Super charging questions - Spark plugs - EGR Delete - IMRCs Delete - head cooling mod

[OU812IC]

Let's see if this section gets so e action - the HP area is kinda dead.

98 LSC - Paxton 1500 hoping to aftercooler in case it matters.

Getting down to the a few more details...

Plugs Autolite XP103 - what gap do you think? .045 closed enough? They are one range colder than stock and same temp as 03-04 cobras.

Delete or keep EGR? I am thinking delete it as well as the IMRCs.

I am looking at doing the driverside head cooling mod. Looking at it I am doubting I can get in there to do the mod. I am hoping you are going to tell me that once I get in there disassembling the IMRCs and deleting the EGR there is more room. If I can get in there is there anything wrong with tying it into the return line to the return line to the line that goes from the radiator to the overflow tank?

Since the cross over tube kit from Vortech is $500 ball busting dollars I am looking for an alternative. I see the MMR kit is not much better and am not a fan of assembling AN fittings. It is hard to tell from pictures what the differences are from stock to the Vortech one.

I have mad some progress with the other parts. Mounting bracket and hardware, along with oil lines should be here by the end of the week. Injectors are coming. I found a Carter Focus SVT pump only... a bit cheaper than buying the whole assembly.

Thanks to everyone who has helped me out. It is amazing all the reading you can do and still not "find" it all. I cant believe how many links I find that go back almost a decade about this swap. Crazy how many dead end and have broken links to pics and other resourses. I promise to build a collection of pics and information together when I am done.

Thanks again guys...

 

[Don Pfau]

Gap .032, I am still running the IMRC's and the EGR. No aftercooler I have alcohol injection. Plus no cooling mods except for the electric water pump but it loves to run. It is faster hot making runs back to back so it has no cooling troubles at all. But if it matters mines is a 93 first generation.

 

[97Mark8]

Its up to you, but in my opinion their is NO reason to be running IMRCs. They get all carboned up and cause nothing but issues. You dont even have to spend the 280$ on the billet MMR IMRC delete plates, you can easily make your own out of your own factor mark 8 IMRC plates. Remove the butterfly and rod from each port in the plate. The aluminum factory ones are preferred because they can be welded, but the other later plastic kind are fine to mod as well, if you have plastic ones fill the holes in the side of each port with JB weld . make SURE they are spotlessly clean when you go to JB weld them if you have the plastic ones or you may have issues. PM me if you have questions making your own, i just did mine. The imrc deletes might make a slight loss of power down low, but in the upper rpms its going to add some power for sure. Its a free mod that prevents problems later down the road. As for the EGR just delete it. IF you have a 96-98 cobra intake manifold you can completely remove the EGR provision on the side if you delete the EGR in your tune. Ive also seen that done.

 

[chris2523]

with a supercharger, the IMRC debate changes, but i highly suggest against IMRC deletes on a stock or mostly stock car.
if you are not running a minimum of a 3000 stall converter with 3.73 or more gearing, i would leave them in place.

 

[OU812IC]

All great stuff! Dumb question coming.... I don't quite understand with the DIY deletes is if I pull the flies and shaft out, then plug the shaft ends what is the big deal about leaving the shaft passage(s) openbetween the ports? It is not like they can leak atmospheric vacuum, the fuel shoots in from below the would be shaft area. I can see where there would be a difference in and NA motor possibly. With FI I dont quite understand. PLEASE understand i am not challenging anyone, I am asking for a better understanding position. All the reading i have done no one says why they are plugging the holes, aside from the shaft ends and that is obvious.The only thing I can thing of is that during the intake stroke it could rob air from adjacent cylinders and disturb the "natural flow" of the said cylinder on the intake stroke.

Maybe I just answered my own question.....

 

[OU812IC]

with a supercharger, the IMRC debate changes, but i highly suggest against IMRC deletes on a stock or mostly stock car.
if you are not running a minimum of a 3000 stall converter with 3.73 or more gearing, i would leave them in place.

I have the 410s and posi in the garage(check or the 3.73 or higher). NOVI 1500 and tubing on the bench. Mounting hardware and oil lines end of the week, crossing fingers(uncheck stock or mostly stock , I think).

Trans cooler, Convertor and Jmod by spring, may not make the winter list.

One of the things I may be missing out on is the Cobra intake. I think I can live without it. Eventually I will find one that is listed below market value and have the cash at the same time.

I am trying to do everything I can without having to take the exhaust off. Hopefully by the time I get to the convertor I will be ready to do the exhaust. I kinda looks like the trans R&R would be easier without the exhaust.

 

[unity]

Better idea, pick up the BMW M70 engine in my garage and install it onto the Mark. Someone needs a V12 Mark!

 

[97Mark8]

Unity. I bet I make more power at the tire n/a with my 4.6 DOHC with stock stroke and displacement than one of those BMW engines make at the crank when my build is done. As for not filling in the side ports of the IMRC deletes when the rod goes through. The purpose of this is to prevent the scavenging of air from port to port because of the holes. I've heard one guy on SVT performance ran IMRC deletes with the rod removed and the holes opened and didn't gain much performance, filled them in and dropped .2 off of his et after, Ofcourse I don't want to sound like a bench racer or make false claims or accusations about the IMRC deletes, I don't want someone to read my post and say "oh this guy dropped .2 blah blah blah" everyone is gonna see different results. However for those of us that have actually had their engines apart it's pretty obvious to see why deleting your IMRC is beneficial, Supercharged or not. The Gains would be more on a forced induction car. And whatever you do, DO NOT skip the 96-98 Cobra intake, look up a "short runner" cobra Intake. You need one

 

[97Mark8]

I'm going to be posting my own cobra Intake mod thread soon, probably within a month. You can check out what's done to mine and maybe get some ideas. My upper lid has been extensively modified as well, not just the lower Intake. As long as my deal on the SHM stage 3 cams goes through I'm gonna be making big power.

 

[97Mark8]

I have 4.10s, track lock and a edge racing 3400 stall so bottom end from the IMRC deletes is no issue from me. So many people will tell you "oh you'll loose too much bottom end" tell those people to shove sand up their vag. With a converter and low gears like that you don't even have much of a bottom end. BTW their are guys picking up 4-5 mph n/a with a stock motor by swapping on the cobra Intake, the typical gen 2 mark Viii will drop about .3-.5 off of their et by swapping on a cobra Intake on a stock motor if they have the supporting mods