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DC Crew
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Discussion Starter #1
Okay - I explored this for a little while earlier this year when an Accel Gen VII DFI system fell in my lap - however, the complications involved in swapping over a perfectly good working 1986 TPI to that wasn 't worth it for the other expense.

So...been thinking though. Why can't I find a low rise four bbl style EFI intake - install it on the 86 Vette with a quality elbow allowing me to put the throttle body in nearly the same stock position...then hook it all up? I know the EGR would be off-line, but why won't this work..

AND - obtain the higher RPM that it lacks so badly????

Yes, you can slap a TPIS miniram on...or do a big mouth conversion, but both are very expensive.

Why spend $1,500 plus dollars on a $4,000 car?

I'm wondering if this could be done with some elbow grease and about $500.

The stealthram is too high and requires machine work, as well as the Edelbrock intake.

Why won't this work????

This style intake with a fuel rail conversion and stock injector swap



This on top modified to accept the throttle body

 

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DC Crew
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The edlebrock only requires slight grinding to fit. My concern with the setup you mention is will it be too much intake for a stock motor
 

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if you are going that route moddifying the intake to accept the TPI tthrottle body might be difficult at best. they are too different in size/shape.
I'd suggest getting a stock round maf and adapting the pin outs to the new MAF.

You'll need to adopt a tunning program anyway for this to run.. With the new MAF you can adjust the volts to flow gm/sec with the software.

I'm with raid though that this will be way too much intake for idle operations on anything short of a 383.
 

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DC Crew
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Discussion Starter #5
I've seen a few of those Edelbrock swaps - not too impressed considering some of the fitment issues and cost involved.

I'm not convinced that intake is too large for the stock engine.


Just a dang shame the new Pro-Flow wasn't designed in consideration of the C4 hood issues.
 

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DC Crew
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Discussion Starter #7
Okay....

Snow + Ice + un shoveled driveway...and the need...the need for speed after just putting new valve stem seals in the 86 = :partyon:

Just took her out to make sure its all good - had my son with me, came back and turned the driveway into a figure 8 track for a few.

Anyway...looking at the rest of the winter project season and trying to figure out the potential of pulling this off and creating something inexpensive and un-ordinary that might pull a few more upper RPM ponies out of the machine.
 

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I've seen a few of those Edelbrock swaps - not too impressed considering some of the fitment issues and cost involved.

I'm not convinced that intake is too large for the stock engine.


Just a dang shame the new Pro-Flow wasn't designed in consideration of the C4 hood issues.
Im running a 395 Ci motor with big mouth intake. and 58MM TB. Stock the butterflys were open in order for it to idle-- now they are closed and base idle is controlled solely by the IAC. That means no matter how I tried the tune I can't get it to idle below 900 RPM without it hunting using the IAC as the method of air flow at idle...
 

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if you are going that route moddifying the intake to accept the TPI tthrottle body might be difficult at best. they are too different in size/shape.
There are off the shelf hats from custom makers that fit stock style TB to 4 bbl intake




Plenty have made their own custom hat to add some plenum volume




Or a low profile carb hat on a 4bbl TB

 

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DC Crew
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Discussion Starter #11
Hey Vettoz....


Those are some awesome pictures.

The first one looks way too tall - but this is the idea.

I had seen a C4 on Corvette Forum that has this basic set up running, but can't find those pictures now.

Anybody can bust out the Visa card and make something happen - if I wanted to do that I'd slap a miniram on there.

What I want to do is poke and pick around to see what is out there along these lines to pull something together - small amount of $$$ - large amount of elbow grease...and NO hole cut in the hood.
 

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Is not currently listed but Intake Elbows.com used to make a 4 bbl hat that dropped a TPI/ LTX TB down to same level as TPI one

See top pic RH rear

http://www.intakeelbows.com/
shot AAron an email-- they only build for round throttle bodies not our stock TPI
 

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I know you want to keep the stock hood, but I am doing something similar. I am using the Accel EFI intake with an elbow pointing backwards and an LSX throttle body. This way I can take advantage of the cowl hood Im putting on.

The LSX throttle bodies use the same TPS and IAC wiring as our L98 cars do, but they use a different connector. You can get early to late adapters from FAST ($10 ea.) or just splice the LSX plug onto the L98 wiring. It is also very tunable for our computers.

If you are going with a carb EFI intake and custom elbow you will gain much more if using a single blade LSX throttle body. For a mostly stock engine though I doubt you need much more than a stock throttle body. I got one with sensors (that work) off a wrecked LS1 Trans Am for $50. I will most likely port it but the stock size should be plenty of CFM for stock or mild engines. You need to get a throttle body from an LS1 Camaro, Trans Am, or GTO because they are sill cable driven. Only difference is the throttle cable goes on the pass side instead of the driver.

This is the intake Im going to use:


It comes with fuel rails and uses the same injectors that the L98 does. Only $500. Like me all you would need is to make your own elbow, some connectors, and a LS1 TB. If you make your own elbow you can make it fit under the hood, or have the intake elbow people make one to your dimensions.

Im still gathering parts but I plan to have the new engine in by spring.
 

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DC Crew
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Discussion Starter #16
Thanks Kubs...that's what I'm talking about!

I also wonder how tricky it would be to drill out a non-EFI 4BBL manifold for the injectors and adapt the stock rail. Now we would be talking about a whole weekend of Bubba engineering, some fittings...and super low bucks.

I was thinking if the rails were threaded where the cross tubes and regulator go in, that they could be plugged and just tap them on the back for the cross over and return. The accel FPR is really bulking and is going to take up a lot of space compared to the stock style.

I can add a bit to that in terms of parts. The 2000 or so trucks with the LQ engines have the same throttle body as the F body. I know because I have a LS1 in my 69 Camaro that I swapped a truck T/B for a while back.

Here is a big question though...the TPS is adjustable on the C4, and not on the LS style. Do you slot it out or something to make it work for the base idle set????
 

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Here is a big question though...the TPS is adjustable on the C4, and not on the LS style. Do you slot it out or something to make it work for the base idle set????
Prob going to have to slot it for adjustment.

C4 '165 MAF ECM looks for .54V ; key on
The later TPI MAP ( and LTX ) cars take the voltage 1st seen and use that as the base ( throttle closed ) voltage
 

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Prob going to have to slot it for adjustment.

C4 '165 MAF ECM looks for .54V ; key on
The later TPI MAP ( and LTX ) cars take the voltage 1st seen and use that as the base ( throttle closed ) voltage
Mine is a '90 MAP car so I wasnt worried about this issue. I guess slotting it will have to do.
 
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