. Someday it will probably have an LSx series engine, but with my 2nd child coming in Aug, I will be focusing on upgrades to the current engine for the next couple of years.
The main focus of the test mule is not peak HP or building a drag only car. It purpose is for an excessive performance daily driver that is enjoyable to drive every single day and with daily driver reliability and road manners. This SBC has been running in the Fiero for 25K miles since installed, been a long hauler on 2 hotrod powertours (one pulling a 1K lb trailer), and has pretty much been issue free for the last 3 years... I just get in and drive it all over the place without worries.
I think it is doing exactly what it was planned to do and it is time to start working on increasing the HP levels.
Autotech, I have kicked around the idea of running NOS, and probably towards the end of this engines useful life I might install it for grins!
[This message has been edited by fieroguru (edited 05-23-2008).]
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11:34 AM
Formula88 Member
Posts: 53788 From: Raleigh NC Registered: Jan 2001
According to the ZZ4 specs, it's HP peak is at 5250 and I think torque peak is around 3500, so that definitely looks like you've got some flow restriction coming in up top. Vortec heads should put out a bit more than the ZZ4 heads, I believe, so it looks like you could pick up quite a bit more with just intake and exhaust flow. All theoretical, of course, but it looks like you've got a solid combo with some untapped potential.
Time to get 'a tappin'.
BTW, I've always loved the look of that engine. The Ram Jet intake just looks awesome. It's the button head fasteners that put it over the top, though.
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02:10 PM
fieroguru Member
Posts: 12480 From: Champaign, IL Registered: Aug 2003
According to the ZZ4 specs, it's HP peak is at 5250 and I think torque peak is around 3500, so that definitely looks like you've got some flow restriction coming in up top. Vortec heads should put out a bit more than the ZZ4 heads, I believe, so it looks like you could pick up quite a bit more with just intake and exhaust flow. All theoretical, of course, but it looks like you've got a solid combo with some untapped potential.
Time to get 'a tappin'.
Agreed!
quote
Originally posted by Formula88: BTW, I've always loved the look of that engine. The Ram Jet intake just looks awesome. It's the button head fasteners that put it over the top, though.
Agreed! I really like the look of the Ramjet intake as well! The stainless steel button heads are a sickness, what can I say.
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08:56 PM
PFF
System Bot
kwagner Member
Posts: 4258 From: Pittsburgh, PA Registered: Apr 2005
Originally posted by fieroguru: ...an excessive performance daily driver...
That's the first rule, isn't it? If "more" is enough, then "too much" is just right.
Good show on the dyno!
------------------ Raydar 88 4.9 Formula IMSA Fasback..........................88 3.4 coupe -soon to be something other than red Read Nealz Nuze!Praise the Lowered!
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11:36 PM
May 24th, 2008
Alex4mula Member
Posts: 7405 From: Canton, MI US Registered: Dec 1999
The numbers above are rear wheel, so assuming 12-15% driveline loss it is producing between 317 to 325 crank HP. The ZZ4 cam is very mild by todays standards and the Vortec heads flow pretty good for stock castings. This motor probably should make 350-360ish hp at the crank if all parts are properly matched and would be a very mild manner SBC.
I have about 4K in building the engine, complete exhaust, intake and real-time fully programable EFI unit. Compared to the cost of the ZZ4 crate motor fully dressed and ready to run or the Ramjet 350 crate motor, I saved several K on the build. Sure I am not quite to their HP levels yet, but is mainly due to my choice of exhaust manifolds. The performance loss on the engine is flow related, not tune. It most likely is the manifolds so I have some plans on replacing them with something unique.
They are Speedway Motors cast stainless steel - an aftermarket enhancement to the rams horns. When i installed them in early 2007, I knew there could be a potential flow issue, but I wanted to try them anyway (tired of cracking headers).
The overall purpose of my blue car is a test mule. It was originally a 2.5 car and since 2000 it has had a 2.8, 4.5 caddilac, 283 SBC, 350 SBC with carb, and has spent the last 3 years in EFI format with several changes to the exhaust system. Someday it will probably have an LSx series engine, but with my 2nd child coming in Aug, I will be focusing on upgrades to the current engine for the next couple of years.
The main focus of the test mule is not peak HP or building a drag only car. It purpose is for an excessive performance daily driver that is enjoyable to drive every single day and with daily driver reliability and road manners. This SBC has been running in the Fiero for 25K miles since installed, been a long hauler on 2 hotrod powertours (one pulling a 1K lb trailer), and has pretty much been issue free for the last 3 years... I just get in and drive it all over the place without worries.
I think it is doing exactly what it was planned to do and it is time to start working on increasing the HP levels.
Autotech, I have kicked around the idea of running NOS, and probably towards the end of this engines useful life I might install it for grins!
You seem to be 20+rwhp lower than the typical ZZ4 but with much less torque. You manifolds are supposed to be better than ram horns so I don't think there are 20hp there. Then with your intake I would expect better flow for higher hp than a Performer carb setup in a ZZ4 but probably less torque (as you show). Do you know how much your intake flows? Finally I think the ZZ4 has fastburn heads and not Vortecs. Maybe the fast burn flow better. If it is a test mule I would invest in a better set of heads and maybe a better cam to really wake it up. That will give you more for suere. I think your exhaust is open enough as it is now.
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08:11 AM
fieroguru Member
Posts: 12480 From: Champaign, IL Registered: Aug 2003
For comparison, here are the dyno sheets for the ZZ4 and RamJet crate engines (these are engine HP ratings with headers and minimal accessories) taken from the GM Performance Parts website.
RamJet 350 Crate Engine:
ZZ4 350 Crate Engine:
While these engines have very similar peak HP/Torque values, the Ramjet does this with a much smaller cam Ramjet: 196/206 duration .431/.451 lift ZZ4: 208/221 duration .474/.510 lift
This tells me that the Ramjet/Vortec combo flows better than the traditional ZZ4 intake/head combo. The ZZ4 cam gives up about 40 lb-ft of torque at 2000 rpm vs. the Ramjet and is most likely a factor of cam size.
quote
Originally posted by Alex4mula: You seem to be 20+rwhp lower than the typical ZZ4 but with much less torque. You manifolds are supposed to be better than ram horns so I don't think there are 20hp there. Then with your intake I would expect better flow for higher hp than a Performer carb setup in a ZZ4 but probably less torque (as you show). Do you know how much your intake flows? Finally I think the ZZ4 has fastburn heads and not Vortecs. Maybe the fast burn flow better. If it is a test mule I would invest in a better set of heads and maybe a better cam to really wake it up. That will give you more for suere. I think your exhaust is open enough as it is now.
The ZZ4 heads are based off the aluminum L98 heads. The FastBurn heads are aluminum Vortecs with larger ports and valves. There is a FastBurn crate motor that is based on a ZZ4 lower end & cam, but with the Fastburn Heads. It peaks about 385 hp. Here is its dyno:
The Ramjet intake flows 278 CFM and is comparable the to the Holley StealthRam at 275 CFM.
Upgrading the heads is out of the budget for this year, but I agree doing do so should pay huge dividends. The exhaust is the easiest to focus on right now, since I do not have to pull the engine for it. A cam upgrade would be my next choice since it requires the engine to come out, so that most likely will not happen till after the 25th.
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01:41 PM
mafv8 Member
Posts: 554 From: Northville, Michigan, USA Registered: Aug 2001
The SBC in my car has a very similar spec to yours 355 fully balanced with Vortec Heads, ZZ4 cam, 1.52 roller tip rockers, 2,5" Brzezinski ramhorns and Edelbrock pro-flow fuel injection, I ran it on a dyno late last year, it was a Mustang dyno 235hp and 275ft/lbs. At the time of the dyno run I had a 2.25" exhaust from Tuffy not very efficient, and I noticed my max power came at 4800rpm, since then I have got a 2.5" mandrel bent system, that goes to a 3" inlet/twin 2.5" outlet muffler, and it certainly feels better than before, I need to re-run it to see the improvement. Anyway I shall be watching your future posts to see what mods you do, keep up the good work.
------------------ 84SE, aero body, 4 speed and an injected 355 V8
