Brad-ManQ45

Envy that Euro exhaust manifold...

I would suggest that if the car is basically street/highway driven that you size the A/R of the turbine section so that you are not in boost when cruising on the expressway for gas mileage purposes. Perhaps those with experience can make a suggestion based on the 50 trim compressor section turbo and the GT35...

Having lived w/ turbo cars since the mid 80's I would suggest that any car that will be used as a daily driver have a water cooler center section. When by '83ZXT's turbo finally shot craps I used a Turbonetics water cooler T3 and it currently has more miles than the original turbo and is going strong. YMMV...

That looks like the non ducted Xenon urethane air dam...also their side skirts

I wonder if one of those wires is to the TPS... Don't have a schematic handy...

To make sure that the terminology is correct - a Splitter extends forward from the bottom of the front bumper/air dam and divides the flow of air above and below. The Undertray is what is after the bumper/air dam extending back to or even past the front of the engine. I believe the OP was about the Undertray having either a kick up or a kick down and which would provide more downforce. I don't KNOW and can only SUSPECT that an Undertray that slnts UP from behind the air dam before it flattens out to the front of the engine ar even further back (providing that it doesn't impinge on the airflow through the radiator) would help with little aero drag - might even help keep the front end down... A kickdowm would create more turbulence and disrupt airflow after the plate. Designing the undertray to direct air toward the wheelwell from above the tray while keeping the flow as straight as possible below would seem to be the best bet. Keep in mind that in this scenario that ideally the bottom of the air dam if only using an Undertray or if using a splitter the height of the splitter would be below the level of the floor pans. The amount of kick up is therefore limited by the difference in height above ground of those 2 measurements. If there is no difference then no kick up. If the floor pans are lower than the height of the bottom of the air dam/splitter then a gradual taper to that height would smooth the flow under the car, but I could see that providing some lift at the expense of less drag.

What turbine A/R are you running on those for the 2.0 and would you change for a 2.8? Inquiring mind wants to know.... Thx!

Sounds like what happens when electrcal connections get wet. Check the TPS...

Please be aware that the EFI units used on the L series engines are analog and not digital. Also the use of an AFM instead of a MAS creates a restriction. I have yet to see an instance of a modern EFI system properly tuned NOT providing more hp, torque, driveability and gas mileage throughout the entire power range vs a carb setup. In the case of high horsepower/rpm setups operating in a narrow range a carb setup can work just as well and be simpler.

NewZed - apparently you are reading something into my posts that I did not put there. I have simply said that I am disappointed that they do not wish to build an intake to my specifications backed by not only real world experience as testified to by others on this forum but by racers and hot fodder since the 60's when I first started working on our '65 Mustang convertible. I have no problem with their right to refuse the work. I just don't think their reasoning was very well thought out. It appears that they are after that last % in power and don't want to associate with all-round performance. If they did then their comments about my request for an anti-reversion step for what is to be a max 6k rpm engine used as a daily driver being against their principles/experience seems not only narrow-minded but flies in the face of what others experience has been. Please don't go putting words in my mouth.

Just wanted to let people know that ATI still can make their kit for this. I orders one in Feb. and got it last month...so it takes a while.

I may be wrong, but I believe the .82 on the 30 series is pretty much the equivalent of the .63 on the 35 series as far as flow goes. It's been a while since I looked at the maps for the housings...

I may be wr9ng and if so I'm sure TonyD or someone else will correct me - but I believe the stock cams ARE assymetrical...

Interesting Climber... Will have to keep an eye on what you come up with... As I might have stated, because I will have a GM 4L60E behind the engine I am imposing a 6K rpm limit. Combined with my preference to use my hydraulic lifters I am looking to maximize flow throughout the stock rpm range. Hence the anti-reversion step and need for a custom plenum. I have scoped out a supplier for tapered runners and velocity stacks. Am thing the stacks that protrude into the plenum and runners that taper down to ~33-34mm and of course well ported heads will combine to work to make ~400 up at a relatively low boost. As guru TonyD has so often said - it's the PACKAGE as a whole that determines success or failure. I can't help but think that a custom manifold would be better than trying to work with the stock one.

The stock manifold is less than ideal as far as airflow distribution - particularly to cylinder #1.

Then I guess I'm better off letting him sell expensive stuff that won't work as well to stupid street racers buying bling... Not really... He undoubtedly has MAD fab skills and for people who want to wring the last 3% out of an engine what he seems to want to provide will definitely work better than the stock manifold. I definitely do not want anything resembling a traditional log type manifold because of the short shrift cylinder #1 gets. I have an extra manifold and a mm 175 MIG - perhaps I'll buy a spool gun and use my band saw to make my own. But I already have enough projects and that piece is highly visible - I do not consider myself to have mad fab skills. I have only built a rotisserie and 1/2 a firewall and inner fender and battery tray to fix what rusted from a battery explosion, putting beads in the panels to match what was stock. Never have worked w/aluminum. Perhaps just source materials and fab it and have someone else weld it. Just seemed to me he had what I was looking for and made the statement "we build to your specs". That is an proven lie. They SHOULD say that we build to your specs long as we agree with them. They certainly have not impressed me with their knowledge and willingness to work with their customer - but their fab skills are definitely impressive.

I am/was willing to pay whatever they wanted, realising that shipping would also be a hefty amount. They simply never responded after I sent the link from here and said it was for a daily driver and I didn't need a 75mm or larger TB... The fact that they gave no justification simply irks me no end as I believe I have good justification for my specs. Perhaps CUSTOM should not be in their business name.

I am/was willing to pay whatever they wanted, realising that shipping would also be a hefty amount. They simply never responded after I sent the link from here and said it was for a daily driver and I didn't need a 75mm or larger TB... The fact that they gave no justification simply irks me no end as I believe I have good justification for my specs. Perhaps CUSTOM should not be in their business name.

To answer questions in no particular order... Some people have said that on a stock manifold that the lost low speed driveability withe even a 60mm 240SX TB and wished they hadn't made the change. Being an old hot fodder (I am 62) I am well aware of reversion and it's effects and I merely acknowledged TonyD's c moments on the subject that were also backed up by JeffP's resulting experiences. I don't feel that my secs were anywhere near out of line for a custom intake given the daily driver/under 6k rpm/less than 18 lbs boost scenario that is my vision. I still haven't seen anyone's answer to my questiono - am I looking at this wrong? Let me rephrase. If you area custom manufacturer and you give the customer exactly what they wanted and paid for are you reasonable? In the same scenario are you being reasonable if you refuse to make it without at least explaining why you won't?

I just had a refusal to fabricate a manifold from these people to my specifications for my L28et. https://www.facebook.com/customplenumcreations/ They asked what I wanted spec-wise and I said that I wanted to use a 240SX throttle body and have the runners 33mm inside diameter for the 35mm ports on my head. Here is what they said: "Sorry Brad I would not make a manifold along those lines. Making a manifold with a smaller port diametre vs the head will defeat all logic since it will cause more turbulence and a restriction to flow at the port entry throwing all your porting work out the window and the almost immeasurable benefit you may get from trying to reduce reversion." I then sent them to this thread on HybridZ about real world experience with JeffP's turbo'd engine: http://forums.hybridz.org/topic/101589-port-match and have heard nothing back. Since my car will be a daily driver and will have a 4l60E behind it it will be limited to 6000 RPM to keep the tranny alive. I just don't understand their thinking.....

Does anybody know?

I don't think he is talking about a splitter - just a panel from the bottom of the front spoiler/air dam back to the engine... Might a kick up before/after the radiator (providing there is clearance) and then flatten out to the front of the engine provide a minimal amount of downforce?

Thanks Rossman. I saw that page but wondered about what he did for the area from ports 1-4 coming into the plenum. There was absolutely no mention of smoothing or enlarging which is why I thought I may have miss3d a page...

I saw the porting for the exhaust manifold already, I was wondering about the cutting open and welding like they say they can do on the intake manifold.

Hi guys! It's been a long hard road the last 5 years and needless to say the '83ZXT project has been on hold. I've done my due diligence and for the life of me cannot understand why you would have the same size pipes before and after the intercooler. To me, simple physics would lead me to think that a smaller pipe after the intercooler would provide less pressure loss because cooler air is more dense and a smaller pipe would keep the pressure and speed up whereas the same size piping would cause the pressure and speed to drop. In the real world is the difference too small to consider? Would the numer of bends and length of the tubing after the intercooler enter into the equation? This inquiring mind wishes to learn...