91 MR2 SW20 Gen2 3SGTE 500whp

[jaypat01]

91 SW20 MR2 chassis

EFI System:

-Link G4+ Thunder

-1zz COP direct spark 

-5s 36-2 crank sensor and trigger

-Gen 2 3s distributor used for cam sync 

-BM 2-wire knock sensor

-GM 4bar MAP sensor

-GM Flex Fuel sensor (modeled fuel mode, dual fuel mapping from E10-E80)

Engine:

-2.0L forged Gen 2 3sgte block maintaining factory compression

-Gen 2 3sgte head with Engle valve springs and GSC S1 (268) cams, adjustable cam gears (E:7deg retard, I:0deg)

-Modified ATS straight runner intake manifold

-Custom intercooler system utilizing a CSF A2W core

-Custom exhaust manifold and downpipe with recirculated Tial MVR 48mm EWG, XonaRotor XR7164 turbo with 0.82 v-banded hotside

-3” Berk dual exhaust

-ID1700xds injectors supplied with a Walbro 450lph pump

-Custom air cooled oil cooler system with Setrab cooler and Mocal oil thermostat, relocated oil filter

-IAG universal AOS with three -10 crank case breathers 

Transmission:

-Stock E153 w/ factory LSD

-Clutch Masters 725 series twin disk w/ steel flywheel

-Drive Shaft Shop axles 

Car made 495whp/385wft-lbs on a Mustang Dyno on a 95degF day and 70% humidity and a heat soaked IC system (120F IC water temp) because the heat exchangers were being starved of airflow. Boost pressure was on 20psi tapering to 23psi at redline and fuel was E79. 
 

It had a lot more steam in it, but I stopped where I did because I didn’t want to exceed 350ftlbs-lbs around natural peak torque and 380ftlbs-lbs closer to redline because it is a 3sgte block prone to fatigue cracking on the cylinder walls. Plan is to run it like this until I build a 5s block with a partial block fill.

This car is more wired than a new BMW  and the Link ecu is the nervous center for it and handles everything I throw at it. All auxiliary systems that have to do with motor function are controlled by the ecu and I have more sensors on the car than are probably necessary. The IC system alone has 5 temps sensors, one water flow sensor and one level sensor in the reservoir just to give you an idea haha. But I love data and since the Link has access to all of it, I can change how each system functions just by a simple software change.

[Ducie54]

Nice ride, one of the biggest things I learnt with my W2A setup is run the biggest pump and lines possible. 

Can't go wrong with plenty of sensors, without data it's just an assumption.

[jaypat01]

On 6/25/2021 at 6:52 PM, Ducie54 said:

Nice ride, one of the biggest things I learnt with my W2A setup is run the biggest pump and lines possible. 

Can't go wrong with plenty of sensors, without data it's just an assumption.

So not saying I’m doing it the right way, but on my setup…I’m running -12 lines with two Johnson CM30P7-1 pumps in series (one in the front and the back). It seems to be working fantastic. I opted for this because the cooling loop is so long and I wanted the redundancy of two pumps. In this configuration, I keep the flow rate low (which I feel too fast of flow can diminish heat transfer rate) and if one pump dies, I see a drop in the flow rate, which triggers an alarm on my MXG dash, but the system isn’t rendered completely useless until I replace the failed pump. 
 

Just for reference…while on the street, my IC water temp stays in between 5-10degF above ambient temp. Also, my IATs always match the water temp going into my IC…it’s a very efficient core.

[Ducie54]

If you PM me ur email I'll send you some log files where I test water flow speed through a radiator. 

 

[dx4picco]

7 hours ago, jaypat01 said:

 In this configuration, I keep the flow rate low (which I feel too fast of flow can diminish heat transfer rate)

Unless you are cavitating somewhere, more is better in regard of flow for Heat transfert (boundary layer thinner)

[jaypat01]

16 hours ago, dx4picco said:

Unless you are cavitating somewhere, more is better in regard of flow for Heat transfert (boundary layer thinner)

Interesting…and yes cavitation was one of my concerns with running one larger pump vs the two smaller ones in series. But your suggestion with flow makes sense (you are bringing back memories of my fluid dynamics classes lol). You are referring to the non-slip condition between the heat exchanger inner surface and the water. This is why I added all of these sensors in my system. One of the variables I was going to play with was flow to see if I could optimize the heat transfer. Like I said before, my IC heat transfer cannot possibly get better. The air coming out of the IC always matches my water temp entering the IC, no matter what the pre-IC air temp is. But, I feel like my heat exchangers could do a better job removing the heat from the system. 

[Ducie54]

If your still running AC you can get creative with the cold side AC hose to cool your water  

[jaypat01]

1 minute ago, Ducie54 said:

If your still running AC you can get creative with the cold side AC hose to cool your water  

Oh @Ducie54 I have thought about this many times. I know this has been done by oems before and sometimes in Motorsport applications. The power consumed by running the AC compressor was less than the power gained by cooling the charge temps. Before I go crazy I’m going to try and shroud my IC heat exchangers better. Right now they Are stuffed under each head light in the sides of the bumper. I 3D printer air diverters that bolt in place of my foglights to force air into the sides of the bumper and then the air passes through the exchanger and exhausts through the fender liner. Theory was the vacuum created on the front wheel well while driving at speed would naturally try to draw air through it. 

@Ducie54 here is the backside of one of the heat exchangers with the fender liner removed. I have a mirror version on the opposite side of the car. The exchangers are dual pass and the water flows through them in series.

[Ducie54]

Nice looking setup there. I don't have AC so I'm using a dry ice tank inside my main water tank when I want my temps under ambient. 

Have you measured the water pressure in your lines after the pump? You could have some head pressure reducing the water flow.

I would also run a Differential pressure gauge accros your radiators as you may find your wheel well is not as negative as you think. 

[jaypat01]

On 6/27/2021 at 11:32 PM, Ducie54 said:

Nice looking setup there. I don't have AC so I'm using a dry ice tank inside my main water tank when I want my temps under ambient. 

Have you measured the water pressure in your lines after the pump? You could have some head pressure reducing the water flow.

I would also run a Differential pressure gauge accros your radiators as you may find your wheel well is not as negative as you think. 

So there was actually a test someone did with an sw20 in a wind tunnel to see how the air flowed around the car and when they moved the smoke stream to the front fog light (even with the fender liner fully intact and not vented) the smoke actually was pulled into and out of the wheel well through the bumper. Now of course there are some things I could do to help create more negative pressure on the wheel well like a small deflector running up the front of the wheel well edge or spacing out the fender where it meets the door, but I’m going to mess with other things first as I’m trying to keep the body looking oem. Also, my fans are controlled off differential temp between ambient air and the water coming out of the heat exchanger (low speed always comes on when the car is under 20mph and high speed is turned on when the delta temp is 5F and the car is under 20mph). I do this because in most cases running the fans at higher vehicle speeds can reduce airflow if the air speed is greater than air velocity produced by the fan. But, this condition may never happen where the exchangers are mounted so next course of action will be removing the speed lockout and seeing if I can pull heat out quicker with the fans running while the car is at speeds above 20mph.

Now all this being said, my goal is just to get my water temps as close to ambient air as possible and hold it steady…for the most part, I see between 5-10F difference between the ambient air and the water coming out of the heat exchanger on a hot day (90F). This is a street car and I don’t have a massive reservoir because I’m never putting ice in it. I’m not trying to be the fastest thing out there or break records, I just find pleasure in properly designed systems that work well.